This source file includes following definitions.
- blkif_get_x86_32_req
- blkif_get_x86_64_req
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27 #ifndef __XEN_BLKIF__BACKEND__COMMON_H__
28 #define __XEN_BLKIF__BACKEND__COMMON_H__
29
30 #include <linux/module.h>
31 #include <linux/interrupt.h>
32 #include <linux/slab.h>
33 #include <linux/blkdev.h>
34 #include <linux/vmalloc.h>
35 #include <linux/wait.h>
36 #include <linux/io.h>
37 #include <linux/rbtree.h>
38 #include <asm/setup.h>
39 #include <asm/pgalloc.h>
40 #include <asm/hypervisor.h>
41 #include <xen/grant_table.h>
42 #include <xen/page.h>
43 #include <xen/xenbus.h>
44 #include <xen/interface/io/ring.h>
45 #include <xen/interface/io/blkif.h>
46 #include <xen/interface/io/protocols.h>
47
48 extern unsigned int xen_blkif_max_ring_order;
49 extern unsigned int xenblk_max_queues;
50
51
52
53
54 #define MAX_INDIRECT_SEGMENTS 256
55
56
57
58
59
60 #define XEN_PAGES_PER_SEGMENT (PAGE_SIZE / XEN_PAGE_SIZE)
61
62 #define XEN_PAGES_PER_INDIRECT_FRAME \
63 (XEN_PAGE_SIZE/sizeof(struct blkif_request_segment))
64 #define SEGS_PER_INDIRECT_FRAME \
65 (XEN_PAGES_PER_INDIRECT_FRAME / XEN_PAGES_PER_SEGMENT)
66
67 #define MAX_INDIRECT_PAGES \
68 ((MAX_INDIRECT_SEGMENTS + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
69 #define INDIRECT_PAGES(_segs) DIV_ROUND_UP(_segs, XEN_PAGES_PER_INDIRECT_FRAME)
70
71
72
73
74
75 struct blkif_common_request {
76 char dummy;
77 };
78
79
80
81 struct blkif_x86_32_request_rw {
82 uint8_t nr_segments;
83 blkif_vdev_t handle;
84 uint64_t id;
85 blkif_sector_t sector_number;
86 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
87 } __attribute__((__packed__));
88
89 struct blkif_x86_32_request_discard {
90 uint8_t flag;
91 blkif_vdev_t _pad1;
92 uint64_t id;
93 blkif_sector_t sector_number;
94 uint64_t nr_sectors;
95 } __attribute__((__packed__));
96
97 struct blkif_x86_32_request_other {
98 uint8_t _pad1;
99 blkif_vdev_t _pad2;
100 uint64_t id;
101 } __attribute__((__packed__));
102
103 struct blkif_x86_32_request_indirect {
104 uint8_t indirect_op;
105 uint16_t nr_segments;
106 uint64_t id;
107 blkif_sector_t sector_number;
108 blkif_vdev_t handle;
109 uint16_t _pad1;
110 grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST];
111
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117
118 uint64_t _pad2;
119 } __attribute__((__packed__));
120
121 struct blkif_x86_32_request {
122 uint8_t operation;
123 union {
124 struct blkif_x86_32_request_rw rw;
125 struct blkif_x86_32_request_discard discard;
126 struct blkif_x86_32_request_other other;
127 struct blkif_x86_32_request_indirect indirect;
128 } u;
129 } __attribute__((__packed__));
130
131
132
133 struct blkif_x86_64_request_rw {
134 uint8_t nr_segments;
135 blkif_vdev_t handle;
136 uint32_t _pad1;
137 uint64_t id;
138 blkif_sector_t sector_number;
139 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
140 } __attribute__((__packed__));
141
142 struct blkif_x86_64_request_discard {
143 uint8_t flag;
144 blkif_vdev_t _pad1;
145 uint32_t _pad2;
146 uint64_t id;
147 blkif_sector_t sector_number;
148 uint64_t nr_sectors;
149 } __attribute__((__packed__));
150
151 struct blkif_x86_64_request_other {
152 uint8_t _pad1;
153 blkif_vdev_t _pad2;
154 uint32_t _pad3;
155 uint64_t id;
156 } __attribute__((__packed__));
157
158 struct blkif_x86_64_request_indirect {
159 uint8_t indirect_op;
160 uint16_t nr_segments;
161 uint32_t _pad1;
162 uint64_t id;
163 blkif_sector_t sector_number;
164 blkif_vdev_t handle;
165 uint16_t _pad2;
166 grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST];
167
168
169
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173
174 uint32_t _pad3;
175 } __attribute__((__packed__));
176
177 struct blkif_x86_64_request {
178 uint8_t operation;
179 union {
180 struct blkif_x86_64_request_rw rw;
181 struct blkif_x86_64_request_discard discard;
182 struct blkif_x86_64_request_other other;
183 struct blkif_x86_64_request_indirect indirect;
184 } u;
185 } __attribute__((__packed__));
186
