[Intel-gfx] [PATCH 3/4] drm/i915: handle walking compact dma scatter lists
Daniel Vetter
daniel at ffwll.ch
Sat Feb 9 23:51:26 CET 2013
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 at 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?
-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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> Intel-gfx at lists.freedesktop.org
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--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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