Re: [PATCH] cleanup: Add 'struct dev' in the TTM layer to be passed in for DMA API calls.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi, Konrad,

Is passing a struct device to the DMA api really *strictly* necessary?

I'd like to avoid that at all cost, since we don't want pages that are backing buffer objects
(coherent pages) to be associated with a specific device.

The reason for this is that we probably soon will want to move ttm buffer objects between devices, and that should ideally be a simple operation: If the memory type the buffer object currently resides in is not shared between two devices, then move it out to system memory and change its struct bo_device pointer.

If pages are associated with a specific device, this will become much harder. Basically we need to change backing pages and copy all the data.

/Thomas


On 03/08/2011 04:39 PM, Konrad Rzeszutek Wilk wrote:
These two patches are not strictly required but they do a bit of
cleanup and also fix a false reporting issue when the kernel is compiled
with CONFIG_DEBUG_DMA_API.

Essentially the patchset modifies 'struct ttm_tt' and 'struct ttm_bo_device'
to contain a pointer to 'struct device'. Passing of the 'struct device'
is done via the 'tt_bo_device_init'. The 'struct device' is then used
during the allocation/deallocation of pages when TTM_PAGE_FLAG_DMA32 flag
is set.

At first it seems that we would need to keep a copy of
'struct device' in the struct ttm_bo_device only and use that. However,
when 'ttm_tt_destroy' is called it sets ttm->be (which contains
the 'struct ttm_bo_device') to NULL so we cannot use it. Hence
we copy the 'struct device' pointer to the 'struct ttm_tm' and keep
it there.

I've put the patches on:

git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git devel/ttm.pci-api.v5

The testing was a bit difficult b/c I could not persuade the machine to unload
either the nouveau or radeon driver (I had a serial console hooked so I figured
it would fallback to that?). Ended up calling 'unbind' on the
/sys/pci/.../$BDF/driver/[radeon,nouveau] to trigger the de-allocation path.

Thomas,

What is the best way to test vmw-gfx*? Does the Workstation (5?) support
this particular frontend?

Konrad Rzeszutek Wilk (2):
       ttm: Include the 'struct dev' when using the DMA API.
       ttm: Pass in 'struct device' to TTM so it can do DMA API on behalf of device.

  drivers/gpu/drm/nouveau/nouveau_mem.c |    3 ++-
  drivers/gpu/drm/radeon/radeon_ttm.c   |    3 ++-
  drivers/gpu/drm/ttm/ttm_bo.c          |    4 +++-
  drivers/gpu/drm/ttm/ttm_page_alloc.c  |   11 ++++++-----
  drivers/gpu/drm/ttm/ttm_tt.c          |    5 +++--
  drivers/gpu/drm/vmwgfx/vmwgfx_drv.c   |    4 ++--
  include/drm/ttm/ttm_bo_driver.h       |    7 ++++++-
  include/drm/ttm/ttm_page_alloc.h      |    8 ++++++--
  8 files changed, 30 insertions(+), 15 deletions(-)


The full diff:

diff --git a/drivers/gpu/drm/nouveau/nouveau_mem.c b/drivers/gpu/drm/nouveau/nouveau_mem.c
index 26347b7..3706156 100644
--- a/drivers/gpu/drm/nouveau/nouveau_mem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_mem.c
@@ -412,7 +412,8 @@ nouveau_mem_vram_init(struct drm_device *dev)
  	ret = ttm_bo_device_init(&dev_priv->ttm.bdev,
  				 dev_priv->ttm.bo_global_ref.ref.object,
  				&nouveau_bo_driver, DRM_FILE_PAGE_OFFSET,
-				 dma_bits<= 32 ? true : false);
+				 dma_bits<= 32 ? true : false,
+				 dev->dev);
  	if (ret) {
  		NV_ERROR(dev, "Error initialising bo driver: %d\n", ret);
  		return ret;
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 9ead11f..371890c 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -517,7 +517,8 @@ int radeon_ttm_init(struct radeon_device *rdev)
  	r = ttm_bo_device_init(&rdev->mman.bdev,
  			       rdev->mman.bo_global_ref.ref.object,
  			&radeon_bo_driver, DRM_FILE_PAGE_OFFSET,
-			       rdev->need_dma32);
+			       rdev->need_dma32,
+			       rdev->dev);
  	if (r) {
  		DRM_ERROR("failed initializing buffer object driver(%d).\n", r);
  		return r;
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index af61fc2..278a2d3 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1526,12 +1526,14 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
  		       struct ttm_bo_global *glob,
  		       struct ttm_bo_driver *driver,
  		       uint64_t file_page_offset,
-		       bool need_dma32)
+		       bool need_dma32,
+		       struct device *dev)
  {
  	int ret = -EINVAL;

