xref: /openbmc/linux/drivers/gpu/drm/i915/i915_gem.c (revision 9c1f8594)
1 /*
2  * Copyright © 2008 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  * Authors:
24  *    Eric Anholt <eric@anholt.net>
25  *
26  */
27 
28 #include "drmP.h"
29 #include "drm.h"
30 #include "i915_drm.h"
31 #include "i915_drv.h"
32 #include "i915_trace.h"
33 #include "intel_drv.h"
34 #include <linux/shmem_fs.h>
35 #include <linux/slab.h>
36 #include <linux/swap.h>
37 #include <linux/pci.h>
38 
39 static __must_check int i915_gem_object_flush_gpu_write_domain(struct drm_i915_gem_object *obj);
40 static void i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj);
41 static void i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj);
42 static __must_check int i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj,
43 							  bool write);
44 static __must_check int i915_gem_object_set_cpu_read_domain_range(struct drm_i915_gem_object *obj,
45 								  uint64_t offset,
46 								  uint64_t size);
47 static void i915_gem_object_set_to_full_cpu_read_domain(struct drm_i915_gem_object *obj);
48 static __must_check int i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
49 						    unsigned alignment,
50 						    bool map_and_fenceable);
51 static void i915_gem_clear_fence_reg(struct drm_device *dev,
52 				     struct drm_i915_fence_reg *reg);
53 static int i915_gem_phys_pwrite(struct drm_device *dev,
54 				struct drm_i915_gem_object *obj,
55 				struct drm_i915_gem_pwrite *args,
56 				struct drm_file *file);
57 static void i915_gem_free_object_tail(struct drm_i915_gem_object *obj);
58 
59 static int i915_gem_inactive_shrink(struct shrinker *shrinker,
60 				    struct shrink_control *sc);
61 
62 /* some bookkeeping */
63 static void i915_gem_info_add_obj(struct drm_i915_private *dev_priv,
64 				  size_t size)
65 {
66 	dev_priv->mm.object_count++;
67 	dev_priv->mm.object_memory += size;
68 }
69 
70 static void i915_gem_info_remove_obj(struct drm_i915_private *dev_priv,
71 				     size_t size)
72 {
73 	dev_priv->mm.object_count--;
74 	dev_priv->mm.object_memory -= size;
75 }
76 
77 static int
78 i915_gem_wait_for_error(struct drm_device *dev)
79 {
80 	struct drm_i915_private *dev_priv = dev->dev_private;
81 	struct completion *x = &dev_priv->error_completion;
82 	unsigned long flags;
83 	int ret;
84 
85 	if (!atomic_read(&dev_priv->mm.wedged))
86 		return 0;
87 
88 	ret = wait_for_completion_interruptible(x);
89 	if (ret)
90 		return ret;
91 
92 	if (atomic_read(&dev_priv->mm.wedged)) {
93 		/* GPU is hung, bump the completion count to account for
94 		 * the token we just consumed so that we never hit zero and
95 		 * end up waiting upon a subsequent completion event that
96 		 * will never happen.
97 		 */
98 		spin_lock_irqsave(&x->wait.lock, flags);
99 		x->done++;
100 		spin_unlock_irqrestore(&x->wait.lock, flags);
101 	}
102 	return 0;
103 }
104 
105 int i915_mutex_lock_interruptible(struct drm_device *dev)
106 {
107 	int ret;
108 
109 	ret = i915_gem_wait_for_error(dev);
110 	if (ret)
111 		return ret;
112 
113 	ret = mutex_lock_interruptible(&dev->struct_mutex);
114 	if (ret)
115 		return ret;
116 
117 	WARN_ON(i915_verify_lists(dev));
118 	return 0;
119 }
120 
121 static inline bool
122 i915_gem_object_is_inactive(struct drm_i915_gem_object *obj)
123 {
124 	return obj->gtt_space && !obj->active && obj->pin_count == 0;
125 }
126 
127 void i915_gem_do_init(struct drm_device *dev,
128 		      unsigned long start,
129 		      unsigned long mappable_end,
130 		      unsigned long end)
131 {
132 	drm_i915_private_t *dev_priv = dev->dev_private;
133 
134 	drm_mm_init(&dev_priv->mm.gtt_space, start, end - start);
135 
136 	dev_priv->mm.gtt_start = start;
137 	dev_priv->mm.gtt_mappable_end = mappable_end;
138 	dev_priv->mm.gtt_end = end;
139 	dev_priv->mm.gtt_total = end - start;
140 	dev_priv->mm.mappable_gtt_total = min(end, mappable_end) - start;
141 
142 	/* Take over this portion of the GTT */
143 	intel_gtt_clear_range(start / PAGE_SIZE, (end-start) / PAGE_SIZE);
144 }
145 
146 int
147 i915_gem_init_ioctl(struct drm_device *dev, void *data,
148 		    struct drm_file *file)
149 {
150 	struct drm_i915_gem_init *args = data;
151 
152 	if (args->gtt_start >= args->gtt_end ||
153 	    (args->gtt_end | args->gtt_start) & (PAGE_SIZE - 1))
154 		return -EINVAL;
155 
156 	mutex_lock(&dev->struct_mutex);
157 	i915_gem_do_init(dev, args->gtt_start, args->gtt_end, args->gtt_end);
158 	mutex_unlock(&dev->struct_mutex);
159 
160 	return 0;
161 }
162 
163 int
164 i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
165 			    struct drm_file *file)
166 {
167 	struct drm_i915_private *dev_priv = dev->dev_private;
168 	struct drm_i915_gem_get_aperture *args = data;
169 	struct drm_i915_gem_object *obj;
170 	size_t pinned;
171 
172 	if (!(dev->driver->driver_features & DRIVER_GEM))
173 		return -ENODEV;
174 
175 	pinned = 0;
176 	mutex_lock(&dev->struct_mutex);
177 	list_for_each_entry(obj, &dev_priv->mm.pinned_list, mm_list)
178 		pinned += obj->gtt_space->size;
179 	mutex_unlock(&dev->struct_mutex);
180 
181 	args->aper_size = dev_priv->mm.gtt_total;
182 	args->aper_available_size = args->aper_size -pinned;
183 
184 	return 0;
185 }
186 
187 static int
188 i915_gem_create(struct drm_file *file,
189 		struct drm_device *dev,
190 		uint64_t size,
191 		uint32_t *handle_p)
192 {
193 	struct drm_i915_gem_object *obj;
194 	int ret;
195 	u32 handle;
196 
197 	size = roundup(size, PAGE_SIZE);
198 
199 	/* Allocate the new object */
200 	obj = i915_gem_alloc_object(dev, size);
201 	if (obj == NULL)
202 		return -ENOMEM;
203 
204 	ret = drm_gem_handle_create(file, &obj->base, &handle);
205 	if (ret) {
206 		drm_gem_object_release(&obj->base);
207 		i915_gem_info_remove_obj(dev->dev_private, obj->base.size);
208 		kfree(obj);
209 		return ret;
210 	}
211 
212 	/* drop reference from allocate - handle holds it now */
213 	drm_gem_object_unreference(&obj->base);
214 	trace_i915_gem_object_create(obj);
215 
216 	*handle_p = handle;
217 	return 0;
218 }
219 
220 int
221 i915_gem_dumb_create(struct drm_file *file,
222 		     struct drm_device *dev,
223 		     struct drm_mode_create_dumb *args)
224 {
225 	/* have to work out size/pitch and return them */
226 	args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
227 	args->size = args->pitch * args->height;
228 	return i915_gem_create(file, dev,
229 			       args->size, &args->handle);
230 }
231 
232 int i915_gem_dumb_destroy(struct drm_file *file,
233 			  struct drm_device *dev,
234 			  uint32_t handle)
235 {
236 	return drm_gem_handle_delete(file, handle);
237 }
238 
239 /**
240  * Creates a new mm object and returns a handle to it.
241  */
242 int
243 i915_gem_create_ioctl(struct drm_device *dev, void *data,
244 		      struct drm_file *file)
245 {
246 	struct drm_i915_gem_create *args = data;
247 	return i915_gem_create(file, dev,
248 			       args->size, &args->handle);
249 }
250 
251 static int i915_gem_object_needs_bit17_swizzle(struct drm_i915_gem_object *obj)
252 {
253 	drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
254 
255 	return dev_priv->mm.bit_6_swizzle_x == I915_BIT_6_SWIZZLE_9_10_17 &&
256 		obj->tiling_mode != I915_TILING_NONE;
257 }
258 
259 static inline void
260 slow_shmem_copy(struct page *dst_page,
261 		int dst_offset,
262 		struct page *src_page,
263 		int src_offset,
264 		int length)
265 {
266 	char *dst_vaddr, *src_vaddr;
267 
268 	dst_vaddr = kmap(dst_page);
269 	src_vaddr = kmap(src_page);
270 
271 	memcpy(dst_vaddr + dst_offset, src_vaddr + src_offset, length);
272 
273 	kunmap(src_page);
274 	kunmap(dst_page);
275 }
276 
277 static inline void
278 slow_shmem_bit17_copy(struct page *gpu_page,
279 		      int gpu_offset,
280 		      struct page *cpu_page,
281 		      int cpu_offset,
282 		      int length,
283 		      int is_read)
284 {
285 	char *gpu_vaddr, *cpu_vaddr;
286 
287 	/* Use the unswizzled path if this page isn't affected. */
288 	if ((page_to_phys(gpu_page) & (1 << 17)) == 0) {
289 		if (is_read)
290 			return slow_shmem_copy(cpu_page, cpu_offset,
291 					       gpu_page, gpu_offset, length);
292 		else
293 			return slow_shmem_copy(gpu_page, gpu_offset,
294 					       cpu_page, cpu_offset, length);
295 	}
296 
297 	gpu_vaddr = kmap(gpu_page);
298 	cpu_vaddr = kmap(cpu_page);
299 
300 	/* Copy the data, XORing A6 with A17 (1). The user already knows he's
301 	 * XORing with the other bits (A9 for Y, A9 and A10 for X)
302 	 */
303 	while (length > 0) {
304 		int cacheline_end = ALIGN(gpu_offset + 1, 64);
305 		int this_length = min(cacheline_end - gpu_offset, length);
306 		int swizzled_gpu_offset = gpu_offset ^ 64;
307 
308 		if (is_read) {
309 			memcpy(cpu_vaddr + cpu_offset,
310 			       gpu_vaddr + swizzled_gpu_offset,
311 			       this_length);
312 		} else {
313 			memcpy(gpu_vaddr + swizzled_gpu_offset,
314 			       cpu_vaddr + cpu_offset,
315 			       this_length);
316 		}
317 		cpu_offset += this_length;
318 		gpu_offset += this_length;
319 		length -= this_length;
320 	}
321 
322 	kunmap(cpu_page);
323 	kunmap(gpu_page);
324 }
325 
326 /**
327  * This is the fast shmem pread path, which attempts to copy_from_user directly
328  * from the backing pages of the object to the user's address space.  On a
329  * fault, it fails so we can fall back to i915_gem_shmem_pwrite_slow().
330  */
331 static int
332 i915_gem_shmem_pread_fast(struct drm_device *dev,
333 			  struct drm_i915_gem_object *obj,
334 			  struct drm_i915_gem_pread *args,
335 			  struct drm_file *file)
336 {
337 	struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
338 	ssize_t remain;
339 	loff_t offset;
340 	char __user *user_data;
341 	int page_offset, page_length;
342 
343 	user_data = (char __user *) (uintptr_t) args->data_ptr;
344 	remain = args->size;
345 
346 	offset = args->offset;
347 
348 	while (remain > 0) {
349 		struct page *page;
350 		char *vaddr;
351 		int ret;
352 
353 		/* Operation in this page
354 		 *
355 		 * page_offset = offset within page
356 		 * page_length = bytes to copy for this page
357 		 */
358 		page_offset = offset_in_page(offset);
359 		page_length = remain;
360 		if ((page_offset + remain) > PAGE_SIZE)
361 			page_length = PAGE_SIZE - page_offset;
362 
363 		page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT);
364 		if (IS_ERR(page))
365 			return PTR_ERR(page);
366 
367 		vaddr = kmap_atomic(page);
368 		ret = __copy_to_user_inatomic(user_data,
369 					      vaddr + page_offset,
370 					      page_length);
371 		kunmap_atomic(vaddr);
372 
373 		mark_page_accessed(page);
374 		page_cache_release(page);
375 		if (ret)
376 			return -EFAULT;
377 
378 		remain -= page_length;
379 		user_data += page_length;
380 		offset += page_length;
381 	}
382 
383 	return 0;
384 }
385 
386 /**
387  * This is the fallback shmem pread path, which allocates temporary storage
388  * in kernel space to copy_to_user into outside of the struct_mutex, so we
389  * can copy out of the object's backing pages while holding the struct mutex
390  * and not take page faults.
391  */
392 static int
393 i915_gem_shmem_pread_slow(struct drm_device *dev,
394 			  struct drm_i915_gem_object *obj,
395 			  struct drm_i915_gem_pread *args,
396 			  struct drm_file *file)
397 {
398 	struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
399 	struct mm_struct *mm = current->mm;
400 	struct page **user_pages;
401 	ssize_t remain;
402 	loff_t offset, pinned_pages, i;
403 	loff_t first_data_page, last_data_page, num_pages;
404 	int shmem_page_offset;
405 	int data_page_index, data_page_offset;
406 	int page_length;
407 	int ret;
408 	uint64_t data_ptr = args->data_ptr;
409 	int do_bit17_swizzling;
410 
411 	remain = args->size;
412 
413 	/* Pin the user pages containing the data.  We can't fault while
414 	 * holding the struct mutex, yet we want to hold it while
415 	 * dereferencing the user data.
416 	 */
417 	first_data_page = data_ptr / PAGE_SIZE;
418 	last_data_page = (data_ptr + args->size - 1) / PAGE_SIZE;
419 	num_pages = last_data_page - first_data_page + 1;
420 
421 	user_pages = drm_malloc_ab(num_pages, sizeof(struct page *));
422 	if (user_pages == NULL)
423 		return -ENOMEM;
424 
425 	mutex_unlock(&dev->struct_mutex);
426 	down_read(&mm->mmap_sem);
427 	pinned_pages = get_user_pages(current, mm, (uintptr_t)args->data_ptr,
428 				      num_pages, 1, 0, user_pages, NULL);
429 	up_read(&mm->mmap_sem);
430 	mutex_lock(&dev->struct_mutex);
431 	if (pinned_pages < num_pages) {
432 		ret = -EFAULT;
433 		goto out;
434 	}
435 
436 	ret = i915_gem_object_set_cpu_read_domain_range(obj,
437 							args->offset,
438 							args->size);
439 	if (ret)
440 		goto out;
441 
442 	do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj);
443 
444 	offset = args->offset;
445 
446 	while (remain > 0) {
447 		struct page *page;
448 
449 		/* Operation in this page
450 		 *
451 		 * shmem_page_offset = offset within page in shmem file
452 		 * data_page_index = page number in get_user_pages return
453 		 * data_page_offset = offset with data_page_index page.
454 		 * page_length = bytes to copy for this page
455 		 */
456 		shmem_page_offset = offset_in_page(offset);
457 		data_page_index = data_ptr / PAGE_SIZE - first_data_page;
458 		data_page_offset = offset_in_page(data_ptr);
459 
460 		page_length = remain;
461 		if ((shmem_page_offset + page_length) > PAGE_SIZE)
462 			page_length = PAGE_SIZE - shmem_page_offset;
463 		if ((data_page_offset + page_length) > PAGE_SIZE)
464 			page_length = PAGE_SIZE - data_page_offset;
465 
466 		page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT);
467 		if (IS_ERR(page)) {
468 			ret = PTR_ERR(page);
469 			goto out;
470 		}
471 
472 		if (do_bit17_swizzling) {
473 			slow_shmem_bit17_copy(page,
474 					      shmem_page_offset,
475 					      user_pages[data_page_index],
476 					      data_page_offset,
477 					      page_length,
478 					      1);
479 		} else {
480 			slow_shmem_copy(user_pages[data_page_index],
481 					data_page_offset,
482 					page,
483 					shmem_page_offset,
484 					page_length);
485 		}
486 
487 		mark_page_accessed(page);
488 		page_cache_release(page);
489 
490 		remain -= page_length;
491 		data_ptr += page_length;
492 		offset += page_length;
493 	}
494 
495 out:
496 	for (i = 0; i < pinned_pages; i++) {
497 		SetPageDirty(user_pages[i]);
498 		mark_page_accessed(user_pages[i]);
499 		page_cache_release(user_pages[i]);
500 	}
501 	drm_free_large(user_pages);
502 
503 	return ret;
504 }
505 
506 /**
507  * Reads data from the object referenced by handle.
508  *
509  * On error, the contents of *data are undefined.
510  */
511 int
512 i915_gem_pread_ioctl(struct drm_device *dev, void *data,
513 		     struct drm_file *file)
514 {
515 	struct drm_i915_gem_pread *args = data;
516 	struct drm_i915_gem_object *obj;
517 	int ret = 0;
518 
519 	if (args->size == 0)
520 		return 0;
521 
522 	if (!access_ok(VERIFY_WRITE,
523 		       (char __user *)(uintptr_t)args->data_ptr,
524 		       args->size))
525 		return -EFAULT;
526 
527 	ret = fault_in_pages_writeable((char __user *)(uintptr_t)args->data_ptr,
528 				       args->size);
529 	if (ret)
530 		return -EFAULT;
531 
532 	ret = i915_mutex_lock_interruptible(dev);
533 	if (ret)
534 		return ret;
535 
536 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
537 	if (&obj->base == NULL) {
538 		ret = -ENOENT;
539 		goto unlock;
540 	}
541 
542 	/* Bounds check source.  */
543 	if (args->offset > obj->base.size ||
544 	    args->size > obj->base.size - args->offset) {
545 		ret = -EINVAL;
546 		goto out;
547 	}
548 
549 	trace_i915_gem_object_pread(obj, args->offset, args->size);
550 
551 	ret = i915_gem_object_set_cpu_read_domain_range(obj,
552 							args->offset,
553 							args->size);
554 	if (ret)
555 		goto out;
556 
557 	ret = -EFAULT;
558 	if (!i915_gem_object_needs_bit17_swizzle(obj))
559 		ret = i915_gem_shmem_pread_fast(dev, obj, args, file);
560 	if (ret == -EFAULT)
561 		ret = i915_gem_shmem_pread_slow(dev, obj, args, file);
562 
563 out:
564 	drm_gem_object_unreference(&obj->base);
565 unlock:
566 	mutex_unlock(&dev->struct_mutex);
567 	return ret;
568 }
569 
570 /* This is the fast write path which cannot handle
571  * page faults in the source data
572  */
573 
574 static inline int
575 fast_user_write(struct io_mapping *mapping,
576 		loff_t page_base, int page_offset,
577 		char __user *user_data,
578 		int length)
579 {
580 	char *vaddr_atomic;
581 	unsigned long unwritten;
582 
583 	vaddr_atomic = io_mapping_map_atomic_wc(mapping, page_base);
584 	unwritten = __copy_from_user_inatomic_nocache(vaddr_atomic + page_offset,
585 						      user_data, length);
586 	io_mapping_unmap_atomic(vaddr_atomic);
587 	return unwritten;
588 }
589 
590 /* Here's the write path which can sleep for
591  * page faults
592  */
593 
594 static inline void
595 slow_kernel_write(struct io_mapping *mapping,
596 		  loff_t gtt_base, int gtt_offset,
597 		  struct page *user_page, int user_offset,
598 		  int length)
599 {
600 	char __iomem *dst_vaddr;
601 	char *src_vaddr;
602 
603 	dst_vaddr = io_mapping_map_wc(mapping, gtt_base);
604 	src_vaddr = kmap(user_page);
605 
606 	memcpy_toio(dst_vaddr + gtt_offset,
607 		    src_vaddr + user_offset,
608 		    length);
609 
610 	kunmap(user_page);
611 	io_mapping_unmap(dst_vaddr);
612 }
613 
614 /**
615  * This is the fast pwrite path, where we copy the data directly from the
616  * user into the GTT, uncached.
