1 /* exynos_drm_gem.c
2  *
3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
4  * Author: Inki Dae <inki.dae@samsung.com>
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  */
11 
12 #include <drm/drmP.h>
13 #include <drm/drm_vma_manager.h>
14 
15 #include <linux/shmem_fs.h>
16 #include <drm/exynos_drm.h>
17 
18 #include "exynos_drm_drv.h"
19 #include "exynos_drm_gem.h"
20 #include "exynos_drm_buf.h"
21 #include "exynos_drm_iommu.h"
22 
23 static unsigned int convert_to_vm_err_msg(int msg)
24 {
25 	unsigned int out_msg;
26 
27 	switch (msg) {
28 	case 0:
29 	case -ERESTARTSYS:
30 	case -EINTR:
31 		out_msg = VM_FAULT_NOPAGE;
32 		break;
33 
34 	case -ENOMEM:
35 		out_msg = VM_FAULT_OOM;
36 		break;
37 
38 	default:
39 		out_msg = VM_FAULT_SIGBUS;
40 		break;
41 	}
42 
43 	return out_msg;
44 }
45 
46 static int check_gem_flags(unsigned int flags)
47 {
48 	if (flags & ~(EXYNOS_BO_MASK)) {
49 		DRM_ERROR("invalid flags.\n");
50 		return -EINVAL;
51 	}
52 
53 	return 0;
54 }
55 
56 static void update_vm_cache_attr(struct exynos_drm_gem_obj *obj,
57 					struct vm_area_struct *vma)
58 {
59 	DRM_DEBUG_KMS("flags = 0x%x\n", obj->flags);
60 
61 	/* non-cachable as default. */
62 	if (obj->flags & EXYNOS_BO_CACHABLE)
63 		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
64 	else if (obj->flags & EXYNOS_BO_WC)
65 		vma->vm_page_prot =
66 			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
67 	else
68 		vma->vm_page_prot =
69 			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
70 }
71 
72 static unsigned long roundup_gem_size(unsigned long size, unsigned int flags)
73 {
74 	/* TODO */
75 
76 	return roundup(size, PAGE_SIZE);
77 }
78 
79 static int exynos_drm_gem_map_buf(struct drm_gem_object *obj,
80 					struct vm_area_struct *vma,
81 					unsigned long f_vaddr,
82 					pgoff_t page_offset)
83 {
84 	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
85 	struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
86 	struct scatterlist *sgl;
87 	unsigned long pfn;
88 	int i;
89 
90 	if (!buf->sgt)
91 		return -EINTR;
92 
93 	if (page_offset >= (buf->size >> PAGE_SHIFT)) {
94 		DRM_ERROR("invalid page offset\n");
95 		return -EINVAL;
96 	}
97 
98 	sgl = buf->sgt->sgl;
99 	for_each_sg(buf->sgt->sgl, sgl, buf->sgt->nents, i) {
100 		if (page_offset < (sgl->length >> PAGE_SHIFT))
101 			break;
102 		page_offset -=	(sgl->length >> PAGE_SHIFT);
103 	}
104 
105 	pfn = __phys_to_pfn(sg_phys(sgl)) + page_offset;
106 
107 	return vm_insert_mixed(vma, f_vaddr, pfn);
108 }
109 
110 static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
111 					struct drm_file *file_priv,
112 					unsigned int *handle)
113 {
114 	int ret;
115 
116 	/*
117 	 * allocate a id of idr table where the obj is registered
118 	 * and handle has the id what user can see.
119 	 */
120 	ret = drm_gem_handle_create(file_priv, obj, handle);
121 	if (ret)
122 		return ret;
123 
124 	DRM_DEBUG_KMS("gem handle = 0x%x\n", *handle);
125 
126 	/* drop reference from allocate - handle holds it now. */
127 	drm_gem_object_unreference_unlocked(obj);
128 
129 	return 0;
130 }
131 
132 void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
133 {
134 	struct drm_gem_object *obj;
135 	struct exynos_drm_gem_buf *buf;
136 
137 	obj = &exynos_gem_obj->base;
138 	buf = exynos_gem_obj->buffer;
139 
140 	DRM_DEBUG_KMS("handle count = %d\n", obj->handle_count);
141 
142 	/*
143 	 * do not release memory region from exporter.
