From efc5b2e73cc0a8aabf377bcbd9296546e9cc9b2d Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Sun, 4 Oct 2020 18:43:38 +0300 Subject: tools/testing/scatterlist: Rejuvenate bit-rotten test A couple small tweaks are needed to make the test build and run on current kernels. Link: https://lore.kernel.org/r/20201004154340.1080481-3-leon@kernel.org Signed-off-by: Tvrtko Ursulin Cc: Maor Gottlieb Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- tools/testing/scatterlist/Makefile | 3 ++- tools/testing/scatterlist/linux/mm.h | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+), 1 deletion(-) (limited to 'tools') diff --git a/tools/testing/scatterlist/Makefile b/tools/testing/scatterlist/Makefile index cbb003d9305e..c65233876622 100644 --- a/tools/testing/scatterlist/Makefile +++ b/tools/testing/scatterlist/Makefile @@ -14,7 +14,7 @@ targets: include $(TARGETS) main: $(OFILES) clean: - $(RM) $(TARGETS) $(OFILES) scatterlist.c linux/scatterlist.h linux/highmem.h linux/kmemleak.h asm/io.h + $(RM) $(TARGETS) $(OFILES) scatterlist.c linux/scatterlist.h linux/highmem.h linux/kmemleak.h linux/slab.h asm/io.h @rmdir asm scatterlist.c: ../../../lib/scatterlist.c @@ -28,4 +28,5 @@ include: ../../../include/linux/scatterlist.h @touch asm/io.h @touch linux/highmem.h @touch linux/kmemleak.h + @touch linux/slab.h @cp $< linux/scatterlist.h diff --git a/tools/testing/scatterlist/linux/mm.h b/tools/testing/scatterlist/linux/mm.h index 6f9ac14aa800..6ae907f375d2 100644 --- a/tools/testing/scatterlist/linux/mm.h +++ b/tools/testing/scatterlist/linux/mm.h @@ -114,6 +114,12 @@ static inline void *kmalloc(unsigned int size, unsigned int flags) return malloc(size); } +static inline void * +kmalloc_array(unsigned int n, unsigned int size, unsigned int flags) +{ + return malloc(n * size); +} + #define kfree(x) free(x) #define kmemleak_alloc(a, b, c, d) @@ -122,4 +128,33 @@ static inline void *kmalloc(unsigned int size, unsigned int flags) #define PageSlab(p) (0) #define flush_kernel_dcache_page(p) +#define MAX_ERRNO 4095 + +#define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO) + +static inline void * __must_check ERR_PTR(long error) +{ + return (void *) error; +} + +static inline long __must_check PTR_ERR(__force const void *ptr) +{ + return (long) ptr; +} + +static inline bool __must_check IS_ERR(__force const void *ptr) +{ + return IS_ERR_VALUE((unsigned long)ptr); +} + +static inline int __must_check PTR_ERR_OR_ZERO(__force const void *ptr) +{ + if (IS_ERR(ptr)) + return PTR_ERR(ptr); + else + return 0; +} + +#define IS_ENABLED(x) (0) + #endif -- cgit v1.2.3-70-g09d2 From 29d88681fb49f1e8225addd1e783bad1f7d95afc Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Sun, 4 Oct 2020 18:43:39 +0300 Subject: tools/testing/scatterlist: Show errors in human readable form Instead of just asserting dump some more useful info about what the test saw versus what it expected to see. Link: https://lore.kernel.org/r/20201004154340.1080481-4-leon@kernel.org Signed-off-by: Tvrtko Ursulin Cc: Maor Gottlieb Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- tools/testing/scatterlist/main.c | 44 +++++++++++++++++++++++++++++++--------- 1 file changed, 34 insertions(+), 10 deletions(-) (limited to 'tools') diff --git a/tools/testing/scatterlist/main.c b/tools/testing/scatterlist/main.c index 0a1464181226..c6db0a1989b2 100644 --- a/tools/testing/scatterlist/main.c +++ b/tools/testing/scatterlist/main.c @@ -5,6 +5,15 @@ #define MAX_PAGES (64) +struct test { + int alloc_ret; + unsigned num_pages; + unsigned *pfn; + unsigned size; + unsigned int max_seg; + unsigned int expected_segments; +}; + static void set_pages(struct page **pages, const unsigned *array, unsigned num) { unsigned int i; @@ -17,17 +26,32 @@ static void set_pages(struct page **pages, const unsigned *array, unsigned num) #define pfn(...) (unsigned []){ __VA_ARGS__ } +static void fail(struct test *test, struct sg_table *st, const char *cond) +{ + unsigned int i; + + fprintf(stderr, "Failed on '%s'!