1 files changed, 1486 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
new file mode 100644
index 000000000000..531d501be01f
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -0,0 +1,1486 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#include <linux/stop_machine.h>
+
+#include <asm/set_memory.h>
+#include <asm/smp.h>
+
+#include "intel_gt.h"
+#include "i915_drv.h"
+#include "i915_scatterlist.h"
+#include "i915_vgpu.h"
+
+#include "intel_gtt.h"
+
+static int
+i915_get_ggtt_vma_pages(struct i915_vma *vma);
+
+static void i915_ggtt_color_adjust(const struct drm_mm_node *node,
+				   unsigned long color,
+				   u64 *start,
+				   u64 *end)
+{
+	if (i915_node_color_differs(node, color))
+		*start += I915_GTT_PAGE_SIZE;
+
+	/*
+	 * Also leave a space between the unallocated reserved node after the
+	 * GTT and any objects within the GTT, i.e. we use the color adjustment
+	 * to insert a guard page to prevent prefetches crossing over the
+	 * GTT boundary.
+	 */
+	node = list_next_entry(node, node_list);
+	if (node->color != color)
+		*end -= I915_GTT_PAGE_SIZE;
+}
+
+static int ggtt_init_hw(struct i915_ggtt *ggtt)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+
+	i915_address_space_init(&ggtt->vm, VM_CLASS_GGTT);
+
+	ggtt->vm.is_ggtt = true;
+
+	/* Only VLV supports read-only GGTT mappings */
+	ggtt->vm.has_read_only = IS_VALLEYVIEW(i915);
+
+	if (!HAS_LLC(i915) && !HAS_PPGTT(i915))
+		ggtt->vm.mm.color_adjust = i915_ggtt_color_adjust;
+
+	if (ggtt->mappable_end) {
+		if (!io_mapping_init_wc(&ggtt->iomap,
+					ggtt->gmadr.start,
+					ggtt->mappable_end)) {
+			ggtt->vm.cleanup(&ggtt->vm);
+			return -EIO;
+		}
+
+		ggtt->mtrr = arch_phys_wc_add(ggtt->gmadr.start,
+					      ggtt->mappable_end);
+	}
+
+	i915_ggtt_init_fences(ggtt);
+
+	return 0;
+}
+
+/**
+ * i915_ggtt_init_hw - Initialize GGTT hardware
+ * @i915: i915 device
+ */
+int i915_ggtt_init_hw(struct drm_i915_private *i915)
+{
+	int ret;
+
+	stash_init(&i915->mm.wc_stash);
+
+	/*
+	 * Note that we use page colouring to enforce a guard page at the
+	 * end of the address space. This is required as the CS may prefetch
+	 * beyond the end of the batch buffer, across the page boundary,
+	 * and beyond the end of the GTT if we do not provide a guard.
+	 */
+	ret = ggtt_init_hw(&i915->ggtt);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * Certain Gen5 chipsets require require idling the GPU before
+ * unmapping anything from the GTT when VT-d is enabled.
+ */
+static bool needs_idle_maps(struct drm_i915_private *i915)
+{
+	/*
+	 * Query intel_iommu to see if we need the workaround. Presumably that
+	 * was loaded first.
+	 */
+	return IS_GEN(i915, 5) && IS_MOBILE(i915) && intel_vtd_active();
+}
+
+static void ggtt_suspend_mappings(struct i915_ggtt *ggtt)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+
+	/*
+	 * Don't bother messing with faults pre GEN6 as we have little
+	 * documentation supporting that it's a good idea.
+	 */
+	if (INTEL_GEN(i915) < 6)
+		return;
+
+	intel_gt_check_and_clear_faults(ggtt->vm.gt);
+
+	ggtt->vm.clear_range(&ggtt->vm, 0, ggtt->vm.total);
+
+	ggtt->invalidate(ggtt);
+}
+
+void i915_gem_suspend_gtt_mappings(struct drm_i915_private *i915)
+{
+	ggtt_suspend_mappings(&i915->ggtt);
+}
+
+void gen6_ggtt_invalidate(struct i915_ggtt *ggtt)
+{
+	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
+
+	spin_lock_irq(&uncore->lock);
+	intel_uncore_write_fw(uncore, GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
+	intel_uncore_read_fw(uncore, GFX_FLSH_CNTL_GEN6);
+	spin_unlock_irq(&uncore->lock);
+}
+
+static void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
+{
+	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
+
+	/*
+	 * Note that as an uncached mmio write, this will flush the
+	 * WCB of the writes into the GGTT before it triggers the invalidate.
+	 */
+	intel_uncore_write_fw(uncore, GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
+}
+
+static void guc_ggtt_invalidate(struct i915_ggtt *ggtt)
+{
+	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+
+	gen8_ggtt_invalidate(ggtt);
+
+	if (INTEL_GEN(i915) >= 12)
+		intel_uncore_write_fw(uncore, GEN12_GUC_TLB_INV_CR,
+				      GEN12_GUC_TLB_INV_CR_INVALIDATE);
+	else
+		intel_uncore_write_fw(uncore, GEN8_GTCR, GEN8_GTCR_INVALIDATE);
+}
+
+static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
+{
+	intel_gtt_chipset_flush();
+}
+
+static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
+{
+	writeq(pte, addr);
+}
+
+static void gen8_ggtt_insert_page(struct i915_address_space *vm,
+				  dma_addr_t addr,
+				  u64 offset,
+				  enum i915_cache_level level,
+				  u32 unused)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	gen8_pte_t __iomem *pte =
+		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
+
+	gen8_set_pte(pte, gen8_pte_encode(addr, level, 0));
+
+	ggtt->invalidate(ggtt);
+}
+
+static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
+				     struct i915_vma *vma,
+				     enum i915_cache_level level,
+				     u32 flags)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	struct sgt_iter sgt_iter;
+	gen8_pte_t __iomem *gtt_entries;
+	const gen8_pte_t pte_encode = gen8_pte_encode(0, level, 0);
+	dma_addr_t addr;
+
+	/*
+	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
+	 * not to allow the user to override access to a read only page.
+	 */
+
+	gtt_entries = (gen8_pte_t __iomem *)ggtt->gsm;
+	gtt_entries += vma->node.start / I915_GTT_PAGE_SIZE;
+	for_each_sgt_daddr(addr, sgt_iter, vma->pages)
+		gen8_set_pte(gtt_entries++, pte_encode | addr);
+
+	/*
+	 * We want to flush the TLBs only after we're certain all the PTE
+	 * updates have finished.
+	 */
+	ggtt->invalidate(ggtt);
+}
+
+static void gen6_ggtt_insert_page(struct i915_address_space *vm,
+				  dma_addr_t addr,
+				  u64 offset,
+				  enum i915_cache_level level,
+				  u32 flags)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	gen6_pte_t __iomem *pte =
+		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
+
+	iowrite32(vm->pte_encode(addr, level, flags), pte);
+
+	ggtt->invalidate(ggtt);
+}
+
+/*
+ * Binds an object into the global gtt with the specified cache level.
+ * The object will be accessible to the GPU via commands whose operands
+ * reference offsets within the global GTT as well as accessible by the GPU
+ * through the GMADR mapped BAR (i915->mm.gtt->gtt).
+ */
+static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
+				     struct i915_vma *vma,
+				     enum i915_cache_level level,
+				     u32 flags)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	gen6_pte_t __iomem *entries = (gen6_pte_t __iomem *)ggtt->gsm;
+	unsigned int i = vma->node.start / I915_GTT_PAGE_SIZE;
+	struct sgt_iter iter;
+	dma_addr_t addr;
+
+	for_each_sgt_daddr(addr, iter, vma->pages)
+		iowrite32(vm->pte_encode(addr, level, flags), &entries[i++]);
+
+	/*
+	 * We want to flush the TLBs only after we're certain all the PTE
+	 * updates have finished.
+	 */
+	ggtt->invalidate(ggtt);
+}
+
+static void nop_clear_range(struct i915_address_space *vm,
+			    u64 start, u64 length)
+{
+}
+
+static void gen8_ggtt_clear_range(struct i915_address_space *vm,
+				  u64 start, u64 length)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
+	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
+	const gen8_pte_t scratch_pte = vm->scratch[0].encode;
+	gen8_pte_t __iomem *gtt_base =
+		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
+	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
+	int i;
+
+	if (WARN(num_entries > max_entries,
+		 "First entry = %d; Num entries = %d (max=%d)\n",
+		 first_entry, num_entries, max_entries))
+		num_entries = max_entries;
+
+	for (i = 0; i < num_entries; i++)
+		gen8_set_pte(&gtt_base[i], scratch_pte);
+}
+
+static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
+{
+	/*
+	 * Make sure the internal GAM fifo has been cleared of all GTT
+	 * writes before exiting stop_machine(). This guarantees that
+	 * any aperture accesses waiting to start in another process
+	 * cannot back up behind the GTT writes causing a hang.
+	 * The register can be any arbitrary GAM register.
+	 */
+	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
+}
+
+struct insert_page {
+	struct i915_address_space *vm;
+	dma_addr_t addr;
+	u64 offset;
+	enum i915_cache_level level;
+};
+
+static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
+{
+	struct insert_page *arg = _arg;
+
+	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
+	bxt_vtd_ggtt_wa(arg->vm);
+
+	return 0;
+}
+
+static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
+					  dma_addr_t addr,
+					  u64 offset,
+					  enum i915_cache_level level,
+					  u32 unused)
+{
+	struct insert_page arg = { vm, addr, offset, level };
+
+	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
+}
+
+struct insert_entries {
+	struct i915_address_space *vm;
+	struct i915_vma *vma;
+	enum i915_cache_level level;
+	u32 flags;
+};
+
+static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
+{
+	struct insert_entries *arg = _arg;
+
+	gen8_ggtt_insert_entries(arg->vm, arg->vma, arg->level, arg->flags);
+	bxt_vtd_ggtt_wa(arg->vm);
+
+	return 0;
+}
+
+static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
+					     struct i915_vma *vma,
+					     enum i915_cache_level level,
+					     u32 flags)
+{
+	struct insert_entries arg = { vm, vma, level, flags };
+
+	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
+}
+
+struct clear_range {
+	struct i915_address_space *vm;
+	u64 start;
+	u64 length;
+};
+
+static int bxt_vtd_ggtt_clear_range__cb(void *_arg)
+{
+	struct clear_range *arg = _arg;
+
+	gen8_ggtt_clear_range(arg->vm, arg->start, arg->length);
+	bxt_vtd_ggtt_wa(arg->vm);
+
+	return 0;
+}
+
+static void bxt_vtd_ggtt_clear_range__BKL(struct i915_address_space *vm,
+					  u64 start,
+					  u64 length)
+{
+	struct clear_range arg = { vm, start, length };
+
+	stop_machine(bxt_vtd_ggtt_clear_range__cb, &arg, NULL);
+}
+
+static void gen6_ggtt_clear_range(struct i915_address_space *vm,
+				  u64 start, u64 length)
+{
+	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
+	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
+	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
+	gen6_pte_t scratch_pte, __iomem *gtt_base =
+		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
+	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
+	int i;
+
+	if (WARN(num_entries > max_entries,
+		 "First entry = %d; Num entries = %d (max=%d)\n",
+		 first_entry, num_entries, max_entries))
+		num_entries = max_entries;
+
+	scratch_pte = vm->scratch[0].encode;
+	for (i = 0; i < num_entries; i++)
+		iowrite32(scratch_pte, &gtt_base[i]);
+}
+
+static void i915_ggtt_insert_page(struct i915_address_space *vm,
+				  dma_addr_t addr,
+				  u64 offset,
+				  enum i915_cache_level cache_level,
+				  u32 unused)
+{
+	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
+		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
+
+	intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
+}
+
+static void i915_ggtt_insert_entries(struct i915_address_space *vm,
+				     struct i915_vma *vma,
+				     enum i915_cache_level cache_level,
+				     u32 unused)
+{
+	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
+		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
+
+	intel_gtt_insert_sg_entries(vma->pages, vma->node.start >> PAGE_SHIFT,
+				    flags);
+}
+
+static void i915_ggtt_clear_range(struct i915_address_space *vm,
+				  u64 start, u64 length)
+{
+	intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
+}
+
+static int ggtt_bind_vma(struct i915_vma *vma,
+			 enum i915_cache_level cache_level,
+			 u32 flags)
+{
+	struct drm_i915_gem_object *obj = vma->obj;
+	u32 pte_flags;
+
+	/* Applicable to VLV (gen8+ do not support RO in the GGTT) */
+	pte_flags = 0;
+	if (i915_gem_object_is_readonly(obj))
+		pte_flags |= PTE_READ_ONLY;
+
+	vma->vm->insert_entries(vma->vm, vma, cache_level, pte_flags);
+
+	vma->page_sizes.gtt = I915_GTT_PAGE_SIZE;
+
+	/*
+	 * Without aliasing PPGTT there's no difference between
+	 * GLOBAL/LOCAL_BIND, it's all the same ptes. Hence unconditionally
+	 * upgrade to both bound if we bind either to avoid double-binding.
+	 */
+	atomic_or(I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND, &vma->flags);
+
+	return 0;
+}
+
+static void ggtt_unbind_vma(struct i915_vma *vma)
+{
+	vma->vm->clear_range(vma->vm, vma->node.start, vma->size);
+}
+
+static int ggtt_reserve_guc_top(struct i915_ggtt *ggtt)
+{
+	u64 size;
+	int ret;
+
+	if (!USES_GUC(ggtt->vm.i915))
+		return 0;
+
+	GEM_BUG_ON(ggtt->vm.total <= GUC_GGTT_TOP);
+	size = ggtt->vm.total - GUC_GGTT_TOP;
+
+	ret = i915_gem_gtt_reserve(&ggtt->vm, &ggtt->uc_fw, size,
+				   GUC_GGTT_TOP, I915_COLOR_UNEVICTABLE,
+				   PIN_NOEVICT);
+	if (ret)
+		DRM_DEBUG_DRIVER("Failed to reserve top of GGTT for GuC\n");
+
+	return ret;
+}
+
+static void ggtt_release_guc_top(struct i915_ggtt *ggtt)
+{
+	if (drm_mm_node_allocated(&ggtt->uc_fw))
+		drm_mm_remove_node(&ggtt->uc_fw);
+}
+
+static void cleanup_init_ggtt(struct i915_ggtt *ggtt)
+{
+	ggtt_release_guc_top(ggtt);
+	if (drm_mm_node_allocated(&ggtt->error_capture))
+		drm_mm_remove_node(&ggtt->error_capture);
+	mutex_destroy(&ggtt->error_mutex);
+}
+
+static int init_ggtt(struct i915_ggtt *ggtt)
+{
+	/*
+	 * Let GEM Manage all of the aperture.
+	 *
+	 * However, leave one page at the end still bound to the scratch page.
+	 * There are a number of places where the hardware apparently prefetches
+	 * past the end of the object, and we've seen multiple hangs with the
+	 * GPU head pointer stuck in a batchbuffer bound at the last page of the
+	 * aperture.  One page should be enough to keep any prefetching inside
+	 * of the aperture.
+	 */
+	unsigned long hole_start, hole_end;
+	struct drm_mm_node *entry;
+	int ret;
+
+	/*
+	 * GuC requires all resources that we're sharing with it to be placed in
+	 * non-WOPCM memory. If GuC is not present or not in use we still need a
+	 * small bias as ring wraparound at offset 0 sometimes hangs. No idea
+	 * why.
+	 */
+	ggtt->pin_bias = max_t(u32, I915_GTT_PAGE_SIZE,
+			       intel_wopcm_guc_size(&ggtt->vm.i915->wopcm));
+
+	ret = intel_vgt_balloon(ggtt);
+	if (ret)
+		return ret;
+
+	mutex_init(&ggtt->error_mutex);
+	if (ggtt->mappable_end) {
+		/* Reserve a mappable slot for our lockless error capture */
+		ret = drm_mm_insert_node_in_range(&ggtt->vm.mm,
+						  &ggtt->error_capture,
+						  PAGE_SIZE, 0,
+						  I915_COLOR_UNEVICTABLE,
+						  0, ggtt->mappable_end,
+						  DRM_MM_INSERT_LOW);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * The upper portion of the GuC address space has a sizeable hole
+	 * (several MB) that is inaccessible by GuC. Reserve this range within
+	 * GGTT as it can comfortably hold GuC/HuC firmware images.
+	 */
+	ret = ggtt_reserve_guc_top(ggtt);
+	if (ret)
+		goto err;
+
+	/* Clear any non-preallocated blocks */
+	drm_mm_for_each_hole(entry, &ggtt->vm.mm, hole_start, hole_end) {
+		DRM_DEBUG_KMS("clearing unused GTT space: [%lx, %lx]\n",
+			      hole_start, hole_end);
+		ggtt->vm.clear_range(&ggtt->vm, hole_start,
+				     hole_end - hole_start);
+	}
+
+	/* And finally clear the reserved guard page */
+	ggtt->vm.clear_range(&ggtt->vm, ggtt->vm.total - PAGE_SIZE, PAGE_SIZE);
+
+	return 0;
+
+err:
+	cleanup_init_ggtt(ggtt);
+	return ret;
+}
+
+static int aliasing_gtt_bind_vma(struct i915_vma *vma,
+				 enum i915_cache_level cache_level,
+				 u32 flags)
+{
+	u32 pte_flags;
+	int ret;
+
+	/* Currently applicable only to VLV */
+	pte_flags = 0;
+	if (i915_gem_object_is_readonly(vma->obj))
+		pte_flags |= PTE_READ_ONLY;
+
+	if (flags & I915_VMA_LOCAL_BIND) {
+		struct i915_ppgtt *alias = i915_vm_to_ggtt(vma->vm)->alias;
+
+		if (flags & I915_VMA_ALLOC) {
+			ret = alias->vm.allocate_va_range(&alias->vm,
+							  vma->node.start,
+							  vma->size);
+			if (ret)
+				return ret;
+
+			set_bit(I915_VMA_ALLOC_BIT, __i915_vma_flags(vma));
+		}
+
+		GEM_BUG_ON(!test_bit(I915_VMA_ALLOC_BIT,
+				     __i915_vma_flags(vma)));
+		alias->vm.insert_entries(&alias->vm, vma,
+					 cache_level, pte_flags);
+	}
+
+	if (flags & I915_VMA_GLOBAL_BIND)
+		vma->vm->insert_entries(vma->vm, vma, cache_level, pte_flags);
+
+	return 0;
+}
+
+static void aliasing_gtt_unbind_vma(struct i915_vma *vma)
+{
+	if (i915_vma_is_bound(vma, I915_VMA_GLOBAL_BIND)) {
+		struct i915_address_space *vm = vma->vm;
+
+		vm->clear_range(vm, vma->node.start, vma->size);
+	}
+
+	if (test_and_clear_bit(I915_VMA_ALLOC_BIT, __i915_vma_flags(vma))) {
+		struct i915_address_space *vm =
+			&i915_vm_to_ggtt(vma->vm)->alias->vm;
+
+		vm->clear_range(vm, vma->node.start, vma->size);
+	}
+}
+
+static int init_aliasing_ppgtt(struct i915_ggtt *ggtt)
+{
+	struct i915_ppgtt *ppgtt;
+	int err;
+
+	ppgtt = i915_ppgtt_create(ggtt->vm.gt);
+	if (IS_ERR(ppgtt))
+		return PTR_ERR(ppgtt);
+
+	if (GEM_WARN_ON(ppgtt->vm.total < ggtt->vm.total)) {
+		err = -ENODEV;
+		goto err_ppgtt;
+	}
+
+	/*
+	 * Note we only pre-allocate as far as the end of the global
+	 * GTT. On 48b / 4-level page-tables, the difference is very,
+	 * very significant! We have to preallocate as GVT/vgpu does
+	 * not like the page directory disappearing.
+	 */
+	err = ppgtt->vm.allocate_va_range(&ppgtt->vm, 0, ggtt->vm.total);
+	if (err)
+		goto err_ppgtt;
+
+	ggtt->alias = ppgtt;
+	ggtt->vm.bind_async_flags |= ppgtt->vm.bind_async_flags;
+
+	GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != ggtt_bind_vma);
+	ggtt->vm.vma_ops.bind_vma = aliasing_gtt_bind_vma;
+
+	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != ggtt_unbind_vma);
+	ggtt->vm.vma_ops.unbind_vma = aliasing_gtt_unbind_vma;
+
+	return 0;
+
+err_ppgtt:
+	i915_vm_put(&ppgtt->vm);
+	return err;
+}
+
+static void fini_aliasing_ppgtt(struct i915_ggtt *ggtt)
+{
+	struct i915_ppgtt *ppgtt;
+
+	ppgtt = fetch_and_zero(&ggtt->alias);
+	if (!ppgtt)
+		return;
+
+	i915_vm_put(&ppgtt->vm);
+
+	ggtt->vm.vma_ops.bind_vma   = ggtt_bind_vma;
+	ggtt->vm.vma_ops.unbind_vma = ggtt_unbind_vma;
+}
+
+int i915_init_ggtt(struct drm_i915_private *i915)
+{
+	int ret;
+
+	ret = init_ggtt(&i915->ggtt);
+	if (ret)
+		return ret;
+
+	if (INTEL_PPGTT(i915) == INTEL_PPGTT_ALIASING) {
+		ret = init_aliasing_ppgtt(&i915->ggtt);
+		if (ret)
+			cleanup_init_ggtt(&i915->ggtt);
+	}
+
+	return 0;
+}
+
+static void ggtt_cleanup_hw(struct i915_ggtt *ggtt)
+{
+	struct i915_vma *vma, *vn;
+
+	atomic_set(&ggtt->vm.open, 0);
+
+	rcu_barrier(); /* flush the RCU'ed__i915_vm_release */
+	flush_workqueue(ggtt->vm.i915->wq);
+
+	mutex_lock(&ggtt->vm.mutex);
+
+	list_for_each_entry_safe(vma, vn, &ggtt->vm.bound_list, vm_link)
+		WARN_ON(__i915_vma_unbind(vma));
+
+	if (drm_mm_node_allocated(&ggtt->error_capture))
+		drm_mm_remove_node(&ggtt->error_capture);
+	mutex_destroy(&ggtt->error_mutex);
+
+	ggtt_release_guc_top(ggtt);
+	intel_vgt_deballoon(ggtt);
+
+	ggtt->vm.cleanup(&ggtt->vm);
+
+	mutex_unlock(&ggtt->vm.mutex);
+	i915_address_space_fini(&ggtt->vm);
+
+	arch_phys_wc_del(ggtt->mtrr);
+
+	if (ggtt->iomap.size)
+		io_mapping_fini(&ggtt->iomap);
+}
+
+/**
+ * i915_ggtt_driver_release - Clean up GGTT hardware initialization
+ * @i915: i915 device
+ */
+void i915_ggtt_driver_release(struct drm_i915_private *i915)
+{
+	struct pagevec *pvec;
+
+	fini_aliasing_ppgtt(&i915->ggtt);
+
+	ggtt_cleanup_hw(&i915->ggtt);
+
+	pvec = &i915->mm.wc_stash.pvec;
+	if (pvec->nr) {
+		set_pages_array_wb(pvec->pages, pvec->nr);
+		__pagevec_release(pvec);
+	}
+}
+
+static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
+{
+	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
+	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
+	return snb_gmch_ctl << 20;
+}
+
+static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
+{
+	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
+	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
+	if (bdw_gmch_ctl)
+		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
+
+#ifdef CONFIG_X86_32
+	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
+	if (bdw_gmch_ctl > 4)
+		bdw_gmch_ctl = 4;
+#endif
+
+	return bdw_gmch_ctl << 20;
+}
+
+static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
+{
+	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
+	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
+
+	if (gmch_ctrl)
+		return 1 << (20 + gmch_ctrl);
+
+	return 0;
+}
+
+static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+	struct pci_dev *pdev = i915->drm.pdev;
+	phys_addr_t phys_addr;
+	int ret;
+
+	/* For Modern GENs the PTEs and register space are split in the BAR */
+	phys_addr = pci_resource_start(pdev, 0) + pci_resource_len(pdev, 0) / 2;
+
+	/*
+	 * On BXT+/CNL+ writes larger than 64 bit to the GTT pagetable range
+	 * will be dropped. For WC mappings in general we have 64 byte burst
+	 * writes when the WC buffer is flushed, so we can't use it, but have to
+	 * resort to an uncached mapping. The WC issue is easily caught by the
+	 * readback check when writing GTT PTE entries.
