[PATCH rdma-next v4 1/3] lib/scatterlist: Provide a dedicated function to support table append
From: Maor Gottlieb
Date: Tue Aug 24 2021 - 10:26:24 EST
RDMA is the only in-kernel user that uses __sg_alloc_table_from_pages to
append pages dynamically. In the next patch. That mode will be extended
and that function will get more parameters. So separate it into a unique
function to make such change more clear.
Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
drivers/gpu/drm/drm_prime.c | 13 ++++---
drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 11 +++---
drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 14 +++-----
drivers/infiniband/core/umem.c | 4 +--
include/linux/scatterlist.h | 39 ++++++++++++++++++---
lib/scatterlist.c | 36 ++++++++++---------
tools/testing/scatterlist/main.c | 25 +++++++++----
7 files changed, 90 insertions(+), 52 deletions(-)
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 2a54f86856af..cf3278041f9c 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -807,8 +807,8 @@ struct sg_table *drm_prime_pages_to_sg(struct drm_device *dev,
struct page **pages, unsigned int nr_pages)
{
struct sg_table *sg;
- struct scatterlist *sge;
size_t max_segment = 0;
+ int err;
sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
if (!sg)
@@ -818,13 +818,12 @@ struct sg_table *drm_prime_pages_to_sg(struct drm_device *dev,
max_segment = dma_max_mapping_size(dev->dev);
if (max_segment == 0)
max_segment = UINT_MAX;
- sge = __sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
- nr_pages << PAGE_SHIFT,
- max_segment,
- NULL, 0, GFP_KERNEL);
- if (IS_ERR(sge)) {
+ err = sg_alloc_table_from_pages_segment(sg, pages, nr_pages, 0,
+ nr_pages << PAGE_SHIFT,
+ max_segment, GFP_KERNEL);
+ if (err) {
kfree(sg);
- sg = ERR_CAST(sge);
+ sg = ERR_PTR(err);
}
return sg;
}
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
index 7487bab11f0b..458f797a9e1e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
@@ -133,7 +133,6 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
unsigned int max_segment = i915_sg_segment_size();
struct sg_table *st;
unsigned int sg_page_sizes;
- struct scatterlist *sg;
struct page **pvec;
int ret;
@@ -153,13 +152,11 @@ static int i915_gem_userptr_get_pages(struct drm_i915_gem_object *obj)
spin_unlock(&i915->mm.notifier_lock);
alloc_table:
- sg = __sg_alloc_table_from_pages(st, pvec, num_pages, 0,
- num_pages << PAGE_SHIFT, max_segment,
- NULL, 0, GFP_KERNEL);
- if (IS_ERR(sg)) {
- ret = PTR_ERR(sg);
+ ret = sg_alloc_table_from_pages_segment(st, pvec, num_pages, 0,
+ num_pages << PAGE_SHIFT,
+ max_segment, GFP_KERNEL);
+ if (ret)
goto err;
- }
ret = i915_gem_gtt_prepare_pages(obj, st);
if (ret) {
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
index 0488042fb287..fc372d2e52a1 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
@@ -363,7 +363,6 @@ static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
int ret = 0;
static size_t sgl_size;
static size_t sgt_size;
- struct scatterlist *sg;
if (vmw_tt->mapped)
return 0;
@@ -386,15 +385,12 @@ static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
if (unlikely(ret != 0))
return ret;
- sg = __sg_alloc_table_from_pages(&vmw_tt->sgt, vsgt->pages,
- vsgt->num_pages, 0,
- (unsigned long) vsgt->num_pages << PAGE_SHIFT,
- dma_get_max_seg_size(dev_priv->drm.dev),
- NULL, 0, GFP_KERNEL);
- if (IS_ERR(sg)) {
- ret = PTR_ERR(sg);
+ ret = sg_alloc_table_from_pages_segment(
+ &vmw_tt->sgt, vsgt->pages, vsgt->num_pages, 0,
+ (unsigned long)vsgt->num_pages << PAGE_SHIFT,
+ dma_get_max_seg_size(dev_priv->drm.dev), GFP_KERNEL);
+ if (ret)
goto out_sg_alloc_fail;
- }
if (vsgt->num_pages > vmw_tt->sgt.orig_nents) {
uint64_t over_alloc =
