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1/*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License version 2
4 * as published by the Free Software Foundation; or, when distributed
5 * separately from the Linux kernel or incorporated into other
6 * software packages, subject to the following license:
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this source file (the "Software"), to deal in the Software without
10 * restriction, including without limitation the rights to use, copy, modify,
11 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
12 * and to permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24 * IN THE SOFTWARE.
25 */
26
27#ifndef __XEN_BLKIF__BACKEND__COMMON_H__
28#define __XEN_BLKIF__BACKEND__COMMON_H__
29
30#include <linux/version.h>
31#include <linux/module.h>
32#include <linux/interrupt.h>
33#include <linux/slab.h>
34#include <linux/blkdev.h>
35#include <linux/vmalloc.h>
36#include <linux/wait.h>
37#include <linux/io.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/xenbus.h>
43#include <xen/interface/io/ring.h>
44#include <xen/interface/io/blkif.h>
45#include <xen/interface/io/protocols.h>
46
47#define DRV_PFX "xen-blkback:"
48#define DPRINTK(fmt, args...) \
49 pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \
50 __func__, __LINE__, ##args)
51
52
53/* Not a real protocol. Used to generate ring structs which contain
54 * the elements common to all protocols only. This way we get a
55 * compiler-checkable way to use common struct elements, so we can
56 * avoid using switch(protocol) in a number of places. */
57struct blkif_common_request {
58 char dummy;
59};
60struct blkif_common_response {
61 char dummy;
62};
63
64/* i386 protocol version */
65#pragma pack(push, 4)
66struct blkif_x86_32_request {
67 uint8_t operation; /* BLKIF_OP_??? */
68 uint8_t nr_segments; /* number of segments */
69 blkif_vdev_t handle; /* only for read/write requests */
70 uint64_t id; /* private guest value, echoed in resp */
71 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
72 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
73};
74struct blkif_x86_32_response {
75 uint64_t id; /* copied from request */
76 uint8_t operation; /* copied from request */
77 int16_t status; /* BLKIF_RSP_??? */
78};
79#pragma pack(pop)
80
81/* x86_64 protocol version */
82struct blkif_x86_64_request {
83 uint8_t operation; /* BLKIF_OP_??? */
84 uint8_t nr_segments; /* number of segments */
85 blkif_vdev_t handle; /* only for read/write requests */
86 uint64_t __attribute__((__aligned__(8))) id;
87 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
88 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
89};
90struct blkif_x86_64_response {
91 uint64_t __attribute__((__aligned__(8))) id;
92 uint8_t operation; /* copied from request */
93 int16_t status; /* BLKIF_RSP_??? */
94};
95
96DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
97 struct blkif_common_response);
98DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
99 struct blkif_x86_32_response);
100DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
101 struct blkif_x86_64_response);
102
103union blkif_back_rings {
104 struct blkif_back_ring native;
105 struct blkif_common_back_ring common;
106 struct blkif_x86_32_back_ring x86_32;
107 struct blkif_x86_64_back_ring x86_64;
108};
109
110enum blkif_protocol {
111 BLKIF_PROTOCOL_NATIVE = 1,
112 BLKIF_PROTOCOL_X86_32 = 2,
113 BLKIF_PROTOCOL_X86_64 = 3,
114};
115
116struct xen_vbd {
117 /* What the domain refers to this vbd as. */
118 blkif_vdev_t handle;
119 /* Non-zero -> read-only */
120 unsigned char readonly;
121 /* VDISK_xxx */
122 unsigned char type;
123 /* phys device that this vbd maps to. */
124 u32 pdevice;
125 struct block_device *bdev;
126 /* Cached size parameter. */
127 sector_t size;
128 bool flush_support;
