1 /*
2  * Copyright © 2010 Daniel Vetter
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  */
24 
25 #include <drm/drmP.h>
26 #include <drm/i915_drm.h>
27 #include "i915_drv.h"
28 #include "i915_trace.h"
29 #include "intel_drv.h"
30 
31 /* PPGTT stuff */
32 #define GEN6_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0xff0))
33 
34 #define GEN6_PDE_VALID			(1 << 0)
35 /* gen6+ has bit 11-4 for physical addr bit 39-32 */
36 #define GEN6_PDE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
37 
38 #define GEN6_PTE_VALID			(1 << 0)
39 #define GEN6_PTE_UNCACHED		(1 << 1)
40 #define HSW_PTE_UNCACHED		(0)
41 #define GEN6_PTE_CACHE_LLC		(2 << 1)
42 #define GEN6_PTE_CACHE_LLC_MLC		(3 << 1)
43 #define GEN6_PTE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
44 
45 static gen6_gtt_pte_t gen6_pte_encode(struct drm_device *dev,
46 				      dma_addr_t addr,
47 				      enum i915_cache_level level)
48 {
49 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
50 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
51 
52 	switch (level) {
53 	case I915_CACHE_LLC_MLC:
54 		pte |= GEN6_PTE_CACHE_LLC_MLC;
55 		break;
56 	case I915_CACHE_LLC:
57 		pte |= GEN6_PTE_CACHE_LLC;
58 		break;
59 	case I915_CACHE_NONE:
60 		pte |= GEN6_PTE_UNCACHED;
61 		break;
62 	default:
63 		BUG();
64 	}
65 
66 	return pte;
67 }
68 
69 #define BYT_PTE_WRITEABLE		(1 << 1)
70 #define BYT_PTE_SNOOPED_BY_CPU_CACHES	(1 << 2)
71 
72 static gen6_gtt_pte_t byt_pte_encode(struct drm_device *dev,
73 				     dma_addr_t addr,
74 				     enum i915_cache_level level)
75 {
76 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
77 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
78 
79 	/* Mark the page as writeable.  Other platforms don't have a
80 	 * setting for read-only/writable, so this matches that behavior.
81 	 */
82 	pte |= BYT_PTE_WRITEABLE;
83 
84 	if (level != I915_CACHE_NONE)
85 		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
86 
87 	return pte;
88 }
89 
90 static gen6_gtt_pte_t hsw_pte_encode(struct drm_device *dev,
91 				     dma_addr_t addr,
92 				     enum i915_cache_level level)
93 {
94 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
95 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
96 
97 	if (level != I915_CACHE_NONE)
98 		pte |= GEN6_PTE_CACHE_LLC;
99 
100 	return pte;
101 }
102 
103 static void gen6_write_pdes(struct i915_hw_ppgtt *ppgtt)
104 {
105 	struct drm_i915_private *dev_priv = ppgtt->dev->dev_private;
106 	gen6_gtt_pte_t __iomem *pd_addr;
107 	uint32_t pd_entry;
108 	int i;
109 
110 	WARN_ON(ppgtt->pd_offset & 0x3f);
111 	pd_addr = (gen6_gtt_pte_t __iomem*)dev_priv->gtt.gsm +
112 		ppgtt->pd_offset / sizeof(gen6_gtt_pte_t);
113 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
114 		dma_addr_t pt_addr;
115 
116 		pt_addr = ppgtt->pt_dma_addr[i];
117 		pd_entry = GEN6_PDE_ADDR_ENCODE(pt_addr);
118 		pd_entry |= GEN6_PDE_VALID;
119 
120 		writel(pd_entry, pd_addr + i);
121 	}
122 	readl(pd_addr);
123 }
124 
125 static int gen6_ppgtt_enable(struct drm_device *dev)
126 {
127 	drm_i915_private_t *dev_priv = dev->dev_private;
128 	uint32_t pd_offset;
129 	struct intel_ring_buffer *ring;
130 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
131 	int i;
132 
133 	BUG_ON(ppgtt->pd_offset & 0x3f);
134 
135 	gen6_write_pdes(ppgtt);
136 