144 	 *
145 	 * the region will be released by exporter
146 	 * once dmabuf's refcount becomes 0.
147 	 */
148 	if (obj->import_attach)
149 		goto out;
150 
151 	exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags, buf);
152 
153 out:
154 	exynos_drm_fini_buf(obj->dev, buf);
155 	exynos_gem_obj->buffer = NULL;
156 
157 	drm_gem_free_mmap_offset(obj);
158 
159 	/* release file pointer to gem object. */
160 	drm_gem_object_release(obj);
161 
162 	kfree(exynos_gem_obj);
163 	exynos_gem_obj = NULL;
164 }
165 
166 unsigned long exynos_drm_gem_get_size(struct drm_device *dev,
167 						unsigned int gem_handle,
168 						struct drm_file *file_priv)
169 {
170 	struct exynos_drm_gem_obj *exynos_gem_obj;
171 	struct drm_gem_object *obj;
172 
173 	obj = drm_gem_object_lookup(dev, file_priv, gem_handle);
174 	if (!obj) {
175 		DRM_ERROR("failed to lookup gem object.\n");
176 		return 0;
177 	}
178 
179 	exynos_gem_obj = to_exynos_gem_obj(obj);
180 
181 	drm_gem_object_unreference_unlocked(obj);
182 
183 	return exynos_gem_obj->buffer->size;
184 }
185 
186 
187 struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
188 						      unsigned long size)
189 {
190 	struct exynos_drm_gem_obj *exynos_gem_obj;
191 	struct drm_gem_object *obj;
192 	int ret;
193 
194 	exynos_gem_obj = kzalloc(sizeof(*exynos_gem_obj), GFP_KERNEL);
195 	if (!exynos_gem_obj)
196 		return NULL;
197 
198 	exynos_gem_obj->size = size;
199 	obj = &exynos_gem_obj->base;
200 
201 	ret = drm_gem_object_init(dev, obj, size);
202 	if (ret < 0) {
203 		DRM_ERROR("failed to initialize gem object\n");
204 		kfree(exynos_gem_obj);
205 		return NULL;
206 	}
207 
208 	DRM_DEBUG_KMS("created file object = 0x%x\n", (unsigned int)obj->filp);
209 
210 	return exynos_gem_obj;
211 }
212 
213 struct exynos_drm_gem_obj *exynos_drm_gem_create(struct drm_device *dev,
214 						unsigned int flags,
215 						unsigned long size)
216 {
217 	struct exynos_drm_gem_obj *exynos_gem_obj;
218 	struct exynos_drm_gem_buf *buf;
219 	int ret;
220 
221 	if (!size) {
222 		DRM_ERROR("invalid size.\n");
223 		return ERR_PTR(-EINVAL);
224 	}
225 
226 	size = roundup_gem_size(size, flags);
227 
228 	ret = check_gem_flags(flags);
229 	if (ret)
230 		return ERR_PTR(ret);
231 
232 	buf = exynos_drm_init_buf(dev, size);
233 	if (!buf)
234 		return ERR_PTR(-ENOMEM);
235 
236 	exynos_gem_obj = exynos_drm_gem_init(dev, size);
237 	if (!exynos_gem_obj) {
238 		ret = -ENOMEM;
239 		goto err_fini_buf;
240 	}
241 
242 	exynos_gem_obj->buffer = buf;
243 
244 	/* set memory type and cache attribute from user side. */
245 	exynos_gem_obj->flags = flags;
246 
247 	ret = exynos_drm_alloc_buf(dev, buf, flags);
248 	if (ret < 0)
249 		goto err_gem_fini;
250 
251 	return exynos_gem_obj;
252 
253 err_gem_fini:
254 	drm_gem_object_release(&exynos_gem_obj->base);
255 	kfree(exynos_gem_obj);
256 err_fini_buf:
257 	exynos_drm_fini_buf(dev, buf);
258 	return ERR_PTR(ret);
259 }
260 
261 int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
262 				struct drm_file *file_priv)
263 {
264 	struct drm_exynos_gem_create *args = data;
265 	struct exynos_drm_gem_obj *exynos_gem_obj;
266 	int ret;
267 
268 	exynos_gem_obj = exynos_drm_gem_create(dev, args->flags, args->size);
269 	if (IS_ERR(exynos_gem_obj))
