1
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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24
25#define SCATTERLIST_MAX_SEGMENT (UINT_MAX & PAGE_MASK)
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33
34#define sg_dma_address(sg) ((sg)->dma_address)
35
36#ifdef CONFIG_NEED_SG_DMA_LENGTH
37#define sg_dma_len(sg) ((sg)->dma_length)
38#else
39#define sg_dma_len(sg) ((sg)->length)
40#endif
41
42struct sg_table {
43 struct scatterlist *sgl;
44 unsigned int nents;
45 unsigned int orig_nents;
46};
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63
64#define SG_CHAIN 0x01UL
65#define SG_END 0x02UL
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71
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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86
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);
90
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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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138
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}
147
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150
151#define for_each_sg(sglist, sg, nr, __i) \
152 for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg))
153
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156
157#define for_each_sgtable_sg(sgt, sg, i) \
158 for_each_sg((sgt)->sgl, sg, (sgt)->orig_nents, i)
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164
165#define for_each_sgtable_dma_sg(sgt, sg, i) \
166 for_each_sg((sgt)->sgl, sg, (sgt)->nents, i)
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177
178static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
179 struct scatterlist *sgl)
180{
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184 prv[prv_nents - 1].offset = 0;
185 prv[prv_nents - 1].length = 0;
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191 prv[prv_nents - 1].page_link = ((unsigned long) sgl | SG_CHAIN)
192 & ~SG_END;
193}
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203
204static inline void sg_mark_end(struct scatterlist *sg)
205{
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209 sg->page_link |= SG_END;
210 sg->page_link &= ~SG_CHAIN;
211}
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220
221static inline void sg_unmark_end(struct scatterlist *sg)
222{
223 sg->page_link &= ~SG_END;
224}
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236static inline dma_addr_t sg_phys(struct scatterlist *sg)
237{
238 return page_to_phys(sg_page(sg)) + sg->offset;
239}
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250
251static inline void *sg_virt(struct scatterlist *sg)
252{
253 return page_address(sg_page(sg)) + sg->offset;
254}
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261
262static inline void sg_init_marker(struct scatterlist *sgl,
263 unsigned int nents)
264{
265 sg_mark_end(&sgl[nents - 1]);
266}
267
268int sg_nents(struct scatterlist *sg);
269int sg_nents_for_len(struct scatterlist *sg, u64 len);
270struct scatterlist *sg_next(struct scatterlist *);
271struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
272void sg_init_table(struct scatterlist *, unsigned int);
273void sg_init_one(struct scatterlist *, const void *, unsigned int);
274int sg_split(struct scatterlist *in, const int in_mapped_nents,
275 const off_t skip, const int nb_splits,
276 const size_t *split_sizes,
277 struct scatterlist **out, int *out_mapped_nents,
278 gfp_t gfp_mask);
279
280typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t);
281typedef void (sg_free_fn)(struct scatterlist *, unsigned int);
282
283void __sg_free_table(struct sg_table *, unsigned int, unsigned int,
284 sg_free_fn *);
285void sg_free_table(struct sg_table *);
286int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
287 struct scatterlist *, unsigned int, gfp_t, sg_alloc_fn *);
288int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
289int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
290 unsigned int n_pages, unsigned int offset,
291 unsigned long size, unsigned int max_segment,
292 gfp_t gfp_mask);
293int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
294 unsigned int n_pages, unsigned int offset,
295 unsigned long size, gfp_t gfp_mask);
296
297#ifdef CONFIG_SGL_ALLOC
298struct scatterlist *sgl_alloc_order(unsigned long long length,
299 unsigned int order, bool chainable,
300 gfp_t gfp, unsigned int *nent_p);
301struct scatterlist *sgl_alloc(unsigned long long length, gfp_t gfp,
302 unsigned int *nent_p);
303void sgl_free_n_order(struct scatterlist *sgl, int nents, int order);
304void sgl_free_order(struct scatterlist *sgl, int order);
305void sgl_free(struct scatterlist *sgl);
306#endif
307
308size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
309 size_t buflen, off_t skip, bool to_buffer);
310
311size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents,
312 const void *buf, size_t buflen);
313size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
314 void *buf, size_t buflen);
315
316size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents,
317 const void *buf, size_t buflen, off_t skip);
318size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
319 void *buf, size_t buflen, off_t skip);
320size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents,
321 size_t buflen, off_t skip);
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326
327#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))
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336#define SG_CHUNK_SIZE 128
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342#ifdef CONFIG_ARCH_NO_SG_CHAIN
343#define SG_MAX_SEGMENTS SG_CHUNK_SIZE
344#else
345#define SG_MAX_SEGMENTS 2048
346#endif
347
348#ifdef CONFIG_SG_POOL
349void sg_free_table_chained(struct sg_table *table,
350 unsigned nents_first_chunk);
351int sg_alloc_table_chained(struct sg_table *table, int nents,
352 struct scatterlist *first_chunk,
353 unsigned nents_first_chunk);
354#endif
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365
366struct sg_page_iter {
367 struct scatterlist *sg;
368 unsigned int sg_pgoffset;
369
370
371 unsigned int __nents;
372 int __pg_advance;
373
374};
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382
383struct sg_dma_page_iter {
384 struct sg_page_iter base;
385};
386
387bool __sg_page_iter_next(struct sg_page_iter *piter);
388bool __sg_page_iter_dma_next(struct sg_dma_page_iter *dma_iter);
389void __sg_page_iter_start(struct sg_page_iter *piter,
390 struct scatterlist *sglist, unsigned int nents,
391 unsigned long pgoffset);
392
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395
396static inline struct page *sg_page_iter_page(struct sg_page_iter *piter)
397{
398 return nth_page(sg_page(piter->sg), piter->sg_pgoffset);
399}
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406static inline dma_addr_t
407sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter)
408{
409 return sg_dma_address(dma_iter->base.sg) +
410 (dma_iter->base.sg_pgoffset << PAGE_SHIFT);
411}
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423#define for_each_sg_page(sglist, piter, nents, pgoffset) \
424 for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \
425 __sg_page_iter_next(piter);)
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438#define for_each_sg_dma_page(sglist, dma_iter, dma_nents, pgoffset) \
439 for (__sg_page_iter_start(&(dma_iter)->base, sglist, dma_nents, \
440 pgoffset); \
441 __sg_page_iter_dma_next(dma_iter);)
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453#define for_each_sgtable_page(sgt, piter, pgoffset) \
454 for_each_sg_page((sgt)->sgl, piter, (sgt)->orig_nents, pgoffset)
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467#define for_each_sgtable_dma_page(sgt, dma_iter, pgoffset) \
468 for_each_sg_dma_page((sgt)->sgl, dma_iter, (sgt)->nents, pgoffset)
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487#define SG_MITER_ATOMIC (1 << 0)
488#define SG_MITER_TO_SG (1 << 1)
489#define SG_MITER_FROM_SG (1 << 2)
490
491struct sg_mapping_iter {
492
493 struct page *page;
494 void *addr;
495 size_t length;
496 size_t consumed;
497 struct sg_page_iter piter;
498
499
500 unsigned int __offset;
501 unsigned int __remaining;
502 unsigned int __flags;
503};
504
505void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl,
506 unsigned int nents, unsigned int flags);
507bool sg_miter_skip(struct sg_mapping_iter *miter, off_t offset);
508bool sg_miter_next(struct sg_mapping_iter *miter);
509void sg_miter_stop(struct sg_mapping_iter *miter);
510
511#endif
512