617  */
618 static int
619 i915_gem_gtt_pwrite_fast(struct drm_device *dev,
620 			 struct drm_i915_gem_object *obj,
621 			 struct drm_i915_gem_pwrite *args,
622 			 struct drm_file *file)
623 {
624 	drm_i915_private_t *dev_priv = dev->dev_private;
625 	ssize_t remain;
626 	loff_t offset, page_base;
627 	char __user *user_data;
628 	int page_offset, page_length;
629 
630 	user_data = (char __user *) (uintptr_t) args->data_ptr;
631 	remain = args->size;
632 
633 	offset = obj->gtt_offset + args->offset;
634 
635 	while (remain > 0) {
636 		/* Operation in this page
637 		 *
638 		 * page_base = page offset within aperture
639 		 * page_offset = offset within page
640 		 * page_length = bytes to copy for this page
641 		 */
642 		page_base = offset & PAGE_MASK;
643 		page_offset = offset_in_page(offset);
644 		page_length = remain;
645 		if ((page_offset + remain) > PAGE_SIZE)
646 			page_length = PAGE_SIZE - page_offset;
647 
648 		/* If we get a fault while copying data, then (presumably) our
649 		 * source page isn't available.  Return the error and we'll
650 		 * retry in the slow path.
651 		 */
652 		if (fast_user_write(dev_priv->mm.gtt_mapping, page_base,
653 				    page_offset, user_data, page_length))
654 			return -EFAULT;
655 
656 		remain -= page_length;
657 		user_data += page_length;
658 		offset += page_length;
659 	}
660 
661 	return 0;
662 }
663 
664 /**
665  * This is the fallback GTT pwrite path, which uses get_user_pages to pin
666  * the memory and maps it using kmap_atomic for copying.
667  *
668  * This code resulted in x11perf -rgb10text consuming about 10% more CPU
669  * than using i915_gem_gtt_pwrite_fast on a G45 (32-bit).
670  */
671 static int
672 i915_gem_gtt_pwrite_slow(struct drm_device *dev,
673 			 struct drm_i915_gem_object *obj,
674 			 struct drm_i915_gem_pwrite *args,
675 			 struct drm_file *file)
676 {
677 	drm_i915_private_t *dev_priv = dev->dev_private;
678 	ssize_t remain;
679 	loff_t gtt_page_base, offset;
680 	loff_t first_data_page, last_data_page, num_pages;
681 	loff_t pinned_pages, i;
682 	struct page **user_pages;
683 	struct mm_struct *mm = current->mm;
684 	int gtt_page_offset, data_page_offset, data_page_index, page_length;
685 	int ret;
686 	uint64_t data_ptr = args->data_ptr;
687 
688 	remain = args->size;
689 
690 	/* Pin the user pages containing the data.  We can't fault while
691 	 * holding the struct mutex, and all of the pwrite implementations
692 	 * want to hold it while dereferencing the user data.
693 	 */
694 	first_data_page = data_ptr / PAGE_SIZE;
695 	last_data_page = (data_ptr + args->size - 1) / PAGE_SIZE;
696 	num_pages = last_data_page - first_data_page + 1;
697 
698 	user_pages = drm_malloc_ab(num_pages, sizeof(struct page *));
699 	if (user_pages == NULL)
700 		return -ENOMEM;
701 
702 	mutex_unlock(&dev->struct_mutex);
703 	down_read(&mm->mmap_sem);
704 	pinned_pages = get_user_pages(current, mm, (uintptr_t)args->data_ptr,
705 				      num_pages, 0, 0, user_pages, NULL);
706 	up_read(&mm->mmap_sem);
707 	mutex_lock(&dev->struct_mutex);
708 	if (pinned_pages < num_pages) {
709 		ret = -EFAULT;
710 		goto out_unpin_pages;
711 	}
712 
713 	ret = i915_gem_object_set_to_gtt_domain(obj, true);
714 	if (ret)
715 		goto out_unpin_pages;
716 
717 	ret = i915_gem_object_put_fence(obj);
718 	if (ret)
719 		goto out_unpin_pages;
720 
721 	offset = obj->gtt_offset + args->offset;
722 
723 	while (remain > 0) {
724 		/* Operation in this page
725 		 *
726 		 * gtt_page_base = page offset within aperture
727 		 * gtt_page_offset = offset within page in aperture
728 		 * data_page_index = page number in get_user_pages return
729 		 * data_page_offset = offset with data_page_index page.
730 		 * page_length = bytes to copy for this page
731 		 */
732 		gtt_page_base = offset & PAGE_MASK;
733 		gtt_page_offset = offset_in_page(offset);
734 		data_page_index = data_ptr / PAGE_SIZE - first_data_page;
735 		data_page_offset = offset_in_page(data_ptr);
736 
737 		page_length = remain;
738 		if ((gtt_page_offset + page_length) > PAGE_SIZE)
739 			page_length = PAGE_SIZE - gtt_page_offset;
740 		if ((data_page_offset + page_length) > PAGE_SIZE)
741 			page_length = PAGE_SIZE - data_page_offset;
742 
743 		slow_kernel_write(dev_priv->mm.gtt_mapping,
744 				  gtt_page_base, gtt_page_offset,
745 				  user_pages[data_page_index],
746 				  data_page_offset,
747 				  page_length);
748 
749 		remain -= page_length;
750 		offset += page_length;
751 		data_ptr += page_length;
752 	}
753 
754 out_unpin_pages:
755 	for (i = 0; i < pinned_pages; i++)
756 		page_cache_release(user_pages[i]);
757 	drm_free_large(user_pages);
758 
759 	return ret;
760 }
761 
762 /**
763  * This is the fast shmem pwrite path, which attempts to directly
764  * copy_from_user into the kmapped pages backing the object.
765  */
766 static int
767 i915_gem_shmem_pwrite_fast(struct drm_device *dev,
768 			   struct drm_i915_gem_object *obj,
769 			   struct drm_i915_gem_pwrite *args,
770 			   struct drm_file *file)
771 {
772 	struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
773 	ssize_t remain;
774 	loff_t offset;
775 	char __user *user_data;
776 	int page_offset, page_length;
777 
778 	user_data = (char __user *) (uintptr_t) args->data_ptr;
779 	remain = args->size;
780 
781 	offset = args->offset;
782 	obj->dirty = 1;
783 
784 	while (remain > 0) {
785 		struct page *page;
786 		char *vaddr;
787 		int ret;
788 
789 		/* Operation in this page
790 		 *
791 		 * page_offset = offset within page
792 		 * page_length = bytes to copy for this page
793 		 */
794 		page_offset = offset_in_page(offset);
795 		page_length = remain;
796 		if ((page_offset + remain) > PAGE_SIZE)
797 			page_length = PAGE_SIZE - page_offset;
798 
799 		page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT);
800 		if (IS_ERR(page))
801 			return PTR_ERR(page);
802 
803 		vaddr = kmap_atomic(page, KM_USER0);
804 		ret = __copy_from_user_inatomic(vaddr + page_offset,
805 						user_data,
806 						page_length);
807 		kunmap_atomic(vaddr, KM_USER0);
808 
809 		set_page_dirty(page);
810 		mark_page_accessed(page);
811 		page_cache_release(page);
812 
813 		/* If we get a fault while copying data, then (presumably) our
814 		 * source page isn't available.  Return the error and we'll
815 		 * retry in the slow path.
816 		 */
817 		if (ret)
818 			return -EFAULT;
819 
820 		remain -= page_length;
821 		user_data += page_length;
822 		offset += page_length;
823 	}
824 
825 	return 0;
826 }
827 
828 /**
829  * This is the fallback shmem pwrite path, which uses get_user_pages to pin
830  * the memory and maps it using kmap_atomic for copying.
831  *
832  * This avoids taking mmap_sem for faulting on the user's address while the
833  * struct_mutex is held.
834  */
835 static int
836 i915_gem_shmem_pwrite_slow(struct drm_device *dev,
837 			   struct drm_i915_gem_object *obj,
838 			   struct drm_i915_gem_pwrite *args,
839 			   struct drm_file *file)
840 {
841 	struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
842 	struct mm_struct *mm = current->mm;
843 	struct page **user_pages;
844 	ssize_t remain;
845 	loff_t offset, pinned_pages, i;
846 	loff_t first_data_page, last_data_page, num_pages;
847 	int shmem_page_offset;
848 	int data_page_index,  data_page_offset;
849 	int page_length;
850 	int ret;
851 	uint64_t data_ptr = args->data_ptr;
852 	int do_bit17_swizzling;
853 
854 	remain = args->size;
855 
856 	/* Pin the user pages containing the data.  We can't fault while
857 	 * holding the struct mutex, and all of the pwrite implementations
858 	 * want to hold it while dereferencing the user data.
859 	 */
860 	first_data_page = data_ptr / PAGE_SIZE;
861 	last_data_page = (data_ptr + args->size - 1) / PAGE_SIZE;
862 	num_pages = last_data_page - first_data_page + 1;
863 
864 	user_pages = drm_malloc_ab(num_pages, sizeof(struct page *));
865 	if (user_pages == NULL)
866 		return -ENOMEM;
867 
868 	mutex_unlock(&dev->struct_mutex);
869 	down_read(&mm->mmap_sem);
870 	pinned_pages = get_user_pages(current, mm, (uintptr_t)args->data_ptr,
871 				      num_pages, 0, 0, user_pages, NULL);
872 	up_read(&mm->mmap_sem);
873 	mutex_lock(&dev->struct_mutex);
874 	if (pinned_pages < num_pages) {
875 		ret = -EFAULT;
876 		goto out;
877 	}
878 
879 	ret = i915_gem_object_set_to_cpu_domain(obj, 1);
880 	if (ret)
881 		goto out;
882 
883 	do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj);
884 
885 	offset = args->offset;
886 	obj->dirty = 1;
887 
888 	while (remain > 0) {
889 		struct page *page;
890 
891 		/* Operation in this page
892 		 *
893 		 * shmem_page_offset = offset within page in shmem file
894 		 * data_page_index = page number in get_user_pages return
895 		 * data_page_offset = offset with data_page_index page.
896 		 * page_length = bytes to copy for this page
897 		 */
898 		shmem_page_offset = offset_in_page(offset);
899 		data_page_index = data_ptr / PAGE_SIZE - first_data_page;
900 		data_page_offset = offset_in_page(data_ptr);
901 
902 		page_length = remain;
903 		if ((shmem_page_offset + page_length) > PAGE_SIZE)
904 			page_length = PAGE_SIZE - shmem_page_offset;
905 		if ((data_page_offset + page_length) > PAGE_SIZE)
906 			page_length = PAGE_SIZE - data_page_offset;
907 
908 		page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT);
909 		if (IS_ERR(page)) {
910 			ret = PTR_ERR(page);
911 			goto out;
912 		}
913 
914 		if (do_bit17_swizzling) {
915 			slow_shmem_bit17_copy(page,
916 					      shmem_page_offset,
917 					      user_pages[data_page_index],
918 					      data_page_offset,
919 					      page_length,
920 					      0);
921 		} else {
922 			slow_shmem_copy(page,
923 					shmem_page_offset,
924 					user_pages[data_page_index],
925 					data_page_offset,
926 					page_length);
927 		}
928 
929 		set_page_dirty(page);
930 		mark_page_accessed(page);
931 		page_cache_release(page);
932 
933 		remain -= page_length;
934 		data_ptr += page_length;
935 		offset += page_length;
936 	}
937 
938 out:
939 	for (i = 0; i < pinned_pages; i++)
940 		page_cache_release(user_pages[i]);
941 	drm_free_large(user_pages);
942 
943 	return ret;
944 }
945 
946 /**
947  * Writes data to the object referenced by handle.
948  *
949  * On error, the contents of the buffer that were to be modified are undefined.
950  */
951 int
952 i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
953 		      struct drm_file *file)
954 {
955 	struct drm_i915_gem_pwrite *args = data;
956 	struct drm_i915_gem_object *obj;
957 	int ret;
958 
959 	if (args->size == 0)
960 		return 0;
961 
962 	if (!access_ok(VERIFY_READ,
963 		       (char __user *)(uintptr_t)args->data_ptr,
964 		       args->size))
965 		return -EFAULT;
966 
967 	ret = fault_in_pages_readable((char __user *)(uintptr_t)args->data_ptr,
968 				      args->size);
969 	if (ret)
970 		return -EFAULT;
971 
972 	ret = i915_mutex_lock_interruptible(dev);
973 	if (ret)
974 		return ret;
975 
976 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
977 	if (&obj->base == NULL) {
978 		ret = -ENOENT;
979 		goto unlock;
980 	}
981 
982 	/* Bounds check destination. */
983 	if (args->offset > obj->base.size ||
984 	    args->size > obj->base.size - args->offset) {
985 		ret = -EINVAL;
986 		goto out;
987 	}
988 
989 	trace_i915_gem_object_pwrite(obj, args->offset, args->size);
990 
991 	/* We can only do the GTT pwrite on untiled buffers, as otherwise
992 	 * it would end up going through the fenced access, and we'll get
993 	 * different detiling behavior between reading and writing.
994 	 * pread/pwrite currently are reading and writing from the CPU
995 	 * perspective, requiring manual detiling by the client.
996 	 */
997 	if (obj->phys_obj)
998 		ret = i915_gem_phys_pwrite(dev, obj, args, file);
999 	else if (obj->gtt_space &&
1000 		 obj->base.write_domain != I915_GEM_DOMAIN_CPU) {
1001 		ret = i915_gem_object_pin(obj, 0, true);
1002 		if (ret)
1003 			goto out;
1004 
1005 		ret = i915_gem_object_set_to_gtt_domain(obj, true);
1006 		if (ret)
1007 			goto out_unpin;
1008 
1009 		ret = i915_gem_object_put_fence(obj);
1010 		if (ret)
1011 			goto out_unpin;
1012 
1013 		ret = i915_gem_gtt_pwrite_fast(dev, obj, args, file);
1014 		if (ret == -EFAULT)
1015 			ret = i915_gem_gtt_pwrite_slow(dev, obj, args, file);
1016 
1017 out_unpin:
1018 		i915_gem_object_unpin(obj);
1019 	} else {
1020 		ret = i915_gem_object_set_to_cpu_domain(obj, 1);
1021 		if (ret)
1022 			goto out;
1023 
1024 		ret = -EFAULT;
1025 		if (!i915_gem_object_needs_bit17_swizzle(obj))
1026 			ret = i915_gem_shmem_pwrite_fast(dev, obj, args, file);
1027 		if (ret == -EFAULT)
1028 			ret = i915_gem_shmem_pwrite_slow(dev, obj, args, file);
1029 	}
1030 
1031 out:
1032 	drm_gem_object_unreference(&obj->base);
1033 unlock:
1034 	mutex_unlock(&dev->struct_mutex);
1035 	return ret;
1036 }
1037 
1038 /**
1039  * Called when user space prepares to use an object with the CPU, either
1040  * through the mmap ioctl's mapping or a GTT mapping.
1041  */
1042 int
1043 i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
1044 			  struct drm_file *file)
1045 {
1046 	struct drm_i915_gem_set_domain *args = data;
1047 	struct drm_i915_gem_object *obj;
1048 	uint32_t read_domains = args->read_domains;
1049 	uint32_t write_domain = args->write_domain;
1050 	int ret;
1051 
1052 	if (!(dev->driver->driver_features & DRIVER_GEM))
1053 		return -ENODEV;
1054 
1055 	/* Only handle setting domains to types used by the CPU. */
1056 	if (write_domain & I915_GEM_GPU_DOMAINS)
1057 		return -EINVAL;
1058 
1059 	if (read_domains & I915_GEM_GPU_DOMAINS)
1060 		return -EINVAL;
1061 
1062 	/* Having something in the write domain implies it's in the read
1063 	 * domain, and only that read domain.  Enforce that in the request.
1064 	 */
1065 	if (write_domain != 0 && read_domains != write_domain)
1066 		return -EINVAL;
1067 
1068 	ret = i915_mutex_lock_interruptible(dev);
1069 	if (ret)
1070 		return ret;
1071 
1072 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
1073 	if (&obj->base == NULL) {
1074 		ret = -ENOENT;
1075 		goto unlock;
1076 	}
1077 
1078 	if (read_domains & I915_GEM_DOMAIN_GTT) {
1079 		ret = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0);
1080 
1081 		/* Silently promote "you're not bound, there was nothing to do"
1082 		 * to success, since the client was just asking us to
1083 		 * make sure everything was done.
1084 		 */
1085 		if (ret == -EINVAL)
1086 			ret = 0;
1087 	} else {
1088 		ret = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0);
1089 	}
1090 
1091 	drm_gem_object_unreference(&obj->base);
1092 unlock:
1093 	mutex_unlock(&dev->struct_mutex);
1094 	return ret;
1095 }
1096 
1097 /**
1098  * Called when user space has done writes to this buffer
1099  */
1100 int
1101 i915_gem_sw_finish_ioctl(struct drm_device *dev, void *data,
1102 			 struct drm_file *file)
1103 {
1104 	struct drm_i915_gem_sw_finish *args = data;
1105 	struct drm_i915_gem_object *obj;
1106 	int ret = 0;
1107 
1108 	if (!(dev->driver->driver_features & DRIVER_GEM))
1109 		return -ENODEV;
1110 
1111 	ret = i915_mutex_lock_interruptible(dev);
1112 	if (ret)
1113 		return ret;
1114 
1115 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
1116 	if (&obj->base == NULL) {
1117 		ret = -ENOENT;
1118 		goto unlock;
1119 	}
1120 
1121 	/* Pinned buffers may be scanout, so flush the cache */
1122 	if (obj->pin_count)
1123 		i915_gem_object_flush_cpu_write_domain(obj);
1124 
1125 	drm_gem_object_unreference(&obj->base);
1126 unlock:
1127 	mutex_unlock(&dev->struct_mutex);
1128 	return ret;
1129 }
1130 
1131 /**
1132  * Maps the contents of an object, returning the address it is mapped
1133  * into.
1134  *
1135  * While the mapping holds a reference on the contents of the object, it doesn't
1136  * imply a ref on the object itself.
1137  */
1138 int
1139 i915_gem_mmap_ioctl(struct drm_device *dev, void *data,
1140 		    struct drm_file *file)
1141 {
1142 	struct drm_i915_private *dev_priv = dev->dev_private;
1143 	struct drm_i915_gem_mmap *args = data;
1144 	struct drm_gem_object *obj;
1145 	unsigned long addr;
1146 
1147 	if (!(dev->driver->driver_features & DRIVER_GEM))
1148 		return -ENODEV;
1149 
1150 	obj = drm_gem_object_lookup(dev, file, args->handle);
1151 	if (obj == NULL)
1152 		return -ENOENT;
1153 
1154 	if (obj->size > dev_priv->mm.gtt_mappable_end) {
1155 		drm_gem_object_unreference_unlocked(obj);
1156 		return -E2BIG;
1157 	}
1158 
1159 	down_write(&current->mm->mmap_sem);
1160 	addr = do_mmap(obj->filp, 0, args->size,
1161 		       PROT_READ | PROT_WRITE, MAP_SHARED,
1162 		       args->offset);
1163 	up_write(&current->mm->mmap_sem);
1164 	drm_gem_object_unreference_unlocked(obj);
1165 	if (IS_ERR((void *)addr))
1166 		return addr;
1167 
1168 	args->addr_ptr = (uint64_t) addr;
1169 
1170 	return 0;
1171 }
1172 
1173 /**
1174  * i915_gem_fault - fault a page into the GTT
1175  * vma: VMA in question
1176  * vmf: fault info
1177  *
1178  * The fault handler is set up by drm_gem_mmap() when a object is GTT mapped
1179  * from userspace.  The fault handler takes care of binding the object to
1180  * the GTT (if needed), allocating and programming a fence register (again,
1181  * only if needed based on whether the old reg is still valid or the object
1182  * is tiled) and inserting a new PTE into the faulting process.