  	rwlock_init(&bdev->vm_lock);
  	bdev->driver = driver;
+	bdev->dev = dev;

  	memset(bdev->man, 0, sizeof(bdev->man));

diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index 737a2a2..35849db 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -664,7 +664,7 @@ out:
   */
  int ttm_get_pages(struct list_head *pages, int flags,
  		  enum ttm_caching_state cstate, unsigned count,
-		  dma_addr_t *dma_address)
+		  dma_addr_t *dma_address, struct device *dev)
  {
  	struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
  	struct page *p = NULL;
@@ -685,7 +685,7 @@ int ttm_get_pages(struct list_head *pages, int flags,
  		for (r = 0; r<  count; ++r) {
  			if ((flags&  TTM_PAGE_FLAG_DMA32)&&  dma_address) {
  				void *addr;
-				addr = dma_alloc_coherent(NULL, PAGE_SIZE,
+				addr = dma_alloc_coherent(dev, PAGE_SIZE,
  							&dma_address[r],
  							  gfp_flags);
  				if (addr == NULL)
@@ -730,7 +730,7 @@ int ttm_get_pages(struct list_head *pages, int flags,
  			printk(KERN_ERR TTM_PFX
  			       "Failed to allocate extra pages "
  			       "for large request.");
-			ttm_put_pages(pages, 0, flags, cstate, NULL);
+			ttm_put_pages(pages, 0, flags, cstate, NULL, NULL);
  			return r;
  		}
  	}
@@ -741,7 +741,8 @@ int ttm_get_pages(struct list_head *pages, int flags,

  /* Put all pages in pages list to correct pool to wait for reuse */
  void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
-		   enum ttm_caching_state cstate, dma_addr_t *dma_address)
+		   enum ttm_caching_state cstate, dma_addr_t *dma_address,
+		   struct device *dev)
  {
  	unsigned long irq_flags;
  	struct ttm_page_pool *pool = ttm_get_pool(flags, cstate);
@@ -757,7 +758,7 @@ void ttm_put_pages(struct list_head *pages, unsigned page_count, int flags,
  				void *addr = page_address(p);
  				WARN_ON(!addr || !dma_address[r]);
  				if (addr)
-					dma_free_coherent(NULL, PAGE_SIZE,
+					dma_free_coherent(dev, PAGE_SIZE,
  							  addr,
  							  dma_address[r]);
  				dma_address[r] = 0;
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 86d5b17..354f9d9 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -110,7 +110,7 @@ static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
  		INIT_LIST_HEAD(&h);

  		ret = ttm_get_pages(&h, ttm->page_flags, ttm->caching_state, 1,
-				&ttm->dma_address[index]);
+				&ttm->dma_address[index], ttm->dev);

  		if (ret != 0)
  			return NULL;
@@ -304,7 +304,7 @@ static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
  		}
  	}
  	ttm_put_pages(&h, count, ttm->page_flags, ttm->caching_state,
-		      ttm->dma_address);
+		      ttm->dma_address, ttm->dev);
  	ttm->state = tt_unpopulated;
  	ttm->first_himem_page = ttm->num_pages;
  	ttm->last_lomem_page = -1;
@@ -397,6 +397,7 @@ struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
  	ttm->last_lomem_page = -1;
  	ttm->caching_state = tt_cached;
  	ttm->page_flags = page_flags;
+	ttm->dev = bdev->dev;

  	ttm->dummy_read_page = dummy_read_page;