\n\n", cond); + + printf("size = %u, max segment = %u, expected nents = %u\nst->nents = %u, st->orig_nents= %u\n", + test->size, test->max_seg, test->expected_segments, st->nents, + st->orig_nents); + + printf("%u input PFNs:", test->num_pages); + for (i = 0; i < test->num_pages; i++) + printf(" %x", test->pfn[i]); + printf("\n"); + + exit(1); +} + +#define VALIDATE(cond, st, test) \ + if (!(cond)) \ + fail((test), (st), #cond); + int main(void) { const unsigned int sgmax = SCATTERLIST_MAX_SEGMENT; - struct test { - int alloc_ret; - unsigned num_pages; - unsigned *pfn; - unsigned size; - unsigned int max_seg; - unsigned int expected_segments; - } *test, tests[] = { + struct test *test, tests[] = { { -EINVAL, 1, pfn(0), PAGE_SIZE, PAGE_SIZE + 1, 1 }, { -EINVAL, 1, pfn(0), PAGE_SIZE, 0, 1 }, { -EINVAL, 1, pfn(0), PAGE_SIZE, sgmax + 1, 1 }, @@ -67,8 +91,8 @@ int main(void) if (test->alloc_ret) continue; - assert(st.nents == test->expected_segments); - assert(st.orig_nents == test->expected_segments); + VALIDATE(st.nents == test->expected_segments, &st, test); + VALIDATE(st.orig_nents == test->expected_segments, &st, test); sg_free_table(&st); } -- cgit v1.2.3-70-g09d2 From 07da1223ec939982497db3caccd6215b55acc35c Mon Sep 17 00:00:00 2001 From: Maor Gottlieb Date: Sun, 4 Oct 2020 18:43:37 +0300 Subject: lib/scatterlist: Add support in dynamic allocation of SG table from pages Extend __sg_alloc_table_from_pages to support dynamic allocation of SG table from pages. It should be used by drivers that can't supply all the pages at one time. This function returns the last populated SGE in the table. Users should pass it as an argument to the function from the second call and forward. As before, nents will be equal to the number of populated SGEs (chunks). With this new extension, drivers can benefit the optimization of merging contiguous pages without a need to allocate all pages in advance and hold them in a large buffer. E.g. with the Infiniband driver that allocates a single page for hold the pages. For 1TB memory registration, the temporary buffer would consume only 4KB, instead of 2GB. Link: https://lore.kernel.org/r/20201004154340.1080481-2-leon@kernel.org Signed-off-by: Maor Gottlieb Reviewed-by: Christoph Hellwig Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 12 +-- drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 15 ++-- include/linux/scatterlist.h | 38 +++++---- lib/scatterlist.c | 125 ++++++++++++++++++++++------ tools/testing/scatterlist/main.c | 9 +- 5 files changed, 142 insertions(+), 57 deletions(-) (limited to 'tools') diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 12b30075134a..f2eaed6aca3d 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -403,6 +403,7 @@ __i915_gem_userptr_alloc_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; int ret; st = kmalloc(sizeof(*st), GFP_KERNEL); @@ -410,13 +411,12 @@ __i915_gem_userptr_alloc_pages(struct drm_i915_gem_object *obj, return ERR_PTR(-ENOMEM); alloc_table: - ret = __sg_alloc_table_from_pages(st, pvec, num_pages, - 0, num_pages << PAGE_SHIFT, - max_segment, - GFP_KERNEL); - if (ret) { + 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)) { kfree(st); - return ERR_PTR(ret); + return ERR_CAST(sg); } ret = i915_gem_gtt_prepare_pages(obj, st); diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c index ab524ab3b0b4..f22acd398b1f 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c @@ -419,6 +419,7 @@ 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; @@ -441,13 +442,15 @@ static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt) if (unlikely(ret != 0)) return ret; - ret = __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->dev->dev), - GFP_KERNEL); - if (unlikely(ret != 0)) + 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->dev->dev), + NULL, 0, GFP_KERNEL); + if (IS_ERR(sg)) { + ret = PTR_ERR(sg); goto out_sg_alloc_fail; + } if (vsgt->num_pages > vmw_tt->sgt.nents) { uint64_t over_alloc = diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 45cf7b69d852..36c47e7e66a2 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -165,6 +165,22 @@ static inline void sg_set_buf(struct scatterlist *sg, const void *buf, #define for_each_sgtable_dma_sg(sgt, sg, i) \ for_each_sg((sgt)->sgl, sg, (sgt)->nents, i) +static inline void __sg_chain(struct scatterlist *chain_sg, + struct scatterlist *sgl) +{ + /* + * offset and length are unused for chain entry. Clear them. + */ + chain_sg->offset = 0; + chain_sg->length = 0; + + /* + * Set lowest bit to indicate a link pointer, and make sure to clear + * the termination bit if it happens to be set. + */ + chain_sg->page_link = ((unsigned long) sgl | SG_CHAIN) & ~SG_END; +} + /** * sg_chain - Chain two sglists together * @prv: First scatterlist @@ -178,18 +194,7 @@ static inline void sg_set_buf(struct scatterlist *sg, const void *buf, static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents, struct scatterlist *sgl) { - /* - * offset and length are unused for chain entry. Clear them. - */ - prv[prv_nents - 1].offset = 0; - prv[prv_nents - 1].length = 0; - - /* - * Set lowest bit to indicate a link pointer, and make sure to clear - * the termination bit if it happens to be set. - */ - prv[prv_nents - 1].page_link = ((unsigned long) sgl | SG_CHAIN) - & ~SG_END; + __sg_chain(&prv[prv_nents - 1], sgl); } /** @@ -286,10 +291,11 @@ 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); -int __sg_alloc_table_from_pages(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); +struct scatterlist *__sg_alloc_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); diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 5d63a8857f36..e102fdfaa75b 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -365,6 +365,37 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask) } EXPORT_SYMBOL(sg_alloc_table); +static struct scatterlist *get_next_sg(struct sg_table *table, + struct scatterlist *cur, + unsigned long needed_sges, + gfp_t gfp_mask) +{ + struct scatterlist *new_sg, *next_sg; + unsigned int alloc_size; + + if (cur) { + next_sg = sg_next(cur); + /* Check if last entry should be keeped for chainning */ + if (!sg_is_last(next_sg) || needed_sges == 1) + return next_sg; + } + + alloc_size = min_t(unsigned long, needed_sges, SG_MAX_SINGLE_ALLOC); + new_sg = sg_kmalloc(alloc_size, gfp_mask); + if (!new_sg) + return ERR_PTR(-ENOMEM); + sg_init_table(new_sg, alloc_size); + if (cur) { + __sg_chain(next_sg, new_sg); + table->orig_nents += alloc_size - 1; + } else { + table->sgl = new_sg; + table->orig_nents = alloc_size; + table->nents = 0; + } + return new_sg; +} + /** * __sg_alloc_table_from_pages - Allocate and initialize an sg table from * an array of pages @@ -374,29 +405,63 @@ EXPORT_SYMBOL(sg_alloc_table); * @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 node in bytes (page aligned) + * @prv: Last populated sge in sgt + * @left_pages: Left pages caller have to set after this call * @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 up to the - * maximum size specified in @max_segment. An 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. + * Description: + * If @prv is NULL, allocate and initialize an sg table from a list of pages, + * else reuse the scatterlist