1183  *
1184  * Note that the faulting process may involve evicting existing objects
1185  * from the GTT and/or fence registers to make room.  So performance may
1186  * suffer if the GTT working set is large or there are few fence registers
1187  * left.
1188  */
1189 int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1190 {
1191 	struct drm_i915_gem_object *obj = to_intel_bo(vma->vm_private_data);
1192 	struct drm_device *dev = obj->base.dev;
1193 	drm_i915_private_t *dev_priv = dev->dev_private;
1194 	pgoff_t page_offset;
1195 	unsigned long pfn;
1196 	int ret = 0;
1197 	bool write = !!(vmf->flags & FAULT_FLAG_WRITE);
1198 
1199 	/* We don't use vmf->pgoff since that has the fake offset */
1200 	page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
1201 		PAGE_SHIFT;
1202 
1203 	ret = i915_mutex_lock_interruptible(dev);
1204 	if (ret)
1205 		goto out;
1206 
1207 	trace_i915_gem_object_fault(obj, page_offset, true, write);
1208 
1209 	/* Now bind it into the GTT if needed */
1210 	if (!obj->map_and_fenceable) {
1211 		ret = i915_gem_object_unbind(obj);
1212 		if (ret)
1213 			goto unlock;
1214 	}
1215 	if (!obj->gtt_space) {
1216 		ret = i915_gem_object_bind_to_gtt(obj, 0, true);
1217 		if (ret)
1218 			goto unlock;
1219 
1220 		ret = i915_gem_object_set_to_gtt_domain(obj, write);
1221 		if (ret)
1222 			goto unlock;
1223 	}
1224 
1225 	if (obj->tiling_mode == I915_TILING_NONE)
1226 		ret = i915_gem_object_put_fence(obj);
1227 	else
1228 		ret = i915_gem_object_get_fence(obj, NULL);
1229 	if (ret)
1230 		goto unlock;
1231 
1232 	if (i915_gem_object_is_inactive(obj))
1233 		list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
1234 
1235 	obj->fault_mappable = true;
1236 
1237 	pfn = ((dev->agp->base + obj->gtt_offset) >> PAGE_SHIFT) +
1238 		page_offset;
1239 
1240 	/* Finally, remap it using the new GTT offset */
1241 	ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
1242 unlock:
1243 	mutex_unlock(&dev->struct_mutex);
1244 out:
1245 	switch (ret) {
1246 	case -EIO:
1247 	case -EAGAIN:
1248 		/* Give the error handler a chance to run and move the
1249 		 * objects off the GPU active list. Next time we service the
1250 		 * fault, we should be able to transition the page into the
1251 		 * GTT without touching the GPU (and so avoid further
1252 		 * EIO/EGAIN). If the GPU is wedged, then there is no issue
1253 		 * with coherency, just lost writes.
1254 		 */
1255 		set_need_resched();
1256 	case 0:
1257 	case -ERESTARTSYS:
1258 	case -EINTR:
1259 		return VM_FAULT_NOPAGE;
1260 	case -ENOMEM:
1261 		return VM_FAULT_OOM;
1262 	default:
1263 		return VM_FAULT_SIGBUS;
1264 	}
1265 }
1266 
1267 /**
1268  * i915_gem_create_mmap_offset - create a fake mmap offset for an object
1269  * @obj: obj in question
1270  *
1271  * GEM memory mapping works by handing back to userspace a fake mmap offset
1272  * it can use in a subsequent mmap(2) call.  The DRM core code then looks
1273  * up the object based on the offset and sets up the various memory mapping
1274  * structures.
1275  *
1276  * This routine allocates and attaches a fake offset for @obj.
1277  */
1278 static int
1279 i915_gem_create_mmap_offset(struct drm_i915_gem_object *obj)
1280 {
1281 	struct drm_device *dev = obj->base.dev;
1282 	struct drm_gem_mm *mm = dev->mm_private;
1283 	struct drm_map_list *list;
1284 	struct drm_local_map *map;
1285 	int ret = 0;
1286 
1287 	/* Set the object up for mmap'ing */
1288 	list = &obj->base.map_list;
1289 	list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
1290 	if (!list->map)
1291 		return -ENOMEM;
1292 
1293 	map = list->map;
1294 	map->type = _DRM_GEM;
1295 	map->size = obj->base.size;
1296 	map->handle = obj;
1297 
1298 	/* Get a DRM GEM mmap offset allocated... */
1299 	list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
1300 						    obj->base.size / PAGE_SIZE,
1301 						    0, 0);
1302 	if (!list->file_offset_node) {
1303 		DRM_ERROR("failed to allocate offset for bo %d\n",
1304 			  obj->base.name);
1305 		ret = -ENOSPC;
1306 		goto out_free_list;
1307 	}
1308 
1309 	list->file_offset_node = drm_mm_get_block(list->file_offset_node,
1310 						  obj->base.size / PAGE_SIZE,
1311 						  0);
1312 	if (!list->file_offset_node) {
1313 		ret = -ENOMEM;
1314 		goto out_free_list;
1315 	}
1316 
1317 	list->hash.key = list->file_offset_node->start;
1318 	ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
1319 	if (ret) {
1320 		DRM_ERROR("failed to add to map hash\n");
1321 		goto out_free_mm;
1322 	}
1323 
1324 	return 0;
1325 
1326 out_free_mm:
1327 	drm_mm_put_block(list->file_offset_node);
1328 out_free_list:
1329 	kfree(list->map);
1330 	list->map = NULL;
1331 
1332 	return ret;
1333 }
1334 
1335 /**
1336  * i915_gem_release_mmap - remove physical page mappings
1337  * @obj: obj in question
1338  *
1339  * Preserve the reservation of the mmapping with the DRM core code, but
1340  * relinquish ownership of the pages back to the system.
1341  *
1342  * It is vital that we remove the page mapping if we have mapped a tiled
1343  * object through the GTT and then lose the fence register due to
1344  * resource pressure. Similarly if the object has been moved out of the
1345  * aperture, than pages mapped into userspace must be revoked. Removing the
1346  * mapping will then trigger a page fault on the next user access, allowing
1347  * fixup by i915_gem_fault().
1348  */
1349 void
1350 i915_gem_release_mmap(struct drm_i915_gem_object *obj)
1351 {
1352 	if (!obj->fault_mappable)
1353 		return;
1354 
1355 	if (obj->base.dev->dev_mapping)
1356 		unmap_mapping_range(obj->base.dev->dev_mapping,
1357 				    (loff_t)obj->base.map_list.hash.key<<PAGE_SHIFT,
1358 				    obj->base.size, 1);
1359 
1360 	obj->fault_mappable = false;
1361 }
1362 
1363 static void
1364 i915_gem_free_mmap_offset(struct drm_i915_gem_object *obj)
1365 {
1366 	struct drm_device *dev = obj->base.dev;
1367 	struct drm_gem_mm *mm = dev->mm_private;
1368 	struct drm_map_list *list = &obj->base.map_list;
1369 
1370 	drm_ht_remove_item(&mm->offset_hash, &list->hash);
1371 	drm_mm_put_block(list->file_offset_node);
1372 	kfree(list->map);
1373 	list->map = NULL;
1374 }
1375 
1376 static uint32_t
1377 i915_gem_get_gtt_size(struct drm_device *dev, uint32_t size, int tiling_mode)
1378 {
1379 	uint32_t gtt_size;
1380 
1381 	if (INTEL_INFO(dev)->gen >= 4 ||
1382 	    tiling_mode == I915_TILING_NONE)
1383 		return size;
1384 
1385 	/* Previous chips need a power-of-two fence region when tiling */
1386 	if (INTEL_INFO(dev)->gen == 3)
1387 		gtt_size = 1024*1024;
1388 	else
1389 		gtt_size = 512*1024;
1390 
1391 	while (gtt_size < size)
1392 		gtt_size <<= 1;
1393 
1394 	return gtt_size;
1395 }
1396 
1397 /**
1398  * i915_gem_get_gtt_alignment - return required GTT alignment for an object
1399  * @obj: object to check
1400  *
1401  * Return the required GTT alignment for an object, taking into account
1402  * potential fence register mapping.
1403  */
1404 static uint32_t
1405 i915_gem_get_gtt_alignment(struct drm_device *dev,
1406 			   uint32_t size,
1407 			   int tiling_mode)
1408 {
1409 	/*
1410 	 * Minimum alignment is 4k (GTT page size), but might be greater
1411 	 * if a fence register is needed for the object.
1412 	 */
1413 	if (INTEL_INFO(dev)->gen >= 4 ||
1414 	    tiling_mode == I915_TILING_NONE)
1415 		return 4096;
1416 
1417 	/*
1418 	 * Previous chips need to be aligned to the size of the smallest
1419 	 * fence register that can contain the object.
1420 	 */
1421 	return i915_gem_get_gtt_size(dev, size, tiling_mode);
1422 }
1423 
1424 /**
1425  * i915_gem_get_unfenced_gtt_alignment - return required GTT alignment for an
1426  *					 unfenced object
1427  * @dev: the device
1428  * @size: size of the object
1429  * @tiling_mode: tiling mode of the object
1430  *
1431  * Return the required GTT alignment for an object, only taking into account
1432  * unfenced tiled surface requirements.
1433  */
1434 uint32_t
1435 i915_gem_get_unfenced_gtt_alignment(struct drm_device *dev,
1436 				    uint32_t size,
1437 				    int tiling_mode)
1438 {
1439 	/*
1440 	 * Minimum alignment is 4k (GTT page size) for sane hw.
1441 	 */
1442 	if (INTEL_INFO(dev)->gen >= 4 || IS_G33(dev) ||
1443 	    tiling_mode == I915_TILING_NONE)
1444 		return 4096;
1445 
1446 	/* Previous hardware however needs to be aligned to a power-of-two
1447 	 * tile height. The simplest method for determining this is to reuse
1448 	 * the power-of-tile object size.
1449 	 */
1450 	return i915_gem_get_gtt_size(dev, size, tiling_mode);
1451 }
1452 
1453 int
1454 i915_gem_mmap_gtt(struct drm_file *file,
1455 		  struct drm_device *dev,
1456 		  uint32_t handle,
1457 		  uint64_t *offset)
1458 {
1459 	struct drm_i915_private *dev_priv = dev->dev_private;
1460 	struct drm_i915_gem_object *obj;
1461 	int ret;
1462 
1463 	if (!(dev->driver->driver_features & DRIVER_GEM))
1464 		return -ENODEV;
1465 
1466 	ret = i915_mutex_lock_interruptible(dev);
1467 	if (ret)
1468 		return ret;
1469 
1470 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, handle));
1471 	if (&obj->base == NULL) {
1472 		ret = -ENOENT;
1473 		goto unlock;
1474 	}
1475 
1476 	if (obj->base.size > dev_priv->mm.gtt_mappable_end) {
1477 		ret = -E2BIG;
1478 		goto unlock;
1479 	}
1480 
1481 	if (obj->madv != I915_MADV_WILLNEED) {
1482 		DRM_ERROR("Attempting to mmap a purgeable buffer\n");
1483 		ret = -EINVAL;
1484 		goto out;
1485 	}
1486 
1487 	if (!obj->base.map_list.map) {
1488 		ret = i915_gem_create_mmap_offset(obj);
1489 		if (ret)
1490 			goto out;
1491 	}
1492 
1493 	*offset = (u64)obj->base.map_list.hash.key << PAGE_SHIFT;
1494 
1495 out:
1496 	drm_gem_object_unreference(&obj->base);
1497 unlock:
1498 	mutex_unlock(&dev->struct_mutex);
1499 	return ret;
1500 }
1501 
1502 /**
1503  * i915_gem_mmap_gtt_ioctl - prepare an object for GTT mmap'ing
1504  * @dev: DRM device
1505  * @data: GTT mapping ioctl data
1506  * @file: GEM object info
1507  *
1508  * Simply returns the fake offset to userspace so it can mmap it.
1509  * The mmap call will end up in drm_gem_mmap(), which will set things
1510  * up so we can get faults in the handler above.
1511  *
1512  * The fault handler will take care of binding the object into the GTT
1513  * (since it may have been evicted to make room for something), allocating
1514  * a fence register, and mapping the appropriate aperture address into
1515  * userspace.
1516  */
1517 int
1518 i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
1519 			struct drm_file *file)
1520 {
1521 	struct drm_i915_gem_mmap_gtt *args = data;
1522 
1523 	if (!(dev->driver->driver_features & DRIVER_GEM))
1524 		return -ENODEV;
1525 
1526 	return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);
1527 }
1528 
1529 
1530 static int
1531 i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj,
1532 			      gfp_t gfpmask)
1533 {
1534 	int page_count, i;
1535 	struct address_space *mapping;
1536 	struct inode *inode;
1537 	struct page *page;
1538 
1539 	/* Get the list of pages out of our struct file.  They'll be pinned
1540 	 * at this point until we release them.
1541 	 */
1542 	page_count = obj->base.size / PAGE_SIZE;
1543 	BUG_ON(obj->pages != NULL);
1544 	obj->pages = drm_malloc_ab(page_count, sizeof(struct page *));
1545 	if (obj->pages == NULL)
1546 		return -ENOMEM;
1547 
1548 	inode = obj->base.filp->f_path.dentry->d_inode;
1549 	mapping = inode->i_mapping;
1550 	gfpmask |= mapping_gfp_mask(mapping);
1551 
1552 	for (i = 0; i < page_count; i++) {
1553 		page = shmem_read_mapping_page_gfp(mapping, i, gfpmask);
1554 		if (IS_ERR(page))
1555 			goto err_pages;
1556 
1557 		obj->pages[i] = page;
1558 	}
1559 
1560 	if (obj->tiling_mode != I915_TILING_NONE)
1561 		i915_gem_object_do_bit_17_swizzle(obj);
1562 
1563 	return 0;
1564 
1565 err_pages:
1566 	while (i--)
1567 		page_cache_release(obj->pages[i]);
1568 
1569 	drm_free_large(obj->pages);
1570 	obj->pages = NULL;
1571 	return PTR_ERR(page);
1572 }
1573 
1574 static void
1575 i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
1576 {
1577 	int page_count = obj->base.size / PAGE_SIZE;
1578 	int i;
1579 
1580 	BUG_ON(obj->madv == __I915_MADV_PURGED);
1581 
1582 	if (obj->tiling_mode != I915_TILING_NONE)
1583 		i915_gem_object_save_bit_17_swizzle(obj);
1584 
1585 	if (obj->madv == I915_MADV_DONTNEED)
1586 		obj->dirty = 0;
1587 
1588 	for (i = 0; i < page_count; i++) {
1589 		if (obj->dirty)
1590 			set_page_dirty(obj->pages[i]);
1591 
1592 		if (obj->madv == I915_MADV_WILLNEED)
1593 			mark_page_accessed(obj->pages[i]);
1594 
1595 		page_cache_release(obj->pages[i]);
1596 	}
1597 	obj->dirty = 0;
1598 
1599 	drm_free_large(obj->pages);
1600 	obj->pages = NULL;
1601 }
1602 
1603 void
1604 i915_gem_object_move_to_active(struct drm_i915_gem_object *obj,
1605 			       struct intel_ring_buffer *ring,
1606 			       u32 seqno)
1607 {
1608 	struct drm_device *dev = obj->base.dev;
1609 	struct drm_i915_private *dev_priv = dev->dev_private;
1610 
1611 	BUG_ON(ring == NULL);
1612 	obj->ring = ring;
1613 
1614 	/* Add a reference if we're newly entering the active list. */
1615 	if (!obj->active) {
1616 		drm_gem_object_reference(&obj->base);
1617 		obj->active = 1;
1618 	}
1619 
1620 	/* Move from whatever list we were on to the tail of execution. */
1621 	list_move_tail(&obj->mm_list, &dev_priv->mm.active_list);
1622 	list_move_tail(&obj->ring_list, &ring->active_list);
1623 
1624 	obj->last_rendering_seqno = seqno;
1625 	if (obj->fenced_gpu_access) {
1626 		struct drm_i915_fence_reg *reg;
1627 
1628 		BUG_ON(obj->fence_reg == I915_FENCE_REG_NONE);
1629 
1630 		obj->last_fenced_seqno = seqno;
1631 		obj->last_fenced_ring = ring;
1632 
1633 		reg = &dev_priv->fence_regs[obj->fence_reg];
1634 		list_move_tail(&reg->lru_list, &dev_priv->mm.fence_list);
1635 	}
1636 }
1637 
1638 static void
1639 i915_gem_object_move_off_active(struct drm_i915_gem_object *obj)
1640 {
1641 	list_del_init(&obj->ring_list);
1642 	obj->last_rendering_seqno = 0;
1643 }
1644 
1645 static void
1646 i915_gem_object_move_to_flushing(struct drm_i915_gem_object *obj)
1647 {
1648 	struct drm_device *dev = obj->base.dev;
1649 	drm_i915_private_t *dev_priv = dev->dev_private;
1650 
1651 	BUG_ON(!obj->active);
1652 	list_move_tail(&obj->mm_list, &dev_priv->mm.flushing_list);
1653 
1654 	i915_gem_object_move_off_active(obj);
1655 }
1656 
1657 static void
1658 i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
1659 {
1660 	struct drm_device *dev = obj->base.dev;
1661 	struct drm_i915_private *dev_priv = dev->dev_private;
1662 
1663 	if (obj->pin_count != 0)
1664 		list_move_tail(&obj->mm_list, &dev_priv->mm.pinned_list);
1665 	else
1666 		list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
1667 
1668 	BUG_ON(!list_empty(&obj->gpu_write_list));
1669 	BUG_ON(!obj->active);
1670 	obj->ring = NULL;
1671 
1672 	i915_gem_object_move_off_active(obj);
1673 	obj->fenced_gpu_access = false;
1674 
1675 	obj->active = 0;
1676 	obj->pending_gpu_write = false;
1677 	drm_gem_object_unreference(&obj->base);
1678 
1679 	WARN_ON(i915_verify_lists(dev));
1680 }
1681 
1682 /* Immediately discard the backing storage */
1683 static void
1684 i915_gem_object_truncate(struct drm_i915_gem_object *obj)
1685 {
1686 	struct inode *inode;
1687 
1688 	/* Our goal here is to return as much of the memory as
1689 	 * is possible back to the system as we are called from OOM.
1690 	 * To do this we must instruct the shmfs to drop all of its
1691 	 * backing pages, *now*.
1692 	 */
1693 	inode = obj->base.filp->f_path.dentry->d_inode;
1694 	shmem_truncate_range(inode, 0, (loff_t)-1);
1695 
1696 	obj->madv = __I915_MADV_PURGED;
1697 }
1698 
1699 static inline int
1700 i915_gem_object_is_purgeable(struct drm_i915_gem_object *obj)
1701 {
1702 	return obj->madv == I915_MADV_DONTNEED;
1703 }
1704 
1705 static void
1706 i915_gem_process_flushing_list(struct intel_ring_buffer *ring,
1707 			       uint32_t flush_domains)
1708 {
1709 	struct drm_i915_gem_object *obj, *next;
1710 
1711 	list_for_each_entry_safe(obj, next,
1712 				 &ring->gpu_write_list,
1713 				 gpu_write_list) {
1714 		if (obj->base.write_domain & flush_domains) {
1715 			uint32_t old_write_domain = obj->base.write_domain;
1716 
1717 			obj->base.write_domain = 0;
1718 			list_del_init(&obj->gpu_write_list);
1719 			i915_gem_object_move_to_active(obj, ring,
1720 						       i915_gem_next_request_seqno(ring));
1721 
1722 			trace_i915_gem_object_change_domain(obj,
1723 							    obj->base.read_domains,
1724 							    old_write_domain);
1725 		}
1726 	}
1727 }
1728 
1729 int
1730 i915_add_request(struct intel_ring_buffer *ring,
1731 		 struct drm_file *file,
1732 		 struct drm_i915_gem_request *request)
1733 {
1734 	drm_i915_private_t *dev_priv = ring->dev->dev_private;
1735 	uint32_t seqno;
1736 	int was_empty;
1737 	int ret;
1738 
1739 	BUG_ON(request == NULL);
1740 
1741 	ret = ring->add_request(ring, &seqno);
1742 	if (ret)
1743 	    return ret;
1744 
1745 	trace_i915_gem_request_add(ring, seqno);
1746 
1747 	request->seqno = seqno;
1748 	request->ring = ring;
1749 	request->emitted_jiffies = jiffies;
1750 	was_empty = list_empty(&ring->request_list);
1751 	list_add_tail(&request->list, &ring->request_list);
1752 
1753 	if (file) {
1754 		struct drm_i915_file_private *file_priv = file->driver_priv;
1755 
1756 		spin_lock(&file_priv->mm.lock);
1757 		request->file_priv = file_priv;
1758 		list_add_tail(&request->client_list,
1759 			      &file_priv->mm.request_list);
1760 		spin_unlock(&file_priv->mm.lock);
1761 	}
1762 
1763 	ring->outstanding_lazy_request = false;
1764 
1765 	if (!dev_priv->mm.suspended) {
1766 		if (i915_enable_hangcheck) {
1767 			mod_timer(&dev_priv->hangcheck_timer,
1768 				  jiffies +
1769 				  msecs_to_jiffies(DRM_I915_HANGCHECK_PERIOD));
1770 		}
1771 		if (was_empty)
1772 			queue_delayed_work(dev_priv->wq,
1773 					   &dev_priv->mm.retire_work, HZ);
1774 	}
1775 	return 0;
1776 }
1777 
1778 static inline void
1779 i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
1780 {
1781 	struct drm_i915_file_private *file_priv = request->file_priv;
1782 
1783 	if (!file_priv)
1784 		return;
1785 
1786 	spin_lock(&file_priv->mm.lock);
1787 	if (request->file_priv) {
1788 		list_del(&request->client_list);
1789 		request->file_priv = NULL;
1790 	}
1791 	spin_unlock(&file_priv->mm.lock);
1792 }
1793 
1794 static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
1795 				      struct intel_ring_buffer *ring)
1796 {
1797 	while (!list_empty(&ring->request_list)) {
1798 		struct drm_i915_gem_request *request;
1799 
1800 		request = list_first_entry(&ring->request_list,
1801 					   struct drm_i915_gem_request,
1802 					   list);
1803 
1804 		list_del(&request->list);
1805 		i915_gem_request_remove_from_client(request);
1806 		kfree(request);
1807 	}
1808 
1809 	while (!list_empty(&ring->active_list)) {
1810 		struct drm_i915_gem_object *obj;
1811 
1812 		obj = list_first_entry(&ring->active_list,
1813 				       struct drm_i915_gem_object,
1814 				       ring_list);
1815 
1816 		obj->base.write_domain = 0;
1817 		list_del_init(&obj->gpu_write_list);
1818 		i915_gem_object_move_to_inactive(obj);
1819 	}
1820 }
1821 
1822 static void i915_gem_reset_fences(struct drm_device *dev)
1823 {
1824 	struct drm_i915_private *dev_priv = dev->dev_private;
1825 	int i;
1826 
1827 	for (i = 0; i < 16; i++) {
1828 		struct drm_i915_fence_reg *reg = &dev_priv->fence_regs[i];
1829 		struct drm_i915_gem_object *obj = reg->obj;
1830 
1831 		if (!obj)
1832 			continue;
1833 
1834 		if (obj->tiling_mode)
1835 			i915_gem_release_mmap(obj);
1836 
1837 		reg->obj->fence_reg = I915_FENCE_REG_NONE;
1838 		reg->obj->fenced_gpu_access = false;
1839 		reg->obj->last_fenced_seqno = 0;
1840 		reg->obj->last_fenced_ring = NULL;
1841 		i915_gem_clear_fence_reg(dev, reg);
1842 	}
1843 }
1844 
1845 void i915_gem_reset(struct drm_device *dev)
1846 {
1847 	struct drm_i915_private *dev_priv = dev->dev_private;
1848 	struct drm_i915_gem_object *obj;
1849 	int i;
1850 
1851 	for (i = 0; i < I915_NUM_RINGS; i++)
1852 		i915_gem_reset_ring_lists(dev_priv, &dev_priv->ring[i]);
1853 
1854 	/* Remove anything from the flushing lists. The GPU cache is likely
1855 	 * to be lost on reset along with the data, so simply move the
1856 	 * lost bo to the inactive list.
1857 	 */
1858 	while (!list_empty(&dev_priv->mm.flushing_list)) {
1859 		obj= list_first_entry(&dev_priv->mm.flushing_list,
1860 				      struct drm_i915_gem_object,
1861 				      mm_list);
1862 
1863 		obj->base.write_domain = 0;
1864 		list_del_init(&obj->gpu_write_list);
1865 		i915_gem_object_move_to_inactive(obj);
1866 	}
1867 
1868 	/* Move everything out of the GPU domains to ensure we do any
1869 	 * necessary invalidation upon reuse.
1870 	 */
1871 	list_for_each_entry(obj,
1872 			    &dev_priv->mm.inactive_list,
1873 			    mm_list)
1874 	{
1875 		obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
1876 	}
1877 
1878 	/* The fence registers are invalidated so clear them out */
1879 	i915_gem_reset_fences(dev);
1880 }
1881 
1882 /**
1883  * This function clears the request list as sequence numbers are passed.
1884  */
1885 static void
1886 i915_gem_retire_requests_ring(struct intel_ring_buffer *ring)
1887 {
1888 	uint32_t seqno;
1889 	int i;
1890 
1891 	if (list_empty(&ring->request_list))
1892 		return;
1893 
1894 	WARN_ON(i915_verify_lists(ring->dev));
1895 
1896 	seqno = ring->get_seqno(ring);
1897 
1898 	for (i = 0; i < ARRAY_SIZE(ring->sync_seqno); i++)
1899 		if (seqno >= ring->sync_seqno[i])
1900 			ring->sync_seqno[i] = 0;
1901 
1902 	while (!list_empty(&ring->request_list)) {
1903 		struct drm_i915_gem_request *request;
1904 
1905 		request = list_first_entry(&ring->request_list,
1906 					   struct drm_i915_gem_request,
1907 					   list);
1908 
1909 		if (!i915_seqno_passed(seqno, request->seqno))
1910 			break;
1911 
1912 		trace_i915_gem_request_retire(ring, request->seqno);
1913 
1914 		list_del(&request->list);
1915 		i915_gem_request_remove_from_client(request);
1916 		kfree(request);
1917 	}
1918 
1919 	/* Move any buffers on the active list that are no longer referenced
1920 	 * by the ringbuffer to the flushing/inactive lists as appropriate.
1921 	 */
1922 	while (!list_empty(&ring->active_list)) {
1923 		struct drm_i915_gem_object *obj;
1924 
1925 		obj= list_first_entry(&ring->active_list,
1926 				      struct drm_i915_gem_object,
1927 				      ring_list);
1928 
1929 		if (!i915_seqno_passed(seqno, obj->last_rendering_seqno))
1930 			break;
1931 
1932 		if (obj->base.write_domain != 0)
1933 			i915_gem_object_move_to_flushing(obj);
1934 		else
1935 			i915_gem_object_move_to_inactive(obj);
1936 	}
1937 
1938 	if (unlikely(ring->trace_irq_seqno &&
1939 		     i915_seqno_passed(seqno, ring->trace_irq_seqno))) {
1940 		ring->irq_put(ring);
1941 		ring->trace_irq_seqno = 0;
1942 	}
1943 
1944 	WARN_ON(i915_verify_lists(ring->dev));
1945 }
1946 
1947 void
1948 i915_gem_retire_requests(struct drm_device *dev)
1949 {
1950 	drm_i915_private_t *dev_priv = dev->dev_private;
1951 	int i;
1952 
1953 	if (!list_empty(&dev_priv->mm.deferred_free_list)) {
1954 	    struct drm_i915_gem_object *obj, *next;
1955 
1956 	    /* We must be careful that during unbind() we do not
1957 	     * accidentally infinitely recurse into retire requests.
1958 	     * Currently:
1959 	     *   retire -> free -> unbind -> wait -> retire_ring
1960 	     */
1961 	    list_for_each_entry_safe(obj, next,
1962 				     &dev_priv->mm.deferred_free_list,
1963 				     mm_list)
1964 		    i915_gem_free_object_tail(obj);
1965 	}
1966 
1967 	for (i = 0; i < I915_NUM_RINGS; i++)
1968 		i915_gem_retire_requests_ring(&dev_priv->ring[i]);
1969 }
1970 
1971 static void
1972 i915_gem_retire_work_handler(struct work_struct *work)
1973 {
1974 	drm_i915_private_t *dev_priv;
1975 	struct drm_device *dev;
1976 	bool idle;
1977 	int i;
1978 
1979 	dev_priv = container_of(work, drm_i915_private_t,
1980 				mm.retire_work.work);
1981 	dev = dev_priv->dev;
1982 
1983 	/* Come back later if the device is busy... */
1984 	if (!mutex_trylock(&dev->struct_mutex)) {
1985 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, HZ);
1986 		return;
1987 	}
1988 
1989 	i915_gem_retire_requests(dev);
1990 
1991 	/* Send a periodic flush down the ring so we don't hold onto GEM
1992 	 * objects indefinitely.
1993 	 */
1994 	idle = true;
1995 	for (i = 0; i < I915_NUM_RINGS; i++) {
1996 		struct intel_ring_buffer *ring = &dev_priv->ring[i];
1997 
1998 		if (!list_empty(&ring->gpu_write_list)) {
1999 			struct drm_i915_gem_request *request;
2000 			int ret;
2001 
2002 			ret = i915_gem_flush_ring(ring,
2003 						  0, I915_GEM_GPU_DOMAINS);
2004 			request = kzalloc(sizeof(*request), GFP_KERNEL);
2005 			if (ret || request == NULL ||
2006 			    i915_add_request(ring, NULL, request))
2007 			    kfree(request);
2008 		}
2009 
2010 		idle &= list_empty(&ring->request_list);
2011 	}
2012 
2013 	if (!dev_priv->mm.suspended && !idle)
2014 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, HZ);
2015 
2016 	mutex_unlock(&dev->struct_mutex);
2017 }
2018 
2019 /**
2020  * Waits for a sequence number to be signaled, and cleans up the
2021  * request and object lists appropriately for that event.
2022  */
2023 int
2024 i915_wait_request(struct intel_ring_buffer *ring,
2025 		  uint32_t seqno)
2026 {
2027 	drm_i915_private_t *dev_priv = ring->dev->dev_private;
2028 	u32 ier;
2029 	int ret = 0;
2030 
2031 	BUG_ON(seqno == 0);
2032 
2033 	if (atomic_read(&dev_priv->mm.wedged)) {
2034 		struct completion *x = &dev_priv->error_completion;
2035 		bool recovery_complete;
2036 		unsigned long flags;
2037 
2038 		/* Give the error handler a chance to run. */
2039 		spin_lock_irqsave(&x->wait.lock, flags);
2040 		recovery_complete = x->done > 0;
2041 		spin_unlock_irqrestore(&x->wait.lock, flags);
2042 
2043 		return recovery_complete ? -EIO : -EAGAIN;
2044 	}
2045 
2046 	if (seqno == ring->outstanding_lazy_request) {
2047 		struct drm_i915_gem_request *request;
2048 
2049 		request = kzalloc(sizeof(*request), GFP_KERNEL);
2050 		if (request == NULL)
2051 			return -ENOMEM;
2052 
2053 		ret = i915_add_request(ring, NULL, request);
2054 		if (ret) {
2055 			kfree(request);
2056 			return ret;
2057 		}
2058 
2059 		seqno = request->seqno;
2060 	}
2061 
2062 	if (!i915_seqno_passed(ring->get_seqno(ring), seqno)) {
2063 		if (HAS_PCH_SPLIT(ring->dev))
2064 			ier = I915_READ(DEIER) | I915_READ(GTIER);
2065 		else
2066 			ier = I915_READ(IER);
2067 		if (!ier) {
2068 			DRM_ERROR("something (likely vbetool) disabled "
2069 				  "interrupts, re-enabling\n");
2070 			ring->dev->driver->irq_preinstall(ring->dev);
2071 			ring->dev->driver->irq_postinstall(ring->dev);
2072 		}
2073 
2074 		trace_i915_gem_request_wait_begin(ring, seqno);
2075 
2076 		ring->waiting_seqno = seqno;
2077 		if (ring->irq_get(ring)) {
2078 			if (dev_priv->mm.interruptible)
2079 				ret = wait_event_interruptible(ring->irq_queue,
2080 							       i915_seqno_passed(ring->get_seqno(ring), seqno)
2081 							       || atomic_read(&dev_priv->mm.wedged));
2082 			else
2083 				wait_event(ring->irq_queue,
2084 					   i915_seqno_passed(ring->get_seqno(ring), seqno)
2085 					   || atomic_read(&dev_priv->mm.wedged));
2086 
2087 			ring->irq_put(ring);
2088 		} else if (wait_for(i915_seqno_passed(ring->get_seqno(ring),
2089 						      seqno) ||
2090 				    atomic_read(&dev_priv->mm.wedged), 3000))
2091 			ret = -EBUSY;
2092 		ring->waiting_seqno = 0;
2093 
2094 		trace_i915_gem_request_wait_end(ring, seqno);
2095 	}
2096 	if (atomic_read(&dev_priv->mm.wedged))
2097 		ret = -EAGAIN;
2098 
2099 	if (ret && ret != -ERESTARTSYS)
2100 		DRM_ERROR("%s returns %d (awaiting %d at %d, next %d)\n",
2101 			  __func__, ret, seqno, ring->get_seqno(ring),
2102 			  dev_priv->next_seqno);
2103 
2104 	/* Directly dispatch request retiring.  While we have the work queue
2105 	 * to handle this, the waiter on a request often wants an associated
2106 	 * buffer to have made it to the inactive list, and we would need
2107 	 * a separate wait queue to handle that.
2108 	 */
2109 	if (ret == 0)
2110 		i915_gem_retire_requests_ring(ring);
2111 
2112 	return ret;
2113 }
2114 
2115 /**
2116  * Ensures that all rendering to the object has completed and the object is
2117  * safe to unbind from the GTT or access from the CPU.
2118  */
2119 int
2120 i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj)
2121 {
2122 	int ret;
2123 
2124 	/* This function only exists to support waiting for existing rendering,
2125 	 * not for emitting required flushes.
2126 	 */
2127 	BUG_ON((obj->base.write_domain & I915_GEM_GPU_DOMAINS) != 0);
2128 
2129 	/* If there is rendering queued on the buffer being evicted, wait for
2130 	 * it.
2131 	 */
2132 	if (obj->active) {
2133 		ret = i915_wait_request(obj->ring, obj->last_rendering_seqno);
2134 		if (ret)
2135 			return ret;
2136 	}
2137 
2138 	return 0;
2139 }
2140 
2141 static void i915_gem_object_finish_gtt(struct drm_i915_gem_object *obj)
2142 {
2143 	u32 old_write_domain, old_read_domains;
2144 
2145 	/* Act a barrier for all accesses through the GTT */
2146 	mb();
2147 
2148 	/* Force a pagefault for domain tracking on next user access */
2149 	i915_gem_release_mmap(obj);
2150 
2151 	if ((obj->base.read_domains & I915_GEM_DOMAIN_GTT) == 0)
2152 		return;
2153 
2154 	old_read_domains = obj->base.read_domains;
2155 	old_write_domain = obj->base.write_domain;
2156 
2157 	obj->base.read_domains &= ~I915_GEM_DOMAIN_GTT;
2158 	obj->base.write_domain &= ~I915_GEM_DOMAIN_GTT;
2159 
2160 	trace_i915_gem_object_change_domain(obj,
2161 					    old_read_domains,
2162 					    old_write_domain);
2163 }
2164 
2165 /**
2166  * Unbinds an object from the GTT aperture.
2167  */
2168 int
2169 i915_gem_object_unbind(struct drm_i915_gem_object *obj)
2170 {
2171 	int ret = 0;
2172 
2173 	if (obj->gtt_space == NULL)
2174 		return 0;
2175 
2176 	if (obj->pin_count != 0) {
2177 		DRM_ERROR("Attempting to unbind pinned buffer\n");
2178 		return -EINVAL;
2179 	}
2180 
2181 	ret = i915_gem_object_finish_gpu(obj);
2182 	if (ret == -ERESTARTSYS)
2183 		return ret;
2184 	/* Continue on if we fail due to EIO, the GPU is hung so we
2185 	 * should be safe and we need to cleanup or else we might
2186 	 * cause memory corruption through use-after-free.
2187 	 */
2188 
2189 	i915_gem_object_finish_gtt(obj);
2190 
2191 	/* Move the object to the CPU domain to ensure that
2192 	 * any possible CPU writes while it's not in the GTT
2193 	 * are flushed when we go to remap it.
2194 	 */
2195 	if (ret == 0)
2196 		ret = i915_gem_object_set_to_cpu_domain(obj, 1);
2197 	if (ret == -ERESTARTSYS)
2198 		return ret;
2199 	if (ret) {
2200 		/* In the event of a disaster, abandon all caches and
2201 		 * hope for the best.
2202 		 */
2203 		i915_gem_clflush_object(obj);
2204 		obj->base.read_domains = obj->base.write_domain = I915_GEM_DOMAIN_CPU;
2205 	}
2206 
2207 	/* release the fence reg _after_ flushing */
2208 	ret = i915_gem_object_put_fence(obj);
2209 	if (ret == -ERESTARTSYS)
2210 		return ret;
2211 
2212 	trace_i915_gem_object_unbind(obj);
2213 
2214 	i915_gem_gtt_unbind_object(obj);
2215 	i915_gem_object_put_pages_gtt(obj);
2216 
2217 	list_del_init(&obj->gtt_list);
2218 	list_del_init(&obj->mm_list);
2219 	/* Avoid an unnecessary call to unbind on rebind. */
2220 	obj->map_and_fenceable = true;
2221 
2222 	drm_mm_put_block(obj->gtt_space);
2223 	obj->gtt_space = NULL;
2224 	obj->gtt_offset = 0;
2225 
2226 	if (i915_gem_object_is_purgeable(obj))
2227 		i915_gem_object_truncate(obj);
2228 
2229 	return ret;
2230 }
2231 
2232 int
2233 i915_gem_flush_ring(struct intel_ring_buffer *ring,
2234 		    uint32_t invalidate_domains,
2235 		    uint32_t flush_domains)
2236 {
2237 	int ret;
2238 
2239 	if (((invalidate_domains | flush_domains) & I915_GEM_GPU_DOMAINS) == 0)
2240 		return 0;
2241 
2242 	trace_i915_gem_ring_flush(ring, invalidate_domains, flush_domains);
2243 
2244 	ret = ring->flush(ring, invalidate_domains, flush_domains);
2245 	if (ret)
2246 		return ret;
2247 
2248 	if (flush_domains & I915_GEM_GPU_DOMAINS)
2249 		i915_gem_process_flushing_list(ring, flush_domains);
2250 
2251 	return 0;
2252 }
2253 
2254 static int i915_ring_idle(struct intel_ring_buffer *ring)
2255 {
2256 	int ret;
2257 
2258 	if (list_empty(&ring->gpu_write_list) && list_empty(&ring->active_list))
2259 		return 0;
2260 
2261 	if (!list_empty(&ring->gpu_write_list)) {
2262 		ret = i915_gem_flush_ring(ring,
2263 				    I915_GEM_GPU_DOMAINS, I915_GEM_GPU_DOMAINS);
2264 		if (ret)
2265 			return ret;
2266 	}
2267 
2268 	return i915_wait_request(ring, i915_gem_next_request_seqno(ring));
2269 }
2270 
2271 int
2272 i915_gpu_idle(struct drm_device *dev)
2273 {
2274 	drm_i915_private_t *dev_priv = dev->dev_private;
2275 	bool lists_empty;
2276 	int ret, i;
2277 
2278 	lists_empty = (list_empty(&dev_priv->mm.flushing_list) &&
2279 		       list_empty(&dev_priv->mm.active_list));
2280 	if (lists_empty)
2281 		return 0;
2282 
2283 	/* Flush everything onto the inactive list. */
2284 	for (i = 0; i < I915_NUM_RINGS; i++) {
2285 		ret = i915_ring_idle(&dev_priv->ring[i]);
2286 		if (ret)
2287 			return ret;
2288 	}
2289 
2290 	return 0;
2291 }
2292 
2293 static int sandybridge_write_fence_reg(struct drm_i915_gem_object *obj,
2294 				       struct intel_ring_buffer *pipelined)
2295 {
2296 	struct drm_device *dev = obj->base.dev;
2297 	drm_i915_private_t *dev_priv = dev->dev_private;
2298 	u32 size = obj->gtt_space->size;
2299 	int regnum = obj->fence_reg;
2300 	uint64_t val;
2301 
2302 	val = (uint64_t)((obj->gtt_offset + size - 4096) &
2303 			 0xfffff000) << 32;
2304 	val |= obj->gtt_offset & 0xfffff000;
2305 	val |= (uint64_t)((obj->stride / 128) - 1) <<
2306 		SANDYBRIDGE_FENCE_PITCH_SHIFT;
2307 
2308 	if (obj->tiling_mode == I915_TILING_Y)
2309 		val |= 1 << I965_FENCE_TILING_Y_SHIFT;
2310 	val |= I965_FENCE_REG_VALID;
2311 
2312 	if (pipelined) {
2313 		int ret = intel_ring_begin(pipelined, 6);
2314 		if (ret)
2315 			return ret;
2316 
2317 		intel_ring_emit(pipelined, MI_NOOP);
2318 		intel_ring_emit(pipelined, MI_LOAD_REGISTER_IMM(2));
2319 		intel_ring_emit(pipelined, FENCE_REG_SANDYBRIDGE_0 + regnum*8);
2320 		intel_ring_emit(pipelined, (u32)val);
2321 		intel_ring_emit(pipelined, FENCE_REG_SANDYBRIDGE_0 + regnum*8 + 4);
2322 		intel_ring_emit(pipelined, (u32)(val >> 32));
2323 		intel_ring_advance(pipelined);
2324 	} else
2325 		I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 + regnum * 8, val);
2326 
2327 	return 0;
2328 }
2329 
2330 static int i965_write_fence_reg(struct drm_i915_gem_object *obj,
2331 				struct intel_ring_buffer *pipelined)
2332 {
2333 	struct drm_device *dev = obj->base.dev;
2334 	drm_i915_private_t *dev_priv = dev->dev_private;
2335 	u32 size = obj->gtt_space->size;
2336 	int regnum = obj->fence_reg;
2337 	uint64_t val;
2338 
2339 	val = (uint64_t)((obj->gtt_offset + size - 4096) &
2340 		    0xfffff000) << 32;
2341 	val |= obj->gtt_offset & 0xfffff000;
2342 	val |= ((obj->stride / 128) - 1) << I965_FENCE_PITCH_SHIFT;
2343 	if (obj->tiling_mode == I915_TILING_Y)
2344 		val |= 1 << I965_FENCE_TILING_Y_SHIFT;
2345 	val |= I965_FENCE_REG_VALID;
2346 
2347 	if (pipelined) {
2348 		int ret = intel_ring_begin(pipelined, 6);
2349 		if (ret)
2350 			return ret;
2351 
2352 		intel_ring_emit(pipelined, MI_NOOP);
2353 		intel_ring_emit(pipelined, MI_LOAD_REGISTER_IMM(2));
2354 		intel_ring_emit(pipelined, FENCE_REG_965_0 + regnum*8);
2355 		intel_ring_emit(pipelined, (u32)val);
2356 		intel_ring_emit(pipelined, FENCE_REG_965_0 + regnum*8 + 4);
2357 		intel_ring_emit(pipelined, (u32)(val >> 32));
2358 		intel_ring_advance(pipelined);
2359 	} else
2360 		I915_WRITE64(FENCE_REG_965_0 + regnum * 8, val);
2361 
2362 	return 0;
2363 }
2364 
2365 static int i915_write_fence_reg(struct drm_i915_gem_object *obj,
2366 				struct intel_ring_buffer *pipelined)
2367 {
2368 	struct drm_device *dev = obj->base.dev;
2369 	drm_i915_private_t *dev_priv = dev->dev_private;
2370 	u32 size = obj->gtt_space->size;
2371 	u32 fence_reg, val, pitch_val;
2372 	int tile_width;
2373 
2374 	if (WARN((obj->gtt_offset & ~I915_FENCE_START_MASK) ||
2375 		 (size & -size) != size ||
2376 		 (obj->gtt_offset & (size - 1)),
2377 		 "object 0x%08x [fenceable? %d] not 1M or pot-size (0x%08x) aligned\n",
2378 		 obj->gtt_offset, obj->map_and_fenceable, size))
2379 		return -EINVAL;
2380 
2381 	if (obj->tiling_mode == I915_TILING_Y && HAS_128_BYTE_Y_TILING(dev))
2382 		tile_width = 128;
2383 	else
2384 		tile_width = 512;
2385 
2386 	/* Note: pitch better be a power of two tile widths */
2387 	pitch_val = obj->stride / tile_width;
2388 	pitch_val = ffs(pitch_val) - 1;
2389 
2390 	val = obj->gtt_offset;
2391 	if (obj->tiling_mode == I915_TILING_Y)
2392 		val |= 1 << I830_FENCE_TILING_Y_SHIFT;
2393 	val |= I915_FENCE_SIZE_BITS(size);
2394 	val |= pitch_val << I830_FENCE_PITCH_SHIFT;
2395 	val |= I830_FENCE_REG_VALID;
2396 
2397 	fence_reg = obj->fence_reg;
2398 	if (fence_reg < 8)
2399 		fence_reg = FENCE_REG_830_0 + fence_reg * 4;
2400 	else
2401 		fence_reg = FENCE_REG_945_8 + (fence_reg - 8) * 4;
2402 
2403 	if (pipelined) {
2404 		int ret = intel_ring_begin(pipelined, 4);
2405 		if (ret)
2406 			return ret;
2407 
2408 		intel_ring_emit(pipelined, MI_NOOP);
2409 		intel_ring_emit(pipelined, MI_LOAD_REGISTER_IMM(1));
2410 		intel_ring_emit(pipelined, fence_reg);
2411 		intel_ring_emit(pipelined, val);
2412 		intel_ring_advance(pipelined);
2413 	} else
2414 		I915_WRITE(fence_reg, val);
2415 
2416 	return 0;
2417 }
2418 
2419 static int i830_write_fence_reg(struct drm_i915_gem_object *obj,
2420 				struct intel_ring_buffer *pipelined)
2421 {
2422 	struct drm_device *dev = obj->base.dev;
2423 	drm_i915_private_t *dev_priv = dev->dev_private;
2424 	u32 size = obj->gtt_space->size;
2425 	int regnum = obj->fence_reg;
2426 	uint32_t val;
2427 	uint32_t pitch_val;
2428 
2429 	if (WARN((obj->gtt_offset & ~I830_FENCE_START_MASK) ||
2430 		 (size & -size) != size ||
2431 		 (obj->gtt_offset & (size - 1)),
2432 		 "object 0x%08x not 512K or pot-size 0x%08x aligned\n",
2433 		 obj->gtt_offset, size))
2434 		return -EINVAL;
2435 
2436 	pitch_val = obj->stride / 128;
2437 	pitch_val = ffs(pitch_val) - 1;
2438 
2439 	val = obj->gtt_offset;
2440 	if (obj->tiling_mode == I915_TILING_Y)
2441 		val |= 1 << I830_FENCE_TILING_Y_SHIFT;
2442 	val |= I830_FENCE_SIZE_BITS(size);
2443 	val |= pitch_val << I830_FENCE_PITCH_SHIFT;
2444 	val |= I830_FENCE_REG_VALID;
2445 
2446 	if (pipelined) {
2447 		int ret = intel_ring_begin(pipelined, 4);
2448 		if (ret)
2449 			return ret;
2450 
2451 		intel_ring_emit(pipelined, MI_NOOP);
2452 		intel_ring_emit(pipelined, MI_LOAD_REGISTER_IMM(1));
2453 		intel_ring_emit(pipelined, FENCE_REG_830_0 + regnum*4);
2454 		intel_ring_emit(pipelined, val);
2455 		intel_ring_advance(pipelined);
2456 	} else
2457 		I915_WRITE(FENCE_REG_830_0 + regnum * 4, val);
2458 
2459 	return 0;
2460 }
2461 
2462 static bool ring_passed_seqno(struct intel_ring_buffer *ring, u32 seqno)
2463 {
2464 	return i915_seqno_passed(ring->get_seqno(ring), seqno);
2465 }
2466 
2467 static int
2468 i915_gem_object_flush_fence(struct drm_i915_gem_object *obj,
2469 			    struct intel_ring_buffer *pipelined)
2470 {
2471 	int ret;
2472 
2473 	if (obj->fenced_gpu_access) {
2474 		if (obj->base.write_domain & I915_GEM_GPU_DOMAINS) {
2475 			ret = i915_gem_flush_ring(obj->last_fenced_ring,
2476 						  0, obj->base.write_domain);
2477 			if (ret)
2478 				return ret;
2479 		}
2480 
2481 		obj->fenced_gpu_access = false;
2482 	}
2483 
2484 	if (obj->last_fenced_seqno && pipelined != obj->last_fenced_ring) {
2485 		if (!ring_passed_seqno(obj->last_fenced_ring,
2486 				       obj->last_fenced_seqno)) {
2487 			ret = i915_wait_request(obj->last_fenced_ring,
2488 						obj->last_fenced_seqno);
2489 			if (ret)
2490 				return ret;
2491 		}
2492 
2493 		obj->last_fenced_seqno = 0;
2494 		obj->last_fenced_ring = NULL;
2495 	}
2496 
2497 	/* Ensure that all CPU reads are completed before installing a fence
2498 	 * and all writes before removing the fence.
2499 	 */
2500 	if (obj->base.read_domains & I915_GEM_DOMAIN_GTT)
2501 		mb();
2502 
2503 	return 0;
2504 }
2505 
2506 int
2507 i915_gem_object_put_fence(struct drm_i915_gem_object *obj)
2508 {
2509 	int ret;
2510 
2511 	if (obj->tiling_mode)
2512 		i915_gem_release_mmap(obj);
2513 
2514 	ret = i915_gem_object_flush_fence(obj, NULL);
2515 	if (ret)
2516 		return ret;
2517 
2518 	if (obj->fence_reg != I915_FENCE_REG_NONE) {
2519 		struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
2520 		i915_gem_clear_fence_reg(obj->base.dev,
2521 					 &dev_priv->fence_regs[obj->fence_reg]);
2522 
2523 		obj->fence_reg = I915_FENCE_REG_NONE;
2524 	}
2525 
2526 	return 0;
2527 }
2528 
2529 static struct drm_i915_fence_reg *
2530 i915_find_fence_reg(struct drm_device *dev,
2531 		    struct intel_ring_buffer *pipelined)
2532 {
2533 	struct drm_i915_private *dev_priv = dev->dev_private;
2534 	struct drm_i915_fence_reg *reg, *first, *avail;
2535 	int i;
2536 
2537 	/* First try to find a free reg */
2538 	avail = NULL;
2539 	for (i = dev_priv->fence_reg_start; i < dev_priv->num_fence_regs; i++) {
2540 		reg = &dev_priv->fence_regs[i];
2541 		if (!reg->obj)
2542 			return reg;
2543 
2544 		if (!reg->obj->pin_count)
2545 			avail = reg;
2546 	}
2547 
2548 	if (avail == NULL)
2549 		return NULL;
2550 
2551 	/* None available, try to steal one or wait for a user to finish */
2552 	avail = first = NULL;
2553 	list_for_each_entry(reg, &dev_priv->mm.fence_list, lru_list) {
2554 		if (reg->obj->pin_count)
2555 			continue;
2556 
2557 		if (first == NULL)
2558 			first = reg;
2559 
2560 		if (!pipelined ||
2561 		    !reg->obj->last_fenced_ring ||
2562 		    reg->obj->last_fenced_ring == pipelined) {
2563 			avail = reg;
2564 			break;
2565 		}
2566 	}
2567 
2568 	if (avail == NULL)
2569 		avail = first;
2570 
2571 	return avail;
2572 }
2573 
2574 /**
2575  * i915_gem_object_get_fence - set up a fence reg for an object
2576  * @obj: object to map through a fence reg
2577  * @pipelined: ring on which to queue the change, or NULL for CPU access
2578  * @interruptible: must we wait uninterruptibly for the register to retire?
2579  *
2580  * When mapping objects through the GTT, userspace wants to be able to write
2581  * to them without having to worry about swizzling if the object is tiled.
2582  *
2583  * This function walks the fence regs looking for a free one for @obj,
2584  * stealing one if it can't find any.
2585  *
2586  * It then sets up the reg based on the object's properties: address, pitch
2587  * and tiling format.
2588  */
2589 int
2590 i915_gem_object_get_fence(struct drm_i915_gem_object *obj,
2591 			  struct intel_ring_buffer *pipelined)
2592 {
2593 	struct drm_device *dev = obj->base.dev;
2594 	struct drm_i915_private *dev_priv = dev->dev_private;
2595 	struct drm_i915_fence_reg *reg;
2596 	int ret;
2597 
2598 	/* XXX disable pipelining. There are bugs. Shocking. */
2599 	pipelined = NULL;
2600 
2601 	/* Just update our place in the LRU if our fence is getting reused. */
2602 	if (obj->fence_reg != I915_FENCE_REG_NONE) {
2603 		reg = &dev_priv->fence_regs[obj->fence_reg];
2604 		list_move_tail(&reg->lru_list, &dev_priv->mm.fence_list);
2605 
2606 		if (obj->tiling_changed) {
2607 			ret = i915_gem_object_flush_fence(obj, pipelined);
2608 			if (ret)
2609 				return ret;
2610 
2611 			if (!obj->fenced_gpu_access && !obj->last_fenced_seqno)
2612 				pipelined = NULL;
2613 
2614 			if (pipelined) {
2615 				reg->setup_seqno =
2616 					i915_gem_next_request_seqno(pipelined);
2617 				obj->last_fenced_seqno = reg->setup_seqno;
2618 				obj->last_fenced_ring = pipelined;
2619 			}
2620 
2621 			goto update;
2622 		}
2623 
2624 		if (!pipelined) {
2625 			if (reg->setup_seqno) {
2626 				if (!ring_passed_seqno(obj->last_fenced_ring,
2627 						       reg->setup_seqno)) {
2628 					ret = i915_wait_request(obj->last_fenced_ring,
2629 								reg->setup_seqno);
2630 					if (ret)
2631 						return ret;
2632 				}
2633 
2634 				reg->setup_seqno = 0;
2635 			}
2636 		} else if (obj->last_fenced_ring &&
2637 			   obj->last_fenced_ring != pipelined) {
2638 			ret = i915_gem_object_flush_fence(obj, pipelined);
2639 			if (ret)
2640 				return ret;
2641 		}
2642 
2643 		return 0;
2644 	}
2645 
2646 	reg = i915_find_fence_reg(dev, pipelined);
2647 	if (reg == NULL)
2648 		return -ENOSPC;
2649 
2650 	ret = i915_gem_object_flush_fence(obj, pipelined);
2651 	if (ret)
2652 		return ret;
2653 
2654 	if (reg->obj) {
2655 		struct drm_i915_gem_object *old = reg->obj;
2656 
2657 		drm_gem_object_reference(&old->base);
2658 
2659 		if (old->tiling_mode)
2660 			i915_gem_release_mmap(old);
2661 
2662 		ret = i915_gem_object_flush_fence(old, pipelined);
2663 		if (ret) {
2664 			drm_gem_object_unreference(&old->base);
2665 			return ret;
2666 		}
2667 
2668 		if (old->last_fenced_seqno == 0 && obj->last_fenced_seqno == 0)
2669 			pipelined = NULL;
2670 
2671 		old->fence_reg = I915_FENCE_REG_NONE;
2672 		old->last_fenced_ring = pipelined;
2673 		old->last_fenced_seqno =
2674 			pipelined ? i915_gem_next_request_seqno(pipelined) : 0;
2675 
2676 		drm_gem_object_unreference(&old->base);
2677 	} else if (obj->last_fenced_seqno == 0)
2678 		pipelined = NULL;
2679 
2680 	reg->obj = obj;
2681 	list_move_tail(&reg->lru_list, &dev_priv->mm.fence_list);
2682 	obj->fence_reg = reg - dev_priv->fence_regs;
2683 	obj->last_fenced_ring = pipelined;
2684 
2685 	reg->setup_seqno =
2686 		pipelined ? i915_gem_next_request_seqno(pipelined) : 0;
2687 	obj->last_fenced_seqno = reg->setup_seqno;
2688 
2689 update:
2690 	obj->tiling_changed = false;
2691 	switch (INTEL_INFO(dev)->gen) {
2692 	case 7:
2693 	case 6:
2694 		ret = sandybridge_write_fence_reg(obj, pipelined);
2695 		break;
2696 	case 5:
2697 	case 4:
2698 		ret = i965_write_fence_reg(obj, pipelined);
2699 		break;
2700 	case 3:
2701 		ret = i915_write_fence_reg(obj, pipelined);
2702 		break;
2703 	case 2:
2704 		ret = i830_write_fence_reg(obj, pipelined);
2705 		break;
2706 	}
2707 
2708 	return ret;
2709 }
2710 
2711 /**
2712  * i915_gem_clear_fence_reg - clear out fence register info
2713  * @obj: object to clear
2714  *
2715  * Zeroes out the fence register itself and clears out the associated
2716  * data structures in dev_priv and obj.