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 10ca97e..803d979 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -322,11 +322,11 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
  	ttm_lock_set_kill(&dev_priv->fbdev_master.lock, false, SIGTERM);
  	dev_priv->active_master =&dev_priv->fbdev_master;

-
  	ret = ttm_bo_device_init(&dev_priv->bdev,
  				 dev_priv->bo_global_ref.ref.object,
  				&vmw_bo_driver, VMWGFX_FILE_PAGE_OFFSET,
-				 false);
+				 false,
+				 dev->dev);
  	if (unlikely(ret != 0)) {
  		DRM_ERROR("Failed initializing TTM buffer object driver.\n");
  		goto out_err1;
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index efed082..2024a74 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -177,6 +177,7 @@ struct ttm_tt {
  		tt_unpopulated,
  	} state;
  	dma_addr_t *dma_address;
+	struct device *dev;
  };

  #define TTM_MEMTYPE_FLAG_FIXED         (1<<  0)	/* Fixed (on-card) PCI memory */
@@ -551,6 +552,7 @@ struct ttm_bo_device {
  	struct list_head device_list;
  	struct ttm_bo_global *glob;
  	struct ttm_bo_driver *driver;
+	struct device *dev;
  	rwlock_t vm_lock;
  	struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
  	spinlock_t fence_lock;
@@ -791,6 +793,8 @@ extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
   * @file_page_offset: Offset into the device address space that is available
   * for buffer data. This ensures compatibility with other users of the
   * address space.
+ * @need_dma32: Allocate pages under 4GB
+ * @dev: 'struct device' of the PCI device.
   *
   * Initializes a struct ttm_bo_device:
   * Returns:
@@ -799,7 +803,8 @@ extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
  extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
  			      struct ttm_bo_global *glob,
  			      struct ttm_bo_driver *driver,
-			      uint64_t file_page_offset, bool need_dma32);
+			      uint64_t file_page_offset, bool need_dma32,
+			      struct device *dev);

  /**
   * ttm_bo_unmap_virtual
diff --git a/include/drm/ttm/ttm_page_alloc.h b/include/drm/ttm/ttm_page_alloc.h
index 8062890..ccb6b7a 100644
--- a/include/drm/ttm/ttm_page_alloc.h
+++ b/include/drm/ttm/ttm_page_alloc.h
@@ -37,12 +37,14 @@
   * @cstate: ttm caching state for the page.
   * @count: number of pages to allocate.
   * @dma_address: The DMA (bus) address of pages (if TTM_PAGE_FLAG_DMA32 set).
+ * @dev: struct device for appropiate DMA accounting.
   */
  int ttm_get_pages(struct list_head *pages,
  		  int flags,
  		  enum ttm_caching_state cstate,
  		  unsigned count,
-		  dma_addr_t *dma_address);
+		  dma_addr_t *dma_address,
+		  struct device *dev);
  /**
   * Put linked list of pages to pool.
   *
@@ -52,12 +54,14 @@ int ttm_get_pages(struct list_head *pages,
   * @flags: ttm flags for page allocation.
   * @cstate: ttm caching state.
   * @dma_address: The DMA (bus) address of pages (if TTM_PAGE_FLAG_DMA32 set).
+ * @dev: struct device for appropiate DMA accounting.
   */
  void ttm_put_pages(struct list_head *pages,
  		   unsigned page_count,
  		   int flags,
  		   enum ttm_caching_state cstate,
-		   dma_addr_t *dma_address);
+		   dma_addr_t *dma_address,
+		   struct device *dev);
  /**
   * Initialize pool allocator.
   */

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/dri-devel


[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux