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 {
63 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
64 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
65 
66 	switch (level) {
67 	case I915_CACHE_L3_LLC:
68 	case I915_CACHE_LLC:
69 		pte |= GEN6_PTE_CACHE_LLC;
70 		break;
71 	case I915_CACHE_NONE:
72 		pte |= GEN6_PTE_UNCACHED;
73 		break;
74 	default:
75 		WARN_ON(1);
76 	}
77 
78 	return pte;
79 }
80 
81 static gen6_gtt_pte_t ivb_pte_encode(dma_addr_t addr,
82 				     enum i915_cache_level level)
83 {
84 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
85 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
86 
87 	switch (level) {
88 	case I915_CACHE_L3_LLC:
89 		pte |= GEN7_PTE_CACHE_L3_LLC;
90 		break;
91 	case I915_CACHE_LLC:
92 		pte |= GEN6_PTE_CACHE_LLC;
93 		break;
94 	case I915_CACHE_NONE:
95 		pte |= GEN6_PTE_UNCACHED;
96 		break;
97 	default:
98 		WARN_ON(1);
99 	}
100 
101 	return pte;
102 }
103 
104 #define BYT_PTE_WRITEABLE		(1 << 1)
105 #define BYT_PTE_SNOOPED_BY_CPU_CACHES	(1 << 2)
106 
107 static gen6_gtt_pte_t byt_pte_encode(dma_addr_t addr,
108 				     enum i915_cache_level level)
109 {
110 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
111 	pte |= GEN6_PTE_ADDR_ENCODE(addr);
112 
113 	/* Mark the page as writeable.  Other platforms don't have a
114 	 * setting for read-only/writable, so this matches that behavior.
115 	 */
116 	pte |= BYT_PTE_WRITEABLE;
117 
118 	if (level != I915_CACHE_NONE)
119 		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
120 
121 	return pte;
122 }
123 
124 static gen6_gtt_pte_t hsw_pte_encode(dma_addr_t addr,
125 				     enum i915_cache_level level)
126 {
127 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
128 	pte |= HSW_PTE_ADDR_ENCODE(addr);
129 
130 	if (level != I915_CACHE_NONE)
131 		pte |= HSW_WB_LLC_AGE3;
132 
133 	return pte;
134 }
135 
136 static gen6_gtt_pte_t iris_pte_encode(dma_addr_t addr,
137 				      enum i915_cache_level level)
138 {
139 	gen6_gtt_pte_t pte = GEN6_PTE_VALID;
140 	pte |= HSW_PTE_ADDR_ENCODE(addr);
141 
142 	switch (level) {
143 	case I915_CACHE_NONE:
144 		break;
145 	case I915_CACHE_WT:
146 		pte |= HSW_WT_ELLC_LLC_AGE0;
147 		break;
148 	default:
149 		pte |= HSW_WB_ELLC_LLC_AGE0;
150 		break;
151 	}
152 
153 	return pte;
154 }
155 
156 static void gen6_write_pdes(struct i915_hw_ppgtt *ppgtt)
157 {
158 	struct drm_i915_private *dev_priv = ppgtt->base.dev->dev_private;
159 	gen6_gtt_pte_t __iomem *pd_addr;
160 	uint32_t pd_entry;
161 	int i;
162 
163 	WARN_ON(ppgtt->pd_offset & 0x3f);
164 	pd_addr = (gen6_gtt_pte_t __iomem*)dev_priv->gtt.gsm +
165 		ppgtt->pd_offset / sizeof(gen6_gtt_pte_t);
166 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
167 		dma_addr_t pt_addr;
168 
169 		pt_addr = ppgtt->pt_dma_addr[i];
170 		pd_entry = GEN6_PDE_ADDR_ENCODE(pt_addr);
171 		pd_entry |= GEN6_PDE_VALID;
172 
173 		writel(pd_entry, pd_addr + i);
174 	}
175 	readl(pd_addr);
176 }
177 
178 static int gen6_ppgtt_enable(struct drm_device *dev)
179 {
180 	drm_i915_private_t *dev_priv = dev->dev_private;
181 	uint32_t pd_offset;
182 	struct intel_ring_buffer *ring;
183 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
184 	int i;
185 
186 	BUG_ON(ppgtt->pd_offset & 0x3f);
187 
188 	gen6_write_pdes(ppgtt);
189 
190 	pd_offset = ppgtt->pd_offset;
191 	pd_offset /= 64; /* in cachelines, */
192 	pd_offset <<= 16;
193 
