Rev 6588 | Details | Compare with Previous | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
3243 | Serge | 1 | #ifndef _LINUX_SCATTERLIST_H |
2 | #define _LINUX_SCATTERLIST_H |
||
3 | |||
4 | #include |
||
6082 | serge | 5 | #include |
3243 | Serge | 6 | #include |
7 | #include |
||
6934 | serge | 8 | #include |
3243 | Serge | 9 | |
6082 | serge | 10 | struct 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 | }; |
||
3243 | Serge | 22 | |
6082 | serge | 23 | /* |
24 | * These macros should be used after a dma_map_sg call has been done |
||
25 | * to get bus addresses of each of the SG entries and their lengths. |
||
26 | * You should only work with the number of sg entries dma_map_sg |
||
27 | * returns, or alternatively stop on the first sg_dma_len(sg) which |
||
28 | * is 0. |
||
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 | |||
3243 | Serge | 38 | struct sg_table { |
39 | struct scatterlist *sgl; /* the list */ |
||
40 | unsigned int nents; /* number of mapped entries */ |
||
41 | unsigned int orig_nents; /* original size of list */ |
||
42 | }; |
||
43 | |||
44 | /* |
||
45 | * Notes on SG table design. |
||
46 | * |
||
6082 | serge | 47 | * We use the unsigned long page_link field in the scatterlist struct to place |
48 | * the page pointer AND encode information about the sg table as well. The two |
||
49 | * lower bits are reserved for this information. |
||
3243 | Serge | 50 | * |
51 | * If bit 0 is set, then the page_link contains a pointer to the next sg |
||
52 | * table list. Otherwise the next entry is at sg + 1. |
||
53 | * |
||
54 | * If bit 1 is set, then this sg entry is the last element in a list. |
||
55 | * |
||
56 | * See sg_next(). |
||
57 | * |
||
58 | */ |
||
59 | |||
60 | #define SG_MAGIC 0x87654321 |
||
61 | |||
62 | /* |
||
63 | * We overload the LSB of the page pointer to indicate whether it's |
||
64 | * a valid sg entry, or whether it points to the start of a new scatterlist. |
||
65 | * Those low bits are there for everyone! (thanks mason :-) |
||
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)) |
||
71 | |||
72 | /** |
||
73 | * sg_assign_page - Assign a given page to an SG entry |
||
74 | * @sg: SG entry |
||
75 | * @page: The page |
||
76 | * |
||
77 | * Description: |
||
78 | * Assign page to sg entry. Also see sg_set_page(), the most commonly used |
||
79 | * variant. |
||
80 | * |
||
81 | **/ |
||
82 | static inline void sg_assign_page(struct scatterlist *sg, struct page *page) |
||
83 | { |
||
84 | unsigned long page_link = sg->page_link & 0x3; |
||
85 | |||
86 | /* |
||
87 | * In order for the low bit stealing approach to work, pages |
||
88 | * must be aligned at a 32-bit boundary as a minimum. |
||
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 | } |
||
97 | |||
98 | /** |
||
99 | * sg_set_page - Set sg entry to point at given page |
||
100 | * @sg: SG entry |
||
101 | * @page: The page |
||
102 | * @len: Length of data |
||
103 | * @offset: Offset into page |
||
104 | * |
||
105 | * Description: |
||
106 | * Use this function to set an sg entry pointing at a page, never assign |
||
107 | * the page directly. We encode sg table information in the lower bits |
||
108 | * of the page pointer. See sg_page() for looking up the page belonging |
||
109 | * to an sg entry. |
||
110 | * |
||
111 | **/ |
||
112 | static 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 | |||
120 | static 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 | } |
||
128 | |||
5270 | serge | 129 | /** |
130 | * sg_set_buf - Set sg entry to point at given data |
||
131 | * @sg: SG entry |
||
132 | * @buf: Data |
||
133 | * @buflen: Data length |
||
134 | * |
||
135 | **/ |
||
6082 | serge | 136 | static 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, (struct page*)((unsigned)buf&0xFFFFF000), buflen, offset_in_page(buf)); |
||
143 | } |
||
5270 | serge | 144 | |
3243 | Serge | 145 | /* |
146 | * Loop over each sg element, following the pointer to a new list if necessary |
||
147 | */ |
||
148 | #define for_each_sg(sglist, sg, nr, __i) \ |
||
149 | for (__i = 0, sg = (sglist); __i < (nr); __i++, sg = sg_next(sg)) |
||
150 | |||
151 | /** |
||
152 | * sg_chain - Chain two sglists together |
||
153 | * @prv: First scatterlist |
||
154 | * @prv_nents: Number of entries in prv |
||
155 | * @sgl: Second scatterlist |
||
156 | * |
||
157 | * Description: |
||
158 | * Links @prv@ and @sgl@ together, to form a longer scatterlist. |
||
159 | * |
||
160 | **/ |
||
161 | static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents, |
||
162 | struct scatterlist *sgl) |
||
163 | { |
||
164 | /* |
||
165 | * offset and length are unused for chain entry. Clear them. |
||
166 | */ |
||
167 | prv[prv_nents - 1].offset = 0; |
||
168 | prv[prv_nents - 1].length = 0; |
||
169 | |||
170 | /* |
||
171 | * Set lowest bit to indicate a link pointer, and make sure to clear |
||
172 | * the termination bit if it happens to be set. |
||
173 | */ |
||
174 | prv[prv_nents - 1].page_link = ((unsigned long) sgl | 0x01) & ~0x02; |
||
175 | } |
||
176 | |||
177 | /** |
||
178 | * sg_mark_end - Mark the end of the scatterlist |
||
179 | * @sg: SG entryScatterlist |
||
180 | * |
||
181 | * Description: |
||
182 | * Marks the passed in sg entry as the termination point for the sg |
||
183 | * table. A call to sg_next() on this entry will return NULL. |
||
184 | * |
||
185 | **/ |
||
186 | static 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 | /* |
||
192 | * Set termination bit, clear potential chain bit |
||
193 | */ |
||
194 | sg->page_link |= 0x02; |
||
195 | sg->page_link &= ~0x01; |
||
196 | } |
||
197 | |||
198 | /** |
||
3747 | Serge | 199 | * sg_unmark_end - Undo setting the end of the scatterlist |
200 | * @sg: SG entryScatterlist |
||
201 | * |
||
202 | * Description: |
||
203 | * Removes the termination marker from the given entry of the scatterlist. |
||
204 | * |
||
205 | **/ |
||
206 | static 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 | } |
||
213 | |||
214 | /** |
||
3243 | Serge | 215 | * sg_phys - Return physical address of an sg entry |
216 | * @sg: SG entry |
||
217 | * |
||
218 | * Description: |
||
219 | * This calls page_to_phys() on the page in this sg entry, and adds the |
||
220 | * sg offset. The caller must know that it is legal to call page_to_phys() |
||
221 | * on the sg page. |
||
222 | * |
||
223 | **/ |
||
224 | static inline dma_addr_t sg_phys(struct scatterlist *sg) |
||
225 | { |
||
226 | return page_to_phys(sg_page(sg)) + sg->offset; |
||
227 | } |
||
228 | |||
229 | /** |
||
230 | * sg_virt - Return virtual address of an sg entry |
||
231 | * @sg: SG entry |
||
232 | * |
||
233 | * Description: |
||
234 | * This calls page_address() on the page in this sg entry, and adds the |
||
235 | * sg offset. The caller must know that the sg page has a valid virtual |
||
236 | * mapping. |
||
237 | * |
||
238 | **/ |
||
239 | //static inline void *sg_virt(struct scatterlist *sg) |
||
240 | //{ |
||
241 | // return page_address(sg_page(sg)) + sg->offset; |
||
242 | //} |
||
243 | |||
244 | int sg_nents(struct scatterlist *sg); |
||
6082 | serge | 245 | int sg_nents_for_len(struct scatterlist *sg, u64 len); |
3243 | Serge | 246 | struct scatterlist *sg_next(struct scatterlist *); |
247 | struct scatterlist *sg_last(struct scatterlist *s, unsigned int); |
||
248 | void sg_init_table(struct scatterlist *, unsigned int); |
||
249 | void sg_init_one(struct scatterlist *, const void *, unsigned int); |
||
6082 | serge | 250 | int 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); |
||
3243 | Serge | 255 | |
256 | typedef struct scatterlist *(sg_alloc_fn)(unsigned int, gfp_t); |
||
257 | typedef void (sg_free_fn)(struct scatterlist *, unsigned int); |
||
258 | |||
5056 | serge | 259 | void __sg_free_table(struct sg_table *, unsigned int, bool, sg_free_fn *); |
3243 | Serge | 260 | void sg_free_table(struct sg_table *); |
5056 | serge | 261 | int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int, |
262 | struct scatterlist *, gfp_t, sg_alloc_fn *); |
||
3243 | Serge | 263 | int sg_alloc_table(struct sg_table *, unsigned int, gfp_t); |
264 | int 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 | |||
6082 | serge | 269 | size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, |
270 | size_t buflen, off_t skip, bool to_buffer); |
||
271 | |||
3243 | Serge | 272 | size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents, |
6082 | serge | 273 | const void *buf, size_t buflen); |
3243 | Serge | 274 | size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents, |
275 | void *buf, size_t buflen); |
||
276 | |||
5056 | serge | 277 | size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents, |
6082 | serge | 278 | const void *buf, size_t buflen, off_t skip); |
5056 | serge | 279 | size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, |
280 | void *buf, size_t buflen, off_t skip); |
||
281 | |||
3243 | Serge | 282 | /* |
283 | * Maximum number of entries that will be allocated in one piece, if |
||
284 | * a list larger than this is required then chaining will be utilized. |
||
285 | */ |
||
6282 | serge | 286 | #define SG_MAX_SINGLE_ALLOC (8*PAGE_SIZE / sizeof(struct scatterlist)) |
3243 | Serge | 287 | |
3747 | Serge | 288 | /* |