2717  */
2718 static void
2719 i915_gem_clear_fence_reg(struct drm_device *dev,
2720 			 struct drm_i915_fence_reg *reg)
2721 {
2722 	drm_i915_private_t *dev_priv = dev->dev_private;
2723 	uint32_t fence_reg = reg - dev_priv->fence_regs;
2724 
2725 	switch (INTEL_INFO(dev)->gen) {
2726 	case 7:
2727 	case 6:
2728 		I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 + fence_reg*8, 0);
2729 		break;
2730 	case 5:
2731 	case 4:
2732 		I915_WRITE64(FENCE_REG_965_0 + fence_reg*8, 0);
2733 		break;
2734 	case 3:
2735 		if (fence_reg >= 8)
2736 			fence_reg = FENCE_REG_945_8 + (fence_reg - 8) * 4;
2737 		else
2738 	case 2:
2739 			fence_reg = FENCE_REG_830_0 + fence_reg * 4;
2740 
2741 		I915_WRITE(fence_reg, 0);
2742 		break;
2743 	}
2744 
2745 	list_del_init(&reg->lru_list);
2746 	reg->obj = NULL;
2747 	reg->setup_seqno = 0;
2748 }
2749 
2750 /**
2751  * Finds free space in the GTT aperture and binds the object there.
2752  */
2753 static int
2754 i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
2755 			    unsigned alignment,
2756 			    bool map_and_fenceable)
2757 {
2758 	struct drm_device *dev = obj->base.dev;
2759 	drm_i915_private_t *dev_priv = dev->dev_private;
2760 	struct drm_mm_node *free_space;
2761 	gfp_t gfpmask = __GFP_NORETRY | __GFP_NOWARN;
2762 	u32 size, fence_size, fence_alignment, unfenced_alignment;
2763 	bool mappable, fenceable;
2764 	int ret;
2765 
2766 	if (obj->madv != I915_MADV_WILLNEED) {
2767 		DRM_ERROR("Attempting to bind a purgeable object\n");
2768 		return -EINVAL;
2769 	}
2770 
2771 	fence_size = i915_gem_get_gtt_size(dev,
2772 					   obj->base.size,
2773 					   obj->tiling_mode);
2774 	fence_alignment = i915_gem_get_gtt_alignment(dev,
2775 						     obj->base.size,
2776 						     obj->tiling_mode);
2777 	unfenced_alignment =
2778 		i915_gem_get_unfenced_gtt_alignment(dev,
2779 						    obj->base.size,
2780 						    obj->tiling_mode);
2781 
2782 	if (alignment == 0)
2783 		alignment = map_and_fenceable ? fence_alignment :
2784 						unfenced_alignment;
2785 	if (map_and_fenceable && alignment & (fence_alignment - 1)) {
2786 		DRM_ERROR("Invalid object alignment requested %u\n", alignment);
2787 		return -EINVAL;
2788 	}
2789 
2790 	size = map_and_fenceable ? fence_size : obj->base.size;
2791 
2792 	/* If the object is bigger than the entire aperture, reject it early
2793 	 * before evicting everything in a vain attempt to find space.
2794 	 */
2795 	if (obj->base.size >
2796 	    (map_and_fenceable ? dev_priv->mm.gtt_mappable_end : dev_priv->mm.gtt_total)) {
2797 		DRM_ERROR("Attempting to bind an object larger than the aperture\n");
2798 		return -E2BIG;
2799 	}
2800 
2801  search_free:
2802 	if (map_and_fenceable)
2803 		free_space =
2804 			drm_mm_search_free_in_range(&dev_priv->mm.gtt_space,
2805 						    size, alignment, 0,
2806 						    dev_priv->mm.gtt_mappable_end,
2807 						    0);
2808 	else
2809 		free_space = drm_mm_search_free(&dev_priv->mm.gtt_space,
2810 						size, alignment, 0);
2811 
2812 	if (free_space != NULL) {
2813 		if (map_and_fenceable)
2814 			obj->gtt_space =
2815 				drm_mm_get_block_range_generic(free_space,
2816 							       size, alignment, 0,
2817 							       dev_priv->mm.gtt_mappable_end,
2818 							       0);
2819 		else
2820 			obj->gtt_space =
2821 				drm_mm_get_block(free_space, size, alignment);
2822 	}
2823 	if (obj->gtt_space == NULL) {
2824 		/* If the gtt is empty and we're still having trouble
2825 		 * fitting our object in, we're out of memory.
2826 		 */
2827 		ret = i915_gem_evict_something(dev, size, alignment,
2828 					       map_and_fenceable);
2829 		if (ret)
2830 			return ret;
2831 
2832 		goto search_free;
2833 	}
2834 
2835 	ret = i915_gem_object_get_pages_gtt(obj, gfpmask);
2836 	if (ret) {
2837 		drm_mm_put_block(obj->gtt_space);
2838 		obj->gtt_space = NULL;
2839 
2840 		if (ret == -ENOMEM) {
2841 			/* first try to reclaim some memory by clearing the GTT */
2842 			ret = i915_gem_evict_everything(dev, false);
2843 			if (ret) {
2844 				/* now try to shrink everyone else */
2845 				if (gfpmask) {
2846 					gfpmask = 0;
2847 					goto search_free;
2848 				}
2849 
2850 				return -ENOMEM;
2851 			}
2852 
2853 			goto search_free;
2854 		}
2855 
2856 		return ret;
2857 	}
2858 
2859 	ret = i915_gem_gtt_bind_object(obj);
2860 	if (ret) {
2861 		i915_gem_object_put_pages_gtt(obj);
2862 		drm_mm_put_block(obj->gtt_space);
2863 		obj->gtt_space = NULL;
2864 
2865 		if (i915_gem_evict_everything(dev, false))
2866 			return ret;
2867 
2868 		goto search_free;
2869 	}
2870 
2871 	list_add_tail(&obj->gtt_list, &dev_priv->mm.gtt_list);
2872 	list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
2873 
2874 	/* Assert that the object is not currently in any GPU domain. As it
2875 	 * wasn't in the GTT, there shouldn't be any way it could have been in
2876 	 * a GPU cache
2877 	 */
2878 	BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS);
2879 	BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS);
2880 
2881 	obj->gtt_offset = obj->gtt_space->start;
2882 
2883 	fenceable =
2884 		obj->gtt_space->size == fence_size &&
2885 		(obj->gtt_space->start & (fence_alignment -1)) == 0;
2886 
2887 	mappable =
2888 		obj->gtt_offset + obj->base.size <= dev_priv->mm.gtt_mappable_end;
2889 
2890 	obj->map_and_fenceable = mappable && fenceable;
2891 
2892 	trace_i915_gem_object_bind(obj, map_and_fenceable);
2893 	return 0;
2894 }
2895 
2896 void
2897 i915_gem_clflush_object(struct drm_i915_gem_object *obj)
2898 {
2899 	/* If we don't have a page list set up, then we're not pinned
2900 	 * to GPU, and we can ignore the cache flush because it'll happen
2901 	 * again at bind time.
2902 	 */
2903 	if (obj->pages == NULL)
2904 		return;
2905 
2906 	/* If the GPU is snooping the contents of the CPU cache,
2907 	 * we do not need to manually clear the CPU cache lines.  However,
2908 	 * the caches are only snooped when the render cache is
2909 	 * flushed/invalidated.  As we always have to emit invalidations
2910 	 * and flushes when moving into and out of the RENDER domain, correct
2911 	 * snooping behaviour occurs naturally as the result of our domain
2912 	 * tracking.
2913 	 */
2914 	if (obj->cache_level != I915_CACHE_NONE)
2915 		return;
2916 
2917 	trace_i915_gem_object_clflush(obj);
2918 
2919 	drm_clflush_pages(obj->pages, obj->base.size / PAGE_SIZE);
2920 }
2921 
2922 /** Flushes any GPU write domain for the object if it's dirty. */
2923 static int
2924 i915_gem_object_flush_gpu_write_domain(struct drm_i915_gem_object *obj)
2925 {
2926 	if ((obj->base.write_domain & I915_GEM_GPU_DOMAINS) == 0)
2927 		return 0;
2928 
2929 	/* Queue the GPU write cache flushing we need. */
2930 	return i915_gem_flush_ring(obj->ring, 0, obj->base.write_domain);
2931 }
2932 
2933 /** Flushes the GTT write domain for the object if it's dirty. */
2934 static void
2935 i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj)
2936 {
2937 	uint32_t old_write_domain;
2938 
2939 	if (obj->base.write_domain != I915_GEM_DOMAIN_GTT)
2940 		return;
2941 
2942 	/* No actual flushing is required for the GTT write domain.  Writes
2943 	 * to it immediately go to main memory as far as we know, so there's
2944 	 * no chipset flush.  It also doesn't land in render cache.
2945 	 *
2946 	 * However, we do have to enforce the order so that all writes through
2947 	 * the GTT land before any writes to the device, such as updates to
2948 	 * the GATT itself.
2949 	 */
2950 	wmb();
2951 
2952 	old_write_domain = obj->base.write_domain;
2953 	obj->base.write_domain = 0;
2954 
2955 	trace_i915_gem_object_change_domain(obj,
2956 					    obj->base.read_domains,
2957 					    old_write_domain);
2958 }
2959 
2960 /** Flushes the CPU write domain for the object if it's dirty. */
2961 static void
2962 i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj)
2963 {
2964 	uint32_t old_write_domain;
2965 
2966 	if (obj->base.write_domain != I915_GEM_DOMAIN_CPU)
2967 		return;
2968 
2969 	i915_gem_clflush_object(obj);
2970 	intel_gtt_chipset_flush();
2971 	old_write_domain = obj->base.write_domain;
2972 	obj->base.write_domain = 0;
2973 
2974 	trace_i915_gem_object_change_domain(obj,
2975 					    obj->base.read_domains,
2976 					    old_write_domain);
2977 }
2978 
2979 /**
2980  * Moves a single object to the GTT read, and possibly write domain.
2981  *
2982  * This function returns when the move is complete, including waiting on
2983  * flushes to occur.
2984  */
2985 int
2986 i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
2987 {
2988 	uint32_t old_write_domain, old_read_domains;
2989 	int ret;
2990 
2991 	/* Not valid to be called on unbound objects. */
2992 	if (obj->gtt_space == NULL)
2993 		return -EINVAL;
2994 
2995 	if (obj->base.write_domain == I915_GEM_DOMAIN_GTT)
2996 		return 0;
2997 
2998 	ret = i915_gem_object_flush_gpu_write_domain(obj);
2999 	if (ret)
3000 		return ret;
3001 
3002 	if (obj->pending_gpu_write || write) {
3003 		ret = i915_gem_object_wait_rendering(obj);
3004 		if (ret)
3005 			return ret;
3006 	}
3007 
3008 	i915_gem_object_flush_cpu_write_domain(obj);
3009 
3010 	old_write_domain = obj->base.write_domain;
3011 	old_read_domains = obj->base.read_domains;
3012 
3013 	/* It should now be out of any other write domains, and we can update
3014 	 * the domain values for our changes.
3015 	 */
3016 	BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_GTT) != 0);
3017 	obj->base.read_domains |= I915_GEM_DOMAIN_GTT;
3018 	if (write) {
3019 		obj->base.read_domains = I915_GEM_DOMAIN_GTT;
3020 		obj->base.write_domain = I915_GEM_DOMAIN_GTT;
3021 		obj->dirty = 1;
3022 	}
3023 
3024 	trace_i915_gem_object_change_domain(obj,
3025 					    old_read_domains,
3026 					    old_write_domain);
3027 
3028 	return 0;
3029 }
3030 
3031 int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
3032 				    enum i915_cache_level cache_level)
3033 {
3034 	int ret;
3035 
3036 	if (obj->cache_level == cache_level)
3037 		return 0;
3038 
3039 	if (obj->pin_count) {
3040 		DRM_DEBUG("can not change the cache level of pinned objects\n");
3041 		return -EBUSY;
3042 	}
3043 
3044 	if (obj->gtt_space) {
3045 		ret = i915_gem_object_finish_gpu(obj);
3046 		if (ret)
3047 			return ret;
3048 
3049 		i915_gem_object_finish_gtt(obj);
3050 
3051 		/* Before SandyBridge, you could not use tiling or fence
3052 		 * registers with snooped memory, so relinquish any fences
3053 		 * currently pointing to our region in the aperture.
3054 		 */
3055 		if (INTEL_INFO(obj->base.dev)->gen < 6) {
3056 			ret = i915_gem_object_put_fence(obj);
3057 			if (ret)
3058 				return ret;
3059 		}
3060 
3061 		i915_gem_gtt_rebind_object(obj, cache_level);
3062 	}
3063 
3064 	if (cache_level == I915_CACHE_NONE) {
3065 		u32 old_read_domains, old_write_domain;
3066 
3067 		/* If we're coming from LLC cached, then we haven't
3068 		 * actually been tracking whether the data is in the
3069 		 * CPU cache or not, since we only allow one bit set
3070 		 * in obj->write_domain and have been skipping the clflushes.
3071 		 * Just set it to the CPU cache for now.
3072 		 */
3073 		WARN_ON(obj->base.write_domain & ~I915_GEM_DOMAIN_CPU);
3074 		WARN_ON(obj->base.read_domains & ~I915_GEM_DOMAIN_CPU);
3075 
3076 		old_read_domains = obj->base.read_domains;
3077 		old_write_domain = obj->base.write_domain;
3078 
3079 		obj->base.read_domains = I915_GEM_DOMAIN_CPU;
3080 		obj->base.write_domain = I915_GEM_DOMAIN_CPU;
3081 
3082 		trace_i915_gem_object_change_domain(obj,
3083 						    old_read_domains,
3084 						    old_write_domain);
3085 	}
3086 
3087 	obj->cache_level = cache_level;
3088 	return 0;
3089 }
3090 
3091 /*
3092  * Prepare buffer for display plane (scanout, cursors, etc).
3093  * Can be called from an uninterruptible phase (modesetting) and allows
3094  * any flushes to be pipelined (for pageflips).
3095  *
3096  * For the display plane, we want to be in the GTT but out of any write
3097  * domains. So in many ways this looks like set_to_gtt_domain() apart from the
3098  * ability to pipeline the waits, pinning and any additional subtleties
3099  * that may differentiate the display plane from ordinary buffers.
3100  */
3101 int
3102 i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj,
3103 				     u32 alignment,
3104 				     struct intel_ring_buffer *pipelined)
3105 {
3106 	u32 old_read_domains, old_write_domain;
3107 	int ret;
3108 
3109 	ret = i915_gem_object_flush_gpu_write_domain(obj);
3110 	if (ret)
3111 		return ret;
3112 
3113 	if (pipelined != obj->ring) {
3114 		ret = i915_gem_object_wait_rendering(obj);
3115 		if (ret == -ERESTARTSYS)
3116 			return ret;
3117 	}
3118 
3119 	/* The display engine is not coherent with the LLC cache on gen6.  As
3120 	 * a result, we make sure that the pinning that is about to occur is
3121 	 * done with uncached PTEs. This is lowest common denominator for all
3122 	 * chipsets.
3123 	 *
3124 	 * However for gen6+, we could do better by using the GFDT bit instead
3125 	 * of uncaching, which would allow us to flush all the LLC-cached data
3126 	 * with that bit in the PTE to main memory with just one PIPE_CONTROL.
3127 	 */
3128 	ret = i915_gem_object_set_cache_level(obj, I915_CACHE_NONE);
3129 	if (ret)
3130 		return ret;
3131 
3132 	/* As the user may map the buffer once pinned in the display plane
3133 	 * (e.g. libkms for the bootup splash), we have to ensure that we
3134 	 * always use map_and_fenceable for all scanout buffers.
3135 	 */
3136 	ret = i915_gem_object_pin(obj, alignment, true);
3137 	if (ret)
3138 		return ret;
3139 
3140 	i915_gem_object_flush_cpu_write_domain(obj);
3141 
3142 	old_write_domain = obj->base.write_domain;
3143 	old_read_domains = obj->base.read_domains;
3144 
3145 	/* It should now be out of any other write domains, and we can update
3146 	 * the domain values for our changes.
3147 	 */
3148 	BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_GTT) != 0);
3149 	obj->base.read_domains |= I915_GEM_DOMAIN_GTT;
3150 
3151 	trace_i915_gem_object_change_domain(obj,
3152 					    old_read_domains,
3153 					    old_write_domain);
3154 
3155 	return 0;
3156 }
3157 
3158 int
3159 i915_gem_object_finish_gpu(struct drm_i915_gem_object *obj)
3160 {
3161 	int ret;
3162 
3163 	if ((obj->base.read_domains & I915_GEM_GPU_DOMAINS) == 0)
3164 		return 0;
3165 
3166 	if (obj->base.write_domain & I915_GEM_GPU_DOMAINS) {
3167 		ret = i915_gem_flush_ring(obj->ring, 0, obj->base.write_domain);
3168 		if (ret)
3169 			return ret;
3170 	}
3171 
3172 	/* Ensure that we invalidate the GPU's caches and TLBs. */
3173 	obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
3174 
3175 	return i915_gem_object_wait_rendering(obj);
3176 }
3177 
3178 /**
3179  * Moves a single object to the CPU read, and possibly write domain.
3180  *
3181  * This function returns when the move is complete, including waiting on
3182  * flushes to occur.
3183  */
3184 static int
3185 i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write)
3186 {
3187 	uint32_t old_write_domain, old_read_domains;
3188 	int ret;
3189 
3190 	if (obj->base.write_domain == I915_GEM_DOMAIN_CPU)
3191 		return 0;
3192 
3193 	ret = i915_gem_object_flush_gpu_write_domain(obj);
3194 	if (ret)
3195 		return ret;
3196 
3197 	ret = i915_gem_object_wait_rendering(obj);
3198 	if (ret)
3199 		return ret;
3200 
3201 	i915_gem_object_flush_gtt_write_domain(obj);
3202 
3203 	/* If we have a partially-valid cache of the object in the CPU,
3204 	 * finish invalidating it and free the per-page flags.
3205 	 */
3206 	i915_gem_object_set_to_full_cpu_read_domain(obj);
3207 
3208 	old_write_domain = obj->base.write_domain;
3209 	old_read_domains = obj->base.read_domains;
3210 
3211 	/* Flush the CPU cache if it's still invalid. */
3212 	if ((obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0) {
3213 		i915_gem_clflush_object(obj);
3214 
3215 		obj->base.read_domains |= I915_GEM_DOMAIN_CPU;
3216 	}
3217 
3218 	/* It should now be out of any other write domains, and we can update
3219 	 * the domain values for our changes.
3220 	 */
3221 	BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_CPU) != 0);
3222 
3223 	/* If we're writing through the CPU, then the GPU read domains will
3224 	 * need to be invalidated at next use.
3225 	 */
3226 	if (write) {
3227 		obj->base.read_domains = I915_GEM_DOMAIN_CPU;
3228 		obj->base.write_domain = I915_GEM_DOMAIN_CPU;
3229 	}
3230 
3231 	trace_i915_gem_object_change_domain(obj,
3232 					    old_read_domains,
3233 					    old_write_domain);
3234 
3235 	return 0;
3236 }
3237 
3238 /**
3239  * Moves the object from a partially CPU read to a full one.
3240  *
3241  * Note that this only resolves i915_gem_object_set_cpu_read_domain_range(),
3242  * and doesn't handle transitioning from !(read_domains & I915_GEM_DOMAIN_CPU).
3243  */
3244 static void
3245 i915_gem_object_set_to_full_cpu_read_domain(struct drm_i915_gem_object *obj)
3246 {
3247 	if (!obj->page_cpu_valid)
3248 		return;
3249 
3250 	/* If we're partially in the CPU read domain, finish moving it in.
3251 	 */
3252 	if (obj->base.read_domains & I915_GEM_DOMAIN_CPU) {
3253 		int i;
3254 
3255 		for (i = 0; i <= (obj->base.size - 1) / PAGE_SIZE; i++) {
3256 			if (obj->page_cpu_valid[i])
3257 				continue;
3258 			drm_clflush_pages(obj->pages + i, 1);
3259 		}
3260 	}
3261 
3262 	/* Free the page_cpu_valid mappings which are now stale, whether
3263 	 * or not we've got I915_GEM_DOMAIN_CPU.
