[09/11] drm/i915: Migrate stolen objects before hibernation

Submitted by ankitprasad.r.sharma@intel.com on May 31, 2016, 6:19 a.m.

Details

Message ID 1464675564-11988-10-git-send-email-ankitprasad.r.sharma@intel.com
State New
Headers show
Series "Support for creating/using Stolen memory backed objects" ( rev: 15 ) in Intel GFX

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Commit Message

ankitprasad.r.sharma@intel.com May 31, 2016, 6:19 a.m.
From: Chris Wilson <chris@chris-wilson.co.uk>

Ville reminded us that stolen memory is not preserved across
hibernation, and a result of this was that context objects now being
allocated from stolen were being corrupted on S4 and promptly hanging
the GPU on resume.

We want to utilise stolen for as much as possible (nothing else will use
that wasted memory otherwise), so we need a strategy for handling
general objects allocated from stolen and hibernation. A simple solution
is to do a CPU copy through the GTT of the stolen object into a fresh
shmemfs backing store and thenceforth treat it as a normal objects. This
can be refined in future to either use a GPU copy to avoid the slow
uncached reads (though it's hibernation!) and recreate stolen objects
upon resume/first-use. For now, a simple approach should suffice for
testing the object migration.

v2:
Swap PTE for pinned bindings over to the shmemfs. This adds a
complicated dance, but is required as many stolen objects are likely to
be pinned for use by the hardware. Swapping the PTEs should not result
in externally visible behaviour, as each PTE update should be atomic and
the two pages identical. (danvet)

safe-by-default, or the principle of least surprise. We need a new flag
to mark objects that we can wilfully discard and recreate across
hibernation. (danvet)

Just use the global_list rather than invent a new stolen_list. This is
the slowpath hibernate and so adding a new list and the associated
complexity isn't worth it.

v3: Rebased on drm-intel-nightly (Ankit)

v4: Use insert_page to map stolen memory backed pages for migration to
shmem (Chris)

v5: Acquire mutex lock while copying stolen buffer objects to shmem (Chris)

v6: Handled file leak, Splitted object migration function, added kerneldoc
for migrate_stolen_to_shmemfs() function (Tvrtko)
Use i915 wrapper function for drm_mm_insert_node_in_range()

v7: Keep the object in cpu domain after get_pages, remove the object from
the unbound list only when marked PURGED, Corrected split of object migration
function (Chris)

v8: Split i915_gem_freeze(), removed redundant use of barrier, corrected
use of set_to_cpu_domain() (Chris)

v9: Replaced WARN_ON by BUG_ON and added a comment explaining it
(Daniel/Tvrtko)

v10: Document use of barriers (Chris)

v11: Resolved list corruption due to not removing obj from global_list
if no reference to pages is held, Rebased (Ankit)

v12: Rebase (Ankit)

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c         |  22 +++-
 drivers/gpu/drm/i915/i915_drv.h         |  10 ++
 drivers/gpu/drm/i915/i915_gem.c         | 204 ++++++++++++++++++++++++++++++--
 drivers/gpu/drm/i915/i915_gem_stolen.c  |  49 ++++++++
 drivers/gpu/drm/i915/intel_display.c    |   3 +
 drivers/gpu/drm/i915/intel_fbdev.c      |   6 +
 drivers/gpu/drm/i915/intel_pm.c         |   2 +
 drivers/gpu/drm/i915/intel_ringbuffer.c |   6 +
 8 files changed, 284 insertions(+), 18 deletions(-)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 943d7b2..827a3fe 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1066,6 +1066,22 @@  static int i915_pm_suspend(struct device *dev)
 	return i915_drm_suspend(drm_dev);
 }
 
+/* freeze: before creating the hibernation_image */
+static int i915_pm_freeze(struct device *dev)
+{
+	int ret;
+
+	ret = i915_gem_freeze(pci_get_drvdata(to_pci_dev(dev)));
+	if (ret)
+		return ret;
+
+	ret = i915_pm_suspend(dev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int i915_pm_suspend_late(struct device *dev)
 {
 	struct drm_device *drm_dev = dev_to_i915(dev)->dev;
@@ -1115,12 +1131,6 @@  static int i915_pm_resume(struct device *dev)
 	return i915_drm_resume(drm_dev);
 }
 