137 	pd_offset = ppgtt->pd_offset;
138 	pd_offset /= 64; /* in cachelines, */
139 	pd_offset <<= 16;
140 
141 	if (INTEL_INFO(dev)->gen == 6) {
142 		uint32_t ecochk, gab_ctl, ecobits;
143 
144 		ecobits = I915_READ(GAC_ECO_BITS);
145 		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_SNB_BIT |
146 					 ECOBITS_PPGTT_CACHE64B);
147 
148 		gab_ctl = I915_READ(GAB_CTL);
149 		I915_WRITE(GAB_CTL, gab_ctl | GAB_CTL_CONT_AFTER_PAGEFAULT);
150 
151 		ecochk = I915_READ(GAM_ECOCHK);
152 		I915_WRITE(GAM_ECOCHK, ecochk | ECOCHK_SNB_BIT |
153 				       ECOCHK_PPGTT_CACHE64B);
154 		I915_WRITE(GFX_MODE, _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
155 	} else if (INTEL_INFO(dev)->gen >= 7) {
156 		uint32_t ecochk, ecobits;
157 
158 		ecobits = I915_READ(GAC_ECO_BITS);
159 		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_PPGTT_CACHE64B);
160 
161 		ecochk = I915_READ(GAM_ECOCHK);
162 		if (IS_HASWELL(dev)) {
163 			ecochk |= ECOCHK_PPGTT_WB_HSW;
164 		} else {
165 			ecochk |= ECOCHK_PPGTT_LLC_IVB;
166 			ecochk &= ~ECOCHK_PPGTT_GFDT_IVB;
167 		}
168 		I915_WRITE(GAM_ECOCHK, ecochk);
169 		/* GFX_MODE is per-ring on gen7+ */
170 	}
171 
172 	for_each_ring(ring, dev_priv, i) {
173 		if (INTEL_INFO(dev)->gen >= 7)
174 			I915_WRITE(RING_MODE_GEN7(ring),
175 				   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
176 
177 		I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
178 		I915_WRITE(RING_PP_DIR_BASE(ring), pd_offset);
179 	}
180 	return 0;
181 }
182 
183 /* PPGTT support for Sandybdrige/Gen6 and later */
184 static void gen6_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
185 				   unsigned first_entry,
186 				   unsigned num_entries)
187 {
188 	gen6_gtt_pte_t *pt_vaddr, scratch_pte;
189 	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
190 	unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
191 	unsigned last_pte, i;
192 
193 	scratch_pte = ppgtt->pte_encode(ppgtt->dev,
194 					ppgtt->scratch_page_dma_addr,
195 					I915_CACHE_LLC);
196 
197 	while (num_entries) {
198 		last_pte = first_pte + num_entries;
199 		if (last_pte > I915_PPGTT_PT_ENTRIES)
200 			last_pte = I915_PPGTT_PT_ENTRIES;
201 
202 		pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
203 
204 		for (i = first_pte; i < last_pte; i++)
205 			pt_vaddr[i] = scratch_pte;
206 
207 		kunmap_atomic(pt_vaddr);
208 
209 		num_entries -= last_pte - first_pte;
210 		first_pte = 0;
211 		act_pt++;
212 	}
213 }
214 
215 static void gen6_ppgtt_insert_entries(struct i915_hw_ppgtt *ppgtt,
216 				      struct sg_table *pages,
217 				      unsigned first_entry,
218 				      enum i915_cache_level cache_level)
219 {
220 	gen6_gtt_pte_t *pt_vaddr;
221 	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
222 	unsigned act_pte = first_entry % I915_PPGTT_PT_ENTRIES;
223 	struct sg_page_iter sg_iter;
224 
225 	pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
226 	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
227 		dma_addr_t page_addr;
228 
229 		page_addr = sg_page_iter_dma_address(&sg_iter);
230 		pt_vaddr[act_pte] = ppgtt->pte_encode(ppgtt->dev, page_addr,
231 						      cache_level);
232 		if (++act_pte == I915_PPGTT_PT_ENTRIES) {
233 			kunmap_atomic(pt_vaddr);
234 			act_pt++;
235 			pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
236 			act_pte = 0;
237 
238 		}
