From 90e7a6de62781c27d6a111fccfb19b807f9b6887 Mon Sep 17 00:00:00 2001 From: Maor Gottlieb Date: Tue, 24 Aug 2021 17:25:29 +0300 Subject: [PATCH] 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 Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- 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); }