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