239 	}
240 	kunmap_atomic(pt_vaddr);
241 }
242 
243 static void gen6_ppgtt_cleanup(struct i915_hw_ppgtt *ppgtt)
244 {
245 	int i;
246 
247 	if (ppgtt->pt_dma_addr) {
248 		for (i = 0; i < ppgtt->num_pd_entries; i++)
249 			pci_unmap_page(ppgtt->dev->pdev,
250 				       ppgtt->pt_dma_addr[i],
251 				       4096, PCI_DMA_BIDIRECTIONAL);
252 	}
253 
254 	kfree(ppgtt->pt_dma_addr);
255 	for (i = 0; i < ppgtt->num_pd_entries; i++)
256 		__free_page(ppgtt->pt_pages[i]);
257 	kfree(ppgtt->pt_pages);
258 	kfree(ppgtt);
259 }
260 
261 static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
262 {
263 	struct drm_device *dev = ppgtt->dev;
264 	struct drm_i915_private *dev_priv = dev->dev_private;
265 	unsigned first_pd_entry_in_global_pt;
266 	int i;
267 	int ret = -ENOMEM;
268 
269 	/* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
270 	 * entries. For aliasing ppgtt support we just steal them at the end for
271 	 * now. */
272 	first_pd_entry_in_global_pt = gtt_total_entries(dev_priv->gtt);
273 
274 	if (IS_HASWELL(dev)) {
275 		ppgtt->pte_encode = hsw_pte_encode;
276 	} else if (IS_VALLEYVIEW(dev)) {
277 		ppgtt->pte_encode = byt_pte_encode;
278 	} else {
279 		ppgtt->pte_encode = gen6_pte_encode;
280 	}
281 	ppgtt->num_pd_entries = I915_PPGTT_PD_ENTRIES;
282 	ppgtt->enable = gen6_ppgtt_enable;
283 	ppgtt->clear_range = gen6_ppgtt_clear_range;
284 	ppgtt->insert_entries = gen6_ppgtt_insert_entries;
285 	ppgtt->cleanup = gen6_ppgtt_cleanup;
286 	ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
287 				  GFP_KERNEL);
288 	if (!ppgtt->pt_pages)
289 		return -ENOMEM;
290 
291 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
292 		ppgtt->pt_pages[i] = alloc_page(GFP_KERNEL);
293 		if (!ppgtt->pt_pages[i])
294 			goto err_pt_alloc;
295 	}
296 
297 	ppgtt->pt_dma_addr = kzalloc(sizeof(dma_addr_t) *ppgtt->num_pd_entries,
298 				     GFP_KERNEL);
299 	if (!ppgtt->pt_dma_addr)
300 		goto err_pt_alloc;
301 
302 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
303 		dma_addr_t pt_addr;
304 
305 		pt_addr = pci_map_page(dev->pdev, ppgtt->pt_pages[i], 0, 4096,
306 				       PCI_DMA_BIDIRECTIONAL);
307 
308 		if (pci_dma_mapping_error(dev->pdev, pt_addr)) {
309 			ret = -EIO;
310 			goto err_pd_pin;
311 
312 		}
313 		ppgtt->pt_dma_addr[i] = pt_addr;
314 	}
315 
316 	ppgtt->clear_range(ppgtt, 0,
317 			   ppgtt->num_pd_entries*I915_PPGTT_PT_ENTRIES);
318 
319 	ppgtt->pd_offset = first_pd_entry_in_global_pt * sizeof(gen6_gtt_pte_t);
320 
321 	return 0;
322 
323 err_pd_pin:
324 	if (ppgtt->pt_dma_addr) {
325 		for (i--; i >= 0; i--)
326 			pci_unmap_page(dev->pdev, ppgtt->pt_dma_addr[i],
327 				       4096, PCI_DMA_BIDIRECTIONAL);
328 	}
329 err_pt_alloc:
330 	kfree(ppgtt->pt_dma_addr);
331 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
332 		if (ppgtt->pt_pages[i])
333 			__free_page(ppgtt->pt_pages[i]);
334 	}
335 	kfree(ppgtt->pt_pages);
336 
337 	return ret;
338 }
339 
340 static int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
341 {
342 	struct drm_i915_private *dev_priv = dev->dev_private;
343 	struct i915_hw_ppgtt *ppgtt;
344 	int ret;
345 
346 	ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
347 	if (!ppgtt)
348 		return -ENOMEM;
349 
350 	ppgtt->dev = dev;
351 	ppgtt->scratch_page_dma_addr = dev_priv->gtt.scratch_page_dma;
352 
