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 typedef uint32_t gen6_gtt_pte_t;
32 
33 /* PPGTT stuff */
34 #define GEN6_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0xff0))
35 
36 #define GEN6_PDE_VALID			(1 << 0)
37 /* gen6+ has bit 11-4 for physical addr bit 39-32 */
38 #define GEN6_PDE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
39 
40 #define GEN6_PTE_VALID			(1 << 0)
41 #define GEN6_PTE_UNCACHED		(1 << 1)
42 #define HSW_PTE_UNCACHED		(0)
43 #define GEN6_PTE_CACHE_LLC		(2 << 1)
44 #define GEN6_PTE_CACHE_LLC_MLC		(3 << 1)
45 #define GEN6_PTE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
46 
47 static inline gen6_gtt_pte_t gen6_pte_encode(struct drm_device *dev,
48 					     dma_addr_t addr,
49 					     enum i915_cache_level level)
50 {
51 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
52 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
53 
54 	switch (level) {
55 	case I915_CACHE_LLC_MLC:
56 		/* Haswell doesn't set L3 this way */
57 		if (IS_HASWELL(dev))
58 			pte |= GEN6_PTE_CACHE_LLC;
59 		else
60 			pte |= GEN6_PTE_CACHE_LLC_MLC;
61 		break;
62 	case I915_CACHE_LLC:
63 		pte |= GEN6_PTE_CACHE_LLC;
64 		break;
65 	case I915_CACHE_NONE:
66 		if (IS_HASWELL(dev))
67 			pte |= HSW_PTE_UNCACHED;
68 		else
69 			pte |= GEN6_PTE_UNCACHED;
70 		break;
71 	default:
72 		BUG();
73 	}
74 
75 	return pte;
76 }
77 
78 static int gen6_ppgtt_enable(struct drm_device *dev)
79 {
80 	drm_i915_private_t *dev_priv = dev->dev_private;
81 	uint32_t pd_offset;
82 	struct intel_ring_buffer *ring;
83 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
84 	gen6_gtt_pte_t __iomem *pd_addr;
85 	uint32_t pd_entry;
86 	int i;
87 
88 	pd_addr = (gen6_gtt_pte_t __iomem*)dev_priv->gtt.gsm +
89 		ppgtt->pd_offset / sizeof(gen6_gtt_pte_t);
90 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
91 		dma_addr_t pt_addr;
92 
93 		pt_addr = ppgtt->pt_dma_addr[i];
94 		pd_entry = GEN6_PDE_ADDR_ENCODE(pt_addr);
95 		pd_entry |= GEN6_PDE_VALID;
96 
97 		writel(pd_entry, pd_addr + i);
98 	}
99 	readl(pd_addr);
100 
101 	pd_offset = ppgtt->pd_offset;
102 	pd_offset /= 64; /* in cachelines, */
103 	pd_offset <<= 16;
104 
105 	if (INTEL_INFO(dev)->gen == 6) {
106 		uint32_t ecochk, gab_ctl, ecobits;
107 
108 		ecobits = I915_READ(GAC_ECO_BITS);
109 		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_SNB_BIT |
110 					 ECOBITS_PPGTT_CACHE64B);
111 
112 		gab_ctl = I915_READ(GAB_CTL);
113 		I915_WRITE(GAB_CTL, gab_ctl | GAB_CTL_CONT_AFTER_PAGEFAULT);
114 
115 		ecochk = I915_READ(GAM_ECOCHK);
116 		I915_WRITE(GAM_ECOCHK, ecochk | ECOCHK_SNB_BIT |
117 				       ECOCHK_PPGTT_CACHE64B);
118 		I915_WRITE(GFX_MODE, _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
119 	} else if (INTEL_INFO(dev)->gen >= 7) {
120 		uint32_t ecochk, ecobits;
121 
122 		ecobits = I915_READ(GAC_ECO_BITS);
123 		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_PPGTT_CACHE64B);
124 
125 		ecochk = I915_READ(GAM_ECOCHK);
126 		if (IS_HASWELL(dev)) {
127 			ecochk |= ECOCHK_PPGTT_WB_HSW;
128 		} else {
129 			ecochk |= ECOCHK_PPGTT_LLC_IVB;
130 			ecochk &= ~ECOCHK_PPGTT_GFDT_IVB;
131 		}
132 		I915_WRITE(GAM_ECOCHK, ecochk);
133 		/* GFX_MODE is per-ring on gen7+ */
134 	}
135 
136 	for_each_ring(ring, dev_priv, i) {
