This source file includes following definitions.
- sg_assign_page
- sg_set_page
- sg_page
- sg_set_buf
- sg_chain
- sg_mark_end
- sg_unmark_end
- sg_phys
- sg_virt
- sg_init_marker
- sg_page_iter_page
- sg_page_iter_dma_address
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
11 struct 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 };
20
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22
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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
42 struct sg_table {
43 struct scatterlist *sgl;
44 unsigned int nents;
45 unsigned int orig_nents;
46 };
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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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87 static 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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116 static 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
124 static 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
139 static 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))
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164 static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
165 struct scatterlist *sgl)
166 {
167
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170 prv[prv_nents - 1].offset = 0;
171 prv[prv_nents - 1].length = 0;
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177 prv[prv_nents - 1].page_link = ((unsigned long) sgl | SG_CHAIN)
178 & ~SG_END;
179 }
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189
190 static inline void sg_mark_end(struct scatterlist *sg)
191 {
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195 sg->page_link |= SG_END;
196 sg->page_link &= ~SG_CHAIN;
197 }
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207 static inline void sg_unmark_end(struct scatterlist *sg)
208 {
209 sg->page_link &= ~SG_END;
210 }
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222 static inline dma_addr_t sg_phys(struct scatterlist *sg)
223 {
224 return page_to_phys(sg_page(sg)) + sg->offset;
225 }
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237 static inline void *sg_virt(struct scatterlist *sg)
238 {
239 return page_address(sg_page(sg)) + sg->offset;
240 }
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246
247
248 static inline void sg_init_marker(struct scatterlist *sgl,
249 unsigned int nents)
250 {
251 sg_mark_end(&sgl[nents - 1]);
252 }
253
254 int sg_nents(struct scatterlist *sg);
255 int sg_nents_for_len(struct scatterlist *sg, u64 len);
256 struct scatterlist *sg_next(struct scatterlist *);
257 struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
258 void sg_init_table(struct scatterlist *, unsigned int);
259 void sg_init_one(struct scatterlist *, const void *, unsigned int);
260 int sg_split(struct scatterlist *in, const int in_mapped_nents,
261 const off_t skip, const int nb_splits,
262 const size_t *split_sizes,
263 struct scatterlist **out, int *out_mapped_nents,
264 gfp_t gfp_mask);
265
266 typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t);
267 typedef void (sg_free_fn)(struct scatterlist *, unsigned int);
268
269 void __sg_free_table(struct sg_table *, unsigned int, unsigned int,
270 sg_free_fn *);
271 void sg_free_table(struct sg_table *);
272 int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
273 struct scatterlist *, unsigned int, gfp_t, sg_alloc_fn *);
274 int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
275 int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
276 unsigned int n_pages, unsigned int offset,
277 unsigned long size, unsigned int max_segment,
278 gfp_t gfp_mask);
279 int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
280 unsigned int n_pages, unsigned int offset,
281 unsigned long size, gfp_t gfp_mask);
282
283 #ifdef CONFIG_SGL_ALLOC
284 struct scatterlist *sgl_alloc_order(unsigned long long length,
285 unsigned int order, bool chainable,
286 gfp_t gfp, unsigned int *nent_p);
287 struct scatterlist *sgl_alloc(unsigned long long length, gfp_t gfp,
288 unsigned int *nent_p);
289 void sgl_free_n_order(struct scatterlist *sgl, int nents, int order);
290 void sgl_free_order(struct scatterlist *sgl, int order);
291 void sgl_free(struct scatterlist *sgl);
292 #endif
293
294 size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
295 size_t buflen, off_t skip, bool to_buffer);
296
297 size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents,
298 const void *buf, size_t buflen);
299 size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
300 void *buf, size_t buflen);
301
302 size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents,
303 const void *buf, size_t buflen, off_t skip);
304 size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents,
305 void *buf, size_t buflen, off_t skip);
306 size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents,
307 size_t buflen, off_t skip);
308
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313 #define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))
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322 #define SG_CHUNK_SIZE 128
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328 #ifdef CONFIG_ARCH_NO_SG_CHAIN
329 #define SG_MAX_SEGMENTS SG_CHUNK_SIZE
330 #else
331 #define SG_MAX_SEGMENTS 2048
332 #endif
333
334 #ifdef CONFIG_SG_POOL
335 void sg_free_table_chained(struct sg_table *table,
336 unsigned nents_first_chunk);
337 int sg_alloc_table_chained(struct sg_table *table, int nents,
338 struct scatterlist *first_chunk,
339 unsigned nents_first_chunk);
340 #endif
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352 struct sg_page_iter {
353 struct scatterlist *sg;
354 unsigned int sg_pgoffset;
355
356
357 unsigned int __nents;
358 int __pg_advance;
359
360 };
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369 struct sg_dma_page_iter {
370 struct sg_page_iter base;
371 };
372
373 bool __sg_page_iter_next(struct sg_page_iter *piter);
374 bool __sg_page_iter_dma_next(struct sg_dma_page_iter *dma_iter);
375 void __sg_page_iter_start(struct sg_page_iter *piter,
376 struct scatterlist *sglist, unsigned int nents,
377 unsigned long pgoffset);
378
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381
382 static inline struct page *sg_page_iter_page(struct sg_page_iter *piter)
383 {
384 return nth_page(sg_page(piter->sg), piter->sg_pgoffset);
385 }
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391
392 static inline dma_addr_t
393 sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter)
394 {
395 return sg_dma_address(dma_iter->base.sg) +
396 (dma_iter->base.sg_pgoffset << PAGE_SHIFT);
397 }
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408 #define for_each_sg_page(sglist, piter, nents, pgoffset) \
409 for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \
410 __sg_page_iter_next(piter);)
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422 #define for_each_sg_dma_page(sglist, dma_iter, dma_nents, pgoffset) \
423 for (__sg_page_iter_start(&(dma_iter)->base, sglist, dma_nents, \
424 pgoffset); \
425 __sg_page_iter_dma_next(dma_iter);)
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443 #define SG_MITER_ATOMIC (1 << 0)
444 #define SG_MITER_TO_SG (1 << 1)
445 #define SG_MITER_FROM_SG (1 << 2)
446
447 struct sg_mapping_iter {
448
449 struct page *page;
450 void *addr;
451 size_t length;
452 size_t consumed;
453 struct sg_page_iter piter;
454
455
456 unsigned int __offset;
457 unsigned int __remaining;
458 unsigned int __flags;
459 };
460
461 void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl,
462 unsigned int nents, unsigned int flags);
463 bool sg_miter_skip(struct sg_mapping_iter *miter, off_t offset);
464 bool sg_miter_next(struct sg_mapping_iter *miter);
465 void sg_miter_stop(struct sg_mapping_iter *miter);
466
467 #endif