187 DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
188 struct blkif_response);
189 DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
190 struct blkif_response __packed);
191 DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
192 struct blkif_response);
193
194 union blkif_back_rings {
195 struct blkif_back_ring native;
196 struct blkif_common_back_ring common;
197 struct blkif_x86_32_back_ring x86_32;
198 struct blkif_x86_64_back_ring x86_64;
199 };
200
201 enum blkif_protocol {
202 BLKIF_PROTOCOL_NATIVE = 1,
203 BLKIF_PROTOCOL_X86_32 = 2,
204 BLKIF_PROTOCOL_X86_64 = 3,
205 };
206
207
208
209
210 #ifdef CONFIG_X86
211 # define BLKIF_PROTOCOL_DEFAULT BLKIF_PROTOCOL_X86_32
212 #else
213 # define BLKIF_PROTOCOL_DEFAULT BLKIF_PROTOCOL_NATIVE
214 #endif
215
216 struct xen_vbd {
217
218 blkif_vdev_t handle;
219
220 unsigned char readonly;
221
222 unsigned char type;
223
224 u32 pdevice;
225 struct block_device *bdev;
226
227 sector_t size;
228 unsigned int flush_support:1;
229 unsigned int discard_secure:1;
230 unsigned int feature_gnt_persistent:1;
231 unsigned int overflow_max_grants:1;
232 };
233
234 struct backend_info;
235
236
237 #define XEN_BLKIF_REQS_PER_PAGE 32
238
239 struct persistent_gnt {
240 struct page *page;
241 grant_ref_t gnt;
242 grant_handle_t handle;
243 unsigned long last_used;
244 bool active;
245 struct rb_node node;
246 struct list_head remove_node;
247 };
248
249
250 struct xen_blkif_ring {
251
252 unsigned int irq;
253 union blkif_back_rings blk_rings;
254 void *blk_ring;
255
256 spinlock_t blk_ring_lock;
257
258 wait_queue_head_t wq;
259 atomic_t inflight;
260 bool active;
261
262 struct task_struct *xenblkd;
263 unsigned int waiting_reqs;
264
265
266 struct list_head pending_free;
267
268 spinlock_t pending_free_lock;
269 wait_queue_head_t pending_free_wq;
270
271
272 struct rb_root persistent_gnts;
273 unsigned int persistent_gnt_c;
274 atomic_t persistent_gnt_in_use;
275 unsigned long next_lru;
276
277
278 unsigned long st_print;
279 unsigned long long st_rd_req;
280 unsigned long long st_wr_req;
281 unsigned long long st_oo_req;
282 unsigned long long st_f_req;
283 unsigned long long st_ds_req;
284 unsigned long long st_rd_sect;
285 unsigned long long st_wr_sect;
286
287
288 struct list_head persistent_purge_list;
289 struct work_struct persistent_purge_work;
290
291
292 spinlock_t free_pages_lock;
293 int free_pages_num;
294 struct list_head free_pages;
295
296 struct work_struct free_work;
297
298 wait_queue_head_t shutdown_wq;
299 struct xen_blkif *blkif;
300 };
301
302 struct xen_blkif {
303
304 domid_t domid;
305 unsigned int handle;
306
307 enum blkif_protocol blk_protocol;
308
309 struct xen_vbd vbd;
310
311 struct backend_info *be;
312 atomic_t refcnt;
313
314 struct completion drain_complete;
315 atomic_t drain;
316
317 struct work_struct free_work;
318 unsigned int nr_ring_pages;
319
320 struct xen_blkif_ring *rings;
321 unsigned int nr_rings;
322 };
323
324 struct seg_buf {
325 unsigned long offset;
326 unsigned int nsec;
327 };
328
329 struct grant_page {
330 struct page *page;
331 struct persistent_gnt *persistent_gnt;
332 grant_handle_t handle;
333 grant_ref_t gref;
334 };
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341
342 struct pending_req {
343 struct xen_blkif_ring *ring;
344 u64 id;
345 int nr_segs;
346 atomic_t pendcnt;
347 unsigned short operation;
348 int status;
349 struct list_head free_list;
350 struct grant_page *segments[MAX_INDIRECT_SEGMENTS];
351
352 struct grant_page *indirect_pages[MAX_INDIRECT_PAGES];
353 struct seg_buf seg[MAX_INDIRECT_SEGMENTS];
354 struct bio *biolist[MAX_INDIRECT_SEGMENTS];
355 struct gnttab_unmap_grant_ref unmap[MAX_INDIRECT_SEGMENTS];
356 struct page *unmap_pages[MAX_INDIRECT_SEGMENTS];
357 struct gntab_unmap_queue_data gnttab_unmap_data;
358 };
359
360
361 #define vbd_sz(_v) ((_v)->bdev->bd_part ? \
362 (_v)->bdev->bd_part->nr_sects : \
363 get_capacity((_v)->bdev->bd_disk))
364
365 #define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
366 #define xen_blkif_put(_b) \