194 	if (INTEL_INFO(dev)->gen == 6) {
195 		uint32_t ecochk, gab_ctl, ecobits;
196 
197 		ecobits = I915_READ(GAC_ECO_BITS);
198 		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_SNB_BIT |
199 					 ECOBITS_PPGTT_CACHE64B);
200 
201 		gab_ctl = I915_READ(GAB_CTL);
202 		I915_WRITE(GAB_CTL, gab_ctl | GAB_CTL_CONT_AFTER_PAGEFAULT);
203 
204 		ecochk = I915_READ(GAM_ECOCHK);
205 		I915_WRITE(GAM_ECOCHK, ecochk | ECOCHK_SNB_BIT |
206 				       ECOCHK_PPGTT_CACHE64B);
207 		I915_WRITE(GFX_MODE, _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
208 	} else if (INTEL_INFO(dev)->gen >= 7) {
209 		uint32_t ecochk, ecobits;
210 
211 		ecobits = I915_READ(GAC_ECO_BITS);
212 		I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_PPGTT_CACHE64B);
213 
214 		ecochk = I915_READ(GAM_ECOCHK);
215 		if (IS_HASWELL(dev)) {
216 			ecochk |= ECOCHK_PPGTT_WB_HSW;
217 		} else {
218 			ecochk |= ECOCHK_PPGTT_LLC_IVB;
219 			ecochk &= ~ECOCHK_PPGTT_GFDT_IVB;
220 		}
221 		I915_WRITE(GAM_ECOCHK, ecochk);
222 		/* GFX_MODE is per-ring on gen7+ */
223 	}
224 
225 	for_each_ring(ring, dev_priv, i) {
226 		if (INTEL_INFO(dev)->gen >= 7)
227 			I915_WRITE(RING_MODE_GEN7(ring),
228 				   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
229 
230 		I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
231 		I915_WRITE(RING_PP_DIR_BASE(ring), pd_offset);
232 	}
233 	return 0;
234 }
235 
236 /* PPGTT support for Sandybdrige/Gen6 and later */
237 static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
238 				   unsigned first_entry,
239 				   unsigned num_entries)
240 {
241 	struct i915_hw_ppgtt *ppgtt =
242 		container_of(vm, struct i915_hw_ppgtt, base);
243 	gen6_gtt_pte_t *pt_vaddr, scratch_pte;
244 	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
245 	unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
246 	unsigned last_pte, i;
247 
248 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC);
249 
250 	while (num_entries) {
251 		last_pte = first_pte + num_entries;
252 		if (last_pte > I915_PPGTT_PT_ENTRIES)
253 			last_pte = I915_PPGTT_PT_ENTRIES;
254 
255 		pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
256 
257 		for (i = first_pte; i < last_pte; i++)
258 			pt_vaddr[i] = scratch_pte;
259 
260 		kunmap_atomic(pt_vaddr);
261 
262 		num_entries -= last_pte - first_pte;
263 		first_pte = 0;
264 		act_pt++;
265 	}
266 }
267 
268 static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
269 				      struct sg_table *pages,
270 				      unsigned first_entry,
271 				      enum i915_cache_level cache_level)
272 {
273 	struct i915_hw_ppgtt *ppgtt =
274 		container_of(vm, struct i915_hw_ppgtt, base);
275 	gen6_gtt_pte_t *pt_vaddr;
276 	unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
277 	unsigned act_pte = first_entry % I915_PPGTT_PT_ENTRIES;
278 	struct sg_page_iter sg_iter;
279 
280 	pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
281 	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
282 		dma_addr_t page_addr;
283 
284 		page_addr = sg_page_iter_dma_address(&sg_iter);
285 		pt_vaddr[act_pte] = vm->pte_encode(page_addr, cache_level);
286 		if (++act_pte == I915_PPGTT_PT_ENTRIES) {
287 			kunmap_atomic(pt_vaddr);
288 			act_pt++;
289 			pt_vaddr = kmap_atomic(ppgtt->pt_pages[act_pt]);
290 			act_pte = 0;
291 
292 		}
293 	}
294 	kunmap_atomic(pt_vaddr);
295 }
296 
297 static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
298 {
299 	struct i915_hw_ppgtt *ppgtt =
300 		container_of(vm, struct i915_hw_ppgtt, base);
301 	int i;
302 
303 	drm_mm_takedown(&ppgtt->base.mm);
304 
305 	if (ppgtt->pt_dma_addr) {
306 		for (i = 0; i < ppgtt->num_pd_entries; i++)
307 			pci_unmap_page(ppgtt->base.dev->pdev,
308 				       ppgtt->pt_dma_addr[i],
309 				       4096, PCI_DMA_BIDIRECTIONAL);
310 	}
311 
312 	kfree(ppgtt->pt_dma_addr);
313 	for (i = 0; i < ppgtt->num_pd_entries; i++)
314 		__free_page(ppgtt->pt_pages[i]);
315 	kfree(ppgtt->pt_pages);
316 	kfree(ppgtt);
317 }
318 
319 static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
320 {
321 	struct drm_device *dev = ppgtt->base.dev;
322 	struct drm_i915_private *dev_priv = dev->dev_private;
323 	unsigned first_pd_entry_in_global_pt;
324 	int i;
325 	int ret = -ENOMEM;
326 
327 	/* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
328 	 * entries. For aliasing ppgtt support we just steal them at the end for
329 	 * now. */
330 	first_pd_entry_in_global_pt = gtt_total_entries(dev_priv->gtt);
331 
332 	ppgtt->base.pte_encode = dev_priv->gtt.base.pte_encode;
333 	ppgtt->num_pd_entries = GEN6_PPGTT_PD_ENTRIES;
334 	ppgtt->enable = gen6_ppgtt_enable;
335 	ppgtt->base.clear_range = gen6_ppgtt_clear_range;
336 	ppgtt->base.insert_entries = gen6_ppgtt_insert_entries;
337 	ppgtt->base.cleanup = gen6_ppgtt_cleanup;
338 	ppgtt->base.scratch = dev_priv->gtt.base.scratch;
339 	ppgtt->pt_pages = kzalloc(sizeof(struct page *)*ppgtt->num_pd_entries,
340 				  GFP_KERNEL);
341 	if (!ppgtt->pt_pages)
342 		return -ENOMEM;
343 
344 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
345 		ppgtt->pt_pages[i] = alloc_page(GFP_KERNEL);
346 		if (!ppgtt->pt_pages[i])
347 			goto err_pt_alloc;
348 	}
349 
350 	ppgtt->pt_dma_addr = kzalloc(sizeof(dma_addr_t) *ppgtt->num_pd_entries,
351 				     GFP_KERNEL);
352 	if (!ppgtt->pt_dma_addr)
353 		goto err_pt_alloc;
354 
355 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
356 		dma_addr_t pt_addr;
357 
358 		pt_addr = pci_map_page(dev->pdev, ppgtt->pt_pages[i], 0, 4096,
359 				       PCI_DMA_BIDIRECTIONAL);
360 
361 		if (pci_dma_mapping_error(dev->pdev, pt_addr)) {
362 			ret = -EIO;
363 			goto err_pd_pin;
364 
365 		}
366 		ppgtt->pt_dma_addr[i] = pt_addr;
367 	}
368 
369 	ppgtt->base.clear_range(&ppgtt->base, 0,
370 				ppgtt->num_pd_entries * I915_PPGTT_PT_ENTRIES);
371 
372 	ppgtt->pd_offset = first_pd_entry_in_global_pt * sizeof(gen6_gtt_pte_t);
373 
374 	return 0;
375 
376 err_pd_pin:
377 	if (ppgtt->pt_dma_addr) {
378 		for (i--; i >= 0; i--)
379 			pci_unmap_page(dev->pdev, ppgtt->pt_dma_addr[i],
380 				       4096, PCI_DMA_BIDIRECTIONAL);
381 	}
382 err_pt_alloc:
383 	kfree(ppgtt->pt_dma_addr);
384 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
385 		if (ppgtt->pt_pages[i])
386 			__free_page(ppgtt->pt_pages[i]);
387 	}
388 	kfree(ppgtt->pt_pages);
389 
390 	return ret;
391 }
392 
393 static int i915_gem_init_aliasing_ppgtt(struct drm_device *dev)
394 {
395 	struct drm_i915_private *dev_priv = dev->dev_private;
396 	struct i915_hw_ppgtt *ppgtt;
397 	int ret;
398 
399 	ppgtt = kzalloc(sizeof(*ppgtt), GFP_KERNEL);
400 	if (!ppgtt)
401 		return -ENOMEM;
402 
403 	ppgtt->base.dev = dev;
404 
405 	if (INTEL_INFO(dev)->gen < 8)
406 		ret = gen6_ppgtt_init(ppgtt);
407 	else
408 		BUG();
409 
410 	if (ret)
411 		kfree(ppgtt);
412 	else {
413 		dev_priv->mm.aliasing_ppgtt = ppgtt;