289 | * sg page iterator |
||
290 | * |
||
291 | * Iterates over sg entries page-by-page. On each successful iteration, |
||
292 | * you can call sg_page_iter_page(@piter) and sg_page_iter_dma_address(@piter) |
||
293 | * to get the current page and its dma address. @piter->sg will point to the |
||
294 | * sg holding this page and @piter->sg_pgoffset to the page's page offset |
||
295 | * within the sg. The iteration will stop either when a maximum number of sg |
||
296 | * entries was reached or a terminating sg (sg_last(sg) == true) was reached. |
||
297 | */ |
||
298 | struct sg_page_iter { |
||
299 | struct scatterlist *sg; /* sg holding the page */ |
||
300 | unsigned int sg_pgoffset; /* page offset within the sg */ |
||
3243 | Serge | 301 | |
3747 | Serge | 302 | /* these are internal states, keep away */ |
303 | unsigned int __nents; /* remaining sg entries */ |
||
304 | int __pg_advance; /* nr pages to advance at the |
||
305 | * next step */ |
||
306 | }; |
||
307 | |||
308 | bool __sg_page_iter_next(struct sg_page_iter *piter); |
||
309 | void __sg_page_iter_start(struct sg_page_iter *piter, |
||
310 | struct scatterlist *sglist, unsigned int nents, |
||
311 | unsigned long pgoffset); |
||
312 | /** |
||
313 | * sg_page_iter_page - get the current page held by the page iterator |
||
314 | * @piter: page iterator holding the page |
||
315 | */ |
||
316 | static inline struct page *sg_page_iter_page(struct sg_page_iter *piter) |
||
317 | { |
||
318 | return nth_page(sg_page(piter->sg), piter->sg_pgoffset); |
||
319 | } |
||
320 | |||
321 | /** |
||
322 | * sg_page_iter_dma_address - get the dma address of the current page held by |
||
323 | * the page iterator. |
||
324 | * @piter: page iterator holding the page |
||
325 | */ |
||
326 | static inline dma_addr_t sg_page_iter_dma_address(struct sg_page_iter *piter) |
||
327 | { |
||
328 | return sg_dma_address(piter->sg) + (piter->sg_pgoffset << PAGE_SHIFT); |
||
329 | } |
||
330 | |||
331 | /** |
||
332 | * for_each_sg_page - iterate over the pages of the given sg list |
||
333 | * @sglist: sglist to iterate over |
||
334 | * @piter: page iterator to hold current page, sg, sg_pgoffset |
||
335 | * @nents: maximum number of sg entries to iterate over |
||
336 | * @pgoffset: starting page offset |
||
337 | */ |
||
338 | #define for_each_sg_page(sglist, piter, nents, pgoffset) \ |
||
339 | for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \ |
||
340 | __sg_page_iter_next(piter);) |
||
341 | |||
3243 | Serge | 342 | /* |
343 | * Mapping sg iterator |
||
344 | * |
||
345 | * Iterates over sg entries mapping page-by-page. On each successful |
||
346 | * iteration, @miter->page points to the mapped page and |
||
347 | * @miter->length bytes of data can be accessed at @miter->addr. As |
||
348 | * long as an interation is enclosed between start and stop, the user |
||
349 | * is free to choose control structure and when to stop. |
||
350 | * |
||
351 | * @miter->consumed is set to @miter->length on each iteration. It |
||
352 | * can be adjusted if the user can't consume all the bytes in one go. |
||
353 | * Also, a stopped iteration can be resumed by calling next on it. |
||
354 | * This is useful when iteration needs to release all resources and |
||
355 | * continue later (e.g. at the next interrupt). |
||
356 | */ |
||
357 | |||
358 | #define SG_MITER_ATOMIC (1 << 0) /* use kmap_atomic */ |
||
359 | #define SG_MITER_TO_SG (1 << 1) /* flush back to phys on unmap */ |
||
360 | #define SG_MITER_FROM_SG (1 << 2) /* nop */ |
||
361 | |||
362 | struct sg_mapping_iter { |
||
363 | /* the following three fields can be accessed directly */ |
||
364 | struct page *page; /* currently mapped page */ |
||
365 | void *addr; /* pointer to the mapped area */ |
||
366 | size_t length; /* length of the mapped area */ |
||
367 | size_t consumed; /* number of consumed bytes */ |
||
3747 | Serge | 368 | struct sg_page_iter piter; /* page iterator */ |
3243 | Serge | 369 | |
370 | /* these are internal states, keep away */ |
||
3747 | Serge | 371 | unsigned int __offset; /* offset within page */ |
372 | unsigned int __remaining; /* remaining bytes on page */ |
||
3243 | Serge | 373 | unsigned int __flags; |
374 | }; |
||
375 | |||
376 | void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl, |
||
377 | unsigned int nents, unsigned int flags); |
||
4568 | Serge | 378 | bool sg_miter_skip(struct sg_mapping_iter *miter, off_t offset); |
3243 | Serge | 379 | bool sg_miter_next(struct sg_mapping_iter *miter); |
380 | void sg_miter_stop(struct sg_mapping_iter *miter); |
||
381 | |||
382 | #endif /* _LINUX_SCATTERLIST_H */><>><>><>><>> |