137 		if (INTEL_INFO(dev)->gen >= 7)
138 			I915_WRITE(RING_MODE_GEN7(ring),
139 				   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
140 
141 		I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
142 		I915_WRITE(RING_PP_DIR_BASE(ring), pd_offset);
143 	}
144 	return 0;
145 }
146 
147 /* PPGTT support for Sandybdrige/Gen6 and later */
148 static void gen6_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
149 				   unsigned first_entry,
150 				   unsigned num_entries)
151 {
152 	gen6_gtt_pte_t *pt_vaddr, scratch_pte;
153 	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
154 	unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
155 	unsigned last_pte, i;
156 
157 	scratch_pte = gen6_pte_encode(ppgtt->dev,
158 				      ppgtt->scratch_page_dma_addr,
159 				      I915_CACHE_LLC);
160 
161 	while (num_entries) {
162 		last_pte = first_pte + num_entries;
163 		if (last_pte > I915_PPGTT_PT_ENTRIES)
164 			last_pte = I915_PPGTT_PT_ENTRIES;
165 
166 		pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
167 
168 		for (i = first_pte; i < last_pte; i++)
169 			pt_vaddr[i] = scratch_pte;
170 
171 		kunmap_atomic(pt_vaddr);
172 
173 		num_entries -= last_pte - first_pte;
174 		first_pte = 0;
175 		act_pt++;
176 	}
177 }
178 
179 static void gen6_ppgtt_insert_entries(struct i915_hw_ppgtt *ppgtt,
180 				      struct sg_table *pages,
181 				      unsigned first_entry,
182 				      enum i915_cache_level cache_level)
183 {
184 	gen6_gtt_pte_t *pt_vaddr;
185 	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
186 	unsigned act_pte = first_entry % I915_PPGTT_PT_ENTRIES;
187 	struct sg_page_iter sg_iter;
188 
189 	pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
190 	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
191 		dma_addr_t page_addr;
192 
193 		page_addr = sg_page_iter_dma_address(&sg_iter);
194 		pt_vaddr[act_pte] = gen6_pte_encode(ppgtt->dev, page_addr,
195 						    cache_level);
196 		if (++act_pte == I915_PPGTT_PT_ENTRIES) {
197 			kunmap_atomic(pt_vaddr);
198 			act_pt++;
199 			pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
200 			act_pte = 0;
201 
202 		}
203 	}
204 	kunmap_atomic(pt_vaddr);
205 }
206 
207 static void gen6_ppgtt_cleanup(struct i915_hw_ppgtt *ppgtt)
208 {
209 	int i;
210 
211 	if (ppgtt->pt_dma_addr) {
212 		for (i = 0; i < ppgtt->num_pd_entries; i++)
213 			pci_unmap_page(ppgtt->dev->pdev,
214 				       ppgtt->pt_dma_addr[i],
215 				       4096, PCI_DMA_BIDIRECTIONAL);
216 	}
217 
218 	kfree(ppgtt->pt_dma_addr);
219 	for (i = 0; i < ppgtt->num_pd_entries; i++)
220 		__free_page(ppgtt->pt_pages[i]);
221 	kfree(ppgtt->pt_pages);
222 	kfree(ppgtt);
223 }
224 
225 static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
226 {
227 	struct drm_device *dev = ppgtt->dev;
228 	struct drm_i915_private *dev_priv = dev->dev_private;
229 	unsigned first_pd_entry_in_global_pt;
230 	int i;
231 	int ret = -ENOMEM;
232 
233 	/* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
234 	 * entries. For aliasing ppgtt support we just steal them at the end for
235 	 * now. */
236        first_pd_entry_in_global_pt = gtt_total_entries(dev_priv->gtt);
237 
238 	ppgtt->num_pd_entries = I915_PPGTT_PD_ENTRIES;
239 	ppgtt->enable = gen6_ppgtt_enable;
240 	ppgtt->clear_range = gen6_ppgtt_clear_range;
241 	ppgtt->insert_entries = gen6_ppgtt_insert_entries;
242 	ppgtt->cleanup = gen6_ppgtt_cleanup;
243 	ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
244 				  GFP_KERNEL);
245 	if (!ppgtt->pt_pages)
246 		return -ENOMEM;
247 
248 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
249 		ppgtt->pt_pages[i] = alloc_page(GFP_KERNEL);
250 		if (!ppgtt->pt_pages[i])
251 			goto err_pt_alloc;
252 	}
253 
254 	ppgtt->pt_dma_addr = kzalloc(sizeof(dma_addr_t) *ppgtt->num_pd_entries,
255 				     GFP_KERNEL);
256 	if (!ppgtt->pt_dma_addr)
257 		goto err_pt_alloc;
258 
259 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
260 		dma_addr_t pt_addr;
261 
262 		pt_addr = pci_map_page(dev->pdev, ppgtt->pt_pages[i], 0, 4096,
263 				       PCI_DMA_BIDIRECTIONAL);
264 
265 		if (pci_dma_mapping_error(dev->pdev, pt_addr)) {
266 			ret = -EIO;
267 			goto err_pd_pin;
268 
269 		}
270 		ppgtt->pt_dma_addr[i] = pt_addr;
271 	}
272 
273 	ppgtt->clear_range(ppgtt, 0,
274 			   ppgtt->num_pd_entries*I915_PPGTT_PT_ENTRIES);
275 
276 	ppgtt->pd_offset = first_pd_entry_in_global_pt * sizeof(gen6_gtt_pte_t);
277 
278 	return 0;
279 
280 err_pd_pin:
281 	if (ppgtt->pt_dma_addr) {
282 		for (i--; i >= 0; i--)
283 			pci_unmap_page(dev->pdev, ppgtt->pt_dma_addr[i],
284 				       4096, PCI_DMA_BIDIRECTIONAL);
285 	}
286 err_pt_alloc:
287 	kfree(ppgtt->pt_dma_addr);
288 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
289 		if (ppgtt->pt_pages[i])
290 			__free_page(ppgtt->pt_pages[i]);
291 	}
292 	kfree(ppgtt->pt_pages);
293 
294 	return ret;
295 }
296 
297 static int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
298 {
299 	struct drm_i915_private *dev_priv = dev->dev_private;
300 	struct i915_hw_ppgtt *ppgtt;
301 	int ret;
302 
303 	ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
304 	if (!ppgtt)
305 		return -ENOMEM;
306 
307 	ppgtt->dev = dev;
308 	ppgtt->scratch_page_dma_addr = dev_priv->gtt.scratch_page_dma;
309 
310 	if (INTEL_INFO(dev)->gen < 8)
311 		ret = gen6_ppgtt_init(ppgtt);
312 	else
313 		BUG();
314 
315 	if (ret)
316 		kfree(ppgtt);
317 	else
318 		dev_priv->mm.aliasing_ppgtt = ppgtt;
319 
320 	return ret;
321 }
322 
323 void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev)
324 {
325 	struct drm_i915_private *dev_priv = dev->dev_private;
326 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
327 
328 	if (!ppgtt)
329 		return;
330 
331 	ppgtt->cleanup(ppgtt);
332 	dev_priv->mm.aliasing_ppgtt = NULL;
333 }
334 
335 void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
336 			    struct drm_i915_gem_object *obj,
337 			    enum i915_cache_level cache_level)
338 {
339 	ppgtt->insert_entries(ppgtt, obj->pages,
340 			      obj->gtt_space->start >> PAGE_SHIFT,
341 			      cache_level);
342 }
343 
344 void i915_ppgtt_unbind_object(struct i915_hw_ppgtt *ppgtt,
345 			      struct drm_i915_gem_object *obj)
346 {
347 	ppgtt->clear_range(ppgtt,
348 			   obj->gtt_space->start >> PAGE_SHIFT,
349 			   obj->base.size >> PAGE_SHIFT);
350 }
351 
352 extern int intel_iommu_gfx_mapped;
353 /* Certain Gen5 chipsets require require idling the GPU before
354  * unmapping anything from the GTT when VT-d is enabled.
