/*- * Copyright (c) 2010 Isilon Systems, Inc. * Copyright (c) 2010 iX Systems, Inc. * Copyright (c) 2010 Panasas, Inc. * Copyright (c) 2013-2017 Mellanox Technologies, Ltd. * Copyright (c) 2015 Matthew Dillon * Copyright (c) 2016 Matthew Macy * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice unmodified, this list of conditions, and the following * disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef _LINUXKPI_LINUX_SCATTERLIST_H_ #define _LINUXKPI_LINUX_SCATTERLIST_H_ #include #include #include #include #include struct bus_dmamap; struct scatterlist { unsigned long page_link; #define SG_PAGE_LINK_CHAIN 0x1UL #define SG_PAGE_LINK_LAST 0x2UL #define SG_PAGE_LINK_MASK 0x3UL unsigned int offset; unsigned int length; dma_addr_t dma_address; struct bus_dmamap *dma_map; /* FreeBSD specific */ }; CTASSERT((sizeof(struct scatterlist) & SG_PAGE_LINK_MASK) == 0); struct sg_table { struct scatterlist *sgl; unsigned int nents; unsigned int orig_nents; }; struct sg_page_iter { struct scatterlist *sg; unsigned int sg_pgoffset; unsigned int maxents; struct { unsigned int nents; int pg_advance; } internal; }; struct sg_dma_page_iter { struct sg_page_iter base; }; #define SCATTERLIST_MAX_SEGMENT (-1U & ~(PAGE_SIZE - 1)) #define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist)) #define SG_MAGIC 0x87654321UL #define SG_CHAIN SG_PAGE_LINK_CHAIN #define SG_END SG_PAGE_LINK_LAST #define sg_is_chain(sg) ((sg)->page_link & SG_PAGE_LINK_CHAIN) #define sg_is_last(sg) ((sg)->page_link & SG_PAGE_LINK_LAST) #define sg_chain_ptr(sg) \ ((struct scatterlist *) ((sg)->page_link & ~SG_PAGE_LINK_MASK)) #define sg_dma_address(sg) (sg)->dma_address #define sg_dma_len(sg) (sg)->length #define for_each_sg_page(sgl, iter, nents, pgoffset) \ for (_sg_iter_init(sgl, iter, nents, pgoffset); \ (iter)->sg; _sg_iter_next(iter)) #define for_each_sg_dma_page(sgl, iter, nents, pgoffset) \ for_each_sg_page(sgl, &(iter)->base, nents, pgoffset) #define for_each_sg(sglist, sg, sgmax, iter) \ for (iter = 0, sg = (sglist); iter < (sgmax); iter++, sg = sg_next(sg)) #define for_each_sgtable_sg(sgt, sg, i) \ for_each_sg((sgt)->sgl, sg, (sgt)->orig_nents, i) #define for_each_sgtable_page(sgt, iter, pgoffset) \ for_each_sg_page((sgt)->sgl, iter, (sgt)->orig_nents, pgoffset) #define for_each_sgtable_dma_sg(sgt, sg, iter) \ for_each_sg((sgt)->sgl, sg, (sgt)->nents, iter) #define for_each_sgtable_dma_page(sgt, iter, pgoffset) \ for_each_sg_dma_page((sgt)->sgl, iter, (sgt)->nents, pgoffset) typedef struct scatterlist *(sg_alloc_fn) (unsigned int, gfp_t); typedef void (sg_free_fn) (struct scatterlist *, unsigned int); static inline void sg_assign_page(struct scatterlist *sg, struct page *page) { unsigned long page_link = sg->page_link & SG_PAGE_LINK_MASK; sg->page_link = page_link | (unsigned long)page; } static inline void sg_set_page(struct scatterlist *sg, struct page *page, unsigned int len, unsigned int offset) { sg_assign_page(sg, page); sg->offset = offset; sg->length = len; } static inline struct page * sg_page(struct scatterlist *sg) { return ((struct page *)((sg)->page_link & ~SG_PAGE_LINK_MASK)); } static inline void sg_set_buf(struct scatterlist *sg, const void *buf, unsigned int buflen) { sg_set_page(sg, virt_to_page(buf), buflen, ((uintptr_t)buf) & (PAGE_SIZE - 1)); } static inline struct scatterlist * sg_next(struct scatterlist *sg) { if (sg_is_last(sg)) return (NULL); sg++; if (sg_is_chain(sg)) sg = sg_chain_ptr(sg); return (sg); } static inline vm_paddr_t sg_phys(struct scatterlist *sg) { return (page_to_phys(sg_page(sg)) + sg->offset); } static inline void * sg_virt(struct scatterlist *sg) { return ((void *)((unsigned long)page_address(sg_page(sg)) + sg->offset)); } static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents, struct scatterlist *sgl) { struct scatterlist *sg = &prv[prv_nents - 1]; sg->offset = 0; sg->length = 0; sg->page_link = ((unsigned long)sgl | SG_PAGE_LINK_CHAIN) & ~SG_PAGE_LINK_LAST; } static inline void sg_mark_end(struct scatterlist *sg) { sg->page_link |= SG_PAGE_LINK_LAST; sg->page_link &= ~SG_PAGE_LINK_CHAIN; } static inline void sg_init_table(struct scatterlist *sg, unsigned int nents) { bzero(sg, sizeof(*sg) * nents); sg_mark_end(&sg[nents - 1]); } static inline void sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen) { sg_init_table(sg, 1); sg_set_buf(sg, buf, buflen); } static struct scatterlist * sg_kmalloc(unsigned int nents, gfp_t gfp_mask) { if (nents == SG_MAX_SINGLE_ALLOC) { return ((void *)__get_free_page(gfp_mask)); } else return (kmalloc(nents * sizeof(struct scatterlist), gfp_mask)); } static inline void sg_kfree(struct scatterlist *sg, unsigned int nents) { if (nents == SG_MAX_SINGLE_ALLOC) { free_page((unsigned long)sg); } else kfree(sg); } static inline void __sg_free_table(struct sg_table *table, unsigned int max_ents, bool skip_first_chunk, sg_free_fn * free_fn) { struct scatterlist *sgl, *next; if (unlikely(!table->sgl)) return; sgl = table->sgl; while (table->orig_nents) { unsigned int alloc_size = table->orig_nents; unsigned int sg_size; if (alloc_size > max_ents) { next = sg_chain_ptr(&sgl[max_ents - 1]); alloc_size = max_ents; sg_size = alloc_size - 1; } else { sg_size = alloc_size; next = NULL; } table->orig_nents -= sg_size; if (skip_first_chunk) skip_first_chunk = 0; else free_fn(sgl, alloc_size); sgl = next; } table->sgl = NULL; } static inline void sg_free_table(struct sg_table *table) { __sg_free_table(table, SG_MAX_SINGLE_ALLOC, 0, sg_kfree); } static inline int __sg_alloc_table(struct sg_table *table, unsigned int nents, unsigned int max_ents, struct scatterlist *first_chunk, gfp_t gfp_mask, sg_alloc_fn *alloc_fn) { struct scatterlist *sg, *prv; unsigned int left; memset(table, 0, sizeof(*table)); if (nents == 0) return (-EINVAL); left = nents; prv = NULL; do { unsigned int sg_size; unsigned int alloc_size = left; if (alloc_size > max_ents) { alloc_size = max_ents; sg_size = alloc_size - 1; } else sg_size = alloc_size; left -= sg_size; if (first_chunk) { sg = first_chunk; first_chunk = NULL; } else { sg = alloc_fn(alloc_size, gfp_mask); } if (unlikely(!sg)) { if (prv) table->nents = ++table->orig_nents; return (-ENOMEM); } sg_init_table(sg, alloc_size); table->nents = table->orig_nents += sg_size; if (prv) sg_chain(prv, max_ents, sg); else table->sgl = sg; if (!left) sg_mark_end(&sg[sg_size - 1]); prv = sg; } while (left); return (0); } static inline int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask) { int ret; ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC, NULL, gfp_mask, sg_kmalloc); if (unlikely(ret)) __sg_free_table(table, SG_MAX_SINGLE_ALLOC, 0, sg_kfree); return (ret); } #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51300 static inline struct scatterlist * __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, unsigned int count, unsigned long off, unsigned long size, unsigned int max_segment, struct scatterlist *prv, unsigned int left_pages, gfp_t gfp_mask) #else static inline int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, unsigned int count, unsigned long off, unsigned long size, unsigned int max_segment, gfp_t gfp_mask) #endif { unsigned int i, segs, cur, len; int rc; struct scatterlist *s, *sg_iter; #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51300 if (prv != NULL) { panic( "Support for prv != NULL not implemented in " "__sg_alloc_table_from_pages()"); } #endif if (__predict_false(!max_segment || offset_in_page(max_segment))) #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51300 return (ERR_PTR(-EINVAL)); #else return (-EINVAL); #endif len = 0; for (segs = i = 1; i < count; ++i) { len += PAGE_SIZE; if (len >= max_segment || page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1) { ++segs; len = 0; } } if (__predict_false((rc = sg_alloc_table(sgt, segs, gfp_mask)))) #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51300 return (ERR_PTR(rc)); #else return (rc); #endif cur = 0; for_each_sg(sgt->sgl, sg_iter, sgt->orig_nents, i) { unsigned long seg_size; unsigned int j; /* * We need to make sure that when we exit this loop "s" has the * last sg in the chain so we can call sg_mark_end() on it. * Only set this inside the loop since sg_iter will be iterated * until it is NULL. */ s = sg_iter; len = 0; for (j = cur + 1; j < count; ++j) { len += PAGE_SIZE; if (len >= max_segment || page_to_pfn(pages[j]) != page_to_pfn(pages[j - 1]) + 1) break; } seg_size = ((j - cur) << PAGE_SHIFT) - off; sg_set_page(s, pages[cur], MIN(size, seg_size), off); size -= seg_size; off = 0; cur = j; } KASSERT(s != NULL, ("s is NULL after loop in __sg_alloc_table_from_pages()")); #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51300 if (left_pages == 0) sg_mark_end(s); return (s); #else return (0); #endif } static inline int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages, unsigned int count, unsigned long off, unsigned long size, gfp_t gfp_mask) { #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51300 return (PTR_ERR_OR_ZERO(__sg_alloc_table_from_pages(sgt, pages, count, off, size, SCATTERLIST_MAX_SEGMENT, NULL, 0, gfp_mask))); #else return (__sg_alloc_table_from_pages(sgt, pages, count, off, size, SCATTERLIST_MAX_SEGMENT, gfp_mask)); #endif } static inline int sg_alloc_table_from_pages_segment(struct sg_table *sgt, struct page **pages, unsigned int count, unsigned int off, unsigned long size, unsigned int max_segment, gfp_t gfp_mask) { #if defined(LINUXKPI_VERSION) && LINUXKPI_VERSION >= 51300 return (PTR_ERR_OR_ZERO(__sg_alloc_table_from_pages(sgt, pages, count, off, size, max_segment, NULL, 0, gfp_mask))); #else return (__sg_alloc_table_from_pages(sgt, pages, count, off, size, max_segment, gfp_mask)); #endif } static inline int sg_nents(struct scatterlist *sg) { int nents; for (nents = 0; sg; sg = sg_next(sg)) nents++; return (nents); } static inline void __sg_page_iter_start(struct sg_page_iter *piter, struct scatterlist *sglist, unsigned int nents, unsigned long pgoffset) { piter->internal.pg_advance = 0; piter->internal.nents = nents; piter->sg = sglist; piter->sg_pgoffset = pgoffset; } static inline void _sg_iter_next(struct sg_page_iter *iter) { struct scatterlist *sg; unsigned int pgcount; sg = iter->sg; pgcount = (sg->offset + sg->length + PAGE_SIZE - 1) >> PAGE_SHIFT; ++iter->sg_pgoffset; while (iter->sg_pgoffset >= pgcount) { iter->sg_pgoffset -= pgcount; sg = sg_next(sg); --iter->maxents; if (sg == NULL || iter->maxents == 0) break; pgcount = (sg->offset + sg->length + PAGE_SIZE - 1) >> PAGE_SHIFT; } iter->sg = sg; } static inline int sg_page_count(struct scatterlist *sg) { return (PAGE_ALIGN(sg->offset + sg->length) >> PAGE_SHIFT); } #define sg_dma_page_count(sg) \ sg_page_count(sg) static inline bool __sg_page_iter_next(struct sg_page_iter *piter) { unsigned int pgcount; if (piter->internal.nents == 0) return (0); if (piter->sg == NULL) return (0); piter->sg_pgoffset += piter->internal.pg_advance; piter->internal.pg_advance = 1; while (1) { pgcount = sg_page_count(piter->sg); if (likely(piter->sg_pgoffset < pgcount)) break; piter->sg_pgoffset -= pgcount; piter->sg = sg_next(piter->sg); if (--piter->internal.nents == 0) return (0); if (piter->sg == NULL) return (0); } return (1); } #define __sg_page_iter_dma_next(itr) \ __sg_page_iter_next(&(itr)->base) static inline void _sg_iter_init(struct scatterlist *sgl, struct sg_page_iter *iter, unsigned int nents, unsigned long pgoffset) { if (nents) { iter->sg = sgl; iter->sg_pgoffset = pgoffset - 1; iter->maxents = nents; _sg_iter_next(iter); } else { iter->sg = NULL; iter->sg_pgoffset = 0; iter->maxents = 0; } } /* * sg_page_iter_dma_address() is implemented as a macro because it * needs to accept two different and identical structure types. This * allows both old and new code to co-exist. The compile time assert * adds some safety, that the structure sizes match. */ #define sg_page_iter_dma_address(spi) ({ \ struct sg_page_iter *__spi = (void *)(spi); \ dma_addr_t __dma_address; \ CTASSERT(sizeof(*(spi)) == sizeof(*__spi)); \ __dma_address = __spi->sg->dma_address + \ (__spi->sg_pgoffset << PAGE_SHIFT); \ __dma_address; \ }) static inline struct page * sg_page_iter_page(struct sg_page_iter *piter) { return (nth_page(sg_page(piter->sg), piter->sg_pgoffset)); } static __inline size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents, const void *buf, size_t buflen, off_t skip) { struct sg_page_iter piter; struct page *page; struct sf_buf *sf; size_t len, copied; char *p, *b; if (buflen == 0) return (0); b = __DECONST(char *, buf); copied = 0; sched_pin(); for_each_sg_page(sgl, &piter, nents, 0) { /* Skip to the start. */ if (piter.sg->length <= skip) { skip -= piter.sg->length; continue; } /* See how much to copy. */ KASSERT(((piter.sg->length - skip) != 0 && (buflen != 0)), ("%s: sg len %u - skip %ju || buflen %zu is 0\n", __func__, piter.sg->length, (uintmax_t)skip, buflen)); len = min(piter.sg->length - skip, buflen); page = sg_page_iter_page(&piter); sf = sf_buf_alloc(page, SFB_CPUPRIVATE | SFB_NOWAIT); if (sf == NULL) break; p = (char *)sf_buf_kva(sf) + piter.sg_pgoffset + skip; memcpy(p, b, len); sf_buf_free(sf); /* We copied so nothing more to skip. */ skip = 0; copied += len; /* Either we exactly filled the page, or we are done. */ buflen -= len; if (buflen == 0) break; b += len; } sched_unpin(); return (copied); } static inline size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents, const void *buf, size_t buflen) { return (sg_pcopy_from_buffer(sgl, nents, buf, buflen, 0)); } static inline size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, size_t buflen, off_t offset) { struct sg_page_iter iter; struct scatterlist *sg; struct page *page; struct sf_buf *sf; char *vaddr; size_t total = 0; size_t len; if (!PMAP_HAS_DMAP) sched_pin(); for_each_sg_page(sgl, &iter, nents, 0) { sg = iter.sg; if (offset >= sg->length) { offset -= sg->length; continue; } len = ulmin(buflen, sg->length - offset); if (len == 0) break; page = sg_page_iter_page(&iter); if (!PMAP_HAS_DMAP) { sf = sf_buf_alloc(page, SFB_CPUPRIVATE | SFB_NOWAIT); if (sf == NULL) break; vaddr = (char *)sf_buf_kva(sf); } else vaddr = (char *)PHYS_TO_DMAP(page_to_phys(page)); memcpy(buf, vaddr + sg->offset + offset, len); if (!PMAP_HAS_DMAP) sf_buf_free(sf); /* start at beginning of next page */ offset = 0; /* advance buffer */ buf = (char *)buf + len; buflen -= len; total += len; } if (!PMAP_HAS_DMAP) sched_unpin(); return (total); } #endif /* _LINUXKPI_LINUX_SCATTERLIST_H_ */