-/* freeze: before creating the hibernation_image */
-static int i915_pm_freeze(struct device *dev)
-{
-	return i915_pm_suspend(dev);
-}
-
 static int i915_pm_freeze_late(struct device *dev)
 {
 	int ret;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d15c018..6b7e790 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2180,6 +2180,12 @@  struct drm_i915_gem_object {
 	 * Advice: are the backing pages purgeable?
 	 */
 	unsigned int madv:2;
+	/**
+	 * Whereas madv is for userspace, there are certain situations
+	 * where we want I915_MADV_DONTNEED behaviour on internal objects
+	 * without conflating the userspace setting.
+	 */
+	unsigned int internal_volatile:1;
 
 	/**
 	 * Current tiling mode for the object.
@@ -3317,6 +3323,9 @@  int __must_check i915_gem_init_hw(struct drm_device *dev);
 void i915_gem_init_swizzling(struct drm_device *dev);
 void i915_gem_cleanup_engines(struct drm_device *dev);
 int __must_check i915_gpu_idle(struct drm_device *dev);
+int __must_check i915_gem_freeze(struct drm_device *dev);
+int __must_check
+i915_gem_object_migrate_stolen_to_shmemfs(struct drm_i915_gem_object *obj);
 int __must_check i915_gem_suspend(struct drm_device *dev);
 void __i915_add_request(struct drm_i915_gem_request *req,
 			struct drm_i915_gem_object *batch_obj,
@@ -3542,6 +3551,7 @@  i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 					       u32 stolen_offset,
 					       u32 gtt_offset,
 					       u32 size);
+int __must_check i915_gem_stolen_freeze(struct drm_i915_private *i915);
 
 /* i915_gem_shrinker.c */
 unsigned long i915_gem_shrink(struct drm_i915_private *dev_priv,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index fca3f6d..e0adb2a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4753,12 +4753,27 @@  static const struct drm_i915_gem_object_ops i915_gem_object_ops = {
 	.put_pages = i915_gem_object_put_pages_gtt,
 };
 
+static struct address_space *
+i915_gem_set_inode_gfp(struct drm_device *dev, struct file *file)
+{
+	struct address_space *mapping = file_inode(file)->i_mapping;
+	gfp_t mask;
+
+	mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
+	if (IS_CRESTLINE(dev) || IS_BROADWATER(dev)) {
+		/* 965gm cannot relocate objects above 4GiB. */
+		mask &= ~__GFP_HIGHMEM;
+		mask |= __GFP_DMA32;
+	}
+	mapping_set_gfp_mask(mapping, mask);
+
+	return mapping;
+}
+
 struct drm_i915_gem_object *i915_gem_object_create(struct drm_device *dev,
-						  size_t size)
+						   size_t size)
 {
 	struct drm_i915_gem_object *obj;
-	struct address_space *mapping;
-	gfp_t mask;
 	int ret;
 
 	obj = i915_gem_object_alloc(dev);
@@ -4769,15 +4784,7 @@  struct drm_i915_gem_object *i915_gem_object_create(struct drm_device *dev,
 	if (ret)
 		goto fail;
 
-	mask = GFP_HIGHUSER | __GFP_RECLAIMABLE;
-	if (IS_CRESTLINE(dev) || IS_BROADWATER(dev)) {
-		/* 965gm cannot relocate objects above 4GiB. */
-		mask &= ~__GFP_HIGHMEM;
-		mask |= __GFP_DMA32;
-	}
-
-	mapping = file_inode(obj->base.filp)->i_mapping;
-	mapping_set_gfp_mask(mapping, mask);
+	i915_gem_set_inode_gfp(dev, obj->base.filp);
 
 	i915_gem_object_init(obj, &i915_gem_object_ops);
 
@@ -4950,6 +4957,179 @@  i915_gem_stop_engines(struct drm_device *dev)
 		dev_priv->gt.stop_engine(engine);
 }
 
+static int
+copy_content(struct drm_i915_gem_object *obj,
+		struct drm_i915_private *i915,
+		struct address_space *mapping)
+{
+	struct i915_ggtt *ggtt = &i915->ggtt;
+	struct drm_mm_node node;
+	int ret, i;
+
+	ret = i915_gem_object_set_to_gtt_domain(obj, false);
+	if (ret)
+		return ret;
+
+	/* stolen objects are already pinned to prevent shrinkage */
+	memset(&node, 0, sizeof(node));
+	ret = insert_mappable_node(i915, &node, PAGE_SIZE);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
+		struct page *page;
+		void *__iomem src;
+		void *dst;
+
+		ggtt->base.insert_page(&ggtt->base,
+				       i915_gem_object_get_dma_address(obj, i),
+				       node.start,
+				       I915_CACHE_NONE, 0);
+
+		page = shmem_read_mapping_page(mapping, i);
+		if (IS_ERR(page)) {
+			ret = PTR_ERR(page);
+			break;
+		}
+
+		src = io_mapping_map_atomic_wc(ggtt->mappable, node.start);
+		dst = kmap_atomic(page);
+		wmb(); /* flush modifications to the GGTT (insert_page) */
+		memcpy_fromio(dst, src, PAGE_SIZE);
+		wmb(); 	/* flush the write before we modify the GGTT */
+		kunmap_atomic(dst);
+		io_mapping_unmap_atomic(src);
+
+		put_page(page);
+	}
+
+	ggtt->base.clear_range(&ggtt->base,
+			       node.start, node.size,
+			       true);
+	remove_mappable_node(&node);
+	if (ret)
+		return ret;
+
+	return i915_gem_object_set_to_cpu_domain(obj, true);
+}
+
+/**
+ * i915_gem_object_migrate_stolen_to_shmemfs() - migrates a stolen backed
+ * object to shmemfs
+ * @obj: stolen backed object to be migrated
+ *
+ * Returns: 0 on successful migration, errno on failure
+ */
+
+int
+i915_gem_object_migrate_stolen_to_shmemfs(struct drm_i915_gem_object *obj)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct i915_vma *vma, *vn;
+	struct file *file;
+	struct address_space *mapping;
+	struct sg_table *stolen_pages, *shmemfs_pages;
+	int ret;
+
+	if (WARN_ON_ONCE(i915_gem_object_needs_bit17_swizzle(obj)))
+		return -EINVAL;
+
+	file = shmem_file_setup("drm mm object", obj->base.size, VM_NORESERVE);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+	mapping = i915_gem_set_inode_gfp(obj->base.dev, file);
+
+	list_for_each_entry_safe(vma, vn, &obj->vma_list, obj_link)
+		if (i915_vma_unbind(vma))
+			continue;
+
+	if (obj->madv != I915_MADV_WILLNEED && list_empty(&obj->vma_list)) {
+		/* Discard the stolen reservation, and replace with
+		 * an unpopulated shmemfs object.
+		 */
+		obj->madv = __I915_MADV_PURGED;
+	} else {
+		ret = copy_content(obj, i915, mapping);
+		if (ret)
+			goto err_file;
+	}
+
+	stolen_pages = obj->pages;
+	obj->pages = NULL;
+
+	obj->base.filp = file;
+
+	/* Recreate any pinned binding with pointers to the new storage */
+	if (!list_empty(&obj->vma_list)) {
+		ret = i915_gem_object_get_pages_gtt(obj);
+		if (ret) {
+			obj->pages = stolen_pages;
+			goto err_file;
+		}
+
+		obj->get_page.sg = obj->pages->sgl;
+		obj->get_page.last = 0;
+
+		list_for_each_entry(vma, &obj->vma_list, obj_link) {
+			if (!drm_mm_node_allocated(&vma->node))
+				continue;
+
+			/* As vma is already allocated and only the PTEs
+			 * have to be reprogrammed, makes this vma_bind
+			 * call extremely unlikely to fail.
+			 */
+			BUG_ON(i915_vma_bind(vma,
+					      obj->cache_level,
+					      PIN_UPDATE));
+		}
+	} else {
+		/* Remove object from global list if no reference to the
+		 * pages is held.
+		 */
+		list_del(&obj->global_list);
+	}
+
+	/* drop the stolen pin and backing */
+	shmemfs_pages = obj->pages;
+	obj->pages = stolen_pages;
+
+	i915_gem_object_unpin_pages(obj);
+	obj->ops->put_pages(obj);
+	if (obj->ops->release)
+		obj->ops->release(obj);
+
+	obj->ops = &i915_gem_object_ops;
+	obj->pages = shmemfs_pages;
+
+	return 0;
+
+err_file:
+	fput(file);
+	obj->base.filp = NULL;
+	return ret;
+}
+
+int
+i915_gem_freeze(struct drm_device *dev)
+{
+	/* Called before i915_gem_suspend() when hibernating */
+	struct drm_i915_private *i915 = to_i915(dev);
+	int ret;
+
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret)
+		return ret;
+
+	/* Across hibernation, the stolen area is not preserved.
+	 * Anything inside stolen must copied back to normal
+	 * memory if we wish to preserve it.
+	 */
+	ret = i915_gem_stolen_freeze(i915);
+
+	mutex_unlock(&dev->struct_mutex);
+	return ret;
+}
+
 int
 i915_gem_suspend(struct drm_device *dev)
 {
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 1b1b9c1..2518ebb 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -853,3 +853,52 @@  err:
 	drm_gem_object_unreference(&obj->base);
 	return ERR_PTR(ret);
 }
+
+int i915_gem_stolen_freeze(struct drm_i915_private *i915)
+{
+	struct drm_i915_gem_object *obj, *tmp;
+	struct list_head *phase[] = {
+		&i915->mm.unbound_list, &i915->mm.bound_list, NULL
+	}, **p;
+	int ret = 0;
+
+	for (p = phase; *p; p++) {
+		struct list_head migrate;
+		int ret;
+
+		INIT_LIST_HEAD(&migrate);
+		list_for_each_entry_safe(obj, tmp, *p, global_list) {
+			if (obj->stolen == NULL)
+				continue;
+
+			if (obj->internal_volatile)
+				continue;
+
+			/* In the general case, this object may only be alive
+			 * due to an active reference, and that may disappear
+			 * when we unbind any of the objects (and so wait upon
+			 * the GPU and retire requests). To prevent one of the
+			 * objects from disappearing beneath us, we need to
+			 * take a reference to each as we build the migration
+			 * list.
+			 *
+			 * This is similar to the strategy required whilst
+			 * shrinking or evicting objects (for the same reason).
+			 */
+			drm_gem_object_reference(&obj->base);
+			list_move(&obj->global_list, &migrate);
+		}
+
+		ret = 0;
+		list_for_each_entry_safe(obj, tmp, &migrate, global_list) {
+			if (ret == 0)
+				ret = i915_gem_object_migrate_stolen_to_shmemfs(obj);
+			drm_gem_object_unreference(&obj->base);
+		}
+		list_splice(&migrate, *p);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4bbda9c..1f4e4a5 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2500,6 +2500,9 @@  intel_alloc_initial_plane_obj(struct intel_crtc *crtc,
 		return false;
 	}
 
+	/* Not to be preserved across hibernation */
+	obj->internal_volatile = true;
+
 	obj->tiling_mode = plane_config->tiling;
 	if (obj->tiling_mode == I915_TILING_X)
 		obj->stride = fb->pitches[0];
diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index e094005..a0c2855 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -157,6 +157,12 @@  static int intelfb_alloc(struct drm_fb_helper *helper,
 		goto out;
 	}
 
+	/* Discard the contents of the BIOS fb across hibernation.
+	 * We really want to completely throwaway the earlier fbdev
+	 * and reconfigure it anyway.
+	 */
+	obj->internal_volatile = true;
+
 	fb = __intel_framebuffer_create(dev, &mode_cmd, obj);
 	if (IS_ERR(fb)) {
 		drm_gem_object_unreference(&obj->base);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 12aa36f..89db045 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5543,6 +5543,8 @@  static void valleyview_setup_pctx(struct drm_i915_private *dev_priv)
 	I915_WRITE(VLV_PCBR, pctx_paddr);
 
 out:
+	/* The power context need not be preserved across hibernation */
+	pctx->internal_volatile = true;
 	DRM_DEBUG_DRIVER("PCBR: 0x%08x\n", I915_READ(VLV_PCBR));
 	dev_priv->vlv_pctx = pctx;
 	mutex_unlock(&dev_priv->dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 586360b..a0dfcab 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2184,6 +2184,12 @@  static int intel_alloc_ringbuffer_obj(struct drm_device *dev,
 	if (IS_ERR(obj))
 		return PTR_ERR(obj);
 
+	/* Ringbuffer objects are by definition volatile - only the commands
+	 * between HEAD and TAIL need to be preserved and whilst there are
+	 * any commands there, the ringbuffer is pinned by activity.
+	 */
+	obj->internal_volatile = true;
+
 	/* mark ring buffers as read-only from GPU side by default */
 	obj->gt_ro = 1;