129};
130
131struct backend_info;
132
133struct xen_blkif {
134 /* Unique identifier for this interface. */
135 domid_t domid;
136 unsigned int handle;
137 /* Physical parameters of the comms window. */
138 unsigned int irq;
139 /* Comms information. */
140 enum blkif_protocol blk_protocol;
141 union blkif_back_rings blk_rings;
142 struct vm_struct *blk_ring_area;
143 /* The VBD attached to this interface. */
144 struct xen_vbd vbd;
145 /* Back pointer to the backend_info. */
146 struct backend_info *be;
147 /* Private fields. */
148 spinlock_t blk_ring_lock;
149 atomic_t refcnt;
150
151 wait_queue_head_t wq;
152 /* One thread per one blkif. */
153 struct task_struct *xenblkd;
154 unsigned int waiting_reqs;
155
156 /* statistics */
157 unsigned long st_print;
158 int st_rd_req;
159 int st_wr_req;
160 int st_oo_req;
161 int st_f_req;
162 int st_rd_sect;
163 int st_wr_sect;
164
165 wait_queue_head_t waiting_to_free;
166
167 grant_handle_t shmem_handle;
168 grant_ref_t shmem_ref;
169};
170
171
172#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
173 (_v)->bdev->bd_part->nr_sects : \
174 get_capacity((_v)->bdev->bd_disk))
175
176#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
177#define xen_blkif_put(_b) \
178 do { \
179 if (atomic_dec_and_test(&(_b)->refcnt)) \
180 wake_up(&(_b)->waiting_to_free);\
181 } while (0)
182
183struct phys_req {
184 unsigned short dev;
185 unsigned short nr_sects;
186 struct block_device *bdev;
187 blkif_sector_t sector_number;
188};
189int xen_blkif_interface_init(void);
190
191int xen_blkif_xenbus_init(void);
192
193irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
194int xen_blkif_schedule(void *arg);
195
196int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
197 struct backend_info *be, int state);
198
199struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
200
201static inline void blkif_get_x86_32_req(struct blkif_request *dst,
202 struct blkif_x86_32_request *src)
203{
204 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
205 dst->operation = src->operation;
206 dst->nr_segments = src->nr_segments;
207 dst->handle = src->handle;
208 dst->id = src->id;
209 dst->u.rw.sector_number = src->sector_number;
210 barrier();
211 if (n > dst->nr_segments)
212 n = dst->nr_segments;
213 for (i = 0; i < n; i++)
214 dst->u.rw.seg[i] = src->seg[i];
215}
216
217static inline void blkif_get_x86_64_req(struct blkif_request *dst,
218 struct blkif_x86_64_request *src)
219{
220 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
221 dst->operation = src->operation;
222 dst->nr_segments = src->nr_segments;
223 dst->handle = src->handle;
224 dst->id = src->id;
225 dst->u.rw.sector_number = src->sector_number;
226 barrier();
227 if (n > dst->nr_segments)
228 n = dst->nr_segments;
229 for (i = 0; i < n; i++)
230 dst->u.rw.seg[i] = src->seg[i];
231}
232
233#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */
1/*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License version 2
4 * as published by the Free Software Foundation; or, when distributed
5 * separately from the Linux kernel or incorporated into other
6 * software packages, subject to the following license:
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this source file (the "Software"), to deal in the Software without
10 * restriction, including without limitation the rights to use, copy, modify,
11 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
12 * and to permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24 * IN THE SOFTWARE.
25 */
26
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
48extern unsigned int xen_blkif_max_ring_order;
49extern unsigned int xenblk_max_queues;
50/*
51 * This is the maximum number of segments that would be allowed in indirect
52 * requests. This value will also be passed to the frontend.
