Re: [Intel-gfx] [PATCH 3/4] drm/i915: handle walking compact dma scatter lists

On Sat, 2013-02-09 at 23:51 +0100, Daniel Vetter wrote:

On Sat, Feb 09, 2013 at 05:27:35PM +0200, Imre Deak wrote:

...

So far the assumption was that each dma scatter list entry contains only a single page. This might not hold in the future, when we'll introduce compact scatter lists, so prepare for this everywhere in the i915 code where we walk such a list.

We'll fix the place _creating_ these lists separately in the next patch to help the reviewing/bisectability.

Reference: http://www.spinics.net/lists/dri-devel/msg33917.html Signed-off-by: Imre Deak imre.deak@intel.com

Since we now have such a nice macro to loop over sg pages ... Care to also convert the two existing (correct loops) in i915_gem_gtt.c and intel-gtt.c in a follow-up patch?

Ok, will do.

--Imre

-Daniel

...

---

drivers/gpu/drm/i915/i915_drv.h | 17 ++++++----------- drivers/gpu/drm/i915/i915_gem.c | 22 ++++++---------------- drivers/gpu/drm/i915/i915_gem_dmabuf.c | 13 +++++++------ drivers/gpu/drm/i915/i915_gem_tiling.c | 18 ++++++++++-------- 4 files changed, 29 insertions(+), 41 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 08c5def..0462428 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1531,17 +1531,12 @@ void i915_gem_lastclose(struct drm_device *dev); int __must_check i915_gem_object_get_pages(struct drm_i915_gem_object *obj); static inline struct page *i915_gem_object_get_page(struct drm_i915_gem_object *obj, int n) {

• struct scatterlist *sg = obj->pages->sgl;
• int nents = obj->pages->nents;
• while (nents > SG_MAX_SINGLE_ALLOC) {

• if (n < SG_MAX_SINGLE_ALLOC - 1)
  

• 	break;
  

• sg = sg_chain_ptr(sg + SG_MAX_SINGLE_ALLOC - 1);
  

• n -= SG_MAX_SINGLE_ALLOC - 1;
  

• nents -= SG_MAX_SINGLE_ALLOC - 1;
  

• }
• return sg_page(sg+n);

• struct drm_sg_iter sg_iter;
• drm_for_each_sg_page(&sg_iter, obj->pages->sgl, n << PAGE_SHIFT)

• return sg_iter.page;
  

• return NULL;

} static inline void i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) { diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index d746177..4a199e0 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -411,8 +411,7 @@ i915_gem_shmem_pread(struct drm_device *dev, int obj_do_bit17_swizzling, page_do_bit17_swizzling; int prefaulted = 0; int needs_clflush = 0;

• struct scatterlist *sg;
• int i;

• struct drm_sg_iter sg_iter;

  user_data = (char __user *) (uintptr_t) args->data_ptr; remain = args->size;

@@ -441,11 +440,8 @@ i915_gem_shmem_pread(struct drm_device *dev,

offset = args->offset;

• for_each_sg(obj->pages->sgl, sg, obj->pages->nents, i) {

• struct page *page;
  

• if (i < offset >> PAGE_SHIFT)
  

• 	continue;
  

• drm_for_each_sg_page(&sg_iter, obj->pages->sgl, offset) {

• struct page *page = sg_iter.page;
  
  

  if (remain <= 0) break;

@@ -460,7 +456,6 @@ i915_gem_shmem_pread(struct drm_device *dev, if ((shmem_page_offset + page_length) > PAGE_SIZE) page_length = PAGE_SIZE - shmem_page_offset;

• page = sg_page(sg);
  

  page_do_bit17_swizzling = obj_do_bit17_swizzling && (page_to_phys(page) & (1 << 17)) != 0;

@@ -732,8 +727,7 @@ i915_gem_shmem_pwrite(struct drm_device *dev, int hit_slowpath = 0; int needs_clflush_after = 0; int needs_clflush_before = 0;

• int i;
• struct scatterlist *sg;

• struct drm_sg_iter sg_iter;

  user_data = (char __user *) (uintptr_t) args->data_ptr; remain = args->size;

@@ -768,13 +762,10 @@ i915_gem_shmem_pwrite(struct drm_device *dev, offset = args->offset; obj->dirty = 1;

• for_each_sg(obj->pages->sgl, sg, obj->pages->nents, i) {

• struct page *page;
  

• drm_for_each_sg_page(&sg_iter, obj->pages->sgl, offset) {

• struct page *page = sg_iter.page;
  

  int partial_cacheline_write;

• if (i < offset >> PAGE_SHIFT)
  

• 	continue;
  

• if (remain <= 0) break;

@@ -796,7 +787,6 @@ i915_gem_shmem_pwrite(struct drm_device *dev, ((shmem_page_offset | page_length) & (boot_cpu_data.x86_clflush_size - 1));

• page = sg_page(sg);
  

  page_do_bit17_swizzling = obj_do_bit17_swizzling && (page_to_phys(page) & (1 << 17)) != 0;

diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c index 6a5af68..ac98792 100644 --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c @@ -62,7 +62,7 @@ static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachme src = obj->pages->sgl; dst = st->sgl; for (i = 0; i < obj->pages->nents; i++) {

• sg_set_page(dst, sg_page(src), PAGE_SIZE, 0);
  

• sg_set_page(dst, sg_page(src), src->length, 0);
  

  dst = sg_next(dst); src = sg_next(src); }

@@ -105,7 +105,7 @@ static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf) { struct drm_i915_gem_object *obj = dma_buf->priv; struct drm_device *dev = obj->base.dev;

• struct scatterlist *sg;

• struct drm_sg_iter sg_iter; struct page **pages; int ret, i;

@@ -124,14 +124,15 @@ static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)

ret = -ENOMEM;

• pages = drm_malloc_ab(obj->pages->nents, sizeof(struct page *));

• pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages)); if (pages == NULL) goto error;

• for_each_sg(obj->pages->sgl, sg, obj->pages->nents, i)

• pages[i] = sg_page(sg);
  

• i = 0;
• drm_for_each_sg_page(&sg_iter, obj->pages->sgl, 0);

• pages[i++] = sg_iter.page;
  
  

• obj->dma_buf_vmapping = vmap(pages, obj->pages->nents, 0, PAGE_KERNEL);

• obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL); drm_free_large(pages);

  if (!obj->dma_buf_vmapping)

diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c index abcba2f..834ed70 100644 --- a/drivers/gpu/drm/i915/i915_gem_tiling.c +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c @@ -473,28 +473,29 @@ i915_gem_swizzle_page(struct page *page) void i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj) {

• struct scatterlist *sg;
• int page_count = obj->base.size >> PAGE_SHIFT;

• struct drm_sg_iter sg_iter; int i;

  if (obj->bit_17 == NULL) return;

• for_each_sg(obj->pages->sgl, sg, page_count, i) {

• struct page *page = sg_page(sg);
  

• i = 0;
• drm_for_each_sg_page(&sg_iter, obj->pages->sgl, 0) {

• struct page *page = sg_iter.page;
  

  char new_bit_17 = page_to_phys(page) >> 17; if ((new_bit_17 & 0x1) != (test_bit(i, obj->bit_17) != 0)) { i915_gem_swizzle_page(page); set_page_dirty(page); }

• i++;
  

  }

}

void i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj) {

• struct scatterlist *sg;

• struct drm_sg_iter sg_iter; int page_count = obj->base.size >> PAGE_SHIFT; int i;

@@ -508,11 +509,12 @@ i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj) } }

• for_each_sg(obj->pages->sgl, sg, page_count, i) {

• struct page *page = sg_page(sg);
  

• if (page_to_phys(page) & (1 << 17))
  

• i = 0;
• drm_for_each_sg_page(&sg_iter, obj->pages->sgl, 0) {

• if (page_to_phys(sg_iter.page) & (1 << 17))
  __set_bit(i, obj->bit_17);
  

  else __clear_bit(i, obj->bit_17);

• i++;
  

  }

}

1.7.10.4

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