[PATCH v2 2/4] 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: Imre Deak
---
drivers/gpu/drm/i915/i915_drv.h| 17 ++---
drivers/gpu/drm/i915/i915_gem.c| 24
drivers/gpu/drm/i915/i915_gem_dmabuf.c | 13 +++--
drivers/gpu/drm/i915/i915_gem_tiling.c | 18 ++
4 files changed, 31 insertions(+), 41 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e95337c..2c03636 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -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)
{
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8413ffc..03037cf 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 sg_page_iter sg_iter;
user_data = (char __user *) (uintptr_t) 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 = (char __user *) (uintptr_t) 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;
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 6a5af68..898615d 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
[PATCH v2 2/4] 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: Imre Deak
---
drivers/gpu/drm/i915/i915_drv.h| 17 ++---
drivers/gpu/drm/i915/i915_gem.c| 24
drivers/gpu/drm/i915/i915_gem_dmabuf.c | 13 +++--
drivers/gpu/drm/i915/i915_gem_tiling.c | 18 ++
4 files changed, 31 insertions(+), 41 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e95337c..2c03636 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -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)
{
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8413ffc..03037cf 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 sg_page_iter sg_iter;
user_data = (char __user *) (uintptr_t) 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 = (char __user *) (uintptr_t) 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;
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 6a5af68..898615d 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;
f