53 */
54#define MAX_INDIRECT_SEGMENTS 256
55
56/*
57 * Xen use 4K pages. The guest may use different page size (4K or 64K)
58 * Number of Xen pages per segment
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/* Not a real protocol. Used to generate ring structs which contain
72 * the elements common to all protocols only. This way we get a
73 * compiler-checkable way to use common struct elements, so we can
74 * avoid using switch(protocol) in a number of places. */
75struct blkif_common_request {
76 char dummy;
77};
78struct blkif_common_response {
79 char dummy;
80};
81
82struct blkif_x86_32_request_rw {
83 uint8_t nr_segments; /* number of segments */
84 blkif_vdev_t handle; /* only for read/write requests */
85 uint64_t id; /* private guest value, echoed in resp */
86 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
87 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
88} __attribute__((__packed__));
89
90struct blkif_x86_32_request_discard {
91 uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
92 blkif_vdev_t _pad1; /* was "handle" for read/write requests */
93 uint64_t id; /* private guest value, echoed in resp */
94 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
95 uint64_t nr_sectors;
96} __attribute__((__packed__));
97
98struct blkif_x86_32_request_other {
99 uint8_t _pad1;
100 blkif_vdev_t _pad2;
101 uint64_t id; /* private guest value, echoed in resp */
102} __attribute__((__packed__));
103
104struct blkif_x86_32_request_indirect {
105 uint8_t indirect_op;
106 uint16_t nr_segments;
107 uint64_t id;
108 blkif_sector_t sector_number;
109 blkif_vdev_t handle;
110 uint16_t _pad1;
111 grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST];
112 /*
113 * The maximum number of indirect segments (and pages) that will
114 * be used is determined by MAX_INDIRECT_SEGMENTS, this value
115 * is also exported to the guest (via xenstore
116 * feature-max-indirect-segments entry), so the frontend knows how
117 * many indirect segments the backend supports.
118 */
119 uint64_t _pad2; /* make it 64 byte aligned */
120} __attribute__((__packed__));
121
122struct blkif_x86_32_request {
123 uint8_t operation; /* BLKIF_OP_??? */
124 union {
125 struct blkif_x86_32_request_rw rw;
126 struct blkif_x86_32_request_discard discard;
127 struct blkif_x86_32_request_other other;
128 struct blkif_x86_32_request_indirect indirect;
129 } u;
130} __attribute__((__packed__));
131
132/* i386 protocol version */
133#pragma pack(push, 4)
134struct blkif_x86_32_response {
135 uint64_t id; /* copied from request */
136 uint8_t operation; /* copied from request */
137 int16_t status; /* BLKIF_RSP_??? */
138};
139#pragma pack(pop)
140/* x86_64 protocol version */
141
142struct blkif_x86_64_request_rw {
143 uint8_t nr_segments; /* number of segments */
144 blkif_vdev_t handle; /* only for read/write requests */
145 uint32_t _pad1; /* offsetof(blkif_reqest..,u.rw.id)==8 */
146 uint64_t id;
147 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
148 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
149} __attribute__((__packed__));
150
151struct blkif_x86_64_request_discard {
152 uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
153 blkif_vdev_t _pad1; /* was "handle" for read/write requests */
154 uint32_t _pad2; /* offsetof(blkif_..,u.discard.id)==8 */
155 uint64_t id;
156 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
157 uint64_t nr_sectors;
158} __attribute__((__packed__));
159
160struct blkif_x86_64_request_other {
161 uint8_t _pad1;
162 blkif_vdev_t _pad2;
163 uint32_t _pad3; /* offsetof(blkif_..,u.discard.id)==8 */
164 uint64_t id; /* private guest value, echoed in resp */
165} __attribute__((__packed__));
166
167struct blkif_x86_64_request_indirect {
168 uint8_t indirect_op;
169 uint16_t nr_segments;
170 uint32_t _pad1; /* offsetof(blkif_..,u.indirect.id)==8 */
171 uint64_t id;
172 blkif_sector_t sector_number;
173 blkif_vdev_t handle;
174 uint16_t _pad2;
175 grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST];
176 /*
177 * The maximum number of indirect segments (and pages) that will
178 * be used is determined by MAX_INDIRECT_SEGMENTS, this value
179 * is also exported to the guest (via xenstore
180 * feature-max-indirect-segments entry), so the frontend knows how
181 * many indirect segments the backend supports.