passed in at @prv. + * Contiguous ranges of the pages are squashed into a single scatterlist + * entry 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: - * 0 on success, negative error on failure + * Last SGE in sgt on success, PTR_ERR on otherwise. + * The allocation in @sgt must be released by sg_free_table. + * + * Notes: + * If this function returns non-0 (eg failure), the caller must call + * sg_free_table() to cleanup any leftover allocations. */ -int __sg_alloc_table_from_pages(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) +struct scatterlist *__sg_alloc_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) { - unsigned int chunks, cur_page, seg_len, i; - int ret; - struct scatterlist *s; + unsigned int chunks, cur_page, seg_len, i, prv_len = 0; + unsigned int added_nents = 0; + struct scatterlist *s = prv; if (WARN_ON(!max_segment || offset_in_page(max_segment))) - return -EINVAL; + return ERR_PTR(-EINVAL); + + if (IS_ENABLED(CONFIG_ARCH_NO_SG_CHAIN) && prv) + return ERR_PTR(-EOPNOTSUPP); + + if (prv) { + unsigned long paddr = (page_to_pfn(sg_page(prv)) * PAGE_SIZE + + prv->offset + prv->length) / + PAGE_SIZE; + + if (WARN_ON(offset)) + return ERR_PTR(-EINVAL); + + /* Merge contiguous pages into the last SG */ + prv_len = prv->length; + while (n_pages && page_to_pfn(pages[0]) == paddr) { + if (prv->length + PAGE_SIZE > max_segment) + break; + prv->length += PAGE_SIZE; + paddr++; + pages++; + n_pages--; + } + if (!n_pages) + goto out; + } /* compute number of contiguous chunks */ chunks = 1; @@ -410,13 +475,9 @@ int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, } } - ret = sg_alloc_table(sgt, chunks, gfp_mask); - if (unlikely(ret)) - return ret; - /* merging chunks and putting them into the scatterlist */ cur_page = 0; - for_each_sg(sgt->sgl, s, sgt->orig_nents, i) { + for (i = 0; i < chunks; i++) { unsigned int j, chunk_size; /* look for the end of the current chunk */ @@ -429,15 +490,30 @@ int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, break; } + /* Pass how many chunks might be left */ + s = get_next_sg(sgt, s, chunks - i + left_pages, gfp_mask); + if (IS_ERR(s)) { + /* + * Adjust entry length to be as before function was + * called. + */ + if (prv) + prv->length = prv_len; + return s; + } chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset; sg_set_page(s, pages[cur_page], min_t(unsigned long, size, chunk_size), offset); + added_nents++; size -= chunk_size; offset = 0; cur_page = j; } - - return 0; + sgt->nents += added_nents; +out: + if (!left_pages) + sg_mark_end(s); + return s; } EXPORT_SYMBOL(__sg_alloc_table_from_pages); @@ -465,8 +541,9 @@ 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(sgt, pages, n_pages, offset, size, - SCATTERLIST_MAX_SEGMENT, gfp_mask); + return PTR_ERR_OR_ZERO(__sg_alloc_table_from_pages(sgt, pages, n_pages, + offset, size, SCATTERLIST_MAX_SEGMENT, + NULL, 0, gfp_mask)); } EXPORT_SYMBOL(sg_alloc_table_from_pages); diff --git a/tools/testing/scatterlist/main.c b/tools/testing/scatterlist/main.c index c6db0a1989b2..b2c7e9f7b8d3 100644 --- a/tools/testing/scatterlist/main.c +++ b/tools/testing/scatterlist/main.c @@ -79,14 +79,13 @@ int main(void) for (i = 0, test = tests; test->expected_segments; test++, i++) { struct page *pages[MAX_PAGES]; struct sg_table st; - int ret; + struct scatterlist *sg; set_pages(pages, test->pfn, test->num_pages); - ret = __sg_alloc_table_from_pages(&st, pages, test->num_pages, - 0, test->size, test->max_seg, - GFP_KERNEL); - assert(ret == test->alloc_ret); + sg = __sg_alloc_table_from_pages(&st, pages, test->num_pages, 0, + test->size, test->max_seg, NULL, 0, GFP_KERNEL); + assert(PTR_ERR_OR_ZERO(sg) == test->alloc_ret); if (test->alloc_ret) continue; -- cgit v1.2.3-70-g09d2