367 do { \
368 if (atomic_dec_and_test(&(_b)->refcnt)) \
369 schedule_work(&(_b)->free_work);\
370 } while (0)
371
372 struct phys_req {
373 unsigned short dev;
374 blkif_sector_t nr_sects;
375 struct block_device *bdev;
376 blkif_sector_t sector_number;
377 };
378 int xen_blkif_interface_init(void);
379
380 int xen_blkif_xenbus_init(void);
381
382 irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
383 int xen_blkif_schedule(void *arg);
384 int xen_blkif_purge_persistent(void *arg);
385 void xen_blkbk_free_caches(struct xen_blkif_ring *ring);
386
387 int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
388 struct backend_info *be, int state);
389
390 int xen_blkbk_barrier(struct xenbus_transaction xbt,
391 struct backend_info *be, int state);
392 struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
393 void xen_blkbk_unmap_purged_grants(struct work_struct *work);
394
395 static inline void blkif_get_x86_32_req(struct blkif_request *dst,
396 struct blkif_x86_32_request *src)
397 {
398 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
399 dst->operation = READ_ONCE(src->operation);
400 switch (dst->operation) {
401 case BLKIF_OP_READ:
402 case BLKIF_OP_WRITE:
403 case BLKIF_OP_WRITE_BARRIER:
404 case BLKIF_OP_FLUSH_DISKCACHE:
405 dst->u.rw.nr_segments = src->u.rw.nr_segments;
406 dst->u.rw.handle = src->u.rw.handle;
407 dst->u.rw.id = src->u.rw.id;
408 dst->u.rw.sector_number = src->u.rw.sector_number;
409 barrier();
410 if (n > dst->u.rw.nr_segments)
411 n = dst->u.rw.nr_segments;
412 for (i = 0; i < n; i++)
413 dst->u.rw.seg[i] = src->u.rw.seg[i];
414 break;
415 case BLKIF_OP_DISCARD:
416 dst->u.discard.flag = src->u.discard.flag;
417 dst->u.discard.id = src->u.discard.id;
418 dst->u.discard.sector_number = src->u.discard.sector_number;
419 dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
420 break;
421 case BLKIF_OP_INDIRECT:
422 dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
423 dst->u.indirect.nr_segments = src->u.indirect.nr_segments;
424 dst->u.indirect.handle = src->u.indirect.handle;
425 dst->u.indirect.id = src->u.indirect.id;
426 dst->u.indirect.sector_number = src->u.indirect.sector_number;
427 barrier();
428 j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments));
429 for (i = 0; i < j; i++)
430 dst->u.indirect.indirect_grefs[i] =
431 src->u.indirect.indirect_grefs[i];
432 break;
433 default:
434
435
436
437
438 dst->u.other.id = src->u.other.id;
439 break;
440 }
441 }
442
443 static inline void blkif_get_x86_64_req(struct blkif_request *dst,
444 struct blkif_x86_64_request *src)
445 {
446 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
447 dst->operation = READ_ONCE(src->operation);
448 switch (dst->operation) {
449 case BLKIF_OP_READ:
450 case BLKIF_OP_WRITE:
451 case BLKIF_OP_WRITE_BARRIER:
452 case BLKIF_OP_FLUSH_DISKCACHE:
453 dst->u.rw.nr_segments = src->u.rw.nr_segments;
454 dst->u.rw.handle = src->u.rw.handle;
455 dst->u.rw.id = src->u.rw.id;
456 dst->u.rw.sector_number = src->u.rw.sector_number;
457 barrier();
458 if (n > dst->u.rw.nr_segments)
459 n = dst->u.rw.nr_segments;
460 for (i = 0; i < n; i++)
461 dst->u.rw.seg[i] = src->u.rw.seg[i];
462 break;
463 case BLKIF_OP_DISCARD:
464 dst->u.discard.flag = src->u.discard.flag;
465 dst->u.discard.id = src->u.discard.id;
466 dst->u.discard.sector_number = src->u.discard.sector_number;
467 dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
468 break;
469 case BLKIF_OP_INDIRECT:
470 dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
471 dst->u.indirect.nr_segments = src->u.indirect.nr_segments;
472 dst->u.indirect.handle = src->u.indirect.handle;
473 dst->u.indirect.id = src->u.indirect.id;
474 dst->u.indirect.sector_number = src->u.indirect.sector_number;
475 barrier();
476 j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments));
477 for (i = 0; i < j; i++)
478 dst->u.indirect.indirect_grefs[i] =
479 src->u.indirect.indirect_grefs[i];
480 break;
481 default:
482
483
484
485
486 dst->u.other.id = src->u.other.id;
487 break;
488 }
489 }
490
491 #endif