353 	if (INTEL_INFO(dev)->gen < 8)
354 		ret = gen6_ppgtt_init(ppgtt);
355 	else
356 		BUG();
357 
358 	if (ret)
359 		kfree(ppgtt);
360 	else
361 		dev_priv->mm.aliasing_ppgtt = ppgtt;
362 
363 	return ret;
364 }
365 
366 void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev)
367 {
368 	struct drm_i915_private *dev_priv = dev->dev_private;
369 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
370 
371 	if (!ppgtt)
372 		return;
373 
374 	ppgtt->cleanup(ppgtt);
375 	dev_priv->mm.aliasing_ppgtt = NULL;
376 }
377 
378 void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
379 			    struct drm_i915_gem_object *obj,
380 			    enum i915_cache_level cache_level)
381 {
382 	ppgtt->insert_entries(ppgtt, obj->pages,
383 			      obj->gtt_space->start >> PAGE_SHIFT,
384 			      cache_level);
385 }
386 
387 void i915_ppgtt_unbind_object(struct i915_hw_ppgtt *ppgtt,
388 			      struct drm_i915_gem_object *obj)
389 {
390 	ppgtt->clear_range(ppgtt,
391 			   obj->gtt_space->start >> PAGE_SHIFT,
392 			   obj->base.size >> PAGE_SHIFT);
393 }
394 
395 extern int intel_iommu_gfx_mapped;
396 /* Certain Gen5 chipsets require require idling the GPU before
397  * unmapping anything from the GTT when VT-d is enabled.
398  */
399 static inline bool needs_idle_maps(struct drm_device *dev)
400 {
401 #ifdef CONFIG_INTEL_IOMMU
402 	/* Query intel_iommu to see if we need the workaround. Presumably that
403 	 * was loaded first.
404 	 */
405 	if (IS_GEN5(dev) && IS_MOBILE(dev) && intel_iommu_gfx_mapped)
406 		return true;
407 #endif
408 	return false;
409 }
410 
411 static bool do_idling(struct drm_i915_private *dev_priv)
412 {
413 	bool ret = dev_priv->mm.interruptible;
414 
415 	if (unlikely(dev_priv->gtt.do_idle_maps)) {
416 		dev_priv->mm.interruptible = false;
417 		if (i915_gpu_idle(dev_priv->dev)) {
418 			DRM_ERROR("Couldn't idle GPU\n");
419 			/* Wait a bit, in hopes it avoids the hang */
420 			udelay(10);
421 		}
422 	}
423 
424 	return ret;
425 }
426 
427 static void undo_idling(struct drm_i915_private *dev_priv, bool interruptible)
428 {
429 	if (unlikely(dev_priv->gtt.do_idle_maps))
430 		dev_priv->mm.interruptible = interruptible;
431 }
432 
433 void i915_gem_restore_gtt_mappings(struct drm_device *dev)
434 {
435 	struct drm_i915_private *dev_priv = dev->dev_private;
436 	struct drm_i915_gem_object *obj;
437 
438 	/* First fill our portion of the GTT with scratch pages */
439 	dev_priv->gtt.gtt_clear_range(dev, dev_priv->gtt.start / PAGE_SIZE,
440 				      dev_priv->gtt.total / PAGE_SIZE);
441 
442 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
443 		i915_gem_clflush_object(obj);
444 		i915_gem_gtt_bind_object(obj, obj->cache_level);
445 	}
446 
447 	i915_gem_chipset_flush(dev);
448 }
449 
450 int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
451 {
452 	if (obj->has_dma_mapping)
453 		return 0;
454 
455 	if (!dma_map_sg(&obj->base.dev->pdev->dev,
456 			obj->pages->sgl, obj->pages->nents,
457 			PCI_DMA_BIDIRECTIONAL))
458 		return -ENOSPC;
459 
460 	return 0;
461 }
462 
463 /*
464  * Binds an object into the global gtt with the specified cache level. The object
465  * will be accessible to the GPU via commands whose operands reference offsets
466  * within the global GTT as well as accessible by the GPU through the GMADR
467  * mapped BAR (dev_priv->mm.gtt->gtt).
468  */
469 static void gen6_ggtt_insert_entries(struct drm_device *dev,
470 				     struct sg_table *st,
471 				     unsigned int first_entry,
472 				     enum i915_cache_level level)
473 {
474 	struct drm_i915_private *dev_priv = dev->dev_private;
475 	gen6_gtt_pte_t __iomem *gtt_entries =
476 		(gen6_gtt_pte_t __iomem *)dev_priv->gtt.gsm + first_entry;
477 	int i = 0;
478 	struct sg_page_iter sg_iter;
479 	dma_addr_t addr;
480 
481 	for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) {
482 		addr = sg_page_iter_dma_address(&sg_iter);
483 		iowrite32(dev_priv->gtt.pte_encode(dev, addr, level),
484 			  &gtt_entries[i]);
485 		i++;
486 	}
487 
488 	/* XXX: This serves as a posting read to make sure that the PTE has
489 	 * actually been updated. There is some concern that even though
490 	 * registers and PTEs are within the same BAR that they are potentially
491 	 * of NUMA access patterns. Therefore, even with the way we assume
492 	 * hardware should work, we must keep this posting read for paranoia.
493 	 */
494 	if (i != 0)
495 		WARN_ON(readl(&gtt_entries[i-1])
496 			!= dev_priv->gtt.pte_encode(dev, addr, level));
497 
498 	/* This next bit makes the above posting read even more important. We
499 	 * want to flush the TLBs only after we're certain all the PTE updates
500 	 * have finished.
501 	 */
502 	I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
503 	POSTING_READ(GFX_FLSH_CNTL_GEN6);
504 }
505 
506 static void gen6_ggtt_clear_range(struct drm_device *dev,
507 				  unsigned int first_entry,
508 				  unsigned int num_entries)
509 {
510 	struct drm_i915_private *dev_priv = dev->dev_private;
511 	gen6_gtt_pte_t scratch_pte, __iomem *gtt_base =
512 		(gen6_gtt_pte_t __iomem *) dev_priv->gtt.gsm + first_entry;
513 	const int max_entries = gtt_total_entries(dev_priv->gtt) - first_entry;
514 	int i;
515 
516 	if (WARN(num_entries > max_entries,
517 		 "First entry = %d; Num entries = %d (max=%d)\n",
518 		 first_entry, num_entries, max_entries))
519 		num_entries = max_entries;
520 
521 	scratch_pte = dev_priv->gtt.pte_encode(dev,
522 					       dev_priv->gtt.scratch_page_dma,
523 					       I915_CACHE_LLC);
524 	for (i = 0; i < num_entries; i++)
525 		iowrite32(scratch_pte, &gtt_base[i]);
526 	readl(gtt_base);
527 }
528 
529 
530 static void i915_ggtt_insert_entries(struct drm_device *dev,
531 				     struct sg_table *st,
532 				     unsigned int pg_start,
533 				     enum i915_cache_level cache_level)
534 {
535 	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
536 		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
537 
538 	intel_gtt_insert_sg_entries(st, pg_start, flags);
539 
540 }
541 
542 static void i915_ggtt_clear_range(struct drm_device *dev,
543 				  unsigned int first_entry,
544 				  unsigned int num_entries)
545 {
546 	intel_gtt_clear_range(first_entry, num_entries);
547 }
548 
549 
550 void i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj,
551 			      enum i915_cache_level cache_level)
552 {
553 	struct drm_device *dev = obj->base.dev;
554 	struct drm_i915_private *dev_priv = dev->dev_private;
555 
556 	dev_priv->gtt.gtt_insert_entries(dev, obj->pages,
557 					 obj->gtt_space->start >> PAGE_SHIFT,
558 					 cache_level);
559 
560 	obj->has_global_gtt_mapping = 1;
561 }
562 
563 void i915_gem_gtt_unbind_object(struct drm_i915_gem_object *obj)
564 {
