Commit 90e7a6de authored by Maor Gottlieb's avatar Maor Gottlieb Committed by Jason Gunthorpe
Browse files

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: default avatarMaor Gottlieb <maorg@nvidia.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 7c60610d

drivers/gpu/drm/drm_prime.c

+6 −7
Original line number Diff line number Diff line
@@ -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,

	err = sg_alloc_table_from_pages_segment(sg, pages, nr_pages, 0,

						nr_pages << PAGE_SHIFT,

					  max_segment,

					  NULL, 0, GFP_KERNEL);

	if (IS_ERR(sge)) {

						max_segment, GFP_KERNEL);

	if (err) {

		kfree(sg);

		sg = ERR_CAST(sge);

		sg = ERR_PTR(err);

	}

	return sg;

}

drivers/gpu/drm/i915/gem/i915_gem_userptr.c

+4 −7
Original line number Diff line number Diff line
@@ -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) {

drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c

+5 −9
Original line number Diff line number Diff line
@@ -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,

		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),

				NULL, 0, GFP_KERNEL);

		if (IS_ERR(sg)) {

			ret = PTR_ERR(sg);

			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 =

drivers/infiniband/core/umem.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

include/linux/scatterlist.h

+35 −4
Original line number Diff line number Diff line
@@ -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,

int sg_alloc_table_from_pages_segment(struct sg_table *sgt, struct page **pages,

				      unsigned int n_pages, unsigned int offset,

			      unsigned long size, gfp_t gfp_mask);

				      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,