1#ifndef _LINUX_SCATTERLIST_H
2#define _LINUX_SCATTERLIST_H
3
4#include <linux/string.h>
5#include <linux/types.h>
6#include <linux/bug.h>
7#include <linux/mm.h>
8#include <asm/io.h>
9
10struct scatterlist {
11#ifdef CONFIG_DEBUG_SG
12 unsigned long sg_magic;
13#endif
14 unsigned long page_link;
15 unsigned int offset;
16 unsigned int length;
17 dma_addr_t dma_address;
18#ifdef CONFIG_NEED_SG_DMA_LENGTH
19 unsigned int dma_length;
20#endif
21};
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29
30#define sg_dma_address(sg) ((sg)->dma_address)
31
32#ifdef CONFIG_NEED_SG_DMA_LENGTH
33#define sg_dma_len(sg) ((sg)->dma_length)
34#else
35#define sg_dma_len(sg) ((sg)->length)
36#endif
37
38struct sg_table {
39 struct scatterlist *sgl;
40 unsigned int nents;
41 unsigned int orig_nents;
42};
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60#define SG_MAGIC 0x87654321
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66
67#define sg_is_chain(sg) ((sg)->page_link & 0x01)
68#define sg_is_last(sg) ((sg)->page_link & 0x02)
69#define sg_chain_ptr(sg) \
70 ((struct scatterlist *) ((sg)->page_link & ~0x03))
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81
82static inline void sg_assign_page(struct scatterlist *sg, struct page *page)
83{
84 unsigned long page_link = sg->page_link & 0x3;
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89
90 BUG_ON((unsigned long) page & 0x03);
91#ifdef CONFIG_DEBUG_SG
92 BUG_ON(sg->sg_magic != SG_MAGIC);
93 BUG_ON(sg_is_chain(sg));
94#endif
95 sg->page_link = page_link | (unsigned long) page;
96}
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112static inline void sg_set_page(struct scatterlist *sg, struct page *page,
113 unsigned int len, unsigned int offset)
114{
115 sg_assign_page(sg, page);
116 sg->offset = offset;
117 sg->length = len;
118}
119
120static inline struct page *sg_page(struct scatterlist *sg)
121{
122#ifdef CONFIG_DEBUG_SG
123 BUG_ON(sg->sg_magic != SG_MAGIC);
124 BUG_ON(sg_is_chain(sg));
125#endif
126 return (struct page *)((sg)->page_link & ~0x3);
127}
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135
136static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
137 unsigned int buflen)
138{
139#ifdef CONFIG_DEBUG_SG
140 BUG_ON(!virt_addr_valid(buf));
141#endif
142 sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
143}
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147
148#define for_each_sg(sglist, sg, nr, __i) \
149 for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
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161static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
162 struct scatterlist *sgl)
163{
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167 prv[prv_nents - 1].offset = 0;
168 prv[prv_nents - 1].length = 0;
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174 prv[prv_nents - 1].page_link = ((unsigned long) sgl | 0x01) & ~0x02;
175}
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185
186static inline void sg_mark_end(struct scatterlist *sg)
187{
188#ifdef CONFIG_DEBUG_SG
189 BUG_ON(sg->sg_magic != SG_MAGIC);
190#endif
191
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194 sg->page_link |= 0x02;
195 sg->page_link &= ~0x01;
196}
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206static inline void sg_unmark_end(struct scatterlist *sg)
207{
208#ifdef CONFIG_DEBUG_SG
209 BUG_ON(sg->sg_magic != SG_MAGIC);
210#endif
211 sg->page_link &= ~0x02;
212}
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224static inline dma_addr_t sg_phys(struct scatterlist *sg)
225{
226 return page_to_phys(sg_page(sg)) + sg->offset;
227}
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239static inline void *sg_virt(struct scatterlist *sg)
240{
241 return page_address(sg_page(sg)) + sg->offset;
242}
243
244int sg_nents(struct scatterlist *sg);
245int sg_nents_for_len(struct scatterlist *sg, u64 len);
246struct scatterlist *sg_next(struct scatterlist *);
247struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
248void sg_init_table(struct scatterlist *, unsigned int);
249void sg_init_one(struct scatterlist *, const void *, unsigned int);
250int sg_split(struct scatterlist *in, const int in_mapped_nents,
251 const off_t skip, const int nb_splits,
252 const size_t *split_sizes,
253 struct scatterlist **out, int *out_mapped_nents,
254 gfp_t gfp_mask);
255
256typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t);
257typedef void (sg_free_fn)(struct scatterlist *, unsigned int);
258
259void __sg_free_table(struct sg_table *, unsigned int, bool, sg_free_fn *);
260void sg_free_table(struct sg_table *);
261int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
262 struct scatterlist *, gfp_t, sg_alloc_fn *);
263int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
264int sg_alloc_table_from_pages(struct sg_table *sgt,
265 struct page **pages, unsigned int n_pages,
266 unsigned long offset, unsigned long size,
267 gfp_t gfp_mask);
268
269size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
270 size_t buflen, off_t skip, bool to_buffer);
271
272size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents,
273 const void *buf, size_t buflen);
274size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
275 void *buf, size_t buflen);
276
277size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents,
278 const void *buf, size_t buflen, off_t skip);
279size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
280 void *buf, size_t buflen, off_t skip);
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286#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))
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295#define SG_CHUNK_SIZE 128
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301#ifdef CONFIG_ARCH_HAS_SG_CHAIN
302#define SG_MAX_SEGMENTS 2048
303#else
304#define SG_MAX_SEGMENTS SG_CHUNK_SIZE
305#endif
306
307#ifdef CONFIG_SG_POOL
308void sg_free_table_chained(struct sg_table *table, bool first_chunk);
309int sg_alloc_table_chained(struct sg_table *table, int nents,
310 struct scatterlist *first_chunk);
311#endif
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323struct sg_page_iter {
324 struct scatterlist *sg;
325 unsigned int sg_pgoffset;
326
327
328 unsigned int __nents;
329 int __pg_advance;
330
331};
332
333bool __sg_page_iter_next(struct sg_page_iter *piter);
334void __sg_page_iter_start(struct sg_page_iter *piter,
335 struct scatterlist *sglist, unsigned int nents,
336 unsigned long pgoffset);
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341static inline struct page *sg_page_iter_page(struct sg_page_iter *piter)
342{
343 return nth_page(sg_page(piter->sg), piter->sg_pgoffset);
344}
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351static inline dma_addr_t sg_page_iter_dma_address(struct sg_page_iter *piter)
352{
353 return sg_dma_address(piter->sg) + (piter->sg_pgoffset << PAGE_SHIFT);
354}
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363#define for_each_sg_page(sglist, piter, nents, pgoffset) \
364 for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \
365 __sg_page_iter_next(piter);)
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383#define SG_MITER_ATOMIC (1 << 0)
384#define SG_MITER_TO_SG (1 << 1)
385#define SG_MITER_FROM_SG (1 << 2)
386
387struct sg_mapping_iter {
388
389 struct page *page;
390 void *addr;
391 size_t length;
392 size_t consumed;
393 struct sg_page_iter piter;
394
395
396 unsigned int __offset;
397 unsigned int __remaining;
398 unsigned int __flags;
399};
400
401void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl,
402 unsigned int nents, unsigned int flags);
403bool sg_miter_skip(struct sg_mapping_iter *miter, off_t offset);
404bool sg_miter_next(struct sg_mapping_iter *miter);
405void sg_miter_stop(struct sg_mapping_iter *miter);
406
407#endif
408