182 */
183 uint32_t _pad3; /* make it 64 byte aligned */
184} __attribute__((__packed__));
185
186struct blkif_x86_64_request {
187 uint8_t operation; /* BLKIF_OP_??? */
188 union {
189 struct blkif_x86_64_request_rw rw;
190 struct blkif_x86_64_request_discard discard;
191 struct blkif_x86_64_request_other other;
192 struct blkif_x86_64_request_indirect indirect;
193 } u;
194} __attribute__((__packed__));
195
196struct blkif_x86_64_response {
197 uint64_t __attribute__((__aligned__(8))) id;
198 uint8_t operation; /* copied from request */
199 int16_t status; /* BLKIF_RSP_??? */
200};
201
202DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
203 struct blkif_common_response);
204DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
205 struct blkif_x86_32_response);
206DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
207 struct blkif_x86_64_response);
208
209union blkif_back_rings {
210 struct blkif_back_ring native;
211 struct blkif_common_back_ring common;
212 struct blkif_x86_32_back_ring x86_32;
213 struct blkif_x86_64_back_ring x86_64;
214};
215
216enum blkif_protocol {
217 BLKIF_PROTOCOL_NATIVE = 1,
218 BLKIF_PROTOCOL_X86_32 = 2,
219 BLKIF_PROTOCOL_X86_64 = 3,
220};
221
222/*
223 * Default protocol if the frontend doesn't specify one.
224 */
225#ifdef CONFIG_X86
226# define BLKIF_PROTOCOL_DEFAULT BLKIF_PROTOCOL_X86_32
227#else
228# define BLKIF_PROTOCOL_DEFAULT BLKIF_PROTOCOL_NATIVE
229#endif
230
231struct xen_vbd {
232 /* What the domain refers to this vbd as. */
233 blkif_vdev_t handle;
234 /* Non-zero -> read-only */
235 unsigned char readonly;
236 /* VDISK_xxx */
237 unsigned char type;
238 /* phys device that this vbd maps to. */
239 u32 pdevice;
240 struct block_device *bdev;
241 /* Cached size parameter. */
242 sector_t size;
243 unsigned int flush_support:1;
244 unsigned int discard_secure:1;
245 unsigned int feature_gnt_persistent:1;
246 unsigned int overflow_max_grants:1;
247};
248
249struct backend_info;
250
251/* Number of available flags */
252#define PERSISTENT_GNT_FLAGS_SIZE 2
253/* This persistent grant is currently in use */
254#define PERSISTENT_GNT_ACTIVE 0
255/*
256 * This persistent grant has been used, this flag is set when we remove the
257 * PERSISTENT_GNT_ACTIVE, to know that this grant has been used recently.
258 */
259#define PERSISTENT_GNT_WAS_ACTIVE 1
260
261/* Number of requests that we can fit in a ring */
262#define XEN_BLKIF_REQS_PER_PAGE 32
263
264struct persistent_gnt {
265 struct page *page;
266 grant_ref_t gnt;
267 grant_handle_t handle;
268 DECLARE_BITMAP(flags, PERSISTENT_GNT_FLAGS_SIZE);
269 struct rb_node node;
270 struct list_head remove_node;
271};
272
273/* Per-ring information. */
274struct xen_blkif_ring {
275 /* Physical parameters of the comms window. */
276 unsigned int irq;
277 union blkif_back_rings blk_rings;
278 void *blk_ring;
279 /* Private fields. */
280 spinlock_t blk_ring_lock;
281
282 wait_queue_head_t wq;
283 atomic_t inflight;
284 /* One thread per blkif ring. */
285 struct task_struct *xenblkd;
286 unsigned int waiting_reqs;
287
288 /* List of all 'pending_req' available */
289 struct list_head pending_free;
290 /* And its spinlock. */
291 spinlock_t pending_free_lock;
292 wait_queue_head_t pending_free_wq;
293
294 /* Tree to store persistent grants. */
295 spinlock_t pers_gnts_lock;
296 struct rb_root persistent_gnts;
297 unsigned int persistent_gnt_c;
298 atomic_t persistent_gnt_in_use;
299 unsigned long next_lru;
300
301 /* Statistics. */
302 unsigned long st_print;
