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2#ifndef _LINUX_SCATTERLIST_H
3#define _LINUX_SCATTERLIST_H
4
5#include <linux/string.h>
6#include <linux/types.h>
7#include <linux/bug.h>
8#include <linux/mm.h>
9#include <asm/io.h>
10
11struct scatterlist {
12 unsigned long page_link;
13 unsigned int offset;
14 unsigned int length;
15 dma_addr_t dma_address;
16#ifdef CONFIG_NEED_SG_DMA_LENGTH
17 unsigned int dma_length;
18#endif
19};
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27
28#define sg_dma_address(sg) ((sg)->dma_address)
29
30#ifdef CONFIG_NEED_SG_DMA_LENGTH
31#define sg_dma_len(sg) ((sg)->dma_length)
32#else
33#define sg_dma_len(sg) ((sg)->length)
34#endif
35
36struct sg_table {
37 struct scatterlist *sgl;
38 unsigned int nents;
39 unsigned int orig_nents;
40};
41
42struct sg_append_table {
43 struct sg_table sgt;
44 struct scatterlist *prv;
45 unsigned int total_nents;
46};
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64#define SG_CHAIN 0x01UL
65#define SG_END 0x02UL
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72#define sg_is_chain(sg) ((sg)->page_link & SG_CHAIN)
73#define sg_is_last(sg) ((sg)->page_link & SG_END)
74#define sg_chain_ptr(sg) \
75 ((struct scatterlist *) ((sg)->page_link & ~(SG_CHAIN | SG_END)))
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87static inline void sg_assign_page(struct scatterlist *sg, struct page *page)
88{
89 unsigned long page_link = sg->page_link & (SG_CHAIN | SG_END);
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94
95 BUG_ON((unsigned long) page & (SG_CHAIN | SG_END));
96#ifdef CONFIG_DEBUG_SG
97 BUG_ON(sg_is_chain(sg));
98#endif
99 sg->page_link = page_link | (unsigned long) page;
100}
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116static inline void sg_set_page(struct scatterlist *sg, struct page *page,
117 unsigned int len, unsigned int offset)
118{
119 sg_assign_page(sg, page);
120 sg->offset = offset;
121 sg->length = len;
122}
123
124static inline struct page *sg_page(struct scatterlist *sg)
125{
126#ifdef CONFIG_DEBUG_SG
127 BUG_ON(sg_is_chain(sg));
128#endif
129 return (struct page *)((sg)->page_link & ~(SG_CHAIN | SG_END));
130}
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139static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
140 unsigned int buflen)
141{
142#ifdef CONFIG_DEBUG_SG
143 BUG_ON(!virt_addr_valid(buf));
144#endif
145 sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
146}
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151#define for_each_sg(sglist, sg, nr, __i) \
152 for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
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157#define for_each_sgtable_sg(sgt, sg, i) \
158 for_each_sg((sgt)->sgl, sg, (sgt)->orig_nents, i)
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165#define for_each_sgtable_dma_sg(sgt, sg, i) \
166 for_each_sg((sgt)->sgl, sg, (sgt)->nents, i)
167
168static inline void __sg_chain(struct scatterlist *chain_sg,
169 struct scatterlist *sgl)
170{
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174 chain_sg->offset = 0;
175 chain_sg->length = 0;
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181 chain_sg->page_link = ((unsigned long) sgl | SG_CHAIN) & ~SG_END;
182}
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194static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
195 struct scatterlist *sgl)
196{
197 __sg_chain(&prv[prv_nents - 1], sgl);
198}
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209static inline void sg_mark_end(struct scatterlist *sg)
210{
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214 sg->page_link |= SG_END;
215 sg->page_link &= ~SG_CHAIN;
216}
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226static inline void sg_unmark_end(struct scatterlist *sg)
227{
228 sg->page_link &= ~SG_END;
229}
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241static inline dma_addr_t sg_phys(struct scatterlist *sg)
242{
243 return page_to_phys(sg_page(sg)) + sg->offset;
244}
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256static inline void *sg_virt(struct scatterlist *sg)
257{
258 return page_address(sg_page(sg)) + sg->offset;
259}
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267static inline void sg_init_marker(struct scatterlist *sgl,
268 unsigned int nents)
269{
270 sg_mark_end(&sgl[nents - 1]);
271}
272
273int sg_nents(struct scatterlist *sg);
274int sg_nents_for_len(struct scatterlist *sg, u64 len);
275struct scatterlist *sg_next(struct scatterlist *);
276struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
277void sg_init_table(struct scatterlist *, unsigned int);
278void sg_init_one(struct scatterlist *, const void *, unsigned int);
279int sg_split(struct scatterlist *in, const int in_mapped_nents,
280 const off_t skip, const int nb_splits,
281 const size_t *split_sizes,
282 struct scatterlist **out, int *out_mapped_nents,
283 gfp_t gfp_mask);
284
285typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t);
286typedef void (sg_free_fn)(struct scatterlist *, unsigned int);
287
288void __sg_free_table(struct sg_table *, unsigned int, unsigned int,
289 sg_free_fn *, unsigned int);
290void sg_free_table(struct sg_table *);
291void sg_free_append_table(struct sg_append_table *sgt);
292int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
293 struct scatterlist *, unsigned int, gfp_t, sg_alloc_fn *);
294int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
295int sg_alloc_append_table_from_pages(struct sg_append_table *sgt,
296 struct page **pages, unsigned int n_pages,
297 unsigned int offset, unsigned long size,
298 unsigned int max_segment,
299 unsigned int left_pages, gfp_t gfp_mask);
300int sg_alloc_table_from_pages_segment(struct sg_table *sgt, struct page **pages,
301 unsigned int n_pages, unsigned int offset,
302 unsigned long size,
303 unsigned int max_segment, gfp_t gfp_mask);
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325static inline int sg_alloc_table_from_pages(struct sg_table *sgt,
326 struct page **pages,
327 unsigned int n_pages,
328 unsigned int offset,
329 unsigned long size, gfp_t gfp_mask)
330{
331 return sg_alloc_table_from_pages_segment(sgt, pages, n_pages, offset,
332 size, UINT_MAX, gfp_mask);
333}
334
335#ifdef CONFIG_SGL_ALLOC
336struct scatterlist *sgl_alloc_order(unsigned long long length,
337 unsigned int order, bool chainable,
338 gfp_t gfp, unsigned int *nent_p);
339struct scatterlist *sgl_alloc(unsigned long long length, gfp_t gfp,
340 unsigned int *nent_p);
341void sgl_free_n_order(struct scatterlist *sgl, int nents, int order);
342void sgl_free_order(struct scatterlist *sgl, int order);
343void sgl_free(struct scatterlist *sgl);
344#endif
345
346size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
347 size_t buflen, off_t skip, bool to_buffer);
348
349size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents,
350 const void *buf, size_t buflen);
351size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
352 void *buf, size_t buflen);
353
354size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents,
355 const void *buf, size_t buflen, off_t skip);
356size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
357 void *buf, size_t buflen, off_t skip);
358size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents,
359 size_t buflen, off_t skip);
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365#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))
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374#define SG_CHUNK_SIZE 128
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380#ifdef CONFIG_ARCH_NO_SG_CHAIN
381#define SG_MAX_SEGMENTS SG_CHUNK_SIZE
382#else
383#define SG_MAX_SEGMENTS 2048
384#endif
385
386#ifdef CONFIG_SG_POOL
387void sg_free_table_chained(struct sg_table *table,
388 unsigned nents_first_chunk);
389int sg_alloc_table_chained(struct sg_table *table, int nents,
390 struct scatterlist *first_chunk,
391 unsigned nents_first_chunk);
392#endif
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404struct sg_page_iter {
405 struct scatterlist *sg;
406 unsigned int sg_pgoffset;
407
408
409 unsigned int __nents;
410 int __pg_advance;
411
412};
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421struct sg_dma_page_iter {
422 struct sg_page_iter base;
423};
424
425bool __sg_page_iter_next(struct sg_page_iter *piter);
426bool __sg_page_iter_dma_next(struct sg_dma_page_iter *dma_iter);
427void __sg_page_iter_start(struct sg_page_iter *piter,
428 struct scatterlist *sglist, unsigned int nents,
429 unsigned long pgoffset);
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434static inline struct page *sg_page_iter_page(struct sg_page_iter *piter)
435{
436 return nth_page(sg_page(piter->sg), piter->sg_pgoffset);
437}
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444static inline dma_addr_t
445sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter)
446{
447 return sg_dma_address(dma_iter->base.sg) +
448 (dma_iter->base.sg_pgoffset << PAGE_SHIFT);
449}
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461#define for_each_sg_page(sglist, piter, nents, pgoffset) \
462 for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \
463 __sg_page_iter_next(piter);)
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476#define for_each_sg_dma_page(sglist, dma_iter, dma_nents, pgoffset) \
477 for (__sg_page_iter_start(&(dma_iter)->base, sglist, dma_nents, \
478 pgoffset); \
479 __sg_page_iter_dma_next(dma_iter);)
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491#define for_each_sgtable_page(sgt, piter, pgoffset) \
492 for_each_sg_page((sgt)->sgl, piter, (sgt)->orig_nents, pgoffset)
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505#define for_each_sgtable_dma_page(sgt, dma_iter, pgoffset) \
506 for_each_sg_dma_page((sgt)->sgl, dma_iter, (sgt)->nents, pgoffset)
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525#define SG_MITER_ATOMIC (1 << 0)
526#define SG_MITER_TO_SG (1 << 1)
527#define SG_MITER_FROM_SG (1 << 2)
528
529struct sg_mapping_iter {
530
531 struct page *page;
532 void *addr;
533 size_t length;
534 size_t consumed;
535 struct sg_page_iter piter;
536
537
538 unsigned int __offset;
539 unsigned int __remaining;
540 unsigned int __flags;
541};
542
543void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl,
544 unsigned int nents, unsigned int flags);
545bool sg_miter_skip(struct sg_mapping_iter *miter, off_t offset);
546bool sg_miter_next(struct sg_mapping_iter *miter);
547void sg_miter_stop(struct sg_mapping_iter *miter);
548
549#endif
550