drm/i915: Convert clflushed pagetables over to WC maps

We flush the entire page every time we update a few bytes, making the update of a page table many, many times slower than is required. If we create a WC map of the page for our updates, we can avoid the clflush but incur additional cost for creating the pagetable. We amoritize that cost by reusing page vmappings, and only changing the page protection in batches. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
2017-02-15 08:43:40 +00:00
parent cbc4e9e6a6
commit 8448661d65
4 changed files with 181 additions and 170 deletions
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2481,8 +2481,6 @@ struct drm_i915_private {
 	/* Used to save the pipe-to-encoder mapping for audio */
 	struct intel_encoder *av_enc_map[I915_MAX_PIPES];

-	I915_SELFTEST_DECLARE(struct fault_attr vm_fault);
-
 	/*
 	 * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
 	 * will be rejected. Instead look for a better place.
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -343,46 +343,72 @@ static gen6_pte_t iris_pte_encode(dma_addr_t addr,
 	return pte;
 }

-static int __setup_page_dma(struct drm_i915_private *dev_priv,
-			    struct i915_page_dma *p, gfp_t flags)
+static struct page *vm_alloc_page(struct i915_address_space *vm, gfp_t gfp)
 {
-	struct device *kdev = &dev_priv->drm.pdev->dev;
+	struct page *page;

-	if (I915_SELFTEST_ONLY(should_fail(&dev_priv->vm_fault, 1)))
-		i915_gem_shrink_all(dev_priv);
+	if (I915_SELFTEST_ONLY(should_fail(&vm->fault_attr, 1)))
+		i915_gem_shrink_all(vm->i915);

-	p->page = alloc_page(flags);
-	if (!p->page)
+	if (vm->free_pages.nr)
+		return vm->free_pages.pages[--vm->free_pages.nr];
+
+	page = alloc_page(gfp);
+	if (!page)
+		return NULL;
+
+	if (vm->pt_kmap_wc)
+		set_pages_array_wc(&page, 1);
+
+	return page;
+}
+
+static void vm_free_pages_release(struct i915_address_space *vm)
+{
+	GEM_BUG_ON(!pagevec_count(&vm->free_pages));
+
+	if (vm->pt_kmap_wc)
+		set_pages_array_wb(vm->free_pages.pages,
+				   pagevec_count(&vm->free_pages));
+
+	__pagevec_release(&vm->free_pages);
+}
+
+static void vm_free_page(struct i915_address_space *vm, struct page *page)
+{
+	if (!pagevec_add(&vm->free_pages, page))
+		vm_free_pages_release(vm);
+}
+
+static int __setup_page_dma(struct i915_address_space *vm,
+			    struct i915_page_dma *p,
+			    gfp_t gfp)
+{
+	p->page = vm_alloc_page(vm, gfp | __GFP_NOWARN | __GFP_NORETRY);
+	if (unlikely(!p->page))
 		return -ENOMEM;

-	p->daddr = dma_map_page(kdev,
-				p->page, 0, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
-
-	if (dma_mapping_error(kdev, p->daddr)) {
-		__free_page(p->page);
-		return -EINVAL;
+	p->daddr = dma_map_page(vm->dma, p->page, 0, PAGE_SIZE,
+				PCI_DMA_BIDIRECTIONAL);
+	if (unlikely(dma_mapping_error(vm->dma, p->daddr))) {
+		vm_free_page(vm, p->page);
+		return -ENOMEM;
 	}

 	return 0;
 }

-static int setup_page_dma(struct drm_i915_private *dev_priv,
+static int setup_page_dma(struct i915_address_space *vm,
 			  struct i915_page_dma *p)
 {
-	return __setup_page_dma(dev_priv, p, I915_GFP_DMA);
+	return __setup_page_dma(vm, p, I915_GFP_DMA);
 }

-static void cleanup_page_dma(struct drm_i915_private *dev_priv,
+static void cleanup_page_dma(struct i915_address_space *vm,
 			     struct i915_page_dma *p)
 {
-	struct pci_dev *pdev = dev_priv->drm.pdev;
-
-	if (WARN_ON(!p->page))
-		return;
-
-	dma_unmap_page(&pdev->dev, p->daddr, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
-	__free_page(p->page);
-	memset(p, 0, sizeof(*p));
+	dma_unmap_page(vm->dma, p->daddr, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+	vm_free_page(vm, p->page);
 }

 static void *kmap_page_dma(struct i915_page_dma *p)
@@ -393,67 +419,54 @@ static void *kmap_page_dma(struct i915_page_dma *p)
 /* We use the flushing unmap only with ppgtt structures:
 * page directories, page tables and scratch pages.
 */
-static void kunmap_page_dma(struct drm_i915_private *dev_priv, void *vaddr)
+static void kunmap_page_dma(void *vaddr)
 {
-	/* There are only few exceptions for gen >=6. chv and bxt.
-	 * And we are not sure about the latter so play safe for now.
-	 */
-	if (IS_CHERRYVIEW(dev_priv) || IS_GEN9_LP(dev_priv))
-		drm_clflush_virt_range(vaddr, PAGE_SIZE);
-
 	kunmap_atomic(vaddr);
 }