270 		return PTR_ERR(exynos_gem_obj);
271 
272 	ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
273 			&args->handle);
274 	if (ret) {
275 		exynos_drm_gem_destroy(exynos_gem_obj);
276 		return ret;
277 	}
278 
279 	return 0;
280 }
281 
282 dma_addr_t *exynos_drm_gem_get_dma_addr(struct drm_device *dev,
283 					unsigned int gem_handle,
284 					struct drm_file *filp)
285 {
286 	struct exynos_drm_gem_obj *exynos_gem_obj;
287 	struct drm_gem_object *obj;
288 
289 	obj = drm_gem_object_lookup(dev, filp, gem_handle);
290 	if (!obj) {
291 		DRM_ERROR("failed to lookup gem object.\n");
292 		return ERR_PTR(-EINVAL);
293 	}
294 
295 	exynos_gem_obj = to_exynos_gem_obj(obj);
296 
297 	return &exynos_gem_obj->buffer->dma_addr;
298 }
299 
300 void exynos_drm_gem_put_dma_addr(struct drm_device *dev,
301 					unsigned int gem_handle,
302 					struct drm_file *filp)
303 {
304 	struct drm_gem_object *obj;
305 
306 	obj = drm_gem_object_lookup(dev, filp, gem_handle);
307 	if (!obj) {
308 		DRM_ERROR("failed to lookup gem object.\n");
309 		return;
310 	}
311 
312 	drm_gem_object_unreference_unlocked(obj);
313 
314 	/*
315 	 * decrease obj->refcount one more time because we has already
316 	 * increased it at exynos_drm_gem_get_dma_addr().
317 	 */
318 	drm_gem_object_unreference_unlocked(obj);
319 }
320 
321 int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem_obj *exynos_gem_obj,
322 				      struct vm_area_struct *vma)
323 {
324 	struct drm_device *drm_dev = exynos_gem_obj->base.dev;
325 	struct exynos_drm_gem_buf *buffer;
326 	unsigned long vm_size;
327 	int ret;
328 
329 	vma->vm_flags &= ~VM_PFNMAP;
330 	vma->vm_pgoff = 0;
331 
332 	vm_size = vma->vm_end - vma->vm_start;
333 
334 	/*
335 	 * a buffer contains information to physically continuous memory
336 	 * allocated by user request or at framebuffer creation.
337 	 */
338 	buffer = exynos_gem_obj->buffer;
339 
340 	/* check if user-requested size is valid. */
341 	if (vm_size > buffer->size)
342 		return -EINVAL;
343 
344 	ret = dma_mmap_attrs(drm_dev->dev, vma, buffer->pages,
345 				buffer->dma_addr, buffer->size,
346 				&buffer->dma_attrs);
347 	if (ret < 0) {
348 		DRM_ERROR("failed to mmap.\n");
349 		return ret;
350 	}
351 
352 	return 0;
353 }
354 
355 int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
356 				      struct drm_file *file_priv)
357 {	struct exynos_drm_gem_obj *exynos_gem_obj;
358 	struct drm_exynos_gem_info *args = data;
359 	struct drm_gem_object *obj;
360 
361 	mutex_lock(&dev->struct_mutex);
362 
363 	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
364 	if (!obj) {
365 		DRM_ERROR("failed to lookup gem object.\n");
366 		mutex_unlock(&dev->struct_mutex);
367 		return -EINVAL;
368 	}
369 
370 	exynos_gem_obj = to_exynos_gem_obj(obj);
371 
372 	args->flags = exynos_gem_obj->flags;
373 	args->size = exynos_gem_obj->size;
374 
375 	drm_gem_object_unreference(obj);
376 	mutex_unlock(&dev->struct_mutex);
377 
378 	return 0;
379 }
380 
381 struct vm_area_struct *exynos_gem_get_vma(struct vm_area_struct *vma)
382 {
383 	struct vm_area_struct *vma_copy;
384 
385 	vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
386 	if (!vma_copy)
387 		return NULL;
388 
389 	if (vma->vm_ops && vma->vm_ops->open)
390 		vma->vm_ops->open(vma);
391 
392 	if (vma->vm_file)
393 		get_file(vma->vm_file);
394 
395 	memcpy(vma_copy, vma, sizeof(*vma));
396 
397 	vma_copy->vm_mm = NULL;
398 	vma_copy->vm_next = NULL;
399 	vma_copy->vm_prev = NULL;
400 
401 	return vma_copy;
402 }
403 
404 void exynos_gem_put_vma(struct vm_area_struct *vma)
405 {
406 	if (!vma)
407 		return;
408 
409 	if (vma->vm_ops && vma->vm_ops->close)
410 		vma->vm_ops->close(vma);
411 
412 	if (vma->vm_file)
413 		fput(vma->vm_file);
414 
415 	kfree(vma);
416 }
417 
418 int exynos_gem_get_pages_from_userptr(unsigned long start,
419 						unsigned int npages,
420 						struct page **pages,
421 						struct vm_area_struct *vma)
422 {
423 	int get_npages;
424 
425 	/* the memory region mmaped with VM_PFNMAP. */
426 	if (vma_is_io(vma)) {
427 		unsigned int i;
428 
429 		for (i = 0; i < npages; ++i, start += PAGE_SIZE) {
430 			unsigned long pfn;
431 			int ret = follow_pfn(vma, start, &pfn);
432 			if (ret)
433 				return ret;
434 
435 			pages[i] = pfn_to_page(pfn);
436 		}
437 
438 		if (i != npages) {
439 			DRM_ERROR("failed to get user_pages.\n");
440 			return -EINVAL;
441 		}
442 
443 		return 0;
444 	}
445 
446 	get_npages = get_user_pages(current, current->mm, start,
447 					npages, 1, 1, pages, NULL);
448 	get_npages = max(get_npages, 0);
449 	if (get_npages != npages) {
450 		DRM_ERROR("failed to get user_pages.\n");
451 		while (get_npages)
452 			put_page(pages[--get_npages]);
453 		return -EFAULT;
454 	}
455 
456 	return 0;
457 }
458 
459 void exynos_gem_put_pages_to_userptr(struct page **pages,
460 					unsigned int npages,
461 					struct vm_area_struct *vma)
462 {
463 	if (!vma_is_io(vma)) {
464 		unsigned int i;
465 
466 		for (i = 0; i < npages; i++) {
467 			set_page_dirty_lock(pages[i]);
468 
469 			/*
470 			 * undo the reference we took when populating
471 			 * the table.
472 			 */
473 			put_page(pages[i]);
474 		}
475 	}
476 }
477 
478 int exynos_gem_map_sgt_with_dma(struct drm_device *drm_dev,
479 				struct sg_table *sgt,
480 				enum dma_data_direction dir)
481 {
482 	int nents;
483 
484 	mutex_lock(&drm_dev->struct_mutex);
485 
486 	nents = dma_map_sg(drm_dev->dev, sgt->sgl, sgt->nents, dir);
487 	if (!nents) {
488 		DRM_ERROR("failed to map sgl with dma.\n");
489 		mutex_unlock(&drm_dev->struct_mutex);
490 		return nents;
491 	}
492 
493 	mutex_unlock(&drm_dev->struct_mutex);
494 	return 0;
495 }
496 
497 void exynos_gem_unmap_sgt_from_dma(struct drm_device *drm_dev,
498 				struct sg_table *sgt,
499 				enum dma_data_direction dir)
500 {
501 	dma_unmap_sg(drm_dev->dev, sgt->sgl, sgt->nents, dir);
502 }
503 
504 void exynos_drm_gem_free_object(struct drm_gem_object *obj)
505 {
506 	struct exynos_drm_gem_obj *exynos_gem_obj;
507 	struct exynos_drm_gem_buf *buf;
508 
509 	exynos_gem_obj = to_exynos_gem_obj(obj);
510 	buf = exynos_gem_obj->buffer;
511 
512 	if (obj->import_attach)
513 		drm_prime_gem_destroy(obj, buf->sgt);
514 
515 	exynos_drm_gem_destroy(to_exynos_gem_obj(obj));
516 }
517 
518 int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
519 			       struct drm_device *dev,
520 			       struct drm_mode_create_dumb *args)
521 {
522 	struct exynos_drm_gem_obj *exynos_gem_obj;
523 	int ret;
524 
525 	/*
526 	 * allocate memory to be used for framebuffer.
