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 #define GEN6_PPGTT_PD_ENTRIES 512
32 #define I915_PPGTT_PT_ENTRIES (PAGE_SIZE / sizeof(gen6_gtt_pte_t))
33 
34 /* PPGTT stuff */
35 #define GEN6_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0xff0))
36 #define HSW_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0x7f0))
37 
38 #define GEN6_PDE_VALID			(1 << 0)
39 /* gen6+ has bit 11-4 for physical addr bit 39-32 */
40 #define GEN6_PDE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
41 
42 #define GEN6_PTE_VALID			(1 << 0)
43 #define GEN6_PTE_UNCACHED		(1 << 1)
44 #define HSW_PTE_UNCACHED		(0)
45 #define GEN6_PTE_CACHE_LLC		(2 << 1)
46 #define GEN7_PTE_CACHE_L3_LLC		(3 << 1)
47 #define GEN6_PTE_ADDR_ENCODE(addr)	GEN6_GTT_ADDR_ENCODE(addr)
48 #define HSW_PTE_ADDR_ENCODE(addr)	HSW_GTT_ADDR_ENCODE(addr)
49 
50 /* Cacheability Control is a 4-bit value. The low three bits are stored in *
51  * bits 3:1 of the PTE, while the fourth bit is stored in bit 11 of the PTE.
52  */
53 #define HSW_CACHEABILITY_CONTROL(bits)	((((bits) & 0x7) << 1) | \
54 					 (((bits) & 0x8) << (11 - 3)))
55 #define HSW_WB_LLC_AGE3			HSW_CACHEABILITY_CONTROL(0x2)
56 #define HSW_WB_LLC_AGE0			HSW_CACHEABILITY_CONTROL(0x3)
57 #define HSW_WB_ELLC_LLC_AGE0		HSW_CACHEABILITY_CONTROL(0xb)
58 #define HSW_WT_ELLC_LLC_AGE0		HSW_CACHEABILITY_CONTROL(0x6)
59 
60 static gen6_gtt_pte_t snb_pte_encode(dma_addr_t addr,
61 				     enum i915_cache_level level,
62 				     bool valid)
63 {
64 	gen6_gtt_pte_t pte = valid ? GEN6_PTE_VALID : 0;
65 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
66 
67 	switch (level) {
68 	case I915_CACHE_L3_LLC:
69 	case I915_CACHE_LLC:
70 		pte |= GEN6_PTE_CACHE_LLC;
71 		break;
72 	case I915_CACHE_NONE:
73 		pte |= GEN6_PTE_UNCACHED;
74 		break;
75 	default:
76 		WARN_ON(1);
77 	}
78 
79 	return pte;
80 }
81 
82 static gen6_gtt_pte_t ivb_pte_encode(dma_addr_t addr,
83 				     enum i915_cache_level level,
84 				     bool valid)
85 {
86 	gen6_gtt_pte_t pte = valid ? GEN6_PTE_VALID : 0;
87 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
88 
89 	switch (level) {
90 	case I915_CACHE_L3_LLC:
91 		pte |= GEN7_PTE_CACHE_L3_LLC;
92 		break;
93 	case I915_CACHE_LLC:
94 		pte |= GEN6_PTE_CACHE_LLC;
95 		break;
96 	case I915_CACHE_NONE:
97 		pte |= GEN6_PTE_UNCACHED;
98 		break;
99 	default:
100 		WARN_ON(1);
101 	}
102 
103 	return pte;
104 }
105 
106 #define BYT_PTE_WRITEABLE		(1 << 1)
107 #define BYT_PTE_SNOOPED_BY_CPU_CACHES	(1 << 2)
108 
109 static gen6_gtt_pte_t byt_pte_encode(dma_addr_t addr,
110 				     enum i915_cache_level level,
111 				     bool valid)
112 {
113 	gen6_gtt_pte_t pte = valid ? GEN6_PTE_VALID : 0;
114 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
115 
116 	/* Mark the page as writeable.  Other platforms don't have a
117 	 * setting for read-only/writable, so this matches that behavior.