3264 	 */
3265 	kfree(obj->page_cpu_valid);
3266 	obj->page_cpu_valid = NULL;
3267 }
3268 
3269 /**
3270  * Set the CPU read domain on a range of the object.
3271  *
3272  * The object ends up with I915_GEM_DOMAIN_CPU in its read flags although it's
3273  * not entirely valid.  The page_cpu_valid member of the object flags which
3274  * pages have been flushed, and will be respected by
3275  * i915_gem_object_set_to_cpu_domain() if it's called on to get a valid mapping
3276  * of the whole object.
3277  *
3278  * This function returns when the move is complete, including waiting on
3279  * flushes to occur.
3280  */
3281 static int
3282 i915_gem_object_set_cpu_read_domain_range(struct drm_i915_gem_object *obj,
3283 					  uint64_t offset, uint64_t size)
3284 {
3285 	uint32_t old_read_domains;
3286 	int i, ret;
3287 
3288 	if (offset == 0 && size == obj->base.size)
3289 		return i915_gem_object_set_to_cpu_domain(obj, 0);
3290 
3291 	ret = i915_gem_object_flush_gpu_write_domain(obj);
3292 	if (ret)
3293 		return ret;
3294 
3295 	ret = i915_gem_object_wait_rendering(obj);
3296 	if (ret)
3297 		return ret;
3298 
3299 	i915_gem_object_flush_gtt_write_domain(obj);
3300 
3301 	/* If we're already fully in the CPU read domain, we're done. */
3302 	if (obj->page_cpu_valid == NULL &&
3303 	    (obj->base.read_domains & I915_GEM_DOMAIN_CPU) != 0)
3304 		return 0;
3305 
3306 	/* Otherwise, create/clear the per-page CPU read domain flag if we're
3307 	 * newly adding I915_GEM_DOMAIN_CPU
3308 	 */
3309 	if (obj->page_cpu_valid == NULL) {
3310 		obj->page_cpu_valid = kzalloc(obj->base.size / PAGE_SIZE,
3311 					      GFP_KERNEL);
3312 		if (obj->page_cpu_valid == NULL)
3313 			return -ENOMEM;
3314 	} else if ((obj->base.read_domains & I915_GEM_DOMAIN_CPU) == 0)
3315 		memset(obj->page_cpu_valid, 0, obj->base.size / PAGE_SIZE);
3316 
3317 	/* Flush the cache on any pages that are still invalid from the CPU's
3318 	 * perspective.
3319 	 */
3320 	for (i = offset / PAGE_SIZE; i <= (offset + size - 1) / PAGE_SIZE;
3321 	     i++) {
3322 		if (obj->page_cpu_valid[i])
3323 			continue;
3324 
3325 		drm_clflush_pages(obj->pages + i, 1);
3326 
3327 		obj->page_cpu_valid[i] = 1;
3328 	}
3329 
3330 	/* It should now be out of any other write domains, and we can update
3331 	 * the domain values for our changes.
3332 	 */
3333 	BUG_ON((obj->base.write_domain & ~I915_GEM_DOMAIN_CPU) != 0);
3334 
3335 	old_read_domains = obj->base.read_domains;
3336 	obj->base.read_domains |= I915_GEM_DOMAIN_CPU;
3337 
3338 	trace_i915_gem_object_change_domain(obj,
3339 					    old_read_domains,
3340 					    obj->base.write_domain);
3341 
3342 	return 0;
3343 }
3344 
3345 /* Throttle our rendering by waiting until the ring has completed our requests
3346  * emitted over 20 msec ago.
3347  *
3348  * Note that if we were to use the current jiffies each time around the loop,
3349  * we wouldn't escape the function with any frames outstanding if the time to
3350  * render a frame was over 20ms.
3351  *
3352  * This should get us reasonable parallelism between CPU and GPU but also
3353  * relatively low latency when blocking on a particular request to finish.
3354  */
3355 static int
3356 i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
3357 {
3358 	struct drm_i915_private *dev_priv = dev->dev_private;
3359 	struct drm_i915_file_private *file_priv = file->driver_priv;
3360 	unsigned long recent_enough = jiffies - msecs_to_jiffies(20);
3361 	struct drm_i915_gem_request *request;
3362 	struct intel_ring_buffer *ring = NULL;
3363 	u32 seqno = 0;
3364 	int ret;
3365 
3366 	if (atomic_read(&dev_priv->mm.wedged))
3367 		return -EIO;
3368 
3369 	spin_lock(&file_priv->mm.lock);
3370 	list_for_each_entry(request, &file_priv->mm.request_list, client_list) {
3371 		if (time_after_eq(request->emitted_jiffies, recent_enough))
3372 			break;
3373 
3374 		ring = request->ring;
3375 		seqno = request->seqno;
3376 	}
3377 	spin_unlock(&file_priv->mm.lock);
3378 
3379 	if (seqno == 0)
3380 		return 0;
3381 
3382 	ret = 0;
3383 	if (!i915_seqno_passed(ring->get_seqno(ring), seqno)) {
3384 		/* And wait for the seqno passing without holding any locks and
3385 		 * causing extra latency for others. This is safe as the irq
3386 		 * generation is designed to be run atomically and so is
3387 		 * lockless.
3388 		 */
3389 		if (ring->irq_get(ring)) {
3390 			ret = wait_event_interruptible(ring->irq_queue,
3391 						       i915_seqno_passed(ring->get_seqno(ring), seqno)
3392 						       || atomic_read(&dev_priv->mm.wedged));
3393 			ring->irq_put(ring);
3394 
3395 			if (ret == 0 && atomic_read(&dev_priv->mm.wedged))
3396 				ret = -EIO;
3397 		}
3398 	}
3399 
3400 	if (ret == 0)
3401 		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, 0);
3402 
3403 	return ret;
3404 }
3405 
3406 int
3407 i915_gem_object_pin(struct drm_i915_gem_object *obj,
3408 		    uint32_t alignment,
3409 		    bool map_and_fenceable)
3410 {
3411 	struct drm_device *dev = obj->base.dev;
3412 	struct drm_i915_private *dev_priv = dev->dev_private;
3413 	int ret;
3414 
3415 	BUG_ON(obj->pin_count == DRM_I915_GEM_OBJECT_MAX_PIN_COUNT);
3416 	WARN_ON(i915_verify_lists(dev));
3417 
3418 	if (obj->gtt_space != NULL) {
3419 		if ((alignment && obj->gtt_offset & (alignment - 1)) ||
3420 		    (map_and_fenceable && !obj->map_and_fenceable)) {
3421 			WARN(obj->pin_count,
3422 			     "bo is already pinned with incorrect alignment:"
3423 			     " offset=%x, req.alignment=%x, req.map_and_fenceable=%d,"
3424 			     " obj->map_and_fenceable=%d\n",
3425 			     obj->gtt_offset, alignment,
3426 			     map_and_fenceable,
3427 			     obj->map_and_fenceable);
3428 			ret = i915_gem_object_unbind(obj);
3429 			if (ret)
3430 				return ret;
3431 		}
3432 	}
3433 
3434 	if (obj->gtt_space == NULL) {
3435 		ret = i915_gem_object_bind_to_gtt(obj, alignment,
3436 						  map_and_fenceable);
3437 		if (ret)
3438 			return ret;
3439 	}
3440 
3441 	if (obj->pin_count++ == 0) {
3442 		if (!obj->active)
3443 			list_move_tail(&obj->mm_list,
3444 				       &dev_priv->mm.pinned_list);
3445 	}
3446 	obj->pin_mappable |= map_and_fenceable;
3447 
3448 	WARN_ON(i915_verify_lists(dev));
3449 	return 0;
3450 }
3451 
3452 void
3453 i915_gem_object_unpin(struct drm_i915_gem_object *obj)
3454 {
3455 	struct drm_device *dev = obj->base.dev;
3456 	drm_i915_private_t *dev_priv = dev->dev_private;
3457 
3458 	WARN_ON(i915_verify_lists(dev));
3459 	BUG_ON(obj->pin_count == 0);
3460 	BUG_ON(obj->gtt_space == NULL);
3461 
3462 	if (--obj->pin_count == 0) {
3463 		if (!obj->active)
3464 			list_move_tail(&obj->mm_list,
3465 				       &dev_priv->mm.inactive_list);
3466 		obj->pin_mappable = false;
3467 	}
3468 	WARN_ON(i915_verify_lists(dev));
3469 }
3470 
3471 int
3472 i915_gem_pin_ioctl(struct drm_device *dev, void *data,
3473 		   struct drm_file *file)
3474 {
3475 	struct drm_i915_gem_pin *args = data;
3476 	struct drm_i915_gem_object *obj;
3477 	int ret;
3478 
3479 	ret = i915_mutex_lock_interruptible(dev);
3480 	if (ret)
3481 		return ret;
3482 
3483 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
3484 	if (&obj->base == NULL) {
3485 		ret = -ENOENT;
3486 		goto unlock;
3487 	}
3488 
3489 	if (obj->madv != I915_MADV_WILLNEED) {
3490 		DRM_ERROR("Attempting to pin a purgeable buffer\n");
3491 		ret = -EINVAL;
3492 		goto out;
3493 	}
3494 
3495 	if (obj->pin_filp != NULL && obj->pin_filp != file) {
3496 		DRM_ERROR("Already pinned in i915_gem_pin_ioctl(): %d\n",
3497 			  args->handle);
3498 		ret = -EINVAL;
3499 		goto out;
3500 	}
3501 
3502 	obj->user_pin_count++;
3503 	obj->pin_filp = file;
3504 	if (obj->user_pin_count == 1) {
3505 		ret = i915_gem_object_pin(obj, args->alignment, true);
3506 		if (ret)
3507 			goto out;
3508 	}
3509 
3510 	/* XXX - flush the CPU caches for pinned objects
3511 	 * as the X server doesn't manage domains yet
3512 	 */
3513 	i915_gem_object_flush_cpu_write_domain(obj);
3514 	args->offset = obj->gtt_offset;
3515 out:
3516 	drm_gem_object_unreference(&obj->base);
3517 unlock:
3518 	mutex_unlock(&dev->struct_mutex);
3519 	return ret;
3520 }
3521 
3522 int
3523 i915_gem_unpin_ioctl(struct drm_device *dev, void *data,
3524 		     struct drm_file *file)
3525 {
3526 	struct drm_i915_gem_pin *args = data;
3527 	struct drm_i915_gem_object *obj;
3528 	int ret;
3529 
3530 	ret = i915_mutex_lock_interruptible(dev);
3531 	if (ret)
3532 		return ret;
3533 
3534 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
3535 	if (&obj->base == NULL) {
3536 		ret = -ENOENT;
3537 		goto unlock;
3538 	}
3539 
3540 	if (obj->pin_filp != file) {
3541 		DRM_ERROR("Not pinned by caller in i915_gem_pin_ioctl(): %d\n",
3542 			  args->handle);
3543 		ret = -EINVAL;
3544 		goto out;
3545 	}
3546 	obj->user_pin_count--;
3547 	if (obj->user_pin_count == 0) {
3548 		obj->pin_filp = NULL;
3549 		i915_gem_object_unpin(obj);
3550 	}
3551 
3552 out:
3553 	drm_gem_object_unreference(&obj->base);
3554 unlock:
3555 	mutex_unlock(&dev->struct_mutex);
3556 	return ret;
3557 }
3558 
3559 int
3560 i915_gem_busy_ioctl(struct drm_device *dev, void *data,
3561 		    struct drm_file *file)
3562 {
3563 	struct drm_i915_gem_busy *args = data;
3564 	struct drm_i915_gem_object *obj;
3565 	int ret;
3566 
3567 	ret = i915_mutex_lock_interruptible(dev);
3568 	if (ret)
3569 		return ret;
3570 
3571 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
3572 	if (&obj->base == NULL) {
3573 		ret = -ENOENT;
3574 		goto unlock;
3575 	}
3576 
3577 	/* Count all active objects as busy, even if they are currently not used
3578 	 * by the gpu. Users of this interface expect objects to eventually
3579 	 * become non-busy without any further actions, therefore emit any
3580 	 * necessary flushes here.
3581 	 */
3582 	args->busy = obj->active;
3583 	if (args->busy) {
3584 		/* Unconditionally flush objects, even when the gpu still uses this
3585 		 * object. Userspace calling this function indicates that it wants to
3586 		 * use this buffer rather sooner than later, so issuing the required
3587 		 * flush earlier is beneficial.
3588 		 */
3589 		if (obj->base.write_domain & I915_GEM_GPU_DOMAINS) {
3590 			ret = i915_gem_flush_ring(obj->ring,
3591 						  0, obj->base.write_domain);
3592 		} else if (obj->ring->outstanding_lazy_request ==
3593 			   obj->last_rendering_seqno) {
3594 			struct drm_i915_gem_request *request;
3595 
3596 			/* This ring is not being cleared by active usage,
3597 			 * so emit a request to do so.
3598 			 */
3599 			request = kzalloc(sizeof(*request), GFP_KERNEL);
3600 			if (request)
3601 				ret = i915_add_request(obj->ring, NULL,request);
3602 			else
3603 				ret = -ENOMEM;
3604 		}
3605 
3606 		/* Update the active list for the hardware's current position.
3607 		 * Otherwise this only updates on a delayed timer or when irqs
3608 		 * are actually unmasked, and our working set ends up being
3609 		 * larger than required.
3610 		 */
3611 		i915_gem_retire_requests_ring(obj->ring);
3612 
3613 		args->busy = obj->active;
3614 	}
3615 
3616 	drm_gem_object_unreference(&obj->base);
3617 unlock:
3618 	mutex_unlock(&dev->struct_mutex);
3619 	return ret;
3620 }
3621 
3622 int
3623 i915_gem_throttle_ioctl(struct drm_device *dev, void *data,
3624 			struct drm_file *file_priv)
3625 {
3626     return i915_gem_ring_throttle(dev, file_priv);
3627 }
3628 
3629 int
3630 i915_gem_madvise_ioctl(struct drm_device *dev, void *data,
3631 		       struct drm_file *file_priv)
3632 {
3633 	struct drm_i915_gem_madvise *args = data;
3634 	struct drm_i915_gem_object *obj;
3635 	int ret;
3636 
3637 	switch (args->madv) {
3638 	case I915_MADV_DONTNEED:
3639 	case I915_MADV_WILLNEED:
3640 	    break;
3641 	default:
3642 	    return -EINVAL;
3643 	}
3644 
3645 	ret = i915_mutex_lock_interruptible(dev);
3646 	if (ret)
3647 		return ret;
3648 
3649 	obj = to_intel_bo(drm_gem_object_lookup(dev, file_priv, args->handle));
3650 	if (&obj->base == NULL) {
3651 		ret = -ENOENT;
3652 		goto unlock;
3653 	}
3654 
3655 	if (obj->pin_count) {
3656 		ret = -EINVAL;
3657 		goto out;
3658 	}
3659 
3660 	if (obj->madv != __I915_MADV_PURGED)
3661 		obj->madv = args->madv;
3662 
3663 	/* if the object is no longer bound, discard its backing storage */
3664 	if (i915_gem_object_is_purgeable(obj) &&
3665 	    obj->gtt_space == NULL)
3666 		i915_gem_object_truncate(obj);
3667 
3668 	args->retained = obj->madv != __I915_MADV_PURGED;
3669 
3670 out:
3671 	drm_gem_object_unreference(&obj->base);
3672 unlock:
3673 	mutex_unlock(&dev->struct_mutex);
3674 	return ret;
3675 }
3676 
3677 struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
3678 						  size_t size)
3679 {
3680 	struct drm_i915_private *dev_priv = dev->dev_private;
3681 	struct drm_i915_gem_object *obj;
3682 	struct address_space *mapping;
3683 
3684 	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
3685 	if (obj == NULL)
3686 		return NULL;
3687 
3688 	if (drm_gem_object_init(dev, &obj->base, size) != 0) {
3689 		kfree(obj);
3690 		return NULL;
3691 	}
3692 
3693 	mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
3694 	mapping_set_gfp_mask(mapping, GFP_HIGHUSER | __GFP_RECLAIMABLE);
3695 
3696 	i915_gem_info_add_obj(dev_priv, size);
3697 
3698 	obj->base.write_domain = I915_GEM_DOMAIN_CPU;
3699 	obj->base.read_domains = I915_GEM_DOMAIN_CPU;
3700 
3701 	if (IS_GEN6(dev)) {
3702 		/* On Gen6, we can have the GPU use the LLC (the CPU
3703 		 * cache) for about a 10% performance improvement
3704 		 * compared to uncached.  Graphics requests other than
3705 		 * display scanout are coherent with the CPU in
3706 		 * accessing this cache.  This means in this mode we
3707 		 * don't need to clflush on the CPU side, and on the
3708 		 * GPU side we only need to flush internal caches to
3709 		 * get data visible to the CPU.
3710 		 *
3711 		 * However, we maintain the display planes as UC, and so
3712 		 * need to rebind when first used as such.
3713 		 */
3714 		obj->cache_level = I915_CACHE_LLC;
3715 	} else
3716 		obj->cache_level = I915_CACHE_NONE;
3717 
3718 	obj->base.driver_private = NULL;
3719 	obj->fence_reg = I915_FENCE_REG_NONE;
3720 	INIT_LIST_HEAD(&obj->mm_list);
3721 	INIT_LIST_HEAD(&obj->gtt_list);
3722 	INIT_LIST_HEAD(&obj->ring_list);
3723 	INIT_LIST_HEAD(&obj->exec_list);
3724 	INIT_LIST_HEAD(&obj->gpu_write_list);
3725 	obj->madv = I915_MADV_WILLNEED;
3726 	/* Avoid an unnecessary call to unbind on the first bind. */
3727 	obj->map_and_fenceable = true;
3728 
3729 	return obj;
3730 }
3731 
3732 int i915_gem_init_object(struct drm_gem_object *obj)
3733 {
3734 	BUG();
3735 
3736 	return 0;
3737 }
3738 
3739 static void i915_gem_free_object_tail(struct drm_i915_gem_object *obj)
3740 {
3741 	struct drm_device *dev = obj->base.dev;
3742 	drm_i915_private_t *dev_priv = dev->dev_private;
3743 	int ret;
3744 
3745 	ret = i915_gem_object_unbind(obj);
3746 	if (ret == -ERESTARTSYS) {
3747 		list_move(&obj->mm_list,
3748 			  &dev_priv->mm.deferred_free_list);
3749 		return;
3750 	}
3751 
3752 	trace_i915_gem_object_destroy(obj);
3753 
3754 	if (obj->base.map_list.map)
3755 		i915_gem_free_mmap_offset(obj);
3756 
3757 	drm_gem_object_release(&obj->base);
3758 	i915_gem_info_remove_obj(dev_priv, obj->base.size);
3759 
3760 	kfree(obj->page_cpu_valid);
3761 	kfree(obj->bit_17);
3762 	kfree(obj);
3763 }
3764 
3765 void i915_gem_free_object(struct drm_gem_object *gem_obj)
3766 {
3767 	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
3768 	struct drm_device *dev = obj->base.dev;
3769 
3770 	while (obj->pin_count > 0)
3771 		i915_gem_object_unpin(obj);
3772 
3773 	if (obj->phys_obj)
3774 		i915_gem_detach_phys_object(dev, obj);
3775 
3776 	i915_gem_free_object_tail(obj);
3777 }
3778 
3779 int
3780 i915_gem_idle(struct drm_device *dev)
3781 {
3782 	drm_i915_private_t *dev_priv = dev->dev_private;
3783 	int ret;
3784 
3785 	mutex_lock(&dev->struct_mutex);
3786 
3787 	if (dev_priv->mm.suspended) {
3788 		mutex_unlock(&dev->struct_mutex);
3789 		return 0;
3790 	}
3791 
3792 	ret = i915_gpu_idle(dev);
3793 	if (ret) {
3794 		mutex_unlock(&dev->struct_mutex);
3795 		return ret;
3796 	}
3797 
3798 	/* Under UMS, be paranoid and evict. */
3799 	if (!drm_core_check_feature(dev, DRIVER_MODESET)) {
3800 		ret = i915_gem_evict_inactive(dev, false);
3801 		if (ret) {
3802 			mutex_unlock(&dev->struct_mutex);
3803 			return ret;
3804 		}
3805 	}
3806 
3807 	i915_gem_reset_fences(dev);
3808 
3809 	/* Hack!  Don't let anybody do execbuf while we don't control the chip.