+	 */
+	if (IS_GEN9_LP(i915) || INTEL_GEN(i915) >= 10)
+		ggtt->gsm = ioremap(phys_addr, size);
+	else
+		ggtt->gsm = ioremap_wc(phys_addr, size);
+	if (!ggtt->gsm) {
+		DRM_ERROR("Failed to map the ggtt page table\n");
+		return -ENOMEM;
+	}
+
+	ret = setup_scratch_page(&ggtt->vm, GFP_DMA32);
+	if (ret) {
+		DRM_ERROR("Scratch setup failed\n");
+		/* iounmap will also get called at remove, but meh */
+		iounmap(ggtt->gsm);
+		return ret;
+	}
+
+	ggtt->vm.scratch[0].encode =
+		ggtt->vm.pte_encode(px_dma(&ggtt->vm.scratch[0]),
+				    I915_CACHE_NONE, 0);
+
+	return 0;
+}
+
+int ggtt_set_pages(struct i915_vma *vma)
+{
+	int ret;
+
+	GEM_BUG_ON(vma->pages);
+
+	ret = i915_get_ggtt_vma_pages(vma);
+	if (ret)
+		return ret;
+
+	vma->page_sizes = vma->obj->mm.page_sizes;
+
+	return 0;
+}
+
+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);
+}
+
+static struct resource pci_resource(struct pci_dev *pdev, int bar)
+{
+	return (struct resource)DEFINE_RES_MEM(pci_resource_start(pdev, bar),
+					       pci_resource_len(pdev, bar));
+}
+
+static int gen8_gmch_probe(struct i915_ggtt *ggtt)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+	struct pci_dev *pdev = i915->drm.pdev;
+	unsigned int size;
+	u16 snb_gmch_ctl;
+	int err;
+
+	/* TODO: We're not aware of mappable constraints on gen8 yet */
+	if (!IS_DGFX(i915)) {
+		ggtt->gmadr = pci_resource(pdev, 2);
+		ggtt->mappable_end = resource_size(&ggtt->gmadr);
+	}
+
+	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(39));
+	if (!err)
+		err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(39));
+	if (err)
+		DRM_ERROR("Can't set DMA mask/consistent mask (%d)\n", err);
+
+	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
+	if (IS_CHERRYVIEW(i915))
+		size = chv_get_total_gtt_size(snb_gmch_ctl);
+	else
+		size = gen8_get_total_gtt_size(snb_gmch_ctl);
+
+	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
+	ggtt->vm.cleanup = gen6_gmch_remove;
+	ggtt->vm.insert_page = gen8_ggtt_insert_page;
+	ggtt->vm.clear_range = nop_clear_range;
+	if (intel_scanout_needs_vtd_wa(i915))
+		ggtt->vm.clear_range = gen8_ggtt_clear_range;
+
+	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
+
+	/* Serialize GTT updates with aperture access on BXT if VT-d is on. */
+	if (intel_ggtt_update_needs_vtd_wa(i915) ||
+	    IS_CHERRYVIEW(i915) /* fails with concurrent use/update */) {
+		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
+		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
+		if (ggtt->vm.clear_range != nop_clear_range)
+			ggtt->vm.clear_range = bxt_vtd_ggtt_clear_range__BKL;
+	}
+
+	ggtt->invalidate = gen8_ggtt_invalidate;
+
+	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
+	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
+	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
+	ggtt->vm.vma_ops.clear_pages = clear_pages;
+
+	ggtt->vm.pte_encode = gen8_pte_encode;
+
+	setup_private_pat(ggtt->vm.gt->uncore);
+
+	return ggtt_probe_common(ggtt, size);
+}
+
+static u64 snb_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	switch (level) {
+	case I915_CACHE_L3_LLC:
+	case I915_CACHE_LLC:
+		pte |= GEN6_PTE_CACHE_LLC;
+		break;
+	case I915_CACHE_NONE:
+		pte |= GEN6_PTE_UNCACHED;
+		break;
+	default:
+		MISSING_CASE(level);
+	}
+
+	return pte;
+}
+
+static u64 ivb_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	switch (level) {
+	case I915_CACHE_L3_LLC:
+		pte |= GEN7_PTE_CACHE_L3_LLC;
+		break;
+	case I915_CACHE_LLC:
+		pte |= GEN6_PTE_CACHE_LLC;
+		break;
+	case I915_CACHE_NONE:
+		pte |= GEN6_PTE_UNCACHED;
+		break;
+	default:
+		MISSING_CASE(level);
+	}
+
+	return pte;
+}
+
+static u64 byt_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	if (!(flags & PTE_READ_ONLY))
+		pte |= BYT_PTE_WRITEABLE;
+
+	if (level != I915_CACHE_NONE)
+		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
+
+	return pte;
+}
+
+static u64 hsw_pte_encode(dma_addr_t addr,
+			  enum i915_cache_level level,
+			  u32 flags)
+{
+	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	if (level != I915_CACHE_NONE)
+		pte |= HSW_WB_LLC_AGE3;
+
+	return pte;
+}
+
+static u64 iris_pte_encode(dma_addr_t addr,
+			   enum i915_cache_level level,
+			   u32 flags)
+{
+	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
+
+	switch (level) {
+	case I915_CACHE_NONE:
+		break;
+	case I915_CACHE_WT:
+		pte |= HSW_WT_ELLC_LLC_AGE3;
+		break;
+	default:
+		pte |= HSW_WB_ELLC_LLC_AGE3;
+		break;
+	}
+
+	return pte;
+}
+
+static int gen6_gmch_probe(struct i915_ggtt *ggtt)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+	struct pci_dev *pdev = i915->drm.pdev;
+	unsigned int size;
+	u16 snb_gmch_ctl;
+	int err;
+
+	ggtt->gmadr = pci_resource(pdev, 2);
+	ggtt->mappable_end = resource_size(&ggtt->gmadr);
+
+	/*
+	 * 64/512MB is the current min/max we actually know of, but this is
+	 * just a coarse sanity check.
+	 */
+	if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > (512<<20)) {
+		DRM_ERROR("Unknown GMADR size (%pa)\n", &ggtt->mappable_end);
+		return -ENXIO;
+	}
+
+	err = pci_set_dma_mask(pdev, DMA_BIT_MASK(40));
+	if (!err)
+		err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(40));
+	if (err)
+		DRM_ERROR("Can't set DMA mask/consistent mask (%d)\n", err);
+	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
+
+	size = gen6_get_total_gtt_size(snb_gmch_ctl);
+	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
+
+	ggtt->vm.clear_range = nop_clear_range;
+	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
+		ggtt->vm.clear_range = gen6_ggtt_clear_range;
+	ggtt->vm.insert_page = gen6_ggtt_insert_page;
+	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
+	ggtt->vm.cleanup = gen6_gmch_remove;
+
+	ggtt->invalidate = gen6_ggtt_invalidate;
+
+	if (HAS_EDRAM(i915))
+		ggtt->vm.pte_encode = iris_pte_encode;
+	else if (IS_HASWELL(i915))
+		ggtt->vm.pte_encode = hsw_pte_encode;
+	else if (IS_VALLEYVIEW(i915))
+		ggtt->vm.pte_encode = byt_pte_encode;
+	else if (INTEL_GEN(i915) >= 7)
+		ggtt->vm.pte_encode = ivb_pte_encode;
+	else
+		ggtt->vm.pte_encode = snb_pte_encode;
+
+	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
+	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
+	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
+	ggtt->vm.vma_ops.clear_pages = clear_pages;
+
+	return ggtt_probe_common(ggtt, size);
+}
+
+static void i915_gmch_remove(struct i915_address_space *vm)
+{
+	intel_gmch_remove();
+}
+
+static int i915_gmch_probe(struct i915_ggtt *ggtt)
+{
+	struct drm_i915_private *i915 = ggtt->vm.i915;
+	phys_addr_t gmadr_base;
+	int ret;
+
+	ret = intel_gmch_probe(i915->bridge_dev, i915->drm.pdev, NULL);
+	if (!ret) {
+		DRM_ERROR("failed to set up gmch\n");
+		return -EIO;
+	}
+
+	intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
+
+	ggtt->gmadr =
+		(struct resource)DEFINE_RES_MEM(gmadr_base, ggtt->mappable_end);
+
+	ggtt->do_idle_maps = needs_idle_maps(i915);
+	ggtt->vm.insert_page = i915_ggtt_insert_page;
+	ggtt->vm.insert_entries = i915_ggtt_insert_entries;
+	ggtt->vm.clear_range = i915_ggtt_clear_range;
+	ggtt->vm.cleanup = i915_gmch_remove;
+
+	ggtt->invalidate = gmch_ggtt_invalidate;
+
+	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
+	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
+	ggtt->vm.vma_ops.set_pages   = ggtt_set_pages;
+	ggtt->vm.vma_ops.clear_pages = clear_pages;
+
+	if (unlikely(ggtt->do_idle_maps))
+		dev_notice(i915->drm.dev,
+			   "Applying Ironlake quirks for intel_iommu\n");
+
+	return 0;
+}
+
+static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
+{
+	struct drm_i915_private *i915 = gt->i915;
+	int ret;
+
+	ggtt->vm.gt = gt;
+	ggtt->vm.i915 = i915;
+	ggtt->vm.dma = &i915->drm.pdev->dev;
+
+	if (INTEL_GEN(i915) <= 5)
+		ret = i915_gmch_probe(ggtt);
+	else if (INTEL_GEN(i915) < 8)
+		ret = gen6_gmch_probe(ggtt);
+	else
+		ret = gen8_gmch_probe(ggtt);
+	if (ret)
+		return ret;
+
+	if ((ggtt->vm.total - 1) >> 32) {
+		DRM_ERROR("We never expected a Global GTT with more than 32bits"
+			  " of address space! Found %lldM!\n",
+			  ggtt->vm.total >> 20);
+		ggtt->vm.total = 1ULL << 32;
+		ggtt->mappable_end =
+			min_t(u64, ggtt->mappable_end, ggtt->vm.total);
+	}
+
+	if (ggtt->mappable_end > ggtt->vm.total) {
+		DRM_ERROR("mappable aperture extends past end of GGTT,"
+			  " aperture=%pa, total=%llx\n",
+			  &ggtt->mappable_end, ggtt->vm.total);
+		ggtt->mappable_end = ggtt->vm.total;
+	}
+
+	/* GMADR is the PCI mmio aperture into the global GTT. */
+	DRM_DEBUG_DRIVER("GGTT size = %lluM\n", ggtt->vm.total >> 20);
+	DRM_DEBUG_DRIVER("GMADR size = %lluM\n", (u64)ggtt->mappable_end >> 20);
+	DRM_DEBUG_DRIVER("DSM size = %lluM\n",
+			 (u64)resource_size(&intel_graphics_stolen_res) >> 20);
+
+	return 0;
+}
+
+/**
+ * i915_ggtt_probe_hw - Probe GGTT hardware location
+ * @i915: i915 device
+ */
+int i915_ggtt_probe_hw(struct drm_i915_private *i915)
+{
+	int ret;
+
+	ret = ggtt_probe_hw(&i915->ggtt, &i915->gt);
+	if (ret)
+		return ret;
+
+	if (intel_vtd_active())
+		dev_info(i915->drm.dev, "VT-d active for gfx access\n");
+
+	return 0;
+}
+
+int i915_ggtt_enable_hw(struct drm_i915_private *i915)
+{
+	if (INTEL_GEN(i915) < 6 && !intel_enable_gtt())
+		return -EIO;
+
+	return 0;
+}
+
+void i915_ggtt_enable_guc(struct i915_ggtt *ggtt)
+{
+	GEM_BUG_ON(ggtt->invalidate != gen8_ggtt_invalidate);
+
+	ggtt->invalidate = guc_ggtt_invalidate;
+
+	ggtt->invalidate(ggtt);
+}
+
+void i915_ggtt_disable_guc(struct i915_ggtt *ggtt)
+{
+	/* XXX Temporary pardon for error unload */
+	if (ggtt->invalidate == gen8_ggtt_invalidate)
+		return;
+
+	/* We should only be called after i915_ggtt_enable_guc() */
+	GEM_BUG_ON(ggtt->invalidate != guc_ggtt_invalidate);
+
+	ggtt->invalidate = gen8_ggtt_invalidate;
+
+	ggtt->invalidate(ggtt);
+}
+
+static void ggtt_restore_mappings(struct i915_ggtt *ggtt)
+{
+	struct i915_vma *vma;
+	bool flush = false;
+	int open;
+
+	intel_gt_check_and_clear_faults(ggtt->vm.gt);
+
+	mutex_lock(&ggtt->vm.mutex);
+
+	/* First fill our portion of the GTT with scratch pages */
+	ggtt->vm.clear_range(&ggtt->vm, 0, ggtt->vm.total);
+
+	/* Skip rewriting PTE on VMA unbind. */
+	open = atomic_xchg(&ggtt->vm.open, 0);
+
+	/* clflush objects bound into the GGTT and rebind them. */
+	list_for_each_entry(vma, &ggtt->vm.bound_list, vm_link) {
+		struct drm_i915_gem_object *obj = vma->obj;
+
+		if (!i915_vma_is_bound(vma, I915_VMA_GLOBAL_BIND))
+			continue;
+
+		clear_bit(I915_VMA_GLOBAL_BIND_BIT, __i915_vma_flags(vma));
+		WARN_ON(i915_vma_bind(vma,
+				      obj ? obj->cache_level : 0,
+				      PIN_GLOBAL, NULL));
+		if (obj) { /* only used during resume => exclusive access */
+			flush |= fetch_and_zero(&obj->write_domain);
+			obj->read_domains |= I915_GEM_DOMAIN_GTT;
+		}
+	}
+
+	atomic_set(&ggtt->vm.open, open);
+	ggtt->invalidate(ggtt);
+
+	mutex_unlock(&ggtt->vm.mutex);
+
+	if (flush)
+		wbinvd_on_all_cpus();
+}
+
+void i915_gem_restore_gtt_mappings(struct drm_i915_private *i915)
+{
+	struct i915_ggtt *ggtt = &i915->ggtt;
+
+	ggtt_restore_mappings(ggtt);
+
+	if (INTEL_GEN(i915) >= 8)
+		setup_private_pat(ggtt->vm.gt->uncore);
+}
+
+static struct scatterlist *
+rotate_pages(struct drm_i915_gem_object *obj, unsigned int offset,
+	     unsigned int width, unsigned int height,
+	     unsigned int stride,
+	     struct sg_table *st, struct scatterlist *sg)
+{
+	unsigned int column, row;
+	unsigned int src_idx;
+
+	for (column = 0; column < width; column++) {
+		src_idx = stride * (height - 1) + column + offset;
+		for (row = 0; row < height; row++) {
+			st->nents++;
+			/*
+			 * We don't need the pages, but need to initialize
+			 * the entries so the sg list can be happily traversed.
+			 * The only thing we need are DMA addresses.
+			 */
+			sg_set_page(sg, NULL, I915_GTT_PAGE_SIZE, 0);
+			sg_dma_address(sg) =
+				i915_gem_object_get_dma_address(obj, src_idx);
+			sg_dma_len(sg) = I915_GTT_PAGE_SIZE;
+			sg = sg_next(sg);
+			src_idx -= stride;
+		}
+	}
+
+	return sg;
+}
+
+static noinline struct sg_table *
+intel_rotate_pages(struct intel_rotation_info *rot_info,
+		   struct drm_i915_gem_object *obj)
+{
+	unsigned int size = intel_rotation_info_size(rot_info);
+	struct sg_table *st;
+	struct scatterlist *sg;
+	int ret = -ENOMEM;
+	int i;
+
+	/* Allocate target SG list. */
+	st = kmalloc(sizeof(*st), GFP_KERNEL);
+	if (!st)
+		goto err_st_alloc;
+
+	ret = sg_alloc_table(st, size, GFP_KERNEL);
+	if (ret)
+		goto err_sg_alloc;
+
+	st->nents = 0;
+	sg = st->sgl;
+
+	for (i = 0 ; i < ARRAY_SIZE(rot_info->plane); i++) {
+		sg = rotate_pages(obj, rot_info->plane[i].offset,
+				  rot_info->plane[i].width, rot_info->plane[i].height,
+				  rot_info->plane[i].stride, st, sg);
+	}
+
+	return st;
+
+err_sg_alloc:
+	kfree(st);
+err_st_alloc:
+
+	DRM_DEBUG_DRIVER("Failed to create rotated mapping for object size %zu! (%ux%u tiles, %u pages)\n",
+			 obj->base.size, rot_info->plane[0].width, rot_info->plane[0].height, size);
+
+	return ERR_PTR(ret);
+}
+
+static struct scatterlist *
+remap_pages(struct drm_i915_gem_object *obj, unsigned int offset,
+	    unsigned int width, unsigned int height,
+	    unsigned int stride,
+	    struct sg_table *st, struct scatterlist *sg)
+{
+	unsigned int row;
+
+	for (row = 0; row < height; row++) {
+		unsigned int left = width * I915_GTT_PAGE_SIZE;
+
+		while (left) {
+			dma_addr_t addr;
+			unsigned int length;
+
+			/*
+			 * We don't need the pages, but need to initialize
+			 * the entries so the sg list can be happily traversed.
+			 * The only thing we need are DMA addresses.
+			 */
+
+			addr = i915_gem_object_get_dma_address_len(obj, offset, &length);
+
+			length = min(left, length);
+
+			st->nents++;
+
+			sg_set_page(sg, NULL, length, 0);
+			sg_dma_address(sg) = addr;
+			sg_dma_len(sg) = length;
+			sg = sg_next(sg);
+
+			offset += length / I915_GTT_PAGE_SIZE;
+			left -= length;
+		}
+
+		offset += stride - width;
+	}
+
+	return sg;
+}
+
+static noinline struct sg_table *
+intel_remap_pages(struct intel_remapped_info *rem_info,
+		  struct drm_i915_gem_object *obj)
+{
+	unsigned int size = intel_remapped_info_size(rem_info);
+	struct sg_table *st;
+	struct scatterlist *sg;
+	int ret = -ENOMEM;
+	int i;
+
+	/* Allocate target SG list. */
+	st = kmalloc(sizeof(*st), GFP_KERNEL);
+	if (!st)
+		goto err_st_alloc;
+
+	ret = sg_alloc_table(st, size, GFP_KERNEL);
+	if (ret)
+		goto err_sg_alloc;
+
+	st->nents = 0;
+	sg = st->sgl;
+
+	for (i = 0 ; i < ARRAY_SIZE(rem_info->plane); i++) {
+		sg = remap_pages(obj, rem_info->plane[i].offset,
+				 rem_info->plane[i].width, rem_info->plane[i].height,
+				 rem_info->plane[i].stride, st, sg);
+	}
+
+	i915_sg_trim(st);
+
+	return st;
+
+err_sg_alloc:
+	kfree(st);
+err_st_alloc:
+
+	DRM_DEBUG_DRIVER("Failed to create remapped mapping for object size %zu! (%ux%u tiles, %u pages)\n",
+			 obj->base.size, rem_info->plane[0].width, rem_info->plane[0].height, size);
+
+	return ERR_PTR(ret);
+}
+
+static noinline struct sg_table *
+intel_partial_pages(const struct i915_ggtt_view *view,
+		    struct drm_i915_gem_object *obj)
+{
+	struct sg_table *st;
+	struct scatterlist *sg, *iter;
+	unsigned int count = view->partial.size;
+	unsigned int offset;
+	int ret = -ENOMEM;
+
+	st = kmalloc(sizeof(*st), GFP_KERNEL);
+	if (!st)
+		goto err_st_alloc;
+
+	ret = sg_alloc_table(st, count, GFP_KERNEL);
+	if (ret)
+		goto err_sg_alloc;
+
+	iter = i915_gem_object_get_sg(obj, view->partial.offset, &offset);
+	GEM_BUG_ON(!iter);
+
+	sg = st->sgl;
+	st->nents = 0;
+	do {
+		unsigned int len;
+
+		len = min(iter->length - (offset << PAGE_SHIFT),
+			  count << PAGE_SHIFT);
+		sg_set_page(sg, NULL, len, 0);
+		sg_dma_address(sg) =
+			sg_dma_address(iter) + (offset << PAGE_SHIFT);
+		sg_dma_len(sg) = len;
+
+		st->nents++;
+		count -= len >> PAGE_SHIFT;
+		if (count == 0) {
+			sg_mark_end(sg);
+			i915_sg_trim(st); /* Drop any unused tail entries. */
+
+			return st;
+		}
+
+		sg = __sg_next(sg);
+		iter = __sg_next(iter);
+		offset = 0;
+	} while (1);
+
+err_sg_alloc:
+	kfree(st);
+err_st_alloc:
+	return ERR_PTR(ret);
+}
+
+static int
+i915_get_ggtt_vma_pages(struct i915_vma *vma)
+{
+	int ret;
+
+	/*
+	 * The vma->pages are only valid within the lifespan of the borrowed
+	 * obj->mm.pages. When the obj->mm.pages sg_table is regenerated, so
+	 * must be the vma->pages. A simple rule is that vma->pages must only
+	 * be accessed when the obj->mm.pages are pinned.
+	 */
+	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(vma->obj));
+
+	switch (vma->ggtt_view.type) {
+	default:
+		GEM_BUG_ON(vma->ggtt_view.type);
+		/* fall through */
+	case I915_GGTT_VIEW_NORMAL:
+		vma->pages = vma->obj->mm.pages;
+		return 0;
+
+	case I915_GGTT_VIEW_ROTATED:
+		vma->pages =
+			intel_rotate_pages(&vma->ggtt_view.rotated, vma->obj);
+		break;
+
+	case I915_GGTT_VIEW_REMAPPED:
+		vma->pages =
+			intel_remap_pages(&vma->ggtt_view.remapped, vma->obj);
+		break;
+
+	case I915_GGTT_VIEW_PARTIAL:
+		vma->pages = intel_partial_pages(&vma->ggtt_view, vma->obj);
+		break;
+	}
+
+	ret = 0;
+	if (IS_ERR(vma->pages)) {
+		ret = PTR_ERR(vma->pages);
+		vma->pages = NULL;
+		DRM_ERROR("Failed to get pages for VMA view type %u (%d)!\n",
+			  vma->ggtt_view.type, ret);
+	}
+	return ret;
+}