118 	 */
119 	pte |= BYT_PTE_WRITEABLE;
120 
121 	if (level != I915_CACHE_NONE)
122 		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
123 
124 	return pte;
125 }
126 
127 static gen6_gtt_pte_t hsw_pte_encode(dma_addr_t addr,
128 				     enum i915_cache_level level,
129 				     bool valid)
130 {
131 	gen6_gtt_pte_t pte = valid ? GEN6_PTE_VALID : 0;
132 	pte |= HSW_PTE_ADDR_ENCODE(addr);
133 
134 	if (level != I915_CACHE_NONE)
135 		pte |= HSW_WB_LLC_AGE3;
136 
137 	return pte;
138 }
139 
140 static gen6_gtt_pte_t iris_pte_encode(dma_addr_t addr,
141 				      enum i915_cache_level level,
142 				      bool valid)
143 {
144 	gen6_gtt_pte_t pte = valid ? GEN6_PTE_VALID : 0;
145 	pte |= HSW_PTE_ADDR_ENCODE(addr);
146 
147 	switch (level) {
148 	case I915_CACHE_NONE:
149 		break;
150 	case I915_CACHE_WT:
151 		pte |= HSW_WT_ELLC_LLC_AGE0;
152 		break;
153 	default:
154 		pte |= HSW_WB_ELLC_LLC_AGE0;
155 		break;
156 	}
157 
158 	return pte;
159 }
160 
161 static void gen6_write_pdes(struct i915_hw_ppgtt *ppgtt)
162 {
163 	struct drm_i915_private *dev_priv = ppgtt->base.dev->dev_private;
164 	gen6_gtt_pte_t __iomem *pd_addr;
165 	uint32_t pd_entry;
166 	int i;
167 
168 	WARN_ON(ppgtt->pd_offset & 0x3f);
169 	pd_addr = (gen6_gtt_pte_t __iomem*)dev_priv->gtt.gsm +
170 		ppgtt->pd_offset / sizeof(gen6_gtt_pte_t);
171 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
172 		dma_addr_t pt_addr;
173 
174 		pt_addr = ppgtt->pt_dma_addr[i];
175 		pd_entry = GEN6_PDE_ADDR_ENCODE(pt_addr);
176 		pd_entry |= GEN6_PDE_VALID;
177 
178 		writel(pd_entry, pd_addr + i);
179 	}
180 	readl(pd_addr);
181 }
182 
183 static int gen6_ppgtt_enable(struct drm_device *dev)
184 {
185 	drm_i915_private_t *dev_priv = dev->dev_private;
186 	uint32_t pd_offset;
187 	struct intel_ring_buffer *ring;
188 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
189 	int i;
190 
191 	BUG_ON(ppgtt->pd_offset & 0x3f);
192 
193 	gen6_write_pdes(ppgtt);
194 
195 	pd_offset = ppgtt->pd_offset;
196 	pd_offset /= 64; /* in cachelines, */
197 	pd_offset <<= 16;
198 
199 	if (INTEL_INFO(dev)->gen == 6) {
200 		uint32_t ecochk, gab_ctl, ecobits;
201 
202 		ecobits = I915_READ(GAC_ECO_BITS);
203 		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_SNB_BIT |
204 					 ECOBITS_PPGTT_CACHE64B);
205 
206 		gab_ctl = I915_READ(GAB_CTL);
207 		I915_WRITE(GAB_CTL, gab_ctl | GAB_CTL_CONT_AFTER_PAGEFAULT);
208 
209 		ecochk = I915_READ(GAM_ECOCHK);
210 		I915_WRITE(GAM_ECOCHK, ecochk | ECOCHK_SNB_BIT |
211 				       ECOCHK_PPGTT_CACHE64B);
212 		I915_WRITE(GFX_MODE, _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
213 	} else if (INTEL_INFO(dev)->gen >= 7) {
214 		uint32_t ecochk, ecobits;
215 
216 		ecobits = I915_READ(GAC_ECO_BITS);
217 		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_PPGTT_CACHE64B);
218 
219 		ecochk = I915_READ(GAM_ECOCHK);
220 		if (IS_HASWELL(dev)) {
221 			ecochk |= ECOCHK_PPGTT_WB_HSW;
222 		} else {
223 			ecochk |= ECOCHK_PPGTT_LLC_IVB;
224 			ecochk &= ~ECOCHK_PPGTT_GFDT_IVB;
225 		}
226 		I915_WRITE(GAM_ECOCHK, ecochk);
227 		/* GFX_MODE is per-ring on gen7+ */
228 	}
229 
230 	for_each_ring(ring, dev_priv, i) {
231 		if (INTEL_INFO(dev)->gen >= 7)
232 			I915_WRITE(RING_MODE_GEN7(ring),
233 				   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
234 
235 		I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
236 		I915_WRITE(RING_PP_DIR_BASE(ring), pd_offset);
237 	}
238 	return 0;
239 }
240 
241 /* PPGTT support for Sandybdrige/Gen6 and later */
242 static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
243 				   unsigned first_entry,
244 				   unsigned num_entries,
245 				   bool use_scratch)
246 {
247 	struct i915_hw_ppgtt *ppgtt =
248 		container_of(vm, struct i915_hw_ppgtt, base);
249 	gen6_gtt_pte_t *pt_vaddr, scratch_pte;
250 	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
251 	unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
252 	unsigned last_pte, i;
253 
254 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, true);
255 
256 	while (num_entries) {
257 		last_pte = first_pte + num_entries;
258 		if (last_pte > I915_PPGTT_PT_ENTRIES)
259 			last_pte = I915_PPGTT_PT_ENTRIES;
260 
261 		pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
262 
263 		for (i = first_pte; i < last_pte; i++)
264 			pt_vaddr[i] = scratch_pte;
265 
266 		kunmap_atomic(pt_vaddr);
267 
268 		num_entries -= last_pte - first_pte;
269 		first_pte = 0;
270 		act_pt++;
271 	}
272 }
273 
274 static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
275 				      struct sg_table *pages,
276 				      unsigned first_entry,
277 				      enum i915_cache_level cache_level)
278 {
279 	struct i915_hw_ppgtt *ppgtt =
280 		container_of(vm, struct i915_hw_ppgtt, base);
281 	gen6_gtt_pte_t *pt_vaddr;
282 	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
283 	unsigned act_pte = first_entry % I915_PPGTT_PT_ENTRIES;
284 	struct sg_page_iter sg_iter;
285 
286 	pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
287 	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
288 		dma_addr_t page_addr;
289 
290 		page_addr = sg_page_iter_dma_address(&sg_iter);
291 		pt_vaddr[act_pte] = vm->pte_encode(page_addr, cache_level, true);
292 		if (++act_pte == I915_PPGTT_PT_ENTRIES) {
293 			kunmap_atomic(pt_vaddr);
294 			act_pt++;
295 			pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
296 			act_pte = 0;
297 
298 		}
299 	}
300 	kunmap_atomic(pt_vaddr);
301 }
302 
303 static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
304 {
305 	struct i915_hw_ppgtt *ppgtt =
306 		container_of(vm, struct i915_hw_ppgtt, base);
307 	int i;
308 
309 	drm_mm_takedown(&ppgtt->base.mm);
310 
311 	if (ppgtt->pt_dma_addr) {
312 		for (i = 0; i < ppgtt->num_pd_entries; i++)
313 			pci_unmap_page(ppgtt->base.dev->pdev,
314 				       ppgtt->pt_dma_addr[i],
315 				       4096, PCI_DMA_BIDIRECTIONAL);
316 	}
317 
318 	kfree(ppgtt->pt_dma_addr);
319 	for (i = 0; i < ppgtt->num_pd_entries; i++)
320 		__free_page(ppgtt->pt_pages[i]);
321 	kfree(ppgtt->pt_pages);
322 	kfree(ppgtt);
323 }
324 
325 static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
326 {
327 	struct drm_device *dev = ppgtt->base.dev;
328 	struct drm_i915_private *dev_priv = dev->dev_private;
329 	unsigned first_pd_entry_in_global_pt;
330 	int i;
331 	int ret = -ENOMEM;
332 
333 	/* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
334 	 * entries. For aliasing ppgtt support we just steal them at the end for
335 	 * now. */
336 	first_pd_entry_in_global_pt = gtt_total_entries(dev_priv->gtt);
337 
338 	ppgtt->base.pte_encode = dev_priv->gtt.base.pte_encode;
339 	ppgtt->num_pd_entries = GEN6_PPGTT_PD_ENTRIES;
340 	ppgtt->enable = gen6_ppgtt_enable;
341 	ppgtt->base.clear_range = gen6_ppgtt_clear_range;
342 	ppgtt->base.insert_entries = gen6_ppgtt_insert_entries;
343 	ppgtt->base.cleanup = gen6_ppgtt_cleanup;
344 	ppgtt->base.scratch = dev_priv->gtt.base.scratch;
345 	ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
346 				  GFP_KERNEL);
347 	if (!ppgtt->pt_pages)
348 		return -ENOMEM;
349 
350 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
351 		ppgtt->pt_pages[i] = alloc_page(GFP_KERNEL);
352 		if (!ppgtt->pt_pages[i])
353 			goto err_pt_alloc;
354 	}
355 
356 	ppgtt->pt_dma_addr = kzalloc(sizeof(dma_addr_t) *ppgtt->num_pd_entries,
357 				     GFP_KERNEL);
358 	if (!ppgtt->pt_dma_addr)
359 		goto err_pt_alloc;
360 
361 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
362 		dma_addr_t pt_addr;
363 
364 		pt_addr = pci_map_page(dev->pdev, ppgtt->pt_pages[i], 0, 4096,
365 				       PCI_DMA_BIDIRECTIONAL);
366 
367 		if (pci_dma_mapping_error(dev->pdev, pt_addr)) {
368 			ret = -EIO;
369 			goto err_pd_pin;
370 
371 		}
372 		ppgtt->pt_dma_addr[i] = pt_addr;
373 	}
374 
375 	ppgtt->base.clear_range(&ppgtt->base, 0,
376 				ppgtt->num_pd_entries * I915_PPGTT_PT_ENTRIES, true);
377 
378 	ppgtt->pd_offset = first_pd_entry_in_global_pt * sizeof(gen6_gtt_pte_t);
379 
380 	return 0;
381 
382 err_pd_pin:
383 	if (ppgtt->pt_dma_addr) {
384 		for (i--; i >= 0; i--)
385 			pci_unmap_page(dev->pdev, ppgtt->pt_dma_addr[i],
386 				       4096, PCI_DMA_BIDIRECTIONAL);
387 	}
388 err_pt_alloc:
389 	kfree(ppgtt->pt_dma_addr);
390 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
391 		if (ppgtt->pt_pages[i])
392 			__free_page(ppgtt->pt_pages[i]);
393 	}
394 	kfree(ppgtt->pt_pages);
395 
396 	return ret;
397 }
398 
399 static int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
400 {
401 	struct drm_i915_private *dev_priv = dev->dev_private;
402 	struct i915_hw_ppgtt *ppgtt;
403 	int ret;
404 
405 	ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
406 	if (!ppgtt)
407 		return -ENOMEM;
408 
409 	ppgtt->base.dev = dev;
410 
411 	if (INTEL_INFO(dev)->gen < 8)
412 		ret = gen6_ppgtt_init(ppgtt);
413 	else
414 		BUG();
415 
416 	if (ret)
417 		kfree(ppgtt);
418 	else {
419 		dev_priv->mm.aliasing_ppgtt = ppgtt;
420 		drm_mm_init(&ppgtt->base.mm, ppgtt->base.start,
421 			    ppgtt->base.total);
422 	}
423 
424 	return ret;
425 }
426 
427 void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev)
428 {
429 	struct drm_i915_private *dev_priv = dev->dev_private;
430 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
431 
432 	if (!ppgtt)
433 		return;
434 
435 	ppgtt->base.cleanup(&ppgtt->base);
436 	dev_priv->mm.aliasing_ppgtt = NULL;
437 }
438 
439 void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
440 			    struct drm_i915_gem_object *obj,
441 			    enum i915_cache_level cache_level)
442 {
443 	ppgtt->base.insert_entries(&ppgtt->base, obj->pages,
444 				   i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT,
445 				   cache_level);
446 }
447 
448 void i915_ppgtt_unbind_object(struct i915_hw_ppgtt *ppgtt,
449 			      struct drm_i915_gem_object *obj)
450 {
451 	ppgtt->base.clear_range(&ppgtt->base,
452 				i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT,
453 				obj->base.size >> PAGE_SHIFT,
454 				true);
455 }
456 
457 extern int intel_iommu_gfx_mapped;
458 /* Certain Gen5 chipsets require require idling the GPU before
459  * unmapping anything from the GTT when VT-d is enabled.
460  */
461 static inline bool needs_idle_maps(struct drm_device *dev)
462 {
463 #ifdef CONFIG_INTEL_IOMMU
464 	/* Query intel_iommu to see if we need the workaround. Presumably that
465 	 * was loaded first.
466 	 */
467 	if (IS_GEN5(dev) && IS_MOBILE(dev) && intel_iommu_gfx_mapped)
468 		return true;
469 #endif
470 	return false;
471 }
472 
473 static bool do_idling(struct drm_i915_private *dev_priv)
474 {
475 	bool ret = dev_priv->mm.interruptible;
476 
477 	if (unlikely(dev_priv->gtt.do_idle_maps)) {
478 		dev_priv->mm.interruptible = false;
479 		if (i915_gpu_idle(dev_priv->dev)) {
480 			DRM_ERROR("Couldn't idle GPU\n");
481 			/* Wait a bit, in hopes it avoids the hang */
482 			udelay(10);
483 		}
484 	}
485 
486 	return ret;
487 }
488 
489 static void undo_idling(struct drm_i915_private *dev_priv, bool interruptible)
490 {
491 	if (unlikely(dev_priv->gtt.do_idle_maps))
492 		dev_priv->mm.interruptible = interruptible;
493 }
494 
495 void i915_check_and_clear_faults(struct drm_device *dev)
496 {
497 	struct drm_i915_private *dev_priv = dev->dev_private;
498 	struct intel_ring_buffer *ring;
499 	int i;
500 
501 	if (INTEL_INFO(dev)->gen < 6)
502 		return;
503 
504 	for_each_ring(ring, dev_priv, i) {
505 		u32 fault_reg;
506 		fault_reg = I915_READ(RING_FAULT_REG(ring));
507 		if (fault_reg & RING_FAULT_VALID) {
508 			DRM_DEBUG_DRIVER("Unexpected fault\n"
509 					 "\tAddr: 0x%08lx\\n"
510 					 "\tAddress space: %s\n"
511 					 "\tSource ID: %d\n"
512 					 "\tType: %d\n",
513 					 fault_reg & PAGE_MASK,
514 					 fault_reg & RING_FAULT_GTTSEL_MASK ? "GGTT" : "PPGTT",
515 					 RING_FAULT_SRCID(fault_reg),
516 					 RING_FAULT_FAULT_TYPE(fault_reg));
517 			I915_WRITE(RING_FAULT_REG(ring),
518 				   fault_reg & ~RING_FAULT_VALID);
519 		}
520 	}
521 	POSTING_READ(RING_FAULT_REG(&dev_priv->ring[RCS]));
522 }
523 
524 void i915_gem_suspend_gtt_mappings(struct drm_device *dev)
525 {
526 	struct drm_i915_private *dev_priv = dev->dev_private;
527 
528 	/* Don't bother messing with faults pre GEN6 as we have little
529 	 * documentation supporting that it's a good idea.
530 	 */
531 	if (INTEL_INFO(dev)->gen < 6)
532 		return;
533 
534 	i915_check_and_clear_faults(dev);
535 
536 	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
537 				       dev_priv->gtt.base.start / PAGE_SIZE,
538 				       dev_priv->gtt.base.total / PAGE_SIZE,
539 				       false);
540 }
541 
542 void i915_gem_restore_gtt_mappings(struct drm_device *dev)
543 {
544 	struct drm_i915_private *dev_priv = dev->dev_private;
545 	struct drm_i915_gem_object *obj;
546 
547 	i915_check_and_clear_faults(dev);
548 
549 	/* First fill our portion of the GTT with scratch pages */
550 	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
551 				       dev_priv->gtt.base.start / PAGE_SIZE,
552 				       dev_priv->gtt.base.total / PAGE_SIZE,
553 				       true);
554 
555 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
556 		i915_gem_clflush_object(obj, obj->pin_display);
557 		i915_gem_gtt_bind_object(obj, obj->cache_level);
558 	}
559 
560 	i915_gem_chipset_flush(dev);
561 }
562 
563 int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
564 {
565 	if (obj->has_dma_mapping)
566 		return 0;
567 
568 	if (!dma_map_sg(&obj->base.dev->pdev->dev,
569 			obj->pages->sgl, obj->pages->nents,
570 			PCI_DMA_BIDIRECTIONAL))
571 		return -ENOSPC;
572 
573 	return 0;
574 }
575 
576 /*
577  * Binds an object into the global gtt with the specified cache level. The object
578  * will be accessible to the GPU via commands whose operands reference offsets
579  * within the global GTT as well as accessible by the GPU through the GMADR
580  * mapped BAR (dev_priv->mm.gtt->gtt).
581  */
582 static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
583 				     struct sg_table *st,
584 				     unsigned int first_entry,
585 				     enum i915_cache_level level)
586 {
587 	struct drm_i915_private *dev_priv = vm->dev->dev_private;
588 	gen6_gtt_pte_t __iomem *gtt_entries =
589 		(gen6_gtt_pte_t __iomem *)dev_priv->gtt.gsm + first_entry;
590 	int i = 0;
591 	struct sg_page_iter sg_iter;
592 	dma_addr_t addr;
593 
594 	for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) {
595 		addr = sg_page_iter_dma_address(&sg_iter);
596 		iowrite32(vm->pte_encode(addr, level, true), &gtt_entries[i]);
597 		i++;
598 	}
599 
600 	/* XXX: This serves as a posting read to make sure that the PTE has
601 	 * actually been updated. There is some concern that even though
602 	 * registers and PTEs are within the same BAR that they are potentially
603 	 * of NUMA access patterns. Therefore, even with the way we assume
604 	 * hardware should work, we must keep this posting read for paranoia.
605 	 */
606 	if (i != 0)
607 		WARN_ON(readl(&gtt_entries[i-1]) !=
608 			vm->pte_encode(addr, level, true));
609 
610 	/* This next bit makes the above posting read even more important. We
611 	 * want to flush the TLBs only after we're certain all the PTE updates
612 	 * have finished.
613 	 */
614 	I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
615 	POSTING_READ(GFX_FLSH_CNTL_GEN6);
616 }
617 
618 static void gen6_ggtt_clear_range(struct i915_address_space *vm,
619 				  unsigned int first_entry,
620 				  unsigned int num_entries,
621 				  bool use_scratch)
622 {
623 	struct drm_i915_private *dev_priv = vm->dev->dev_private;
624 	gen6_gtt_pte_t scratch_pte, __iomem *gtt_base =
625 		(gen6_gtt_pte_t __iomem *) dev_priv->gtt.gsm + first_entry;
626 	const int max_entries = gtt_total_entries(dev_priv->gtt) - first_entry;
627 	int i;
628 
629 	if (WARN(num_entries > max_entries,
630 		 "First entry = %d; Num entries = %d (max=%d)\n",
631 		 first_entry, num_entries, max_entries))
632 		num_entries = max_entries;
633 
634 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, use_scratch);
635 
636 	for (i = 0; i < num_entries; i++)
637 		iowrite32(scratch_pte, &gtt_base[i]);
638 	readl(gtt_base);
639 }
640 
641 
642 static void i915_ggtt_insert_entries(struct i915_address_space *vm,
643 				     struct sg_table *st,
644 				     unsigned int pg_start,
645 				     enum i915_cache_level cache_level)
646 {
647 	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
648 		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
649 
650 	intel_gtt_insert_sg_entries(st, pg_start, flags);
651 
652 }
653 
654 static void i915_ggtt_clear_range(struct i915_address_space *vm,
655 				  unsigned int first_entry,
656 				  unsigned int num_entries,
657 				  bool unused)
658 {
659 	intel_gtt_clear_range(first_entry, num_entries);
660 }
661 
662 
663 void i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj,
664 			      enum i915_cache_level cache_level)
665 {
666 	struct drm_device *dev = obj->base.dev;
667 	struct drm_i915_private *dev_priv = dev->dev_private;
668 	const unsigned long entry = i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT;
669 
670 	dev_priv->gtt.base.insert_entries(&dev_priv->gtt.base, obj->pages,
671 					  entry,
672 					  cache_level);
673 
674 	obj->has_global_gtt_mapping = 1;
675 }
676 
677 void i915_gem_gtt_unbind_object(struct drm_i915_gem_object *obj)
678 {
679 	struct drm_device *dev = obj->base.dev;
680 	struct drm_i915_private *dev_priv = dev->dev_private;
681 	const unsigned long entry = i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT;
682 
683 	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
684 				       entry,
685 				       obj->base.size >> PAGE_SHIFT,
686 				       true);
687 
688 	obj->has_global_gtt_mapping = 0;
689 }
690 
691 void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
692 {
693 	struct drm_device *dev = obj->base.dev;
694 	struct drm_i915_private *dev_priv = dev->dev_private;
695 	bool interruptible;
696 
697 	interruptible = do_idling(dev_priv);
698 
699 	if (!obj->has_dma_mapping)
700 		dma_unmap_sg(&dev->pdev->dev,
701 			     obj->pages->sgl, obj->pages->nents,
702 			     PCI_DMA_BIDIRECTIONAL);
703 
704 	undo_idling(dev_priv, interruptible);
705 }
706 
707 static void i915_gtt_color_adjust(struct drm_mm_node *node,
708 				  unsigned long color,
709 				  unsigned long *start,
710 				  unsigned long *end)
711 {
712 	if (node->color != color)
713 		*start += 4096;
714 
715 	if (!list_empty(&node->node_list)) {
716 		node = list_entry(node->node_list.next,
717 				  struct drm_mm_node,
718 				  node_list);
719 		if (node->allocated && node->color != color)
720 			*end -= 4096;
721 	}
722 }
723 void i915_gem_setup_global_gtt(struct drm_device *dev,
724 			       unsigned long start,
725 			       unsigned long mappable_end,
726 			       unsigned long end)
727 {
728 	/* Let GEM Manage all of the aperture.
729 	 *
730 	 * However, leave one page at the end still bound to the scratch page.
731 	 * There are a number of places where the hardware apparently prefetches
732 	 * past the end of the object, and we've seen multiple hangs with the
733 	 * GPU head pointer stuck in a batchbuffer bound at the last page of the
734 	 * aperture.  One page should be enough to keep any prefetching inside
735 	 * of the aperture.
736 	 */
737 	struct drm_i915_private *dev_priv = dev->dev_private;
738 	struct i915_address_space *ggtt_vm = &dev_priv->gtt.base;
739 	struct drm_mm_node *entry;
740 	struct drm_i915_gem_object *obj;
741 	unsigned long hole_start, hole_end;
742 
743 	BUG_ON(mappable_end > end);
744 
745 	/* Subtract the guard page ... */
746 	drm_mm_init(&ggtt_vm->mm, start, end - start - PAGE_SIZE);
747 	if (!HAS_LLC(dev))
748 		dev_priv->gtt.base.mm.color_adjust = i915_gtt_color_adjust;
749 
750 	/* Mark any preallocated objects as occupied */
751 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
752 		struct i915_vma *vma = i915_gem_obj_to_vma(obj, ggtt_vm);
753 		int ret;
754 		DRM_DEBUG_KMS("reserving preallocated space: %lx + %zx\n",
755 			      i915_gem_obj_ggtt_offset(obj), obj->base.size);
756 
757 		WARN_ON(i915_gem_obj_ggtt_bound(obj));
758 		ret = drm_mm_reserve_node(&ggtt_vm->mm, &vma->node);
759 		if (ret)
760 			DRM_DEBUG_KMS("Reservation failed\n");
761 		obj->has_global_gtt_mapping = 1;
762 		list_add(&vma->vma_link, &obj->vma_list);
763 	}
764 
765 	dev_priv->gtt.base.start = start;
766 	dev_priv->gtt.base.total = end - start;
767 
768 	/* Clear any non-preallocated blocks */
769 	drm_mm_for_each_hole(entry, &ggtt_vm->mm, hole_start, hole_end) {
770 		const unsigned long count = (hole_end - hole_start) / PAGE_SIZE;
771 		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
772 			      hole_start, hole_end);
773 		ggtt_vm->clear_range(ggtt_vm, hole_start / PAGE_SIZE, count, true);
774 	}
775 
776 	/* And finally clear the reserved guard page */
777 	ggtt_vm->clear_range(ggtt_vm, end / PAGE_SIZE - 1, 1, true);
778 }
779 
780 static bool
781 intel_enable_ppgtt(struct drm_device *dev)
782 {
783 	if (i915_enable_ppgtt >= 0)
784 		return i915_enable_ppgtt;
785 
786 #ifdef CONFIG_INTEL_IOMMU
787 	/* Disable ppgtt on SNB if VT-d is on. */
788 	if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped)
789 		return false;
790 #endif
791 
792 	return true;
793 }
794 
795 void i915_gem_init_global_gtt(struct drm_device *dev)
796 {
797 	struct drm_i915_private *dev_priv = dev->dev_private;
798 	unsigned long gtt_size, mappable_size;
799 
800 	gtt_size = dev_priv->gtt.base.total;
801 	mappable_size = dev_priv->gtt.mappable_end;
802 
803 	if (intel_enable_ppgtt(dev) && HAS_ALIASING_PPGTT(dev)) {
804 		int ret;
805 
806 		if (INTEL_INFO(dev)->gen <= 7) {
807 			/* PPGTT pdes are stolen from global gtt ptes, so shrink the
808 			 * aperture accordingly when using aliasing ppgtt. */
809 			gtt_size -= GEN6_PPGTT_PD_ENTRIES * PAGE_SIZE;
810 		}
811 
812 		i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
813 
814 		ret = i915_gem_init_aliasing_ppgtt(dev);
815 		if (!ret)
816 			return;
817 
818 		DRM_ERROR("Aliased PPGTT setup failed %d\n", ret);
819 		drm_mm_takedown(&dev_priv->gtt.base.mm);
820 		gtt_size += GEN6_PPGTT_PD_ENTRIES * PAGE_SIZE;
821 	}
822 	i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
823 }
824 
825 static int setup_scratch_page(struct drm_device *dev)
826 {
827 	struct drm_i915_private *dev_priv = dev->dev_private;
828 	struct page *page;
829 	dma_addr_t dma_addr;
830 
831 	page = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
832 	if (page == NULL)
833 		return -ENOMEM;
834 	get_page(page);
835 	set_pages_uc(page, 1);
836 
837 #ifdef CONFIG_INTEL_IOMMU
838 	dma_addr = pci_map_page(dev->pdev, page, 0, PAGE_SIZE,
839 				PCI_DMA_BIDIRECTIONAL);
840 	if (pci_dma_mapping_error(dev->pdev, dma_addr))
841 		return -EINVAL;
842 #else
843 	dma_addr = page_to_phys(page);
844 #endif
845 	dev_priv->gtt.base.scratch.page = page;
846 	dev_priv->gtt.base.scratch.addr = dma_addr;
847 
848 	return 0;
849 }
850 
851 static void teardown_scratch_page(struct drm_device *dev)
852 {
853 	struct drm_i915_private *dev_priv = dev->dev_private;
854 	struct page *page = dev_priv->gtt.base.scratch.page;
855 
856 	set_pages_wb(page, 1);
857 	pci_unmap_page(dev->pdev, dev_priv->gtt.base.scratch.addr,
858 		       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
859 	put_page(page);
860 	__free_page(page);
861 }
862 
863 static inline unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
864 {
865 	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
866 	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
867 	return snb_gmch_ctl << 20;
868 }
869 
870 static inline size_t gen6_get_stolen_size(u16 snb_gmch_ctl)
871 {
872 	snb_gmch_ctl >>= SNB_GMCH_GMS_SHIFT;
873 	snb_gmch_ctl &= SNB_GMCH_GMS_MASK;
874 	return snb_gmch_ctl << 25; /* 32 MB units */
875 }
876 
877 static int gen6_gmch_probe(struct drm_device *dev,
878 			   size_t *gtt_total,
879 			   size_t *stolen,
880 			   phys_addr_t *mappable_base,
881 			   unsigned long *mappable_end)
882 {
883 	struct drm_i915_private *dev_priv = dev->dev_private;
884 	phys_addr_t gtt_bus_addr;
885 	unsigned int gtt_size;
886 	u16 snb_gmch_ctl;
887 	int ret;
888 
889 	*mappable_base = pci_resource_start(dev->pdev, 2);
890 	*mappable_end = pci_resource_len(dev->pdev, 2);
891 
892 	/* 64/512MB is the current min/max we actually know of, but this is just
893 	 * a coarse sanity check.
894 	 */
895 	if ((*mappable_end < (64<<20) || (*mappable_end > (512<<20)))) {
896 		DRM_ERROR("Unknown GMADR size (%lx)\n",
897 			  dev_priv->gtt.mappable_end);
898 		return -ENXIO;
899 	}
900 
901 	if (!pci_set_dma_mask(dev->pdev, DMA_BIT_MASK(40)))
902 		pci_set_consistent_dma_mask(dev->pdev, DMA_BIT_MASK(40));
903 	pci_read_config_word(dev->pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
904 	gtt_size = gen6_get_total_gtt_size(snb_gmch_ctl);
905 
906 	*stolen = gen6_get_stolen_size(snb_gmch_ctl);
907 	*gtt_total = (gtt_size / sizeof(gen6_gtt_pte_t)) << PAGE_SHIFT;
908 
909 	/* For Modern GENs the PTEs and register space are split in the BAR */
910 	gtt_bus_addr = pci_resource_start(dev->pdev, 0) +
911 		(pci_resource_len(dev->pdev, 0) / 2);
912 
913 	dev_priv->gtt.gsm = ioremap_wc(gtt_bus_addr, gtt_size);
914 	if (!dev_priv->gtt.gsm) {
915 		DRM_ERROR("Failed to map the gtt page table\n");
916 		return -ENOMEM;
917 	}
918 
919 	ret = setup_scratch_page(dev);
920 	if (ret)
921 		DRM_ERROR("Scratch setup failed\n");
922 
923 	dev_priv->gtt.base.clear_range = gen6_ggtt_clear_range;
924 	dev_priv->gtt.base.insert_entries = gen6_ggtt_insert_entries;
925 
926 	return ret;
927 }
928 
929 static void gen6_gmch_remove(struct i915_address_space *vm)
930 {
931 
932 	struct i915_gtt *gtt = container_of(vm, struct i915_gtt, base);
933 	iounmap(gtt->gsm);
934 	teardown_scratch_page(vm->dev);
935 }
936 
937 static int i915_gmch_probe(struct drm_device *dev,
938 			   size_t *gtt_total,
939 			   size_t *stolen,
940 			   phys_addr_t *mappable_base,
941 			   unsigned long *mappable_end)
942 {
943 	struct drm_i915_private *dev_priv = dev->dev_private;
944 	int ret;
945 
946 	ret = intel_gmch_probe(dev_priv->bridge_dev, dev_priv->dev->pdev, NULL);
947 	if (!ret) {
948 		DRM_ERROR("failed to set up gmch\n");
949 		return -EIO;
950 	}
951 
952 	intel_gtt_get(gtt_total, stolen, mappable_base, mappable_end);
953 
954 	dev_priv->gtt.do_idle_maps = needs_idle_maps(dev_priv->dev);
955 	dev_priv->gtt.base.clear_range = i915_ggtt_clear_range;
956 	dev_priv->gtt.base.insert_entries = i915_ggtt_insert_entries;
957 
958 	return 0;
959 }
960 
961 static void i915_gmch_remove(struct i915_address_space *vm)
962 {
963 	intel_gmch_remove();
964 }
965 
966 int i915_gem_gtt_init(struct drm_device *dev)
967 {
968 	struct drm_i915_private *dev_priv = dev->dev_private;
969 	struct i915_gtt *gtt = &dev_priv->gtt;
970 	int ret;
971 
972 	if (INTEL_INFO(dev)->gen <= 5) {
973 		gtt->gtt_probe = i915_gmch_probe;
974 		gtt->base.cleanup = i915_gmch_remove;
975 	} else {
976 		gtt->gtt_probe = gen6_gmch_probe;
977 		gtt->base.cleanup = gen6_gmch_remove;
978 		if (IS_HASWELL(dev) && dev_priv->ellc_size)
979 			gtt->base.pte_encode = iris_pte_encode;
980 		else if (IS_HASWELL(dev))
981 			gtt->base.pte_encode = hsw_pte_encode;
982 		else if (IS_VALLEYVIEW(dev))
983 			gtt->base.pte_encode = byt_pte_encode;
984 		else if (INTEL_INFO(dev)->gen >= 7)
985 			gtt->base.pte_encode = ivb_pte_encode;
986 		else
987 			gtt->base.pte_encode = snb_pte_encode;
988 	}
989 
990 	ret = gtt->gtt_probe(dev, &gtt->base.total, &gtt->stolen_size,
991 			     &gtt->mappable_base, &gtt->mappable_end);
992 	if (ret)
993 		return ret;
994 
995 	gtt->base.dev = dev;
996 
997 	/* GMADR is the PCI mmio aperture into the global GTT. */
998 	DRM_INFO("Memory usable by graphics device = %zdM\n",
999 		 gtt->base.total >> 20);
1000 	DRM_DEBUG_DRIVER("GMADR size = %ldM\n", gtt->mappable_end >> 20);
1001 	DRM_DEBUG_DRIVER("GTT stolen size = %zdM\n", gtt->stolen_size >> 20);
1002 
1003 	return 0;
1004 }
1005