 #define kmap_px(px) kmap_page_dma(px_base(px))
-#define kunmap_px(ppgtt, vaddr) \
-		kunmap_page_dma((ppgtt)->base.i915, (vaddr))
+#define kunmap_px(vaddr) kunmap_page_dma((vaddr))

-#define setup_px(dev_priv, px) setup_page_dma((dev_priv), px_base(px))
-#define cleanup_px(dev_priv, px) cleanup_page_dma((dev_priv), px_base(px))
-#define fill_px(dev_priv, px, v) fill_page_dma((dev_priv), px_base(px), (v))
-#define fill32_px(dev_priv, px, v) \
-		fill_page_dma_32((dev_priv), px_base(px), (v))
+#define setup_px(vm, px) setup_page_dma((vm), px_base(px))
+#define cleanup_px(vm, px) cleanup_page_dma((vm), px_base(px))
+#define fill_px(ppgtt, px, v) fill_page_dma((vm), px_base(px), (v))
+#define fill32_px(ppgtt, px, v) fill_page_dma_32((vm), px_base(px), (v))

-static void fill_page_dma(struct drm_i915_private *dev_priv,
-			  struct i915_page_dma *p, const uint64_t val)
+static void fill_page_dma(struct i915_address_space *vm,
+			  struct i915_page_dma *p,
+			  const u64 val)
 {
+	u64 * const vaddr = kmap_page_dma(p);
 	int i;
-	uint64_t * const vaddr = kmap_page_dma(p);

 	for (i = 0; i < 512; i++)
 		vaddr[i] = val;

-	kunmap_page_dma(dev_priv, vaddr);
+	kunmap_page_dma(vaddr);
 }

-static void fill_page_dma_32(struct drm_i915_private *dev_priv,
-			     struct i915_page_dma *p, const uint32_t val32)
+static void fill_page_dma_32(struct i915_address_space *vm,
+			     struct i915_page_dma *p,
+			     const u32 v)
 {
-	uint64_t v = val32;
-
-	v = v << 32 | val32;
-
-	fill_page_dma(dev_priv, p, v);
+	fill_page_dma(vm, p, (u64)v << 32 | v);
 }

 static int
-setup_scratch_page(struct drm_i915_private *dev_priv,
-		   struct i915_page_dma *scratch,
-		   gfp_t gfp)
+setup_scratch_page(struct i915_address_space *vm, gfp_t gfp)
 {
-	return __setup_page_dma(dev_priv, scratch, gfp | __GFP_ZERO);
+	return __setup_page_dma(vm, &vm->scratch_page, gfp | __GFP_ZERO);
 }

-static void cleanup_scratch_page(struct drm_i915_private *dev_priv,
-				 struct i915_page_dma *scratch)
+static void cleanup_scratch_page(struct i915_address_space *vm)
 {
-	cleanup_page_dma(dev_priv, scratch);
+	cleanup_page_dma(vm, &vm->scratch_page);
 }

-static struct i915_page_table *alloc_pt(struct drm_i915_private *dev_priv)
+static struct i915_page_table *alloc_pt(struct i915_address_space *vm)
 {
 	struct i915_page_table *pt;
-	const size_t count = INTEL_GEN(dev_priv) >= 8 ? GEN8_PTES : GEN6_PTES;
+	const size_t count = INTEL_GEN(vm->i915) >= 8 ? GEN8_PTES : GEN6_PTES;
 	int ret = -ENOMEM;

 	pt = kzalloc(sizeof(*pt), GFP_KERNEL);
@@ -466,7 +479,7 @@ static struct i915_page_table *alloc_pt(struct drm_i915_private *dev_priv)
 	if (!pt->used_ptes)
 		goto fail_bitmap;

-	ret = setup_px(dev_priv, pt);
+	ret = setup_px(vm, pt);
 	if (ret)
 		goto fail_page_m;

@@ -480,10 +493,9 @@ fail_bitmap:
 	return ERR_PTR(ret);
 }

-static void free_pt(struct drm_i915_private *dev_priv,
-		    struct i915_page_table *pt)
+static void free_pt(struct i915_address_space *vm, struct i915_page_table *pt)
 {
-	cleanup_px(dev_priv, pt);
+	cleanup_px(vm, pt);
 	kfree(pt->used_ptes);
 	kfree(pt);
 }
@@ -496,7 +508,7 @@ static void gen8_initialize_pt(struct i915_address_space *vm,
 	scratch_pte = gen8_pte_encode(vm->scratch_page.daddr,
 				      I915_CACHE_LLC);

-	fill_px(vm->i915, pt, scratch_pte);
+	fill_px(vm, pt, scratch_pte);
 }

 static void gen6_initialize_pt(struct i915_address_space *vm,
@@ -509,10 +521,10 @@ static void gen6_initialize_pt(struct i915_address_space *vm,
 	scratch_pte = vm->pte_encode(vm->scratch_page.daddr,
 				     I915_CACHE_LLC, 0);

-	fill32_px(vm->i915, pt, scratch_pte);
+	fill32_px(vm, pt, scratch_pte);
 }

-static struct i915_page_directory *alloc_pd(struct drm_i915_private *dev_priv)
+static struct i915_page_directory *alloc_pd(struct i915_address_space *vm)
 {
 	struct i915_page_directory *pd;
 	int ret = -ENOMEM;
@@ -526,7 +538,7 @@ static struct i915_page_directory *alloc_pd(struct drm_i915_private *dev_priv)
 	if (!pd->used_pdes)
 		goto fail_bitmap;

-	ret = setup_px(dev_priv, pd);
+	ret = setup_px(vm, pd);
 	if (ret)
 		goto fail_page_m;

@@ -540,11 +552,11 @@ fail_bitmap:
 	return ERR_PTR(ret);
 }

-static void free_pd(struct drm_i915_private *dev_priv,
+static void free_pd(struct i915_address_space *vm,
 		    struct i915_page_directory *pd)
 {
 	if (px_page(pd)) {
-		cleanup_px(dev_priv, pd);
+		cleanup_px(vm, pd);
 		kfree(pd->used_pdes);
 		kfree(pd);
 	}
@@ -557,7 +569,7 @@ static void gen8_initialize_pd(struct i915_address_space *vm,

 	scratch_pde = gen8_pde_encode(px_dma(vm->scratch_pt), I915_CACHE_LLC);

-	fill_px(vm->i915, pd, scratch_pde);
+	fill_px(vm, pd, scratch_pde);
 }

 static int __pdp_init(struct drm_i915_private *dev_priv,
@@ -591,23 +603,23 @@ static void __pdp_fini(struct i915_page_directory_pointer *pdp)
 	pdp->page_directory = NULL;
 }

-static struct
-i915_page_directory_pointer *alloc_pdp(struct drm_i915_private *dev_priv)
+static struct i915_page_directory_pointer *
+alloc_pdp(struct i915_address_space *vm)
 {
 	struct i915_page_directory_pointer *pdp;
 	int ret = -ENOMEM;

-	WARN_ON(!USES_FULL_48BIT_PPGTT(dev_priv));
+	WARN_ON(!USES_FULL_48BIT_PPGTT(vm->i915));

 	pdp = kzalloc(sizeof(*pdp), GFP_KERNEL);
 	if (!pdp)
 		return ERR_PTR(-ENOMEM);

-	ret = __pdp_init(dev_priv, pdp);
+	ret = __pdp_init(vm->i915, pdp);
 	if (ret)
 		goto fail_bitmap;

-	ret = setup_px(dev_priv, pdp);
+	ret = setup_px(vm, pdp);
 	if (ret)
 		goto fail_page_m;

@@ -621,12 +633,12 @@ fail_bitmap:
 	return ERR_PTR(ret);
 }

-static void free_pdp(struct drm_i915_private *dev_priv,
+static void free_pdp(struct i915_address_space *vm,
 		     struct i915_page_directory_pointer *pdp)
 {
 	__pdp_fini(pdp);
-	if (USES_FULL_48BIT_PPGTT(dev_priv)) {
-		cleanup_px(dev_priv, pdp);
+	if (USES_FULL_48BIT_PPGTT(vm->i915)) {
+		cleanup_px(vm, pdp);
 		kfree(pdp);
 	}
 }
@@ -638,7 +650,7 @@ static void gen8_initialize_pdp(struct i915_address_space *vm,

 	scratch_pdpe = gen8_pdpe_encode(px_dma(vm->scratch_pd), I915_CACHE_LLC);

-	fill_px(vm->i915, pdp, scratch_pdpe);
+	fill_px(vm, pdp, scratch_pdpe);
 }

 static void gen8_initialize_pml4(struct i915_address_space *vm,
@@ -649,7 +661,7 @@ static void gen8_initialize_pml4(struct i915_address_space *vm,
 	scratch_pml4e = gen8_pml4e_encode(px_dma(vm->scratch_pdp),
 					  I915_CACHE_LLC);

-	fill_px(vm->i915, pml4, scratch_pml4e);
+	fill_px(vm, pml4, scratch_pml4e);
 }

 static void
@@ -665,20 +677,18 @@ gen8_setup_pdpe(struct i915_hw_ppgtt *ppgtt,

 	page_directorypo = kmap_px(pdp);
 	page_directorypo[index] = gen8_pdpe_encode(px_dma(pd), I915_CACHE_LLC);
-	kunmap_px(ppgtt, page_directorypo);
+	kunmap_px(page_directorypo);
 }

 static void
-gen8_setup_pml4e(struct i915_hw_ppgtt *ppgtt,
-		 struct i915_pml4 *pml4,
+gen8_setup_pml4e(struct i915_pml4 *pml4,
 		 struct i915_page_directory_pointer *pdp,
 		 int index)
 {
 	gen8_ppgtt_pml4e_t *pagemap = kmap_px(pml4);

-	WARN_ON(!USES_FULL_48BIT_PPGTT(to_i915(ppgtt->base.dev)));
 	pagemap[index] = gen8_pml4e_encode(px_dma(pdp), I915_CACHE_LLC);
-	kunmap_px(ppgtt, pagemap);
+	kunmap_px(pagemap);
 }

 /* Broadwell Page Directory Pointer Descriptors */
@@ -746,7 +756,6 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm,
 				uint64_t start,
 				uint64_t length)
 {
-	struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
 	unsigned int num_entries = gen8_pte_count(start, length);
 	unsigned int pte = gen8_pte_index(start);
 	unsigned int pte_end = pte + num_entries;
@@ -768,7 +777,7 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm,
 	vaddr = kmap_px(pt);
 	while (pte < pte_end)
 		vaddr[pte++] = scratch_pte;
-	kunmap_px(ppgtt, vaddr);
+	kunmap_px(vaddr);

 	return false;
 }
@@ -781,7 +790,6 @@ static bool gen8_ppgtt_clear_pd(struct i915_address_space *vm,
 				uint64_t start,
 				uint64_t length)
 {
-	struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
 	struct i915_page_table *pt;
 	uint64_t pde;
 	gen8_pde_t *pde_vaddr;
@@ -796,8 +804,8 @@ static bool gen8_ppgtt_clear_pd(struct i915_address_space *vm,
 			__clear_bit(pde, pd->used_pdes);
 			pde_vaddr = kmap_px(pd);
 			pde_vaddr[pde] = scratch_pde;
-			kunmap_px(ppgtt, pde_vaddr);
-			free_pt(vm->i915, pt);
+			kunmap_px(pde_vaddr);
+			free_pt(vm, pt);
 		}
 	}

@@ -826,7 +834,7 @@ static bool gen8_ppgtt_clear_pdp(struct i915_address_space *vm,
 		if (gen8_ppgtt_clear_pd(vm, pd, start, length)) {
 			__clear_bit(pdpe, pdp->used_pdpes);
 			gen8_setup_pdpe(ppgtt, pdp, vm->scratch_pd, pdpe);
-			free_pd(vm->i915, pd);
+			free_pd(vm, pd);
 		}
 	}

@@ -847,7 +855,6 @@ static void gen8_ppgtt_clear_pml4(struct i915_address_space *vm,
 				  uint64_t start,
 				  uint64_t length)
 {
-	struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
 	struct i915_page_directory_pointer *pdp;
 	uint64_t pml4e;

@@ -859,8 +866,8 @@ static void gen8_ppgtt_clear_pml4(struct i915_address_space *vm,

 		if (gen8_ppgtt_clear_pdp(vm, pdp, start, length)) {
 			__clear_bit(pml4e, pml4->used_pml4es);
-			gen8_setup_pml4e(ppgtt, pml4, vm->scratch_pdp, pml4e);
-			free_pdp(vm->i915, pdp);
+			gen8_setup_pml4e(pml4, vm->scratch_pdp, pml4e);
+			free_pdp(vm, pdp);
 		}
 	}
 }
@@ -925,12 +932,12 @@ gen8_ppgtt_insert_pte_entries(struct i915_hw_ppgtt *ppgtt,
 				pde = 0;
 			}

-			kunmap_px(ppgtt, vaddr);
+			kunmap_px(vaddr);
 			vaddr = kmap_px(pd->page_table[pde]);
 			pte = 0;
 		}
 	} while (1);
-	kunmap_px(ppgtt, vaddr);
+	kunmap_px(vaddr);

 	return ret;
 }
@@ -972,7 +979,7 @@ static void gen8_ppgtt_insert_4lvl(struct i915_address_space *vm,
 		;
 }

-static void gen8_free_page_tables(struct drm_i915_private *dev_priv,
+static void gen8_free_page_tables(struct i915_address_space *vm,
 				  struct i915_page_directory *pd)
 {
 	int i;
@@ -984,34 +991,33 @@ static void gen8_free_page_tables(struct drm_i915_private *dev_priv,
 		if (WARN_ON(!pd->page_table[i]))
 			continue;

-		free_pt(dev_priv, pd->page_table[i]);
+		free_pt(vm, pd->page_table[i]);
 		pd->page_table[i] = NULL;
 	}
 }

 static int gen8_init_scratch(struct i915_address_space *vm)
 {
-	struct drm_i915_private *dev_priv = vm->i915;
 	int ret;

-	ret = setup_scratch_page(dev_priv, &vm->scratch_page, I915_GFP_DMA);
+	ret = setup_scratch_page(vm, I915_GFP_DMA);
 	if (ret)
 		return ret;

-	vm->scratch_pt = alloc_pt(dev_priv);
+	vm->scratch_pt = alloc_pt(vm);
 	if (IS_ERR(vm->scratch_pt)) {
 		ret = PTR_ERR(vm->scratch_pt);
 		goto free_scratch_page;
 	}

-	vm->scratch_pd = alloc_pd(dev_priv);
+	vm->scratch_pd = alloc_pd(vm);
 	if (IS_ERR(vm->scratch_pd)) {
 		ret = PTR_ERR(vm->scratch_pd);
 		goto free_pt;
 	}

