lib/scatterlist: Provide a dedicated function to support table append

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.

Link: https://lore.kernel.org/r/20210824142531.3877007-2-maorg@nvidia.com
Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This commit is contained in:
Maor Gottlieb 2021-08-24 17:25:29 +03:00 committed by Jason Gunthorpe
parent 7c60610d47
commit 90e7a6de62
7 changed files with 90 additions and 52 deletions

View File

@ -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;
}

View File

@ -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) {

View File

@ -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 =

View File

@ -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;

View File

@ -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,

View File

@ -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

View File

@ -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);
}