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Commit 67d5a50c authored by Imre Deak's avatar Imre Deak Committed by Daniel Vetter
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drm/i915: handle walking compact dma scatter lists 

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: default avatarImre Deak <imre.deak@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 5bd4687e

drivers/gpu/drm/i915/i915_drv.h

+6 −11
Original line number Diff line number Diff line
@@ -1528,17 +1528,12 @@ 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 sg_page_iter sg_iter;



	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, n)

		return sg_iter.page;



	return NULL;

}

static inline void i915_gem_object_pin_pages(struct drm_i915_gem_object *obj)

{

drivers/gpu/drm/i915/i915_gem.c

+8 −16
Original line number Diff line number Diff line
@@ -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 sg_page_iter sg_iter;



	user_data = to_user_ptr(args->data_ptr);

	remain = args->size;
@@ -441,11 +440,9 @@ 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;

	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents,

			 offset >> PAGE_SHIFT) {

		struct page *page = sg_iter.page;



		if (remain <= 0)

			break;
@@ -460,7 +457,6 @@ 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 +728,7 @@ 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 sg_page_iter sg_iter;



	user_data = to_user_ptr(args->data_ptr);

	remain = args->size;
@@ -768,13 +763,11 @@ 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;

	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents,

			 offset >> PAGE_SHIFT) {

		struct page *page = sg_iter.page;

		int partial_cacheline_write;



		if (i < offset >> PAGE_SHIFT)

			continue;



		if (remain <= 0)

			break;
@@ -796,7 +789,6 @@ 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;

drivers/gpu/drm/i915/i915_gem_dmabuf.c

+7 −6
Original line number Diff line number Diff line
@@ -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 sg_page_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;

	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 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)

drivers/gpu/drm/i915/i915_gem_tiling.c

+10 −8
Original line number Diff line number Diff line
@@ -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 sg_page_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;

	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 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 sg_page_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;

	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0) {

		if (page_to_phys(sg_iter.page) & (1 << 17))

			__set_bit(i, obj->bit_17);

		else

			__clear_bit(i, obj->bit_17);

		i++;

	}

}