414 		drm_mm_init(&ppgtt->base.mm, ppgtt->base.start,
415 			    ppgtt->base.total);
416 	}
417 
418 	return ret;
419 }
420 
421 void i915_gem_cleanup_aliasing_ppgtt(struct drm_device *dev)
422 {
423 	struct drm_i915_private *dev_priv = dev->dev_private;
424 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
425 
426 	if (!ppgtt)
427 		return;
428 
429 	ppgtt->base.cleanup(&ppgtt->base);
430 	dev_priv->mm.aliasing_ppgtt = NULL;
431 }
432 
433 void i915_ppgtt_bind_object(struct i915_hw_ppgtt *ppgtt,
434 			    struct drm_i915_gem_object *obj,
435 			    enum i915_cache_level cache_level)
436 {
437 	ppgtt->base.insert_entries(&ppgtt->base, obj->pages,
438 				   i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT,
439 				   cache_level);
440 }
441 
442 void i915_ppgtt_unbind_object(struct i915_hw_ppgtt *ppgtt,
443 			      struct drm_i915_gem_object *obj)
444 {
445 	ppgtt->base.clear_range(&ppgtt->base,
446 				i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT,
447 				obj->base.size >> PAGE_SHIFT);
448 }
449 
450 extern int intel_iommu_gfx_mapped;
451 /* Certain Gen5 chipsets require require idling the GPU before
452  * unmapping anything from the GTT when VT-d is enabled.
453  */
454 static inline bool needs_idle_maps(struct drm_device *dev)
455 {
456 #ifdef CONFIG_INTEL_IOMMU
457 	/* Query intel_iommu to see if we need the workaround. Presumably that
458 	 * was loaded first.
459 	 */
460 	if (IS_GEN5(dev) && IS_MOBILE(dev) && intel_iommu_gfx_mapped)
461 		return true;
462 #endif
463 	return false;
464 }
465 
466 static bool do_idling(struct drm_i915_private *dev_priv)
467 {
468 	bool ret = dev_priv->mm.interruptible;
469 
470 	if (unlikely(dev_priv->gtt.do_idle_maps)) {
471 		dev_priv->mm.interruptible = false;
472 		if (i915_gpu_idle(dev_priv->dev)) {
473 			DRM_ERROR("Couldn't idle GPU\n");
474 			/* Wait a bit, in hopes it avoids the hang */
475 			udelay(10);
476 		}
477 	}
478 
479 	return ret;
480 }
481 
482 static void undo_idling(struct drm_i915_private *dev_priv, bool interruptible)
483 {
484 	if (unlikely(dev_priv->gtt.do_idle_maps))
485 		dev_priv->mm.interruptible = interruptible;
486 }
487 
488 void i915_gem_restore_gtt_mappings(struct drm_device *dev)
489 {
490 	struct drm_i915_private *dev_priv = dev->dev_private;
491 	struct drm_i915_gem_object *obj;
492 
493 	/* First fill our portion of the GTT with scratch pages */
494 	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
495 				       dev_priv->gtt.base.start / PAGE_SIZE,
496 				       dev_priv->gtt.base.total / PAGE_SIZE);
497 
498 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
499 		i915_gem_clflush_object(obj, obj->pin_display);
500 		i915_gem_gtt_bind_object(obj, obj->cache_level);
501 	}
502 
503 	i915_gem_chipset_flush(dev);
504 }
505 
506 int i915_gem_gtt_prepare_object(struct drm_i915_gem_object *obj)
507 {
508 	if (obj->has_dma_mapping)
509 		return 0;
510 
511 	if (!dma_map_sg(&obj->base.dev->pdev->dev,
512 			obj->pages->sgl, obj->pages->nents,
513 			PCI_DMA_BIDIRECTIONAL))
514 		return -ENOSPC;
515 
516 	return 0;
517 }
518 
519 /*
520  * Binds an object into the global gtt with the specified cache level. The object
521  * will be accessible to the GPU via commands whose operands reference offsets
522  * within the global GTT as well as accessible by the GPU through the GMADR
523  * mapped BAR (dev_priv->mm.gtt->gtt).
524  */
525 static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
526 				     struct sg_table *st,
527 				     unsigned int first_entry,
528 				     enum i915_cache_level level)
529 {
530 	struct drm_i915_private *dev_priv = vm->dev->dev_private;
531 	gen6_gtt_pte_t __iomem *gtt_entries =
532 		(gen6_gtt_pte_t __iomem *)dev_priv->gtt.gsm + first_entry;
533 	int i = 0;
534 	struct sg_page_iter sg_iter;
535 	dma_addr_t addr;
536 
537 	for_each_sg_page(st->sgl, &sg_iter, st->nents, 0) {
538 		addr = sg_page_iter_dma_address(&sg_iter);
539 		iowrite32(vm->pte_encode(addr, level), &gtt_entries[i]);
540 		i++;
541 	}
542 
543 	/* XXX: This serves as a posting read to make sure that the PTE has
544 	 * actually been updated. There is some concern that even though
545 	 * registers and PTEs are within the same BAR that they are potentially
546 	 * of NUMA access patterns. Therefore, even with the way we assume
547 	 * hardware should work, we must keep this posting read for paranoia.
548 	 */
549 	if (i != 0)
550 		WARN_ON(readl(&gtt_entries[i-1]) !=
551 			vm->pte_encode(addr, level));
552 
553 	/* This next bit makes the above posting read even more important. We
554 	 * want to flush the TLBs only after we're certain all the PTE updates
555 	 * have finished.
556 	 */
557 	I915_WRITE(GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
558 	POSTING_READ(GFX_FLSH_CNTL_GEN6);
559 }
560 
561 static void gen6_ggtt_clear_range(struct i915_address_space *vm,
562 				  unsigned int first_entry,
563 				  unsigned int num_entries)
564 {
565 	struct drm_i915_private *dev_priv = vm->dev->dev_private;
566 	gen6_gtt_pte_t scratch_pte, __iomem *gtt_base =
567 		(gen6_gtt_pte_t __iomem *) dev_priv->gtt.gsm + first_entry;
568 	const int max_entries = gtt_total_entries(dev_priv->gtt) - first_entry;
569 	int i;
570 
571 	if (WARN(num_entries > max_entries,
572 		 "First entry = %d; Num entries = %d (max=%d)\n",
573 		 first_entry, num_entries, max_entries))
574 		num_entries = max_entries;
575 
576 	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC);
577 	for (i = 0; i < num_entries; i++)
578 		iowrite32(scratch_pte, &gtt_base[i]);
579 	readl(gtt_base);
580 }
581 
582 
583 static void i915_ggtt_insert_entries(struct i915_address_space *vm,
584 				     struct sg_table *st,
585 				     unsigned int pg_start,
586 				     enum i915_cache_level cache_level)
587 {
588 	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
589 		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
590 
591 	intel_gtt_insert_sg_entries(st, pg_start, flags);
592 
593 }
594 
595 static void i915_ggtt_clear_range(struct i915_address_space *vm,
596 				  unsigned int first_entry,
597 				  unsigned int num_entries)
598 {
599 	intel_gtt_clear_range(first_entry, num_entries);
600 }
601 
602 
603 void i915_gem_gtt_bind_object(struct drm_i915_gem_object *obj,
604 			      enum i915_cache_level cache_level)
605 {
606 	struct drm_device *dev = obj->base.dev;
607 	struct drm_i915_private *dev_priv = dev->dev_private;
608 	const unsigned long entry = i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT;
609 
610 	dev_priv->gtt.base.insert_entries(&dev_priv->gtt.base, obj->pages,
611 					  entry,
612 					  cache_level);
613 
614 	obj->has_global_gtt_mapping = 1;
615 }
616 
617 void i915_gem_gtt_unbind_object(struct drm_i915_gem_object *obj)
618 {
619 	struct drm_device *dev = obj->base.dev;