355  */
356 static inline bool needs_idle_maps(struct drm_device *dev)
357 {
358 #ifdef CONFIG_INTEL_IOMMU
359 	/* Query intel_iommu to see if we need the workaround. Presumably that
360 	 * was loaded first.
361 	 */
362 	if (IS_GEN5(dev) && IS_MOBILE(dev) && intel_iommu_gfx_mapped)
363 		return true;
364 #endif
365 	return false;
366 }
367 
368 static bool do_idling(struct drm_i915_private *dev_priv)
369 {
370 	bool ret = dev_priv->mm.interruptible;
371 
372 	if (unlikely(dev_priv->gtt.do_idle_maps)) {
373 		dev_priv->mm.interruptible = false;
374 		if (i915_gpu_idle(dev_priv->dev)) {
375 			DRM_ERROR("Couldn't idle GPU\n");
376 			/* Wait a bit, in hopes it avoids the hang */
377 			udelay(10);
378 		}
379 	}
380 
381 	return ret;
382 }
383 
384 static void undo_idling(struct drm_i915_private *dev_priv, bool interruptible)
385 {
386 	if (unlikely(dev_priv->gtt.do_idle_maps))
387 		dev_priv->mm.interruptible = interruptible;
388 }
389 
390 void i915_gem_restore_gtt_mappings(struct drm_device *dev)
391 {
392 	struct drm_i915_private *dev_priv = dev->dev_private;
393 	struct drm_i915_gem_object *obj;
394 
395 	/* First fill our portion of the GTT with scratch pages */
396 	dev_priv->gtt.gtt_clear_range(dev, dev_priv->gtt.start / PAGE_SIZE,
397 				      dev_priv->gtt.total / PAGE_SIZE);
398 
399 	list_for_each_entry(obj, &dev_priv->mm.bound_list, gtt_list) {
400 		i915_gem_clflush_object(obj);
401 		i915_gem_gtt_bind_object(obj, obj->cache_level);
402 	}
403 
404 	i915_gem_chipset_flush(dev);
405 }
406 
407 int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
408 {
409 	if (obj->has_dma_mapping)
410 		return 0;
411 
412 	if (!dma_map_sg(&obj->base.dev->pdev->dev,
413 			obj->pages->sgl, obj->pages->nents,
414 			PCI_DMA_BIDIRECTIONAL))
415 		return -ENOSPC;
416 
417 	return 0;
418 }
419 
420 /*
421  * Binds an object into the global gtt with the specified cache level. The object
422  * will be accessible to the GPU via commands whose operands reference offsets
423  * within the global GTT as well as accessible by the GPU through the GMADR
424  * mapped BAR (dev_priv->mm.gtt->gtt).
425  */
426 static void gen6_ggtt_insert_entries(struct drm_device *dev,
427 				     struct sg_table *st,
428 				     unsigned int first_entry,
429 				     enum i915_cache_level level)
430 {
431 	struct drm_i915_private *dev_priv = dev->dev_private;
432 	gen6_gtt_pte_t __iomem *gtt_entries =
433 		(gen6_gtt_pte_t __iomem *)dev_priv->gtt.gsm + first_entry;
434 	int i = 0;
435 	struct sg_page_iter sg_iter;
436 	dma_addr_t addr;
437 
438 	for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) {
439 		addr = sg_page_iter_dma_address(&sg_iter);
440 		iowrite32(gen6_pte_encode(dev, addr, level), &gtt_entries[i]);
441 		i++;
442 	}
443 
444 	/* XXX: This serves as a posting read to make sure that the PTE has
445 	 * actually been updated. There is some concern that even though
446 	 * registers and PTEs are within the same BAR that they are potentially
447 	 * of NUMA access patterns. Therefore, even with the way we assume
448 	 * hardware should work, we must keep this posting read for paranoia.
449 	 */
450 	if (i != 0)
451 		WARN_ON(readl(&gtt_entries[i-1])
452 			!= gen6_pte_encode(dev, addr, level));
453 
454 	/* This next bit makes the above posting read even more important. We
455 	 * want to flush the TLBs only after we're certain all the PTE updates
456 	 * have finished.
457 	 */
458 	I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
459 	POSTING_READ(GFX_FLSH_CNTL_GEN6);
460 }
461 
462 static void gen6_ggtt_clear_range(struct drm_device *dev,
463 				  unsigned int first_entry,
464 				  unsigned int num_entries)
465 {
466 	struct drm_i915_private *dev_priv = dev->dev_private;
467 	gen6_gtt_pte_t scratch_pte, __iomem *gtt_base =
468 		(gen6_gtt_pte_t __iomem *) dev_priv->gtt.gsm + first_entry;
469 	const int max_entries = gtt_total_entries(dev_priv->gtt) - first_entry;
470 	int i;
471 
472 	if (WARN(num_entries > max_entries,
473 		 "First entry = %d; Num entries = %d (max=%d)\n",
474 		 first_entry, num_entries, max_entries))
475 		num_entries = max_entries;
476 
477 	scratch_pte = gen6_pte_encode(dev, dev_priv->gtt.scratch_page_dma,
478 				      I915_CACHE_LLC);
479 	for (i = 0; i < num_entries; i++)
480 		iowrite32(scratch_pte, &gtt_base[i]);
481 	readl(gtt_base);
482 }
483 
484 
485 static void i915_ggtt_insert_entries(struct drm_device *dev,
486 				     struct sg_table *st,
487 				     unsigned int pg_start,
488 				     enum i915_cache_level cache_level)
489 {
490 	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
491 		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
492 
493 	intel_gtt_insert_sg_entries(st, pg_start, flags);
494 
495 }
496 
497 static void i915_ggtt_clear_range(struct drm_device *dev,
498 				  unsigned int first_entry,
499 				  unsigned int num_entries)
500 {
501 	intel_gtt_clear_range(first_entry, num_entries);
502 }
503 
504 
505 void i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj,
506 			      enum i915_cache_level cache_level)
507 {
508 	struct drm_device *dev = obj->base.dev;
509 	struct drm_i915_private *dev_priv = dev->dev_private;
510 
511 	dev_priv->gtt.gtt_insert_entries(dev, obj->pages,
512 					 obj->gtt_space->start >> PAGE_SHIFT,
513 					 cache_level);
514 
515 	obj->has_global_gtt_mapping = 1;
516 }
517 
518 void i915_gem_gtt_unbind_object(struct drm_i915_gem_object *obj)
519 {
520 	struct drm_device *dev = obj->base.dev;
521 	struct drm_i915_private *dev_priv = dev->dev_private;
522 
523 	dev_priv->gtt.gtt_clear_range(obj->base.dev,
524 				      obj->gtt_space->start >> PAGE_SHIFT,
525 				      obj->base.size >> PAGE_SHIFT);
526 
527 	obj->has_global_gtt_mapping = 0;
528 }
529 
530 void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
531 {
532 	struct drm_device *dev = obj->base.dev;
533 	struct drm_i915_private *dev_priv = dev->dev_private;
534 	bool interruptible;
535 
536 	interruptible = do_idling(dev_priv);
537 
538 	if (!obj->has_dma_mapping)
539 		dma_unmap_sg(&dev->pdev->dev,
540 			     obj->pages->sgl, obj->pages->nents,
541 			     PCI_DMA_BIDIRECTIONAL);
542 
543 	undo_idling(dev_priv, interruptible);
544 }
545 
546 static void i915_gtt_color_adjust(struct drm_mm_node *node,
547 				  unsigned long color,
548 				  unsigned long *start,
549 				  unsigned long *end)
550 {
551 	if (node->color != color)
552 		*start += 4096;
553 
554 	if (!list_empty(&node->node_list)) {
555 		node = list_entry(node->node_list.next,
556 				  struct drm_mm_node,
557 				  node_list);
558 		if (node->allocated && node->color != color)
559 			*end -= 4096;
560 	}
561 }
562 void i915_gem_setup_global_gtt(struct drm_device *dev,
563 			       unsigned long start,
564 			       unsigned long mappable_end,
565 			       unsigned long end)
566 {
567 	/* Let GEM Manage all of the aperture.
568 	 *
569 	 * However, leave one page at the end still bound to the scratch page.
570 	 * There are a number of places where the hardware apparently prefetches
571 	 * past the end of the object, and we've seen multiple hangs with the
572 	 * GPU head pointer stuck in a batchbuffer bound at the last page of the
573 	 * aperture.  One page should be enough to keep any prefetching inside
574 	 * of the aperture.
575 	 */
576 	drm_i915_private_t *dev_priv = dev->dev_private;
577 	struct drm_mm_node *entry;
578 	struct drm_i915_gem_object *obj;
579 	unsigned long hole_start, hole_end;
580 
581 	BUG_ON(mappable_end > end);
582 
583 	/* Subtract the guard page ... */
584 	drm_mm_init(&dev_priv->mm.gtt_space, start, end - start - PAGE_SIZE);
585 	if (!HAS_LLC(dev))
586 		dev_priv->mm.gtt_space.color_adjust = i915_gtt_color_adjust;
587 
588 	/* Mark any preallocated objects as occupied */
589 	list_for_each_entry(obj, &dev_priv->mm.bound_list, gtt_list) {
590 		DRM_DEBUG_KMS("reserving preallocated space: %x + %zx\n",
591 			      obj->gtt_offset, obj->base.size);
592 
593 		BUG_ON(obj->gtt_space != I915_GTT_RESERVED);
594 		obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
595 						     obj->gtt_offset,
596 						     obj->base.size,
597 						     false);
598 		obj->has_global_gtt_mapping = 1;
599 	}
600 
601 	dev_priv->gtt.start = start;
602 	dev_priv->gtt.total = end - start;
603 
604 	/* Clear any non-preallocated blocks */
605 	drm_mm_for_each_hole(entry, &dev_priv->mm.gtt_space,
606 			     hole_start, hole_end) {
607 		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
608 			      hole_start, hole_end);
609 		dev_priv->gtt.gtt_clear_range(dev, hole_start / PAGE_SIZE,
610 					      (hole_end-hole_start) / PAGE_SIZE);
611 	}
612 
613 	/* And finally clear the reserved guard page */
614 	dev_priv->gtt.gtt_clear_range(dev, end / PAGE_SIZE - 1, 1);
615 }
616 
617 static bool
618 intel_enable_ppgtt(struct drm_device *dev)
619 {
620 	if (i915_enable_ppgtt >= 0)
621 		return i915_enable_ppgtt;
622 
623 #ifdef CONFIG_INTEL_IOMMU
624 	/* Disable ppgtt on SNB if VT-d is on. */
625 	if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped)
626 		return false;
627 #endif
628 
629 	return true;
630 }
631 
632 void i915_gem_init_global_gtt(struct drm_device *dev)
633 {
634 	struct drm_i915_private *dev_priv = dev->dev_private;
635 	unsigned long gtt_size, mappable_size;
636 
637 	gtt_size = dev_priv->gtt.total;
638 	mappable_size = dev_priv->gtt.mappable_end;
639 
640 	if (intel_enable_ppgtt(dev) && HAS_ALIASING_PPGTT(dev)) {
641 		int ret;
642 
643 		if (INTEL_INFO(dev)->gen <= 7) {
644 			/* PPGTT pdes are stolen from global gtt ptes, so shrink the
645 			 * aperture accordingly when using aliasing ppgtt. */
646 			gtt_size -= I915_PPGTT_PD_ENTRIES*PAGE_SIZE;
647 		}
648 
649 		i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
650 
651 		ret = i915_gem_init_aliasing_ppgtt(dev);
652 		if (!ret)
653 			return;
654 
655 		DRM_ERROR("Aliased PPGTT setup failed %d\n", ret);
656 		drm_mm_takedown(&dev_priv->mm.gtt_space);
657 		gtt_size += I915_PPGTT_PD_ENTRIES*PAGE_SIZE;
658 	}
659 	i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
660 }
661 
662 static int setup_scratch_page(struct drm_device *dev)
663 {
664 	struct drm_i915_private *dev_priv = dev->dev_private;
665 	struct page *page;
666 	dma_addr_t dma_addr;
667 
668 	page = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
669 	if (page == NULL)
670 		return -ENOMEM;
671 	get_page(page);
672 	set_pages_uc(page, 1);
673 
674 #ifdef CONFIG_INTEL_IOMMU
675 	dma_addr = pci_map_page(dev->pdev, page, 0, PAGE_SIZE,
676 				PCI_DMA_BIDIRECTIONAL);
677 	if (pci_dma_mapping_error(dev->pdev, dma_addr))
678 		return -EINVAL;
679 #else
680 	dma_addr = page_to_phys(page);
681 #endif
682 	dev_priv->gtt.scratch_page = page;
683 	dev_priv->gtt.scratch_page_dma = dma_addr;
684 
685 	return 0;
686 }
687 
688 static void teardown_scratch_page(struct drm_device *dev)
689 {
690 	struct drm_i915_private *dev_priv = dev->dev_private;
691 	set_pages_wb(dev_priv->gtt.scratch_page, 1);
692 	pci_unmap_page(dev->pdev, dev_priv->gtt.scratch_page_dma,
693 		       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
694 	put_page(dev_priv->gtt.scratch_page);
695 	__free_page(dev_priv->gtt.scratch_page);
696 }
697 
698 static inline unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
699 {
700 	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
701 	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
702 	return snb_gmch_ctl << 20;
703 }
704 
705 static inline size_t gen6_get_stolen_size(u16 snb_gmch_ctl)
706 {
707 	snb_gmch_ctl >>= SNB_GMCH_GMS_SHIFT;
708 	snb_gmch_ctl &= SNB_GMCH_GMS_MASK;
709 	return snb_gmch_ctl << 25; /* 32 MB units */
710 }
711 
712 static inline size_t gen7_get_stolen_size(u16 snb_gmch_ctl)
713 {
714 	static const int stolen_decoder[] = {
715 		0, 0, 0, 0, 0, 32, 48, 64, 128, 256, 96, 160, 224, 352};
716 	snb_gmch_ctl >>= IVB_GMCH_GMS_SHIFT;
717 	snb_gmch_ctl &= IVB_GMCH_GMS_MASK;
718 	return stolen_decoder[snb_gmch_ctl] << 20;
719 }
720 
721 static int gen6_gmch_probe(struct drm_device *dev,
722 			   size_t *gtt_total,
723 			   size_t *stolen,
724 			   phys_addr_t *mappable_base,
725 			   unsigned long *mappable_end)
726 {
727 	struct drm_i915_private *dev_priv = dev->dev_private;
728 	phys_addr_t gtt_bus_addr;
729 	unsigned int gtt_size;
730 	u16 snb_gmch_ctl;
731 	int ret;
732 
733 	*mappable_base = pci_resource_start(dev->pdev, 2);
734 	*mappable_end = pci_resource_len(dev->pdev, 2);
735 
736 	/* 64/512MB is the current min/max we actually know of, but this is just
737 	 * a coarse sanity check.
738 	 */
739 	if ((*mappable_end < (64<<20) || (*mappable_end > (512<<20)))) {
740 		DRM_ERROR("Unknown GMADR size (%lx)\n",
741 			  dev_priv->gtt.mappable_end);
742 		return -ENXIO;
743 	}
744 
745 	if (!pci_set_dma_mask(dev->pdev, DMA_BIT_MASK(40)))
746 		pci_set_consistent_dma_mask(dev->pdev, DMA_BIT_MASK(40));
747 	pci_read_config_word(dev->pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
748 	gtt_size = gen6_get_total_gtt_size(snb_gmch_ctl);
749 
750 	if (IS_GEN7(dev) && !IS_VALLEYVIEW(dev))
751 		*stolen = gen7_get_stolen_size(snb_gmch_ctl);
752 	else
753 		*stolen = gen6_get_stolen_size(snb_gmch_ctl);
754 
755 	*gtt_total = (gtt_size / sizeof(gen6_gtt_pte_t)) << PAGE_SHIFT;
756 
757 	/* For Modern GENs the PTEs and register space are split in the BAR */
758 	gtt_bus_addr = pci_resource_start(dev->pdev, 0) +
759 		(pci_resource_len(dev->pdev, 0) / 2);
760 
761 	dev_priv->gtt.gsm = ioremap_wc(gtt_bus_addr, gtt_size);
762 	if (!dev_priv->gtt.gsm) {
763 		DRM_ERROR("Failed to map the gtt page table\n");
764 		return -ENOMEM;
765 	}
766 
767 	ret = setup_scratch_page(dev);
768 	if (ret)
769 		DRM_ERROR("Scratch setup failed\n");
770 
771 	dev_priv->gtt.gtt_clear_range = gen6_ggtt_clear_range;
772 	dev_priv->gtt.gtt_insert_entries = gen6_ggtt_insert_entries;
773 
774 	return ret;
775 }
776 
777 static void gen6_gmch_remove(struct drm_device *dev)
778 {
779 	struct drm_i915_private *dev_priv = dev->dev_private;
780 	iounmap(dev_priv->gtt.gsm);
781 	teardown_scratch_page(dev_priv->dev);
782 }
783 
784 static int i915_gmch_probe(struct drm_device *dev,
785 			   size_t *gtt_total,
786 			   size_t *stolen,
787 			   phys_addr_t *mappable_base,
788 			   unsigned long *mappable_end)
789 {
790 	struct drm_i915_private *dev_priv = dev->dev_private;
791 	int ret;
792 
793 	ret = intel_gmch_probe(dev_priv->bridge_dev, dev_priv->dev->pdev, NULL);
794 	if (!ret) {
795 		DRM_ERROR("failed to set up gmch\n");
796 		return -EIO;
797 	}
798 
799 	intel_gtt_get(gtt_total, stolen, mappable_base, mappable_end);
800 
801 	dev_priv->gtt.do_idle_maps = needs_idle_maps(dev_priv->dev);
802 	dev_priv->gtt.gtt_clear_range = i915_ggtt_clear_range;
803 	dev_priv->gtt.gtt_insert_entries = i915_ggtt_insert_entries;
804 
805 	return 0;
806 }
807 
808 static void i915_gmch_remove(struct drm_device *dev)
809 {
810 	intel_gmch_remove();
811 }
812 
813 int i915_gem_gtt_init(struct drm_device *dev)
814 {
815 	struct drm_i915_private *dev_priv = dev->dev_private;
816 	struct i915_gtt *gtt = &dev_priv->gtt;
817 	int ret;
818 
819 	if (INTEL_INFO(dev)->gen <= 5) {
820 		dev_priv->gtt.gtt_probe = i915_gmch_probe;
821 		dev_priv->gtt.gtt_remove = i915_gmch_remove;
822 	} else {
823 		dev_priv->gtt.gtt_probe = gen6_gmch_probe;
824 		dev_priv->gtt.gtt_remove = gen6_gmch_remove;
825 	}
826 
827 	ret = dev_priv->gtt.gtt_probe(dev, &dev_priv->gtt.total,
828 				     &dev_priv->gtt.stolen_size,
829 				     &gtt->mappable_base,
830 				     &gtt->mappable_end);
831 	if (ret)
832 		return ret;
833 
834 	/* GMADR is the PCI mmio aperture into the global GTT. */
835 	DRM_INFO("Memory usable by graphics device = %zdM\n",
836 		 dev_priv->gtt.total >> 20);
837 	DRM_DEBUG_DRIVER("GMADR size = %ldM\n",
838 			 dev_priv->gtt.mappable_end >> 20);
839 	DRM_DEBUG_DRIVER("GTT stolen size = %zdM\n",
840 			 dev_priv->gtt.stolen_size >> 20);
841 
842 	return 0;
843 }
844