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 0eb40025075f..b741758e528f 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -226,8 +226,8 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
cur_base += ret * PAGE_SIZE;
npages -= ret;
- sg = __sg_alloc_table_from_pages(&umem->sg_head, page_list, ret,
- 0, ret << PAGE_SHIFT,
+ sg = sg_alloc_append_table_from_pages(&umem->sg_head, page_list,
+ ret, 0, ret << PAGE_SHIFT,
ib_dma_max_seg_size(device), sg, npages,
GFP_KERNEL);
umem->sg_nents = umem->sg_head.nents;
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index ecf87484814f..5c700f2a0d18 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -285,14 +285,45 @@ void sg_free_table(struct sg_table *);
int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
struct scatterlist *, unsigned int, gfp_t, sg_alloc_fn *);
int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
-struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt,
+struct scatterlist *sg_alloc_append_table_from_pages(struct sg_table *sgt,
struct page **pages, unsigned int n_pages, unsigned int offset,
unsigned long size, unsigned int max_segment,
struct scatterlist *prv, unsigned int left_pages,
gfp_t gfp_mask);
-int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
- unsigned int n_pages, unsigned int offset,
- unsigned long size, gfp_t gfp_mask);
+int sg_alloc_table_from_pages_segment(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size,
+ unsigned int max_segment, gfp_t gfp_mask);
+
+/**
+ * sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @gfp_mask: GFP allocation mask
+ *
+ * Description:
+ * Allocate and initialize an sg table from a list of pages. Contiguous
+ * ranges of the pages are squashed into a single scatterlist node. A user
+ * may provide an offset at a start and a size of valid data in a buffer
+ * specified by the page array. The returned sg table is released by
+ * sg_free_table.
+ *
+ * Returns:
+ * 0 on success, negative error on failure
+ */
+static inline int sg_alloc_table_from_pages(struct sg_table *sgt,
+ struct page **pages,
+ unsigned int n_pages,
+ unsigned int offset,
+ unsigned long size, gfp_t gfp_mask)
+{
+ return sg_alloc_table_from_pages_segment(sgt, pages, n_pages, offset,
+ size, UINT_MAX, gfp_mask);
+}
#ifdef CONFIG_SGL_ALLOC
struct scatterlist *sgl_alloc_order(unsigned long long length,
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 27efa6178153..611c63d4a958 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -397,7 +397,7 @@ static struct scatterlist *get_next_sg(struct sg_table *table,
}
/**
- * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * sg_alloc_append_table_from_pages - Allocate and initialize an sg table from
* an array of pages
* @sgt: The sg table header to use
* @pages: Pointer to an array of page pointers
@@ -425,7 +425,7 @@ static struct scatterlist *get_next_sg(struct sg_table *table,
* If this function returns non-0 (eg failure), the caller must call
* sg_free_table() to cleanup any leftover allocations.
*/
-struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt,
+struct scatterlist *sg_alloc_append_table_from_pages(struct sg_table *sgt,
struct page **pages, unsigned int n_pages, unsigned int offset,
unsigned long size, unsigned int max_segment,
struct scatterlist *prv, unsigned int left_pages,
@@ -520,36 +520,40 @@ struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt,
sg_mark_end(s);
return s;
}
-EXPORT_SYMBOL(__sg_alloc_table_from_pages);
+EXPORT_SYMBOL(sg_alloc_append_table_from_pages);
/**
- * sg_alloc_table_from_pages - Allocate and initialize an sg table from
- * an array of pages
+ * sg_alloc_table_from_pages_segment - Allocate and initialize an sg table from
+ * an array of pages and given maximum
+ * segment.
* @sgt: The sg table header to use
* @pages: Pointer to an array of page pointers
* @n_pages: Number of pages in the pages array
* @offset: Offset from start of the first page to the start of a buffer
* @size: Number of valid bytes in the buffer (after offset)
+ * @max_segment: Maximum size of a scatterlist element in bytes
* @gfp_mask: GFP allocation mask
*
* Description:
* Allocate and initialize an sg table from a list of pages. Contiguous
- * ranges of the pages are squashed into a single scatterlist node. A user
- * may provide an offset at a start and a size of valid data in a buffer
- * specified by the page array. The returned sg table is released by
- * sg_free_table.
+ * ranges of the pages are squashed into a single scatterlist node up to the
+ * maximum size specified in @max_segment. A user may provide an offset at a
+ * start and a size of valid data in a buffer specified by the page array.
*
- * Returns:
+ * The returned sg table is released by sg_free_table.
+ *
+ * Returns:
* 0 on success, negative error on failure
*/
-int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
- unsigned int n_pages, unsigned int offset,
- unsigned long size, gfp_t gfp_mask)
+int sg_alloc_table_from_pages_segment(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, unsigned int max_segment,
+ gfp_t gfp_mask)
{
- return PTR_ERR_OR_ZERO(__sg_alloc_table_from_pages(sgt, pages, n_pages,
- offset, size, UINT_MAX, NULL, 0, gfp_mask));
+ return PTR_ERR_OR_ZERO(sg_alloc_append_table_from_pages(sgt, pages,
+ n_pages, offset, size, max_segment, NULL, 0, gfp_mask));
}
-EXPORT_SYMBOL(sg_alloc_table_from_pages);
+EXPORT_SYMBOL(sg_alloc_table_from_pages_segment);
#ifdef CONFIG_SGL_ALLOC
diff --git a/tools/testing/scatterlist/main.c b/tools/testing/scatterlist/main.c
index 652254754b4c..c2ff9179c2cc 100644
--- a/tools/testing/scatterlist/main.c
+++ b/tools/testing/scatterlist/main.c
@@ -87,28 +87,39 @@ int main(void)
int left_pages = test->pfn_app ? test->num_pages : 0;
struct page *pages[MAX_PAGES];
struct sg_table st;
- struct scatterlist *sg;
+ struct scatterlist *sg = NULL;
+ int ret;
set_pages(pages, test->pfn, test->num_pages);
- sg = __sg_alloc_table_from_pages(&st, pages, test->num_pages, 0,
- test->size, test->max_seg, NULL, left_pages, GFP_KERNEL);
- assert(PTR_ERR_OR_ZERO(sg) == test->alloc_ret);
+ if (test->pfn_app) {
+ sg = sg_alloc_append_table_from_pages(
+ &st, pages, test->num_pages, 0, test->size,
+ test->max_seg, NULL, left_pages, GFP_KERNEL);
+ assert(PTR_ERR_OR_ZERO(sg) == test->alloc_ret);
+ } else {
+ ret = sg_alloc_table_from_pages_segment(
+ &st, pages, test->num_pages, 0, test->size,
+ test->max_seg, GFP_KERNEL);
+ assert(ret == test->alloc_ret);
+ }
if (test->alloc_ret)
continue;
if (test->pfn_app) {
set_pages(pages, test->pfn_app, test->num_pages);
- sg = __sg_alloc_table_from_pages(&st, pages, test->num_pages, 0,
- test->size, test->max_seg, sg, 0, GFP_KERNEL);
+ sg = sg_alloc_append_table_from_pages(
+ &st, pages, test->num_pages, 0, test->size,
+ test->max_seg, sg, 0, GFP_KERNEL);
assert(PTR_ERR_OR_ZERO(sg) == test->alloc_ret);
}
VALIDATE(st.nents == test->expected_segments, &st, test);
if (!test->pfn_app)
- VALIDATE(st.orig_nents == test->expected_segments, &st, test);
+ VALIDATE(st.orig_nents == test->expected_segments, &st,
+ test);
sg_free_table(&st);
}
--
2.25.4