620 	struct drm_i915_private *dev_priv = dev->dev_private;
621 	const unsigned long entry = i915_gem_obj_ggtt_offset(obj) >> PAGE_SHIFT;
622 
623 	dev_priv->gtt.base.clear_range(&dev_priv->gtt.base,
624 				       entry,
625 				       obj->base.size >> PAGE_SHIFT);
626 
627 	obj->has_global_gtt_mapping = 0;
628 }
629 
630 void i915_gem_gtt_finish_object(struct drm_i915_gem_object *obj)
631 {
632 	struct drm_device *dev = obj->base.dev;
633 	struct drm_i915_private *dev_priv = dev->dev_private;
634 	bool interruptible;
635 
636 	interruptible = do_idling(dev_priv);
637 
638 	if (!obj->has_dma_mapping)
639 		dma_unmap_sg(&dev->pdev->dev,
640 			     obj->pages->sgl, obj->pages->nents,
641 			     PCI_DMA_BIDIRECTIONAL);
642 
643 	undo_idling(dev_priv, interruptible);
644 }
645 
646 static void i915_gtt_color_adjust(struct drm_mm_node *node,
647 				  unsigned long color,
648 				  unsigned long *start,
649 				  unsigned long *end)
650 {
651 	if (node->color != color)
652 		*start += 4096;
653 
654 	if (!list_empty(&node->node_list)) {
655 		node = list_entry(node->node_list.next,
656 				  struct drm_mm_node,
657 				  node_list);
658 		if (node->allocated && node->color != color)
659 			*end -= 4096;
660 	}
661 }
662 void i915_gem_setup_global_gtt(struct drm_device *dev,
663 			       unsigned long start,
664 			       unsigned long mappable_end,
665 			       unsigned long end)
666 {
667 	/* Let GEM Manage all of the aperture.
668 	 *
669 	 * However, leave one page at the end still bound to the scratch page.
670 	 * There are a number of places where the hardware apparently prefetches
671 	 * past the end of the object, and we've seen multiple hangs with the
672 	 * GPU head pointer stuck in a batchbuffer bound at the last page of the
673 	 * aperture.  One page should be enough to keep any prefetching inside
674 	 * of the aperture.
675 	 */
676 	struct drm_i915_private *dev_priv = dev->dev_private;
677 	struct i915_address_space *ggtt_vm = &dev_priv->gtt.base;
678 	struct drm_mm_node *entry;
679 	struct drm_i915_gem_object *obj;
680 	unsigned long hole_start, hole_end;
681 
682 	BUG_ON(mappable_end > end);
683 
684 	/* Subtract the guard page ... */
685 	drm_mm_init(&ggtt_vm->mm, start, end - start - PAGE_SIZE);
686 	if (!HAS_LLC(dev))
687 		dev_priv->gtt.base.mm.color_adjust = i915_gtt_color_adjust;
688 
689 	/* Mark any preallocated objects as occupied */
690 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
691 		struct i915_vma *vma = i915_gem_obj_to_vma(obj, ggtt_vm);
692 		int ret;
693 		DRM_DEBUG_KMS("reserving preallocated space: %lx + %zx\n",
694 			      i915_gem_obj_ggtt_offset(obj), obj->base.size);
695 
696 		WARN_ON(i915_gem_obj_ggtt_bound(obj));
697 		ret = drm_mm_reserve_node(&ggtt_vm->mm, &vma->node);
698 		if (ret)
699 			DRM_DEBUG_KMS("Reservation failed\n");
700 		obj->has_global_gtt_mapping = 1;
701 		list_add(&vma->vma_link, &obj->vma_list);
702 	}
703 
704 	dev_priv->gtt.base.start = start;
705 	dev_priv->gtt.base.total = end - start;
706 
707 	/* Clear any non-preallocated blocks */
708 	drm_mm_for_each_hole(entry, &ggtt_vm->mm, hole_start, hole_end) {
709 		const unsigned long count = (hole_end - hole_start) / PAGE_SIZE;
710 		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
711 			      hole_start, hole_end);
712 		ggtt_vm->clear_range(ggtt_vm, hole_start / PAGE_SIZE, count);
713 	}
714 
