diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/scatterlist.c | 155 | ||||
| -rw-r--r-- | lib/sg_pool.c | 3 |
2 files changed, 95 insertions, 63 deletions
diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 27efa6178153..f4b1ff78ab2d 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -182,6 +182,7 @@ static void sg_kfree(struct scatterlist *sg, unsigned int nents) * @nents_first_chunk: Number of entries int the (preallocated) first * scatterlist chunk, 0 means no such preallocated first chunk * @free_fn: Free function + * @num_ents: Number of entries in the table * * Description: * Free an sg table previously allocated and setup with @@ -190,7 +191,8 @@ static void sg_kfree(struct scatterlist *sg, unsigned int nents) * **/ void __sg_free_table(struct sg_table *table, unsigned int max_ents, - unsigned int nents_first_chunk, sg_free_fn *free_fn) + unsigned int nents_first_chunk, sg_free_fn *free_fn, + unsigned int num_ents) { struct scatterlist *sgl, *next; unsigned curr_max_ents = nents_first_chunk ?: max_ents; @@ -199,8 +201,8 @@ void __sg_free_table(struct sg_table *table, unsigned int max_ents, return; sgl = table->sgl; - while (table->orig_nents) { - unsigned int alloc_size = table->orig_nents; + while (num_ents) { + unsigned int alloc_size = num_ents; unsigned int sg_size; /* @@ -218,7 +220,7 @@ void __sg_free_table(struct sg_table *table, unsigned int max_ents, next = NULL; } - table->orig_nents -= sg_size; + num_ents -= sg_size; if (nents_first_chunk) nents_first_chunk = 0; else @@ -232,13 +234,27 @@ void __sg_free_table(struct sg_table *table, unsigned int max_ents, EXPORT_SYMBOL(__sg_free_table); /** + * sg_free_append_table - Free a previously allocated append sg table. + * @table: The mapped sg append table header + * + **/ +void sg_free_append_table(struct sg_append_table *table) +{ + __sg_free_table(&table->sgt, SG_MAX_SINGLE_ALLOC, false, sg_kfree, + table->total_nents); +} +EXPORT_SYMBOL(sg_free_append_table); + + +/** * sg_free_table - Free a previously allocated sg table * @table: The mapped sg table header * **/ void sg_free_table(struct sg_table *table) { - __sg_free_table(table, SG_MAX_SINGLE_ALLOC, false, sg_kfree); + __sg_free_table(table, SG_MAX_SINGLE_ALLOC, false, sg_kfree, + table->orig_nents); } EXPORT_SYMBOL(sg_free_table); @@ -359,13 +375,12 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask) ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC, NULL, 0, gfp_mask, sg_kmalloc); if (unlikely(ret)) - __sg_free_table(table, SG_MAX_SINGLE_ALLOC, 0, sg_kfree); - + sg_free_table(table); return ret; } EXPORT_SYMBOL(sg_alloc_table); -static struct scatterlist *get_next_sg(struct sg_table *table, +static struct scatterlist *get_next_sg(struct sg_append_table *table, struct scatterlist *cur, unsigned long needed_sges, gfp_t gfp_mask) @@ -386,54 +401,52 @@ static struct scatterlist *get_next_sg(struct sg_table *table, return ERR_PTR(-ENOMEM); sg_init_table(new_sg, alloc_size); if (cur) { + table->total_nents += alloc_size - 1; __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; + table->sgt.sgl = new_sg; + table->total_nents = alloc_size; } return new_sg; } /** - * __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 + * sg_alloc_append_table_from_pages - Allocate and initialize an append sg + * table from an array of pages + * @sgt_append: The sg append table 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 - * @prv: Last populated sge in sgt * @left_pages: Left pages caller have to set after this call * @gfp_mask: GFP allocation mask * * 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. + * In the first call it allocate and initialize an sg table from a list of + * pages, else reuse the scatterlist from sgt_append. 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. The + * returned sg table is released by sg_free_append_table * * Returns: - * Last SGE in sgt on success, PTR_ERR on otherwise. - * The allocation in @sgt must be released by sg_free_table. + * 0 on success, negative error on failure * * Notes: * If this function returns non-0 (eg failure), the caller must call - * sg_free_table() to cleanup any leftover allocations. + * sg_free_append_table() to cleanup any leftover allocations. + * + * In the fist call, sgt_append must by initialized. */ -struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt, +int sg_alloc_append_table_from_pages(struct sg_append_table *sgt_append, 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 left_pages, gfp_t gfp_mask) { unsigned int chunks, cur_page, seg_len, i, prv_len = 0; unsigned int added_nents = 0; - struct scatterlist *s = prv; + struct scatterlist *s = sgt_append->prv; /* * The algorithm below requires max_segment to be aligned to PAGE_SIZE @@ -441,25 +454,26 @@ struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt, */ max_segment = ALIGN_DOWN(max_segment, PAGE_SIZE); if (WARN_ON(max_segment < PAGE_SIZE)) - return ERR_PTR(-EINVAL); + return -EINVAL; - if (IS_ENABLED(CONFIG_ARCH_NO_SG_CHAIN) && prv) - return ERR_PTR(-EOPNOTSUPP); + if (IS_ENABLED(CONFIG_ARCH_NO_SG_CHAIN) && sgt_append->prv) + return -EOPNOTSUPP; - if (prv) { - unsigned long paddr = (page_to_pfn(sg_page(prv)) * PAGE_SIZE + - prv->offset + prv->length) / - PAGE_SIZE; + if (sgt_append->prv) { + unsigned long paddr = + (page_to_pfn(sg_page(sgt_append->prv)) * PAGE_SIZE + + sgt_append->prv->offset + sgt_append->prv->length) / + PAGE_SIZE; if (WARN_ON(offset)) - return ERR_PTR(-EINVAL); + return -EINVAL; /* Merge contiguous pages into the last SG */ - prv_len = prv->length; + prv_len = sgt_append->prv->length; while (n_pages && page_to_pfn(pages[0]) == paddr) { - if (prv->length + PAGE_SIZE > max_segment) + if (sgt_append->prv->length + PAGE_SIZE > max_segment) break; - prv->length += PAGE_SIZE; + sgt_append->prv->length += PAGE_SIZE; paddr++; pages++; n_pages--; @@ -496,15 +510,16 @@ struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt, } /* Pass how many chunks might be left */ - s = get_next_sg(sgt, s, chunks - i + left_pages, gfp_mask); + s = get_next_sg(sgt_append, 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; + if (sgt_append->prv) + sgt_append->prv->length = prv_len; + return PTR_ERR(s); } chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset; sg_set_page(s, pages[cur_page], @@ -514,42 +529,58 @@ struct scatterlist *__sg_alloc_table_from_pages(struct sg_table *sgt, offset = 0; cur_page = j; } - sgt->nents += added_nents; + sgt_append->sgt.nents += added_nents; + sgt_append->sgt.orig_nents = sgt_append->sgt.nents; + sgt_append->prv = s; out: if (!left_pages) sg_mark_end(s); - return s; + return 0; } -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)); + struct sg_append_table append = {}; + int err; + + err = sg_alloc_append_table_from_pages(&append, pages, n_pages, offset, + size, max_segment, 0, gfp_mask); + if (err) { + sg_free_append_table(&append); + return err; + } + memcpy(sgt, &append.sgt, sizeof(*sgt)); + WARN_ON(append.total_nents != sgt->orig_nents); + return 0; } -EXPORT_SYMBOL(sg_alloc_table_from_pages); +EXPORT_SYMBOL(sg_alloc_table_from_pages_segment); #ifdef CONFIG_SGL_ALLOC diff --git a/lib/sg_pool.c b/lib/sg_pool.c index db29e5c1f790..a0b1a52cd6f7 100644 --- a/lib/sg_pool.c +++ b/lib/sg_pool.c @@ -90,7 +90,8 @@ void sg_free_table_chained(struct sg_table *table, if (nents_first_chunk == 1) nents_first_chunk = 0; - __sg_free_table(table, SG_CHUNK_SIZE, nents_first_chunk, sg_pool_free); + __sg_free_table(table, SG_CHUNK_SIZE, nents_first_chunk, sg_pool_free, + table->orig_nents); } EXPORT_SYMBOL_GPL(sg_free_table_chained); |