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From: Chris Wilson <chris@chris-wilson.co.uk>
To: intel-gfx@lists.freedesktop.org
Subject: [PATCH 09/29] drm/i915: Pin backing pages whilst exporting through a dmabuf vmap
Date: Sat, 11 Aug 2012 15:41:08 +0100
Message-ID: <1344696088-24760-10-git-send-email-chris@chris-wilson.co.uk> (raw)
In-Reply-To: <1344696088-24760-1-git-send-email-chris@chris-wilson.co.uk>

We need to refcount our pages in order to prevent reaping them at
inopportune times, such as when they currently vmapped or exported to
another driver. However, we also wish to keep the lazy deallocation of
our pages so we need to take a pin/unpinned approach rather than a
simple refcount.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_drv.h        |   12 ++++++++++++
 drivers/gpu/drm/i915/i915_gem.c        |   11 +++++++++--
 drivers/gpu/drm/i915/i915_gem_dmabuf.c |    9 +++++++--
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c42190b..0805040f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -989,6 +989,7 @@ struct drm_i915_gem_object {
 	unsigned int has_global_gtt_mapping:1;
 
 	struct page **pages;
+	int pages_pin_count;
 
 	/**
 	 * DMAR support
@@ -1322,6 +1323,17 @@ void i915_gem_release_mmap(struct drm_i915_gem_object *obj);
 void i915_gem_lastclose(struct drm_device *dev);
 
 int __must_check i915_gem_object_get_pages(struct drm_i915_gem_object *obj);
+static inline void i915_gem_object_pin_pages(struct drm_i915_gem_object *obj)
+{
+	BUG_ON(obj->pages == NULL);
+	obj->pages_pin_count++;
+}
+static inline void i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj)
+{
+	BUG_ON(obj->pages_pin_count == 0);
+	obj->pages_pin_count--;
+}
+
 int __must_check i915_mutex_lock_interruptible(struct drm_device *dev);
 int i915_gem_object_sync(struct drm_i915_gem_object *obj,
 			 struct intel_ring_buffer *to);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ed6a1ec..c90e265 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1455,6 +1455,9 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
 	if (obj->sg_table || obj->pages == NULL)
 		return 0;
 
+	if (obj->pages_pin_count)
+		return -EBUSY;
+
 	ops->put_pages(obj);
 
 	list_del(&obj->gtt_list);
@@ -1586,6 +1589,8 @@ i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
 	if (obj->sg_table || obj->pages)
 		return 0;
 
+	BUG_ON(obj->pages_pin_count);
+
 	ret = ops->get_pages(obj);
 	if (ret)
 		return ret;
@@ -3685,6 +3690,7 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
 		dev_priv->mm.interruptible = was_interruptible;
 	}
 
+	obj->pages_pin_count = 0;
 	i915_gem_object_put_pages(obj);
 	i915_gem_object_free_mmap_offset(obj);
 
@@ -4344,9 +4350,10 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
 
 	cnt = 0;
 	list_for_each_entry(obj, &dev_priv->mm.unbound_list, gtt_list)
-		cnt += obj->base.size >> PAGE_SHIFT;
+		if (obj->pages_pin_count == 0)
+			cnt += obj->base.size >> PAGE_SHIFT;
 	list_for_each_entry(obj, &dev_priv->mm.bound_list, gtt_list)
-		if (obj->pin_count == 0)
+		if (obj->pin_count == 0 && obj->pages_pin_count == 0)
 			cnt += obj->base.size >> PAGE_SHIFT;
 
 	mutex_unlock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 1203460..4a6982e 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -50,6 +50,8 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme
 	/* link the pages into an SG then map the sg */
 	sg = drm_prime_pages_to_sg(obj->pages, npages);
 	nents = dma_map_sg(attachment->dev, sg->sgl, sg->nents, dir);
+	i915_gem_object_pin_pages(obj);
+
 out:
 	mutex_unlock(&dev->struct_mutex);
 	return sg;
@@ -72,6 +74,7 @@ static void i915_gem_dmabuf_release(struct dma_buf *dma_buf)
 		obj->base.export_dma_buf = NULL;
 		drm_gem_object_unreference_unlocked(&obj->base);
 	}
+	i915_gem_object_unpin_pages(obj);
 }
 
 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
@@ -102,6 +105,7 @@ static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 	}
 
 	obj->vmapping_count = 1;
+	i915_gem_object_pin_pages(obj);
 out_unlock:
 	mutex_unlock(&dev->struct_mutex);
 	return obj->dma_buf_vmapping;
@@ -117,10 +121,11 @@ static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 	if (ret)
 		return;
 
-	--obj->vmapping_count;
-	if (obj->vmapping_count == 0) {
+	if (--obj->vmapping_count == 0) {
 		vunmap(obj->dma_buf_vmapping);
 		obj->dma_buf_vmapping = NULL;
+
+		i915_gem_object_unpin_pages(obj);
 	}
 	mutex_unlock(&dev->struct_mutex);
 }
-- 
1.7.10.4

  parent reply index

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-11 14:40 Stolen pages, with a little surprise Chris Wilson
2012-08-11 14:41 ` [PATCH 01/29] drm/i915: Track unbound pages Chris Wilson
2012-08-20  9:00   ` [PATCH 1/2] drm/i915: move functions around Daniel Vetter
2012-08-20  9:00     ` [PATCH 2/2] drm/i915: Track unbound pages Daniel Vetter
2012-08-20  9:23       ` [PATCH] Add some sanity checks to unbound tracking Chris Wilson
2012-08-20  9:36       ` [PATCH 2/2] drm/i915: Track unbound pages Chris Wilson
2012-08-20  9:42         ` Daniel Vetter
2012-08-11 14:41 ` [PATCH 02/29] drm/i915: Show (count, size) of purgeable objects in i915_gem_objects Chris Wilson
2012-08-20  9:04   ` Daniel Vetter
2012-08-20  9:17     ` Chris Wilson
2012-08-11 14:41 ` [PATCH 03/29] drm/i915: Show pin count in debugfs Chris Wilson
2012-08-11 14:41 ` [PATCH 04/29] drm/i915: Try harder to allocate an mmap_offset Chris Wilson
2012-08-20  9:37   ` Daniel Vetter
2012-08-20 11:31     ` Chris Wilson
2012-08-11 14:41 ` [PATCH 05/29] drm/i915: Only pwrite through the GTT if there is space in the aperture Chris Wilson
2012-08-11 14:41 ` [PATCH 06/29] drm/i915: Protect private gem objects from truncate (such as imported dmabuf) Chris Wilson
2012-08-11 14:41 ` [PATCH 07/29] drm/i915: Extract general object init routine Chris Wilson
2012-08-24  0:05   ` Daniel Vetter
2012-08-11 14:41 ` [PATCH 08/29] drm/i915: Introduce drm_i915_gem_object_ops Chris Wilson
2012-08-20 19:35   ` Daniel Vetter
2012-08-11 14:41 ` Chris Wilson [this message]
2012-08-11 14:41 ` [PATCH 10/29] drm/i915: Pin backing pages for pwrite Chris Wilson
2012-08-11 14:41 ` [PATCH 11/29] drm/i915: Pin backing pages for pread Chris Wilson
2012-08-11 14:41 ` [PATCH 12/29] drm/i915: Replace the array of pages with a scatterlist Chris Wilson
2012-08-11 14:41 ` [PATCH 13/29] drm/i915: Convert the dmabuf object to use the new i915_gem_object_ops Chris Wilson
2012-08-11 14:41 ` [PATCH 14/29] drm: Introduce drm_mm_create_block() Chris Wilson
2012-08-11 14:41 ` [PATCH 15/29] drm/i915: Fix detection of stolen base for gen2 Chris Wilson
2012-08-11 14:41 ` [PATCH 16/29] drm/i915: Fix location of stolen memory register for SandyBridge+ Chris Wilson
2012-08-20 19:38   ` Daniel Vetter
2012-08-22 15:54     ` Chris Wilson
2012-08-11 14:41 ` [PATCH 17/29] drm/i915: Avoid clearing preallocated regions from the GTT Chris Wilson
2012-08-11 14:41 ` [PATCH 18/29] drm/i915: Delay allocation of stolen space for FBC Chris Wilson
2012-08-20 19:51   ` Daniel Vetter
2012-08-22 15:51     ` Chris Wilson
2012-08-11 14:41 ` [PATCH 19/29] drm/i915: Allow objects to be created with no backing pages, but stolen space Chris Wilson
2012-08-11 14:41 ` [PATCH 20/29] drm/i915: Differentiate between prime and stolen objects Chris Wilson
2012-08-11 14:41 ` [PATCH 21/29] drm/i915: Support readback of stolen objects upon error Chris Wilson
2012-08-11 14:41 ` [PATCH 22/29] drm/i915: Handle stolen objects in pwrite Chris Wilson
2012-08-20 19:56   ` Daniel Vetter
2012-08-22 15:47     ` Chris Wilson
2012-08-30 15:09     ` Chris Wilson
2012-08-11 14:41 ` [PATCH 23/29] drm/i915: Handle stolen objects for pread Chris Wilson
2012-08-11 14:41 ` [PATCH 24/29] drm/i915: Introduce i915_gem_object_create_stolen() Chris Wilson
2012-08-11 14:41 ` [PATCH 25/29] drm/i915: Allocate fbcon from stolen memory Chris Wilson
2012-08-11 14:41 ` [PATCH 26/29] drm/i915: Allocate ringbuffers " Chris Wilson
2012-08-11 14:41 ` [PATCH 27/29] drm/i915: Allocate overlay registers " Chris Wilson
2012-08-20 21:17   ` Daniel Vetter
2012-08-22 15:45     ` Chris Wilson
2012-08-22 16:26       ` Daniel Vetter
2012-08-11 14:41 ` [PATCH 28/29] drm/i915: Use a slab for object allocation Chris Wilson
2012-08-11 14:41 ` [PATCH 29/29] drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl Chris Wilson

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