715 	/* And finally clear the reserved guard page */
716 	ggtt_vm->clear_range(ggtt_vm, end / PAGE_SIZE - 1, 1);
717 }
718 
719 static bool
720 intel_enable_ppgtt(struct drm_device *dev)
721 {
722 	if (i915_enable_ppgtt >= 0)
723 		return i915_enable_ppgtt;
724 
725 #ifdef CONFIG_INTEL_IOMMU
726 	/* Disable ppgtt on SNB if VT-d is on. */
727 	if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped)
728 		return false;
729 #endif
730 
731 	return true;
732 }
733 
734 void i915_gem_init_global_gtt(struct drm_device *dev)
735 {
736 	struct drm_i915_private *dev_priv = dev->dev_private;
737 	unsigned long gtt_size, mappable_size;
738 
739 	gtt_size = dev_priv->gtt.base.total;
740 	mappable_size = dev_priv->gtt.mappable_end;
741 
742 	if (intel_enable_ppgtt(dev) && HAS_ALIASING_PPGTT(dev)) {
743 		int ret;
744 
745 		if (INTEL_INFO(dev)->gen <= 7) {
746 			/* PPGTT pdes are stolen from global gtt ptes, so shrink the
747 			 * aperture accordingly when using aliasing ppgtt. */
748 			gtt_size -= GEN6_PPGTT_PD_ENTRIES * PAGE_SIZE;
749 		}
750 
751 		i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
752 
753 		ret = i915_gem_init_aliasing_ppgtt(dev);
754 		if (!ret)
755 			return;
756 
757 		DRM_ERROR("Aliased PPGTT setup failed %d\n", ret);
758 		drm_mm_takedown(&dev_priv->gtt.base.mm);
759 		gtt_size += GEN6_PPGTT_PD_ENTRIES * PAGE_SIZE;
760 	}
761 	i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
762 }
763 
764 static int setup_scratch_page(struct drm_device *dev)
765 {
766 	struct drm_i915_private *dev_priv = dev->dev_private;
767 	struct page *page;
768 	dma_addr_t dma_addr;
769 
770 	page = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
771 	if (page == NULL)
772 		return -ENOMEM;
773 	get_page(page);
774 	set_pages_uc(page, 1);
775 
776 #ifdef CONFIG_INTEL_IOMMU
777 	dma_addr = pci_map_page(dev->pdev, page, 0, PAGE_SIZE,
778 				PCI_DMA_BIDIRECTIONAL);
779 	if (pci_dma_mapping_error(dev->pdev, dma_addr))
780 		return -EINVAL;
781 #else
782 	dma_addr = page_to_phys(page);
783 #endif
784 	dev_priv->gtt.base.scratch.page = page;
785 	dev_priv->gtt.base.scratch.addr = dma_addr;
786 
787 	return 0;
788 }
789 
790 static void teardown_scratch_page(struct drm_device *dev)
791 {
792 	struct drm_i915_private *dev_priv = dev->dev_private;
793 	struct page *page = dev_priv->gtt.base.scratch.page;
794 
795 	set_pages_wb(page, 1);
796 	pci_unmap_page(dev->pdev, dev_priv->gtt.base.scratch.addr,
797 		       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
798 	put_page(page);
799 	__free_page(page);
800 }
801 
802 static inline unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
803 {
804 	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
805 	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
806 	return snb_gmch_ctl << 20;
807 }
808 
809 static inline size_t gen6_get_stolen_size(u16 snb_gmch_ctl)
810 {
811 	snb_gmch_ctl >>= SNB_GMCH_GMS_SHIFT;
812 	snb_gmch_ctl &= SNB_GMCH_GMS_MASK;
813 	return snb_gmch_ctl << 25; /* 32 MB units */
814 }
815 
816 static int gen6_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 	phys_addr_t gtt_bus_addr;
824 	unsigned int gtt_size;
825 	u16 snb_gmch_ctl;
826 	int ret;
827 
828 	*mappable_base = pci_resource_start(dev->pdev, 2);
829 	*mappable_end = pci_resource_len(dev->pdev, 2);
830 
831 	/* 64/512MB is the current min/max we actually know of, but this is just
832 	 * a coarse sanity check.