3810 	 * We need to replace this with a semaphore, or something.
3811 	 * And not confound mm.suspended!
3812 	 */
3813 	dev_priv->mm.suspended = 1;
3814 	del_timer_sync(&dev_priv->hangcheck_timer);
3815 
3816 	i915_kernel_lost_context(dev);
3817 	i915_gem_cleanup_ringbuffer(dev);
3818 
3819 	mutex_unlock(&dev->struct_mutex);
3820 
3821 	/* Cancel the retire work handler, which should be idle now. */
3822 	cancel_delayed_work_sync(&dev_priv->mm.retire_work);
3823 
3824 	return 0;
3825 }
3826 
3827 int
3828 i915_gem_init_ringbuffer(struct drm_device *dev)
3829 {
3830 	drm_i915_private_t *dev_priv = dev->dev_private;
3831 	int ret;
3832 
3833 	ret = intel_init_render_ring_buffer(dev);
3834 	if (ret)
3835 		return ret;
3836 
3837 	if (HAS_BSD(dev)) {
3838 		ret = intel_init_bsd_ring_buffer(dev);
3839 		if (ret)
3840 			goto cleanup_render_ring;
3841 	}
3842 
3843 	if (HAS_BLT(dev)) {
3844 		ret = intel_init_blt_ring_buffer(dev);
3845 		if (ret)
3846 			goto cleanup_bsd_ring;
3847 	}
3848 
3849 	dev_priv->next_seqno = 1;
3850 
3851 	return 0;
3852 
3853 cleanup_bsd_ring:
3854 	intel_cleanup_ring_buffer(&dev_priv->ring[VCS]);
3855 cleanup_render_ring:
3856 	intel_cleanup_ring_buffer(&dev_priv->ring[RCS]);
3857 	return ret;
3858 }
3859 
3860 void
3861 i915_gem_cleanup_ringbuffer(struct drm_device *dev)
3862 {
3863 	drm_i915_private_t *dev_priv = dev->dev_private;
3864 	int i;
3865 
3866 	for (i = 0; i < I915_NUM_RINGS; i++)
3867 		intel_cleanup_ring_buffer(&dev_priv->ring[i]);
3868 }
3869 
3870 int
3871 i915_gem_entervt_ioctl(struct drm_device *dev, void *data,
3872 		       struct drm_file *file_priv)
3873 {
3874 	drm_i915_private_t *dev_priv = dev->dev_private;
3875 	int ret, i;
3876 
3877 	if (drm_core_check_feature(dev, DRIVER_MODESET))
3878 		return 0;
3879 
3880 	if (atomic_read(&dev_priv->mm.wedged)) {
3881 		DRM_ERROR("Reenabling wedged hardware, good luck\n");
3882 		atomic_set(&dev_priv->mm.wedged, 0);
3883 	}
3884 
3885 	mutex_lock(&dev->struct_mutex);
3886 	dev_priv->mm.suspended = 0;
3887 
3888 	ret = i915_gem_init_ringbuffer(dev);
3889 	if (ret != 0) {
3890 		mutex_unlock(&dev->struct_mutex);
3891 		return ret;
3892 	}
3893 
3894 	BUG_ON(!list_empty(&dev_priv->mm.active_list));
3895 	BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
3896 	BUG_ON(!list_empty(&dev_priv->mm.inactive_list));
3897 	for (i = 0; i < I915_NUM_RINGS; i++) {
3898 		BUG_ON(!list_empty(&dev_priv->ring[i].active_list));
3899 		BUG_ON(!list_empty(&dev_priv->ring[i].request_list));
3900 	}
3901 	mutex_unlock(&dev->struct_mutex);
3902 
3903 	ret = drm_irq_install(dev);
3904 	if (ret)
3905 		goto cleanup_ringbuffer;
3906 
3907 	return 0;
3908 
3909 cleanup_ringbuffer:
3910 	mutex_lock(&dev->struct_mutex);
3911 	i915_gem_cleanup_ringbuffer(dev);
3912 	dev_priv->mm.suspended = 1;
3913 	mutex_unlock(&dev->struct_mutex);
3914 
3915 	return ret;
3916 }
3917 
3918 int
3919 i915_gem_leavevt_ioctl(struct drm_device *dev, void *data,
3920 		       struct drm_file *file_priv)
3921 {
3922 	if (drm_core_check_feature(dev, DRIVER_MODESET))
3923 		return 0;
3924 
3925 	drm_irq_uninstall(dev);
3926 	return i915_gem_idle(dev);
3927 }
3928 
3929 void
3930 i915_gem_lastclose(struct drm_device *dev)
3931 {
3932 	int ret;
3933 
3934 	if (drm_core_check_feature(dev, DRIVER_MODESET))
3935 		return;
3936 
3937 	ret = i915_gem_idle(dev);
3938 	if (ret)
3939 		DRM_ERROR("failed to idle hardware: %d\n", ret);
3940 }
3941 
3942 static void
3943 init_ring_lists(struct intel_ring_buffer *ring)
3944 {
3945 	INIT_LIST_HEAD(&ring->active_list);
3946 	INIT_LIST_HEAD(&ring->request_list);
3947 	INIT_LIST_HEAD(&ring->gpu_write_list);
3948 }
3949 
3950 void
3951 i915_gem_load(struct drm_device *dev)
3952 {
3953 	int i;
3954 	drm_i915_private_t *dev_priv = dev->dev_private;
3955 
3956 	INIT_LIST_HEAD(&dev_priv->mm.active_list);
3957 	INIT_LIST_HEAD(&dev_priv->mm.flushing_list);
3958 	INIT_LIST_HEAD(&dev_priv->mm.inactive_list);
3959 	INIT_LIST_HEAD(&dev_priv->mm.pinned_list);
3960 	INIT_LIST_HEAD(&dev_priv->mm.fence_list);
3961 	INIT_LIST_HEAD(&dev_priv->mm.deferred_free_list);
3962 	INIT_LIST_HEAD(&dev_priv->mm.gtt_list);
3963 	for (i = 0; i < I915_NUM_RINGS; i++)
3964 		init_ring_lists(&dev_priv->ring[i]);
3965 	for (i = 0; i < 16; i++)
3966 		INIT_LIST_HEAD(&dev_priv->fence_regs[i].lru_list);
3967 	INIT_DELAYED_WORK(&dev_priv->mm.retire_work,
3968 			  i915_gem_retire_work_handler);
3969 	init_completion(&dev_priv->error_completion);
3970 
3971 	/* On GEN3 we really need to make sure the ARB C3 LP bit is set */
3972 	if (IS_GEN3(dev)) {
3973 		u32 tmp = I915_READ(MI_ARB_STATE);
3974 		if (!(tmp & MI_ARB_C3_LP_WRITE_ENABLE)) {
3975 			/* arb state is a masked write, so set bit + bit in mask */
3976 			tmp = MI_ARB_C3_LP_WRITE_ENABLE | (MI_ARB_C3_LP_WRITE_ENABLE << MI_ARB_MASK_SHIFT);
3977 			I915_WRITE(MI_ARB_STATE, tmp);
3978 		}
3979 	}
3980 
3981 	dev_priv->relative_constants_mode = I915_EXEC_CONSTANTS_REL_GENERAL;
3982 
3983 	/* Old X drivers will take 0-2 for front, back, depth buffers */
3984 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
3985 		dev_priv->fence_reg_start = 3;
3986 
3987 	if (INTEL_INFO(dev)->gen >= 4 || IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
3988 		dev_priv->num_fence_regs = 16;
3989 	else
3990 		dev_priv->num_fence_regs = 8;
3991 
3992 	/* Initialize fence registers to zero */
3993 	for (i = 0; i < dev_priv->num_fence_regs; i++) {
3994 		i915_gem_clear_fence_reg(dev, &dev_priv->fence_regs[i]);
3995 	}
3996 
3997 	i915_gem_detect_bit_6_swizzle(dev);
3998 	init_waitqueue_head(&dev_priv->pending_flip_queue);
3999 
4000 	dev_priv->mm.interruptible = true;
4001 
4002 	dev_priv->mm.inactive_shrinker.shrink = i915_gem_inactive_shrink;
4003 	dev_priv->mm.inactive_shrinker.seeks = DEFAULT_SEEKS;
4004 	register_shrinker(&dev_priv->mm.inactive_shrinker);
4005 }
4006 
4007 /*
4008  * Create a physically contiguous memory object for this object
4009  * e.g. for cursor + overlay regs
4010  */
4011 static int i915_gem_init_phys_object(struct drm_device *dev,
4012 				     int id, int size, int align)
4013 {
4014 	drm_i915_private_t *dev_priv = dev->dev_private;
4015 	struct drm_i915_gem_phys_object *phys_obj;
4016 	int ret;
4017 
4018 	if (dev_priv->mm.phys_objs[id - 1] || !size)
4019 		return 0;
4020 
4021 	phys_obj = kzalloc(sizeof(struct drm_i915_gem_phys_object), GFP_KERNEL);
4022 	if (!phys_obj)
4023 		return -ENOMEM;
4024 
4025 	phys_obj->id = id;
4026 
4027 	phys_obj->handle = drm_pci_alloc(dev, size, align);
4028 	if (!phys_obj->handle) {
4029 		ret = -ENOMEM;
4030 		goto kfree_obj;
4031 	}
4032 #ifdef CONFIG_X86
4033 	set_memory_wc((unsigned long)phys_obj->handle->vaddr, phys_obj->handle->size / PAGE_SIZE);
4034 #endif
4035 
4036 	dev_priv->mm.phys_objs[id - 1] = phys_obj;
4037 
4038 	return 0;
4039 kfree_obj:
4040 	kfree(phys_obj);
4041 	return ret;
4042 }
4043 
4044 static void i915_gem_free_phys_object(struct drm_device *dev, int id)
4045 {
4046 	drm_i915_private_t *dev_priv = dev->dev_private;
4047 	struct drm_i915_gem_phys_object *phys_obj;
4048 
4049 	if (!dev_priv->mm.phys_objs[id - 1])
4050 		return;
4051 
4052 	phys_obj = dev_priv->mm.phys_objs[id - 1];
4053 	if (phys_obj->cur_obj) {
4054 		i915_gem_detach_phys_object(dev, phys_obj->cur_obj);
4055 	}
4056 
4057 #ifdef CONFIG_X86
4058 	set_memory_wb((unsigned long)phys_obj->handle->vaddr, phys_obj->handle->size / PAGE_SIZE);
4059 #endif
4060 	drm_pci_free(dev, phys_obj->handle);
4061 	kfree(phys_obj);
4062 	dev_priv->mm.phys_objs[id - 1] = NULL;
4063 }
4064 
4065 void i915_gem_free_all_phys_object(struct drm_device *dev)
4066 {
4067 	int i;
4068 
4069 	for (i = I915_GEM_PHYS_CURSOR_0; i <= I915_MAX_PHYS_OBJECT; i++)
4070 		i915_gem_free_phys_object(dev, i);
4071 }
4072 
4073 void i915_gem_detach_phys_object(struct drm_device *dev,
4074 				 struct drm_i915_gem_object *obj)
4075 {
4076 	struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
4077 	char *vaddr;
4078 	int i;
4079 	int page_count;
4080 
4081 	if (!obj->phys_obj)
4082 		return;
4083 	vaddr = obj->phys_obj->handle->vaddr;
4084 
4085 	page_count = obj->base.size / PAGE_SIZE;
4086 	for (i = 0; i < page_count; i++) {
4087 		struct page *page = shmem_read_mapping_page(mapping, i);
4088 		if (!IS_ERR(page)) {
4089 			char *dst = kmap_atomic(page);
4090 			memcpy(dst, vaddr + i*PAGE_SIZE, PAGE_SIZE);
4091 			kunmap_atomic(dst);
4092 
4093 			drm_clflush_pages(&page, 1);
4094 
4095 			set_page_dirty(page);
4096 			mark_page_accessed(page);
4097 			page_cache_release(page);
4098 		}
4099 	}
4100 	intel_gtt_chipset_flush();
4101 
4102 	obj->phys_obj->cur_obj = NULL;
4103 	obj->phys_obj = NULL;
4104 }
4105 
4106 int
4107 i915_gem_attach_phys_object(struct drm_device *dev,
4108 			    struct drm_i915_gem_object *obj,
4109 			    int id,
4110 			    int align)
4111 {
4112 	struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping;
4113 	drm_i915_private_t *dev_priv = dev->dev_private;
4114 	int ret = 0;
4115 	int page_count;
4116 	int i;
4117 
4118 	if (id > I915_MAX_PHYS_OBJECT)
4119 		return -EINVAL;
4120 
4121 	if (obj->phys_obj) {
4122 		if (obj->phys_obj->id == id)
4123 			return 0;
4124 		i915_gem_detach_phys_object(dev, obj);
4125 	}
4126 
4127 	/* create a new object */
4128 	if (!dev_priv->mm.phys_objs[id - 1]) {
4129 		ret = i915_gem_init_phys_object(dev, id,
4130 						obj->base.size, align);
4131 		if (ret) {
4132 			DRM_ERROR("failed to init phys object %d size: %zu\n",
4133 				  id, obj->base.size);
4134 			return ret;
4135 		}
4136 	}
4137 
4138 	/* bind to the object */
4139 	obj->phys_obj = dev_priv->mm.phys_objs[id - 1];
4140 	obj->phys_obj->cur_obj = obj;
4141 
4142 	page_count = obj->base.size / PAGE_SIZE;
4143 
4144 	for (i = 0; i < page_count; i++) {
4145 		struct page *page;
4146 		char *dst, *src;
4147 
4148 		page = shmem_read_mapping_page(mapping, i);
4149 		if (IS_ERR(page))
4150 			return PTR_ERR(page);
4151 
4152 		src = kmap_atomic(page);
4153 		dst = obj->phys_obj->handle->vaddr + (i * PAGE_SIZE);
4154 		memcpy(dst, src, PAGE_SIZE);
4155 		kunmap_atomic(src);
4156 
4157 		mark_page_accessed(page);
4158 		page_cache_release(page);
4159 	}
4160 
4161 	return 0;
4162 }
4163 
4164 static int
4165 i915_gem_phys_pwrite(struct drm_device *dev,
4166 		     struct drm_i915_gem_object *obj,
4167 		     struct drm_i915_gem_pwrite *args,
4168 		     struct drm_file *file_priv)
4169 {
4170 	void *vaddr = obj->phys_obj->handle->vaddr + args->offset;
4171 	char __user *user_data = (char __user *) (uintptr_t) args->data_ptr;
4172 
4173 	if (__copy_from_user_inatomic_nocache(vaddr, user_data, args->size)) {
4174 		unsigned long unwritten;
4175 
4176 		/* The physical object once assigned is fixed for the lifetime
4177 		 * of the obj, so we can safely drop the lock and continue
4178 		 * to access vaddr.
4179 		 */
4180 		mutex_unlock(&dev->struct_mutex);
4181 		unwritten = copy_from_user(vaddr, user_data, args->size);
4182 		mutex_lock(&dev->struct_mutex);
4183 		if (unwritten)
4184 			return -EFAULT;
4185 	}
4186 
4187 	intel_gtt_chipset_flush();
4188 	return 0;
4189 }
4190 
4191 void i915_gem_release(struct drm_device *dev, struct drm_file *file)
4192 {
4193 	struct drm_i915_file_private *file_priv = file->driver_priv;
4194 
4195 	/* Clean up our request list when the client is going away, so that
4196 	 * later retire_requests won't dereference our soon-to-be-gone
4197 	 * file_priv.
4198 	 */
4199 	spin_lock(&file_priv->mm.lock);
4200 	while (!list_empty(&file_priv->mm.request_list)) {
4201 		struct drm_i915_gem_request *request;
4202 
4203 		request = list_first_entry(&file_priv->mm.request_list,
4204 					   struct drm_i915_gem_request,
4205 					   client_list);
4206 		list_del(&request->client_list);
4207 		request->file_priv = NULL;
4208 	}
4209 	spin_unlock(&file_priv->mm.lock);
4210 }
4211 
4212 static int
4213 i915_gpu_is_active(struct drm_device *dev)
4214 {
4215 	drm_i915_private_t *dev_priv = dev->dev_private;
4216 	int lists_empty;
4217 
4218 	lists_empty = list_empty(&dev_priv->mm.flushing_list) &&
4219 		      list_empty(&dev_priv->mm.active_list);
4220 
4221 	return !lists_empty;
4222 }
4223 
4224 static int
4225 i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
4226 {
4227 	struct drm_i915_private *dev_priv =
4228 		container_of(shrinker,
4229 			     struct drm_i915_private,
4230 			     mm.inactive_shrinker);
4231 	struct drm_device *dev = dev_priv->dev;
4232 	struct drm_i915_gem_object *obj, *next;
4233 	int nr_to_scan = sc->nr_to_scan;
4234 	int cnt;
4235 
4236 	if (!mutex_trylock(&dev->struct_mutex))
4237 		return 0;
4238 
4239 	/* "fast-path" to count number of available objects */
4240 	if (nr_to_scan == 0) {
4241 		cnt = 0;
4242 		list_for_each_entry(obj,
4243 				    &dev_priv->mm.inactive_list,
4244 				    mm_list)
4245 			cnt++;
4246 		mutex_unlock(&dev->struct_mutex);
4247 		return cnt / 100 * sysctl_vfs_cache_pressure;
4248 	}
4249 
4250 rescan:
4251 	/* first scan for clean buffers */
4252 	i915_gem_retire_requests(dev);
4253 
4254 	list_for_each_entry_safe(obj, next,
4255 				 &dev_priv->mm.inactive_list,
4256 				 mm_list) {
4257 		if (i915_gem_object_is_purgeable(obj)) {
4258 			if (i915_gem_object_unbind(obj) == 0 &&
4259 			    --nr_to_scan == 0)
4260 				break;
4261 		}
4262 	}
4263 
4264 	/* second pass, evict/count anything still on the inactive list */
4265 	cnt = 0;
4266 	list_for_each_entry_safe(obj, next,
4267 				 &dev_priv->mm.inactive_list,
4268 				 mm_list) {
4269 		if (nr_to_scan &&
4270 		    i915_gem_object_unbind(obj) == 0)
4271 			nr_to_scan--;
4272 		else
4273 			cnt++;
4274 	}
4275 
4276 	if (nr_to_scan && i915_gpu_is_active(dev)) {
4277 		/*
4278 		 * We are desperate for pages, so as a last resort, wait
4279 		 * for the GPU to finish and discard whatever we can.
4280 		 * This has a dramatic impact to reduce the number of
4281 		 * OOM-killer events whilst running the GPU aggressively.
4282 		 */
4283 		if (i915_gpu_idle(dev) == 0)
4284 			goto rescan;
4285 	}
4286 	mutex_unlock(&dev->struct_mutex);
4287 	return cnt / 100 * sysctl_vfs_cache_pressure;
4288 }
4289