-	if (USES_FULL_48BIT_PPGTT(dev_priv)) {
-		vm->scratch_pdp = alloc_pdp(dev_priv);
+	if (USES_FULL_48BIT_PPGTT(dev)) {
+		vm->scratch_pdp = alloc_pdp(vm);
 		if (IS_ERR(vm->scratch_pdp)) {
 			ret = PTR_ERR(vm->scratch_pdp);
 			goto free_pd;
@@ -1026,11 +1032,11 @@ static int gen8_init_scratch(struct i915_address_space *vm)
 	return 0;

 free_pd:
-	free_pd(dev_priv, vm->scratch_pd);
+	free_pd(vm, vm->scratch_pd);
 free_pt:
-	free_pt(dev_priv, vm->scratch_pt);
+	free_pt(vm, vm->scratch_pt);
 free_scratch_page:
-	cleanup_scratch_page(dev_priv, &vm->scratch_page);
+	cleanup_scratch_page(vm);

 	return ret;
 }
@@ -1068,44 +1074,41 @@ static int gen8_ppgtt_notify_vgt(struct i915_hw_ppgtt *ppgtt, bool create)

 static void gen8_free_scratch(struct i915_address_space *vm)
 {
-	struct drm_i915_private *dev_priv = vm->i915;
-
-	if (USES_FULL_48BIT_PPGTT(dev_priv))
-		free_pdp(dev_priv, vm->scratch_pdp);
-	free_pd(dev_priv, vm->scratch_pd);
-	free_pt(dev_priv, vm->scratch_pt);
-	cleanup_scratch_page(dev_priv, &vm->scratch_page);
+	if (USES_FULL_48BIT_PPGTT(vm->i915))
+		free_pdp(vm, vm->scratch_pdp);
+	free_pd(vm, vm->scratch_pd);
+	free_pt(vm, vm->scratch_pt);
+	cleanup_scratch_page(vm);
 }

-static void gen8_ppgtt_cleanup_3lvl(struct drm_i915_private *dev_priv,
+static void gen8_ppgtt_cleanup_3lvl(struct i915_address_space *vm,
 				    struct i915_page_directory_pointer *pdp)
 {
 	int i;

-	for_each_set_bit(i, pdp->used_pdpes, I915_PDPES_PER_PDP(dev_priv)) {
+	for_each_set_bit(i, pdp->used_pdpes, I915_PDPES_PER_PDP(vm->i915)) {
 		if (WARN_ON(!pdp->page_directory[i]))
 			continue;

-		gen8_free_page_tables(dev_priv, pdp->page_directory[i]);
-		free_pd(dev_priv, pdp->page_directory[i]);
+		gen8_free_page_tables(vm, pdp->page_directory[i]);
+		free_pd(vm, pdp->page_directory[i]);
 	}

-	free_pdp(dev_priv, pdp);
+	free_pdp(vm, pdp);
 }

 static void gen8_ppgtt_cleanup_4lvl(struct i915_hw_ppgtt *ppgtt)
 {
-	struct drm_i915_private *dev_priv = ppgtt->base.i915;
 	int i;

 	for_each_set_bit(i, ppgtt->pml4.used_pml4es, GEN8_PML4ES_PER_PML4) {
 		if (WARN_ON(!ppgtt->pml4.pdps[i]))
 			continue;

-		gen8_ppgtt_cleanup_3lvl(dev_priv, ppgtt->pml4.pdps[i]);
+		gen8_ppgtt_cleanup_3lvl(&ppgtt->base, ppgtt->pml4.pdps[i]);
 	}

-	cleanup_px(dev_priv, &ppgtt->pml4);
+	cleanup_px(&ppgtt->base, &ppgtt->pml4);
 }

 static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
@@ -1116,8 +1119,8 @@ static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
 	if (intel_vgpu_active(dev_priv))
 		gen8_ppgtt_notify_vgt(ppgtt, false);

-	if (!USES_FULL_48BIT_PPGTT(dev_priv))
-		gen8_ppgtt_cleanup_3lvl(dev_priv, &ppgtt->pdp);
+	if (!USES_FULL_48BIT_PPGTT(vm->i915))
+		gen8_ppgtt_cleanup_3lvl(&ppgtt->base, &ppgtt->pdp);
 	else
 		gen8_ppgtt_cleanup_4lvl(ppgtt);

@@ -1148,7 +1151,6 @@ static int gen8_ppgtt_alloc_pagetabs(struct i915_address_space *vm,
 				     uint64_t length,
 				     unsigned long *new_pts)
 {
-	struct drm_i915_private *dev_priv = vm->i915;
 	struct i915_page_table *pt;
 	uint32_t pde;

@@ -1160,7 +1162,7 @@ static int gen8_ppgtt_alloc_pagetabs(struct i915_address_space *vm,
 			continue;
 		}

-		pt = alloc_pt(dev_priv);
+		pt = alloc_pt(vm);
 		if (IS_ERR(pt))
 			goto unwind_out;

@@ -1174,7 +1176,7 @@ static int gen8_ppgtt_alloc_pagetabs(struct i915_address_space *vm,

 unwind_out:
 	for_each_set_bit(pde, new_pts, I915_PDES)
-		free_pt(dev_priv, pd->page_table[pde]);
+		free_pt(vm, pd->page_table[pde]);

 	return -ENOMEM;
 }
@@ -1209,7 +1211,6 @@ gen8_ppgtt_alloc_page_directories(struct i915_address_space *vm,
 				  uint64_t length,
 				  unsigned long *new_pds)
 {
-	struct drm_i915_private *dev_priv = vm->i915;
 	struct i915_page_directory *pd;
 	uint32_t pdpe;
 	uint32_t pdpes = I915_PDPES_PER_PDP(dev_priv);
@@ -1220,7 +1221,7 @@ gen8_ppgtt_alloc_page_directories(struct i915_address_space *vm,
 		if (test_bit(pdpe, pdp->used_pdpes))
 			continue;

-		pd = alloc_pd(dev_priv);
+		pd = alloc_pd(vm);
 		if (IS_ERR(pd))
 			goto unwind_out;

@@ -1234,7 +1235,7 @@ gen8_ppgtt_alloc_page_directories(struct i915_address_space *vm,

 unwind_out:
 	for_each_set_bit(pdpe, new_pds, pdpes)
-		free_pd(dev_priv, pdp->page_directory[pdpe]);
+		free_pd(vm, pdp->page_directory[pdpe]);

 	return -ENOMEM;
 }
@@ -1262,7 +1263,6 @@ gen8_ppgtt_alloc_page_dirpointers(struct i915_address_space *vm,
 				  uint64_t length,
 				  unsigned long *new_pdps)
 {
-	struct drm_i915_private *dev_priv = vm->i915;
 	struct i915_page_directory_pointer *pdp;
 	uint32_t pml4e;

@@ -1270,7 +1270,7 @@ gen8_ppgtt_alloc_page_dirpointers(struct i915_address_space *vm,

 	gen8_for_each_pml4e(pdp, pml4, start, length, pml4e) {
 		if (!test_bit(pml4e, pml4->used_pml4es)) {
-			pdp = alloc_pdp(dev_priv);
+			pdp = alloc_pdp(vm);
 			if (IS_ERR(pdp))
 				goto unwind_out;

@@ -1288,7 +1288,7 @@ gen8_ppgtt_alloc_page_dirpointers(struct i915_address_space *vm,

 unwind_out:
 	for_each_set_bit(pml4e, new_pdps, GEN8_PML4ES_PER_PML4)
-		free_pdp(dev_priv, pml4->pdps[pml4e]);
+		free_pdp(vm, pml4->pdps[pml4e]);

 	return -ENOMEM;
 }
@@ -1337,7 +1337,6 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm,
 {
 	struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
 	unsigned long *new_page_dirs, *new_page_tables;
-	struct drm_i915_private *dev_priv = vm->i915;
 	struct i915_page_directory *pd;
 	const uint64_t orig_start = start;
 	const uint64_t orig_length = length;
@@ -1406,7 +1405,7 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm,
 			 * point we're still relying on insert_entries() */
 		}

-		kunmap_px(ppgtt, page_directory);
+		kunmap_px(page_directory);
 		__set_bit(pdpe, pdp->used_pdpes);
 		gen8_setup_pdpe(ppgtt, pdp, pd, pdpe);
 	}
@@ -1421,12 +1420,11 @@ err_out:

 		for_each_set_bit(temp, new_page_tables + pdpe *
 				BITS_TO_LONGS(I915_PDES), I915_PDES)
-			free_pt(dev_priv,
-				pdp->page_directory[pdpe]->page_table[temp]);
+			free_pt(vm, pdp->page_directory[pdpe]->page_table[temp]);
 	}

 	for_each_set_bit(pdpe, new_page_dirs, pdpes)
-		free_pd(dev_priv, pdp->page_directory[pdpe]);
+		free_pd(vm, pdp->page_directory[pdpe]);

 	free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);
 	mark_tlbs_dirty(ppgtt);
@@ -1439,7 +1437,6 @@ static int gen8_alloc_va_range_4lvl(struct i915_address_space *vm,
 				    uint64_t length)
 {
 	DECLARE_BITMAP(new_pdps, GEN8_PML4ES_PER_PML4);
-	struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
 	struct i915_page_directory_pointer *pdp;
 	uint64_t pml4e;
 	int ret = 0;
@@ -1463,7 +1460,7 @@ static int gen8_alloc_va_range_4lvl(struct i915_address_space *vm,
 		if (ret)
 			goto err_out;

-		gen8_setup_pml4e(ppgtt, pml4, pdp, pml4e);
+		gen8_setup_pml4e(pml4, pdp, pml4e);
 	}

 	bitmap_or(pml4->used_pml4es, new_pdps, pml4->used_pml4es,
@@ -1473,7 +1470,7 @@ static int gen8_alloc_va_range_4lvl(struct i915_address_space *vm,

 err_out:
 	for_each_set_bit(pml4e, new_pdps, GEN8_PML4ES_PER_PML4)
-		gen8_ppgtt_cleanup_3lvl(vm->i915, pml4->pdps[pml4e]);
+		gen8_ppgtt_cleanup_3lvl(vm, pml4->pdps[pml4e]);

 	return ret;
 }
@@ -1489,7 +1486,8 @@ static int gen8_alloc_va_range(struct i915_address_space *vm,
 		return gen8_alloc_va_range_3lvl(vm, &ppgtt->pdp, start, length);
 }

-static void gen8_dump_pdp(struct i915_page_directory_pointer *pdp,
+static void gen8_dump_pdp(struct i915_hw_ppgtt *ppgtt,
+			  struct i915_page_directory_pointer *pdp,
 			  uint64_t start, uint64_t length,
 			  gen8_pte_t scratch_pte,
 			  struct seq_file *m)
@@ -1555,7 +1553,7 @@ static void gen8_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
 		gen8_pte_encode(vm->scratch_page.daddr, I915_CACHE_LLC);

 	if (!USES_FULL_48BIT_PPGTT(vm->i915)) {
-		gen8_dump_pdp(&ppgtt->pdp, start, length, scratch_pte, m);
+		gen8_dump_pdp(ppgtt, &ppgtt->pdp, start, length, scratch_pte, m);
 	} else {
 		uint64_t pml4e;
 		struct i915_pml4 *pml4 = &ppgtt->pml4;
@@ -1566,7 +1564,7 @@ static void gen8_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
 				continue;

 			seq_printf(m, "    PML4E #%llu\n", pml4e);
-			gen8_dump_pdp(pdp, start, length, scratch_pte, m);
+			gen8_dump_pdp(ppgtt, pdp, start, length, scratch_pte, m);
 		}
 	}
 }
@@ -1622,8 +1620,14 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
 	ppgtt->base.bind_vma = ppgtt_bind_vma;
 	ppgtt->debug_dump = gen8_dump_ppgtt;

+	/* There are only few exceptions for gen >=6. chv and bxt.
+	 * And we are not sure about the latter so play safe for now.
+	 */
+	if (IS_CHERRYVIEW(dev_priv) || IS_BROXTON(dev_priv))
+		ppgtt->base.pt_kmap_wc = true;
+
 	if (USES_FULL_48BIT_PPGTT(dev_priv)) {
-		ret = setup_px(dev_priv, &ppgtt->pml4);
+		ret = setup_px(&ppgtt->base, &ppgtt->pml4);
 		if (ret)
 			goto free_scratch;

@@ -1712,7 +1716,7 @@ static void gen6_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
 			}
 			seq_puts(m, "\n");
 		}
-		kunmap_px(ppgtt, pt_vaddr);
+		kunmap_px(pt_vaddr);
 	}
 }

@@ -1909,7 +1913,7 @@ static void gen6_ppgtt_clear_range(struct i915_address_space *vm,
 		for (i = first_pte; i < last_pte; i++)
 			pt_vaddr[i] = scratch_pte;

-		kunmap_px(ppgtt, pt_vaddr);
+		kunmap_px(pt_vaddr);

 		num_entries -= last_pte - first_pte;
 		first_pte = 0;
@@ -1948,12 +1952,12 @@ static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
 		}

 		if (++act_pte == GEN6_PTES) {
-			kunmap_px(ppgtt, vaddr);
+			kunmap_px(vaddr);
 			vaddr = kmap_px(ppgtt->pd.page_table[++act_pt]);
 			act_pte = 0;
 		}
 	} while (1);
-	kunmap_px(ppgtt, vaddr);
+	kunmap_px(vaddr);
 }

 static int gen6_alloc_va_range(struct i915_address_space *vm,
@@ -1987,7 +1991,7 @@ static int gen6_alloc_va_range(struct i915_address_space *vm,
 		/* We've already allocated a page table */
 		WARN_ON(!bitmap_empty(pt->used_ptes, GEN6_PTES));

-		pt = alloc_pt(dev_priv);
+		pt = alloc_pt(vm);
 		if (IS_ERR(pt)) {
 			ret = PTR_ERR(pt);
 			goto unwind_out;
@@ -2035,7 +2039,7 @@ unwind_out:
 		struct i915_page_table *pt = ppgtt->pd.page_table[pde];

 		ppgtt->pd.page_table[pde] = vm->scratch_pt;
-		free_pt(dev_priv, pt);
+		free_pt(vm, pt);
 	}

 	mark_tlbs_dirty(ppgtt);
@@ -2044,16 +2048,15 @@ unwind_out:

 static int gen6_init_scratch(struct i915_address_space *vm)
 {
-	struct drm_i915_private *dev_priv = vm->i915;
 	int ret;

-	ret = setup_scratch_page(dev_priv, &vm->scratch_page, I915_GFP_DMA);
+	ret = setup_scratch_page(vm, I915_GFP_DMA);
 	if (ret)
 		return ret;

-	vm->scratch_pt = alloc_pt(dev_priv);
+	vm->scratch_pt = alloc_pt(vm);
 	if (IS_ERR(vm->scratch_pt)) {
-		cleanup_scratch_page(dev_priv, &vm->scratch_page);
+		cleanup_scratch_page(vm);
 		return PTR_ERR(vm->scratch_pt);
 	}

@@ -2064,17 +2067,14 @@ static int gen6_init_scratch(struct i915_address_space *vm)

 static void gen6_free_scratch(struct i915_address_space *vm)
 {
-	struct drm_i915_private *dev_priv = vm->i915;
-
-	free_pt(dev_priv, vm->scratch_pt);
-	cleanup_scratch_page(dev_priv, &vm->scratch_page);
+	free_pt(vm, vm->scratch_pt);
+	cleanup_scratch_page(vm);
 }

 static void gen6_ppgtt_cleanup(struct i915_address_space *vm)
 {
 	struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
 	struct i915_page_directory *pd = &ppgtt->pd;
-	struct drm_i915_private *dev_priv = vm->i915;
 	struct i915_page_table *pt;
 	uint32_t pde;

@@ -2082,7 +2082,7 @@ static void gen6_ppgtt_cleanup(struct i915_address_space *vm)

 	gen6_for_all_pdes(pt, pd, pde)
 		if (pt != vm->scratch_pt)
-			free_pt(dev_priv, pt);
+			free_pt(vm, pt);

 	gen6_free_scratch(vm);
 }
@@ -2191,6 +2191,7 @@ static int __hw_ppgtt_init(struct i915_hw_ppgtt *ppgtt,
 			   struct drm_i915_private *dev_priv)
 {
 	ppgtt->base.i915 = dev_priv;
+	ppgtt->base.dma = &dev_priv->drm.pdev->dev;

 	if (INTEL_INFO(dev_priv)->gen < 8)
 		return gen6_ppgtt_init(ppgtt);
@@ -2212,10 +2213,14 @@ static void i915_address_space_init(struct i915_address_space *vm,
 	INIT_LIST_HEAD(&vm->unbound_list);

 	list_add_tail(&vm->global_link, &dev_priv->vm_list);
+	pagevec_init(&vm->free_pages, false);
 }

 static void i915_address_space_fini(struct i915_address_space *vm)
 {
+	if (pagevec_count(&vm->free_pages))
+		vm_free_pages_release(vm);
+
 	i915_gem_timeline_fini(&vm->timeline);
 	drm_mm_takedown(&vm->mm);
 	list_del(&vm->global_link);
@@ -2323,9 +2328,8 @@ void i915_ppgtt_release(struct kref *kref)
 	WARN_ON(!list_empty(&ppgtt->base.inactive_list));
 	WARN_ON(!list_empty(&ppgtt->base.unbound_list));

-	i915_address_space_fini(&ppgtt->base);
-
 	ppgtt->base.cleanup(&ppgtt->base);
+	i915_address_space_fini(&ppgtt->base);
 	kfree(ppgtt);
 }

@@ -2991,7 +2995,7 @@ static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
 		return -ENOMEM;
 	}

-	ret = setup_scratch_page(dev_priv, &ggtt->base.scratch_page, GFP_DMA32);
+	ret = setup_scratch_page(&ggtt->base, GFP_DMA32);
 	if (ret) {
 		DRM_ERROR("Scratch setup failed\n");
 		/* iounmap will also get called at remove, but meh */
@@ -3080,7 +3084,7 @@ static void gen6_gmch_remove(struct i915_address_space *vm)
 	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);

 	iounmap(ggtt->gsm);
-	cleanup_scratch_page(vm->i915, &vm->scratch_page);
+	cleanup_scratch_page(vm);
 }

 static int gen8_gmch_probe(struct i915_ggtt *ggtt)
@@ -3231,6 +3235,7 @@ int i915_ggtt_probe_hw(struct drm_i915_private *dev_priv)
 	int ret;

 	ggtt->base.i915 = dev_priv;
+	ggtt->base.dma = &dev_priv->drm.pdev->dev;

 	if (INTEL_GEN(dev_priv) <= 5)
 		ret = i915_gmch_probe(ggtt);
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -36,9 +36,11 @@

 #include <linux/io-mapping.h>
 #include <linux/mm.h>
+#include <linux/pagevec.h>

 #include "i915_gem_timeline.h"
 #include "i915_gem_request.h"
+#include "i915_selftest.h"

 #define I915_GTT_PAGE_SIZE 4096UL
 #define I915_GTT_MIN_ALIGNMENT I915_GTT_PAGE_SIZE
@@ -247,6 +249,7 @@ struct i915_address_space {
 	struct drm_mm mm;
 	struct i915_gem_timeline timeline;
 	struct drm_i915_private *i915;
+	struct device *dma;
 	/* Every address space belongs to a struct file - except for the global
 	 * GTT that is owned by the driver (and so @file is set to NULL). In
 	 * principle, no information should leak from one context to another
@@ -297,6 +300,9 @@ struct i915_address_space {
 	 */
 	struct list_head unbound_list;

+	struct pagevec free_pages;
+	bool pt_kmap_wc;
+
 	/* FIXME: Need a more generic return type */
 	gen6_pte_t (*pte_encode)(dma_addr_t addr,
 				 enum i915_cache_level level,
@@ -326,6 +332,8 @@ struct i915_address_space {
 	int (*bind_vma)(struct i915_vma *vma,
 			enum i915_cache_level cache_level,
 			u32 flags);
+
+	I915_SELFTEST_DECLARE(struct fault_attr fault_attr);
 };

 #define i915_is_ggtt(V) (!(V)->file)
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -832,17 +832,17 @@ static int shrink_hole(struct drm_i915_private *i915,
 	unsigned long prime;
 	int err;

-	i915->vm_fault.probability = 999;
-	atomic_set(&i915->vm_fault.times, -1);
+	vm->fault_attr.probability = 999;
+	atomic_set(&vm->fault_attr.times, -1);

 	for_each_prime_number_from(prime, 0, ULONG_MAX - 1) {
-		i915->vm_fault.interval = prime;
+		vm->fault_attr.interval = prime;
 		err = __shrink_hole(i915, vm, hole_start, hole_end, end_time);
 		if (err)
 			break;
 	}

-	memset(&i915->vm_fault, 0, sizeof(i915->vm_fault));
+	memset(&vm->fault_attr, 0, sizeof(vm->fault_attr));

 	return err;
 }