833 	 */
834 	if ((*mappable_end < (64<<20) || (*mappable_end > (512<<20)))) {
835 		DRM_ERROR("Unknown GMADR size (%lx)\n",
836 			  dev_priv->gtt.mappable_end);
837 		return -ENXIO;
838 	}
839 
840 	if (!pci_set_dma_mask(dev->pdev, DMA_BIT_MASK(40)))
841 		pci_set_consistent_dma_mask(dev->pdev, DMA_BIT_MASK(40));
842 	pci_read_config_word(dev->pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
843 	gtt_size = gen6_get_total_gtt_size(snb_gmch_ctl);
844 
845 	*stolen = gen6_get_stolen_size(snb_gmch_ctl);
846 	*gtt_total = (gtt_size / sizeof(gen6_gtt_pte_t)) << PAGE_SHIFT;
847 
848 	/* For Modern GENs the PTEs and register space are split in the BAR */
849 	gtt_bus_addr = pci_resource_start(dev->pdev, 0) +
850 		(pci_resource_len(dev->pdev, 0) / 2);
851 
852 	dev_priv->gtt.gsm = ioremap_wc(gtt_bus_addr, gtt_size);
853 	if (!dev_priv->gtt.gsm) {
854 		DRM_ERROR("Failed to map the gtt page table\n");
855 		return -ENOMEM;
856 	}
857 
858 	ret = setup_scratch_page(dev);
859 	if (ret)
860 		DRM_ERROR("Scratch setup failed\n");
861 
862 	dev_priv->gtt.base.clear_range = gen6_ggtt_clear_range;
863 	dev_priv->gtt.base.insert_entries = gen6_ggtt_insert_entries;
864 
865 	return ret;
866 }
867 
868 static void gen6_gmch_remove(struct i915_address_space *vm)
869 {
870 
871 	struct i915_gtt *gtt = container_of(vm, struct i915_gtt, base);
872 	iounmap(gtt->gsm);
873 	teardown_scratch_page(vm->dev);
874 }
875 
876 static int i915_gmch_probe(struct drm_device *dev,
877 			   size_t *gtt_total,
878 			   size_t *stolen,
879 			   phys_addr_t *mappable_base,
880 			   unsigned long *mappable_end)
881 {
882 	struct drm_i915_private *dev_priv = dev->dev_private;
883 	int ret;
884 
885 	ret = intel_gmch_probe(dev_priv->bridge_dev, dev_priv->dev->pdev, NULL);
886 	if (!ret) {
887 		DRM_ERROR("failed to set up gmch\n");
888 		return -EIO;
889 	}
890 
891 	intel_gtt_get(gtt_total, stolen, mappable_base, mappable_end);
892 
893 	dev_priv->gtt.do_idle_maps = needs_idle_maps(dev_priv->dev);
894 	dev_priv->gtt.base.clear_range = i915_ggtt_clear_range;
895 	dev_priv->gtt.base.insert_entries = i915_ggtt_insert_entries;
896 
897 	return 0;
898 }
899 
900 static void i915_gmch_remove(struct i915_address_space *vm)
901 {
902 	intel_gmch_remove();
903 }
904 
905 int i915_gem_gtt_init(struct drm_device *dev)
906 {
907 	struct drm_i915_private *dev_priv = dev->dev_private;
908 	struct i915_gtt *gtt = &dev_priv->gtt;
909 	int ret;
910 
911 	if (INTEL_INFO(dev)->gen <= 5) {
912 		gtt->gtt_probe = i915_gmch_probe;
913 		gtt->base.cleanup = i915_gmch_remove;
914 	} else {
915 		gtt->gtt_probe = gen6_gmch_probe;
916 		gtt->base.cleanup = gen6_gmch_remove;
917 		if (IS_HASWELL(dev) && dev_priv->ellc_size)
918 			gtt->base.pte_encode = iris_pte_encode;
919 		else if (IS_HASWELL(dev))
920 			gtt->base.pte_encode = hsw_pte_encode;
921 		else if (IS_VALLEYVIEW(dev))
922 			gtt->base.pte_encode = byt_pte_encode;
923 		else if (INTEL_INFO(dev)->gen >= 7)
924 			gtt->base.pte_encode = ivb_pte_encode;
925 		else
926 			gtt->base.pte_encode = snb_pte_encode;
927 	}
928 
929 	ret = gtt->gtt_probe(dev, &gtt->base.total, &gtt->stolen_size,
930 			     &gtt->mappable_base, &gtt->mappable_end);
931 	if (ret)
932 		return ret;
933 
934 	gtt->base.dev = dev;
935 
936 	/* GMADR is the PCI mmio aperture into the global GTT. */
937 	DRM_INFO("Memory usable by graphics device = %zdM\n",
938 		 gtt->base.total >> 20);
939 	DRM_DEBUG_DRIVER("GMADR size = %ldM\n", gtt->mappable_end >> 20);
940 	DRM_DEBUG_DRIVER("GTT stolen size = %zdM\n", gtt->stolen_size >> 20);
941 
942 	return 0;
943 }
944