527 	 * - this callback would be called by user application
528 	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
529 	 */
530 
531 	args->pitch = args->width * ((args->bpp + 7) / 8);
532 	args->size = args->pitch * args->height;
533 
534 	if (is_drm_iommu_supported(dev)) {
535 		exynos_gem_obj = exynos_drm_gem_create(dev,
536 			EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC,
537 			args->size);
538 	} else {
539 		exynos_gem_obj = exynos_drm_gem_create(dev,
540 			EXYNOS_BO_CONTIG | EXYNOS_BO_WC,
541 			args->size);
542 	}
543 
544 	if (IS_ERR(exynos_gem_obj)) {
545 		dev_warn(dev->dev, "FB allocation failed.\n");
546 		return PTR_ERR(exynos_gem_obj);
547 	}
548 
549 	ret = exynos_drm_gem_handle_create(&exynos_gem_obj->base, file_priv,
550 			&args->handle);
551 	if (ret) {
552 		exynos_drm_gem_destroy(exynos_gem_obj);
553 		return ret;
554 	}
555 
556 	return 0;
557 }
558 
559 int exynos_drm_gem_dumb_map_offset(struct drm_file *file_priv,
560 				   struct drm_device *dev, uint32_t handle,
561 				   uint64_t *offset)
562 {
563 	struct drm_gem_object *obj;
564 	int ret = 0;
565 
566 	mutex_lock(&dev->struct_mutex);
567 
568 	/*
569 	 * get offset of memory allocated for drm framebuffer.
570 	 * - this callback would be called by user application
571 	 *	with DRM_IOCTL_MODE_MAP_DUMB command.
572 	 */
573 
574 	obj = drm_gem_object_lookup(dev, file_priv, handle);
575 	if (!obj) {
576 		DRM_ERROR("failed to lookup gem object.\n");
577 		ret = -EINVAL;
578 		goto unlock;
579 	}
580 
581 	ret = drm_gem_create_mmap_offset(obj);
582 	if (ret)
583 		goto out;
584 
585 	*offset = drm_vma_node_offset_addr(&obj->vma_node);
586 	DRM_DEBUG_KMS("offset = 0x%lx\n", (unsigned long)*offset);
587 
588 out:
589 	drm_gem_object_unreference(obj);
590 unlock:
591 	mutex_unlock(&dev->struct_mutex);
592 	return ret;
593 }
594 
595 int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
596 {
597 	struct drm_gem_object *obj = vma->vm_private_data;
598 	struct drm_device *dev = obj->dev;
599 	unsigned long f_vaddr;
600 	pgoff_t page_offset;
601 	int ret;
602 
603 	page_offset = ((unsigned long)vmf->virtual_address -
604 			vma->vm_start) >> PAGE_SHIFT;
605 	f_vaddr = (unsigned long)vmf->virtual_address;
606 
607 	mutex_lock(&dev->struct_mutex);
608 
609 	ret = exynos_drm_gem_map_buf(obj, vma, f_vaddr, page_offset);
610 	if (ret < 0)
611 		DRM_ERROR("failed to map a buffer with user.\n");
612 
613 	mutex_unlock(&dev->struct_mutex);
614 
615 	return convert_to_vm_err_msg(ret);
616 }
617 
618 int exynos_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
619 {
620 	struct exynos_drm_gem_obj *exynos_gem_obj;
621 	struct drm_gem_object *obj;
622 	int ret;
623 
624 	/* set vm_area_struct. */
625 	ret = drm_gem_mmap(filp, vma);
626 	if (ret < 0) {
627 		DRM_ERROR("failed to mmap.\n");
628 		return ret;
629 	}
630 
631 	obj = vma->vm_private_data;
632 	exynos_gem_obj = to_exynos_gem_obj(obj);
633 
634 	ret = check_gem_flags(exynos_gem_obj->flags);
635 	if (ret)
636 		goto err_close_vm;
637 
638 	update_vm_cache_attr(exynos_gem_obj, vma);
639 
640 	ret = exynos_drm_gem_mmap_buffer(exynos_gem_obj, vma);
641 	if (ret)
642 		goto err_close_vm;
643 
644 	return ret;
645 
646 err_close_vm:
647 	drm_gem_vm_close(vma);
648 	drm_gem_free_mmap_offset(obj);
649 
650 	return ret;
651 }
652