303 unsigned long long st_rd_req;
304 unsigned long long st_wr_req;
305 unsigned long long st_oo_req;
306 unsigned long long st_f_req;
307 unsigned long long st_ds_req;
308 unsigned long long st_rd_sect;
309 unsigned long long st_wr_sect;
310
311 /* Used by the kworker that offload work from the persistent purge. */
312 struct list_head persistent_purge_list;
313 struct work_struct persistent_purge_work;
314
315 /* Buffer of free pages to map grant refs. */
316 spinlock_t free_pages_lock;
317 int free_pages_num;
318 struct list_head free_pages;
319
320 struct work_struct free_work;
321 /* Thread shutdown wait queue. */
322 wait_queue_head_t shutdown_wq;
323 struct xen_blkif *blkif;
324};
325
326struct xen_blkif {
327 /* Unique identifier for this interface. */
328 domid_t domid;
329 unsigned int handle;
330 /* Comms information. */
331 enum blkif_protocol blk_protocol;
332 /* The VBD attached to this interface. */
333 struct xen_vbd vbd;
334 /* Back pointer to the backend_info. */
335 struct backend_info *be;
336 atomic_t refcnt;
337 /* for barrier (drain) requests */
338 struct completion drain_complete;
339 atomic_t drain;
340
341 struct work_struct free_work;
342 unsigned int nr_ring_pages;
343 /* All rings for this device. */
344 struct xen_blkif_ring *rings;
345 unsigned int nr_rings;
346};
347
348struct seg_buf {
349 unsigned long offset;
350 unsigned int nsec;
351};
352
353struct grant_page {
354 struct page *page;
355 struct persistent_gnt *persistent_gnt;
356 grant_handle_t handle;
357 grant_ref_t gref;
358};
359
360/*
361 * Each outstanding request that we've passed to the lower device layers has a
362 * 'pending_req' allocated to it. Each buffer_head that completes decrements
363 * the pendcnt towards zero. When it hits zero, the specified domain has a
364 * response queued for it, with the saved 'id' passed back.
365 */
366struct pending_req {
367 struct xen_blkif_ring *ring;
368 u64 id;
369 int nr_segs;
370 atomic_t pendcnt;
371 unsigned short operation;
372 int status;
373 struct list_head free_list;
374 struct grant_page *segments[MAX_INDIRECT_SEGMENTS];
375 /* Indirect descriptors */
376 struct grant_page *indirect_pages[MAX_INDIRECT_PAGES];
377 struct seg_buf seg[MAX_INDIRECT_SEGMENTS];
378 struct bio *biolist[MAX_INDIRECT_SEGMENTS];
379 struct gnttab_unmap_grant_ref unmap[MAX_INDIRECT_SEGMENTS];
380 struct page *unmap_pages[MAX_INDIRECT_SEGMENTS];
381 struct gntab_unmap_queue_data gnttab_unmap_data;
382};
383
384
385#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
386 (_v)->bdev->bd_part->nr_sects : \
387 get_capacity((_v)->bdev->bd_disk))
388
389#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
390#define xen_blkif_put(_b) \
391 do { \
392 if (atomic_dec_and_test(&(_b)->refcnt)) \
393 schedule_work(&(_b)->free_work);\
394 } while (0)
395
396struct phys_req {
397 unsigned short dev;
398 blkif_sector_t nr_sects;
399 struct block_device *bdev;
400 blkif_sector_t sector_number;
401};
402int xen_blkif_interface_init(void);
403
404int xen_blkif_xenbus_init(void);
405
406irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
407int xen_blkif_schedule(void *arg);
408int xen_blkif_purge_persistent(void *arg);
409void xen_blkbk_free_caches(struct xen_blkif_ring *ring);
410
411int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
412 struct backend_info *be, int state);
413
414int xen_blkbk_barrier(struct xenbus_transaction xbt,
415 struct backend_info *be, int state);
416struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
417void xen_blkbk_unmap_purged_grants(struct work_struct *work);
418
419static inline void blkif_get_x86_32_req(struct blkif_request *dst,
420 struct blkif_x86_32_request *src)
421{
422 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
423 dst->operation = READ_ONCE(src->operation);
424 switch (dst->operation) {
425 case BLKIF_OP_READ:
426 case BLKIF_OP_WRITE:
427 case BLKIF_OP_WRITE_BARRIER:
428 case BLKIF_OP_FLUSH_DISKCACHE:
429 dst->u.rw.nr_segments = src->u.rw.nr_segments;
430 dst->u.rw.handle = src->u.rw.handle;
431 dst->u.rw.id = src->u.rw.id;
432 dst->u.rw.sector_number = src->u.rw.sector_number;
433 barrier();
434 if (n > dst->u.rw.nr_segments)
435 n = dst->u.rw.nr_segments;
436 for (i = 0; i < n; i++)
437 dst->u.rw.seg[i] = src->u.rw.seg[i];
438 break;
439 case BLKIF_OP_DISCARD:
440 dst->u.discard.flag = src->u.discard.flag;
441 dst->u.discard.id = src->u.discard.id;
442 dst->u.discard.sector_number = src->u.discard.sector_number;
443 dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
444 break;
445 case BLKIF_OP_INDIRECT:
446 dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
447 dst->u.indirect.nr_segments = src->u.indirect.nr_segments;
448 dst->u.indirect.handle = src->u.indirect.handle;
449 dst->u.indirect.id = src->u.indirect.id;
450 dst->u.indirect.sector_number = src->u.indirect.sector_number;
451 barrier();
452 j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments));
453 for (i = 0; i < j; i++)
454 dst->u.indirect.indirect_grefs[i] =
455 src->u.indirect.indirect_grefs[i];
456 break;
457 default:
458 /*
459 * Don't know how to translate this op. Only get the
460 * ID so failure can be reported to the frontend.
461 */
462 dst->u.other.id = src->u.other.id;
463 break;
464 }
465}
466
467static inline void blkif_get_x86_64_req(struct blkif_request *dst,
468 struct blkif_x86_64_request *src)
469{
470 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
471 dst->operation = READ_ONCE(src->operation);
472 switch (dst->operation) {
473 case BLKIF_OP_READ:
474 case BLKIF_OP_WRITE:
475 case BLKIF_OP_WRITE_BARRIER:
476 case BLKIF_OP_FLUSH_DISKCACHE:
477 dst->u.rw.nr_segments = src->u.rw.nr_segments;
478 dst->u.rw.handle = src->u.rw.handle;
479 dst->u.rw.id = src->u.rw.id;
480 dst->u.rw.sector_number = src->u.rw.sector_number;
481 barrier();
482 if (n > dst->u.rw.nr_segments)
483 n = dst->u.rw.nr_segments;
484 for (i = 0; i < n; i++)
485 dst->u.rw.seg[i] = src->u.rw.seg[i];
486 break;
487 case BLKIF_OP_DISCARD:
488 dst->u.discard.flag = src->u.discard.flag;
489 dst->u.discard.id = src->u.discard.id;
490 dst->u.discard.sector_number = src->u.discard.sector_number;
491 dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
492 break;
493 case BLKIF_OP_INDIRECT:
494 dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
495 dst->u.indirect.nr_segments = src->u.indirect.nr_segments;
496 dst->u.indirect.handle = src->u.indirect.handle;
497 dst->u.indirect.id = src->u.indirect.id;
498 dst->u.indirect.sector_number = src->u.indirect.sector_number;
499 barrier();
500 j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments));
501 for (i = 0; i < j; i++)
502 dst->u.indirect.indirect_grefs[i] =
503 src->u.indirect.indirect_grefs[i];
504 break;
505 default:
506 /*
507 * Don't know how to translate this op. Only get the
508 * ID so failure can be reported to the frontend.
509 */
510 dst->u.other.id = src->u.other.id;
511 break;
512 }
513}
514
515#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */