2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 #ifndef _LINUX_SCATTERLIST_H_
31 #define _LINUX_SCATTERLIST_H_
33 #include <linux/page.h>
38 struct scatterlist *sg;
47 struct scatterlist *sgl; /* the list */
48 unsigned int nents; /* number of mapped entries */
49 unsigned int orig_nents; /* original size of list */
52 #define sg_dma_address(sg) (sg)->address
53 #define sg_dma_len(sg) (sg)->length
54 #define sg_page(sg) (sg)->sl_un.page
55 #define sg_scatternext(sg) (sg)->sl_un.sg
61 sg_set_page(struct scatterlist *sg, struct page *page, unsigned int len,
67 if (offset > PAGE_SIZE)
68 panic("sg_set_page: Invalid offset %d\n", offset);
72 sg_set_buf(struct scatterlist *sg, const void *buf, unsigned int buflen)
74 sg_set_page(sg, virt_to_page(buf), buflen,
75 ((uintptr_t)buf) & ~PAGE_MASK);
79 sg_init_table(struct scatterlist *sg, unsigned int nents)
81 bzero(sg, sizeof(*sg) * nents);
82 sg[nents - 1].flags = SG_END;
85 static inline struct scatterlist *
86 sg_next(struct scatterlist *sg)
88 if (sg->flags & SG_END)
91 if (sg->flags & SG_CHAIN)
92 sg = sg_scatternext(sg);
96 static inline vm_paddr_t
97 sg_phys(struct scatterlist *sg)
99 return sg_page(sg)->phys_addr + sg->offset;
102 #define for_each_sg(sglist, sg, sgmax, _itr) \
103 for (_itr = 0, sg = (sglist); _itr < (sgmax); _itr++, sg = sg_next(sg))
105 #endif /* _LINUX_SCATTERLIST_H_ */