565 	struct drm_device *dev = obj->base.dev;
566 	struct drm_i915_private *dev_priv = dev->dev_private;
567 
568 	dev_priv->gtt.gtt_clear_range(obj->base.dev,
569 				      obj->gtt_space->start >> PAGE_SHIFT,
570 				      obj->base.size >> PAGE_SHIFT);
571 
572 	obj->has_global_gtt_mapping = 0;
573 }
574 
575 void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
576 {
577 	struct drm_device *dev = obj->base.dev;
578 	struct drm_i915_private *dev_priv = dev->dev_private;
579 	bool interruptible;
580 
581 	interruptible = do_idling(dev_priv);
582 
583 	if (!obj->has_dma_mapping)
584 		dma_unmap_sg(&dev->pdev->dev,
585 			     obj->pages->sgl, obj->pages->nents,
586 			     PCI_DMA_BIDIRECTIONAL);
587 
588 	undo_idling(dev_priv, interruptible);
589 }
590 
591 static void i915_gtt_color_adjust(struct drm_mm_node *node,
592 				  unsigned long color,
593 				  unsigned long *start,
594 				  unsigned long *end)
595 {
596 	if (node->color != color)
597 		*start += 4096;
598 
599 	if (!list_empty(&node->node_list)) {
600 		node = list_entry(node->node_list.next,
601 				  struct drm_mm_node,
602 				  node_list);
603 		if (node->allocated && node->color != color)
604 			*end -= 4096;
605 	}
606 }
607 void i915_gem_setup_global_gtt(struct drm_device *dev,
608 			       unsigned long start,
609 			       unsigned long mappable_end,
610 			       unsigned long end)
611 {
612 	/* Let GEM Manage all of the aperture.
613 	 *
614 	 * However, leave one page at the end still bound to the scratch page.
615 	 * There are a number of places where the hardware apparently prefetches
616 	 * past the end of the object, and we've seen multiple hangs with the
617 	 * GPU head pointer stuck in a batchbuffer bound at the last page of the
618 	 * aperture.  One page should be enough to keep any prefetching inside
619 	 * of the aperture.
620 	 */
621 	drm_i915_private_t *dev_priv = dev->dev_private;
622 	struct drm_mm_node *entry;
623 	struct drm_i915_gem_object *obj;
624 	unsigned long hole_start, hole_end;
625 
626 	BUG_ON(mappable_end > end);
627 
628 	/* Subtract the guard page ... */
629 	drm_mm_init(&dev_priv->mm.gtt_space, start, end - start - PAGE_SIZE);
630 	if (!HAS_LLC(dev))
631 		dev_priv->mm.gtt_space.color_adjust = i915_gtt_color_adjust;
632 
633 	/* Mark any preallocated objects as occupied */
634 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
635 		DRM_DEBUG_KMS("reserving preallocated space: %x + %zx\n",
636 			      obj->gtt_offset, obj->base.size);
637 
638 		BUG_ON(obj->gtt_space != I915_GTT_RESERVED);
639 		obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
640 						     obj->gtt_offset,
641 						     obj->base.size,
642 						     false);
643 		obj->has_global_gtt_mapping = 1;
644 	}
645 
646 	dev_priv->gtt.start = start;
647 	dev_priv->gtt.total = end - start;
648 
649 	/* Clear any non-preallocated blocks */
650 	drm_mm_for_each_hole(entry, &dev_priv->mm.gtt_space,
651 			     hole_start, hole_end) {
652 		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
653 			      hole_start, hole_end);
654 		dev_priv->gtt.gtt_clear_range(dev, hole_start / PAGE_SIZE,
655 					      (hole_end-hole_start) / PAGE_SIZE);
656 	}
657 
658 	/* And finally clear the reserved guard page */
659 	dev_priv->gtt.gtt_clear_range(dev, end / PAGE_SIZE - 1, 1);
660 }
661 
662 static bool
663 intel_enable_ppgtt(struct drm_device *dev)
664 {
665 	if (i915_enable_ppgtt >= 0)
666 		return i915_enable_ppgtt;
667 
668 #ifdef CONFIG_INTEL_IOMMU
669 	/* Disable ppgtt on SNB if VT-d is on. */
670 	if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped)
671 		return false;
672 #endif
673 
674 	return true;
675 }
676 
677 void i915_gem_init_global_gtt(struct drm_device *dev)
678 {
679 	struct drm_i915_private *dev_priv = dev->dev_private;
680 	unsigned long gtt_size, mappable_size;
681 
682 	gtt_size = dev_priv->gtt.total;
683 	mappable_size = dev_priv->gtt.mappable_end;
684 
685 	if (intel_enable_ppgtt(dev) && HAS_ALIASING_PPGTT(dev)) {
686 		int ret;
687 
688 		if (INTEL_INFO(dev)->gen <= 7) {
689 			/* PPGTT pdes are stolen from global gtt ptes, so shrink the
690 			 * aperture accordingly when using aliasing ppgtt. */
691 			gtt_size -= I915_PPGTT_PD_ENTRIES*PAGE_SIZE;
692 		}
693 
694 		i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
695 
696 		ret = i915_gem_init_aliasing_ppgtt(dev);
697 		if (!ret)
698 			return;
699 
700 		DRM_ERROR("Aliased PPGTT setup failed %d\n", ret);
701 		drm_mm_takedown(&dev_priv->mm.gtt_space);
702 		gtt_size += I915_PPGTT_PD_ENTRIES*PAGE_SIZE;
703 	}
704 	i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
705 }
706 
707 static int setup_scratch_page(struct drm_device *dev)
708 {
709 	struct drm_i915_private *dev_priv = dev->dev_private;
710 	struct page *page;
711 	dma_addr_t dma_addr;
712 
713 	page = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
714 	if (page == NULL)
715 		return -ENOMEM;
716 	get_page(page);
717 	set_pages_uc(page, 1);
718 
719 #ifdef CONFIG_INTEL_IOMMU
720 	dma_addr = pci_map_page(dev->pdev, page, 0, PAGE_SIZE,
721 				PCI_DMA_BIDIRECTIONAL);
722 	if (pci_dma_mapping_error(dev->pdev, dma_addr))
723 		return -EINVAL;
724 #else
725 	dma_addr = page_to_phys(page);
726 #endif
727 	dev_priv->gtt.scratch_page = page;
728 	dev_priv->gtt.scratch_page_dma = dma_addr;
729 
730 	return 0;
731 }
732 
733 static void teardown_scratch_page(struct drm_device *dev)
734 {
735 	struct drm_i915_private *dev_priv = dev->dev_private;
736 	set_pages_wb(dev_priv->gtt.scratch_page, 1);
737 	pci_unmap_page(dev->pdev, dev_priv->gtt.scratch_page_dma,
738 		       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
739 	put_page(dev_priv->gtt.scratch_page);
740 	__free_page(dev_priv->gtt.scratch_page);
741 }
742 
743 static inline unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
744 {
745 	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
746 	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
747 	return snb_gmch_ctl << 20;
748 }
749 
750 static inline size_t gen6_get_stolen_size(u16 snb_gmch_ctl)
751 {
752 	snb_gmch_ctl >>= SNB_GMCH_GMS_SHIFT;
753 	snb_gmch_ctl &= SNB_GMCH_GMS_MASK;
754 	return snb_gmch_ctl << 25; /* 32 MB units */
755 }
756 
757 static int gen6_gmch_probe(struct drm_device *dev,
758 			   size_t *gtt_total,
759 			   size_t *stolen,
760 			   phys_addr_t *mappable_base,
761 			   unsigned long *mappable_end)
762 {
763 	struct drm_i915_private *dev_priv = dev->dev_private;
764 	phys_addr_t gtt_bus_addr;
765 	unsigned int gtt_size;
766 	u16 snb_gmch_ctl;
767 	int ret;
768 
769 	*mappable_base = pci_resource_start(dev->pdev, 2);
770 	*mappable_end = pci_resource_len(dev->pdev, 2);
771 
772 	/* 64/512MB is the current min/max we actually know of, but this is just
773 	 * a coarse sanity check.
774 	 */
775 	if ((*mappable_end < (64<<20) || (*mappable_end > (512<<20)))) {
776 		DRM_ERROR("Unknown GMADR size (%lx)\n",
777 			  dev_priv->gtt.mappable_end);
778 		return -ENXIO;
779 	}
780 
781 	if (!pci_set_dma_mask(dev->pdev, DMA_BIT_MASK(40)))
782 		pci_set_consistent_dma_mask(dev->pdev, DMA_BIT_MASK(40));
783 	pci_read_config_word(dev->pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
784 	gtt_size = gen6_get_total_gtt_size(snb_gmch_ctl);
785 
786 	*stolen = gen6_get_stolen_size(snb_gmch_ctl);
787 	*gtt_total = (gtt_size / sizeof(gen6_gtt_pte_t)) << PAGE_SHIFT;
788 
789 	/* For Modern GENs the PTEs and register space are split in the BAR */
790 	gtt_bus_addr = pci_resource_start(dev->pdev, 0) +
791 		(pci_resource_len(dev->pdev, 0) / 2);
792 
793 	dev_priv->gtt.gsm = ioremap_wc(gtt_bus_addr, gtt_size);
794 	if (!dev_priv->gtt.gsm) {
795 		DRM_ERROR("Failed to map the gtt page table\n");
796 		return -ENOMEM;
797 	}
798 
799 	ret = setup_scratch_page(dev);
800 	if (ret)
801 		DRM_ERROR("Scratch setup failed\n");
802 
803 	dev_priv->gtt.gtt_clear_range = gen6_ggtt_clear_range;
804 	dev_priv->gtt.gtt_insert_entries = gen6_ggtt_insert_entries;
805 
806 	return ret;
807 }
808 
809 static void gen6_gmch_remove(struct drm_device *dev)
810 {
811 	struct drm_i915_private *dev_priv = dev->dev_private;
812 	iounmap(dev_priv->gtt.gsm);
813 	teardown_scratch_page(dev_priv->dev);
814 }
815 
816 static int i915_gmch_probe(struct drm_device *dev,
817 			   size_t *gtt_total,
818 			   size_t *stolen,
819 			   phys_addr_t *mappable_base,
820 			   unsigned long *mappable_end)
821 {
822 	struct drm_i915_private *dev_priv = dev->dev_private;
823 	int ret;
824 
825 	ret = intel_gmch_probe(dev_priv->bridge_dev, dev_priv->dev->pdev, NULL);
826 	if (!ret) {
827 		DRM_ERROR("failed to set up gmch\n");
828 		return -EIO;
829 	}
830 
831 	intel_gtt_get(gtt_total, stolen, mappable_base, mappable_end);
832 
833 	dev_priv->gtt.do_idle_maps = needs_idle_maps(dev_priv->dev);
834 	dev_priv->gtt.gtt_clear_range = i915_ggtt_clear_range;
835 	dev_priv->gtt.gtt_insert_entries = i915_ggtt_insert_entries;
836 
837 	return 0;
838 }
839 
840 static void i915_gmch_remove(struct drm_device *dev)
841 {
842 	intel_gmch_remove();
843 }
844 
845 int i915_gem_gtt_init(struct drm_device *dev)
846 {
847 	struct drm_i915_private *dev_priv = dev->dev_private;
848 	struct i915_gtt *gtt = &dev_priv->gtt;
849 	int ret;
850 
851 	if (INTEL_INFO(dev)->gen <= 5) {
852 		dev_priv->gtt.gtt_probe = i915_gmch_probe;
853 		dev_priv->gtt.gtt_remove = i915_gmch_remove;
854 	} else {
855 		dev_priv->gtt.gtt_probe = gen6_gmch_probe;
856 		dev_priv->gtt.gtt_remove = gen6_gmch_remove;
857 		if (IS_HASWELL(dev)) {
858 			dev_priv->gtt.pte_encode = hsw_pte_encode;
859 		} else if (IS_VALLEYVIEW(dev)) {
860 			dev_priv->gtt.pte_encode = byt_pte_encode;
861 		} else {
862 			dev_priv->gtt.pte_encode = gen6_pte_encode;
863 		}
864 	}
865 
866 	ret = dev_priv->gtt.gtt_probe(dev, &dev_priv->gtt.total,
867 				     &dev_priv->gtt.stolen_size,
868 				     &gtt->mappable_base,
869 				     &gtt->mappable_end);
870 	if (ret)
871 		return ret;
872 
873 	/* GMADR is the PCI mmio aperture into the global GTT. */
874 	DRM_INFO("Memory usable by graphics device = %zdM\n",
875 		 dev_priv->gtt.total >> 20);
876 	DRM_DEBUG_DRIVER("GMADR size = %ldM\n",
877 			 dev_priv->gtt.mappable_end >> 20);
878 	DRM_DEBUG_DRIVER("GTT stolen size = %zdM\n",
879 			 dev_priv->gtt.stolen_size >> 20);
880 
881 	return 0;
882 }
883