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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};
78
79/* i386 protocol version */
80
81struct blkif_x86_32_request_rw {
82 uint8_t nr_segments; /* number of segments */
83 blkif_vdev_t handle; /* only for read/write requests */
84 uint64_t id; /* private guest value, echoed in resp */
85 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
86 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
87} __attribute__((__packed__));
88
89struct blkif_x86_32_request_discard {
90 uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
91 blkif_vdev_t _pad1; /* was "handle" for read/write requests */
92 uint64_t id; /* private guest value, echoed in resp */
93 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
94 uint64_t nr_sectors;
95} __attribute__((__packed__));
96
97struct blkif_x86_32_request_other {
98 uint8_t _pad1;
99 blkif_vdev_t _pad2;
100 uint64_t id; /* private guest value, echoed in resp */
101} __attribute__((__packed__));
102
103struct 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 /*
112 * The maximum number of indirect segments (and pages) that will
113 * be used is determined by MAX_INDIRECT_SEGMENTS, this value
114 * is also exported to the guest (via xenstore
115 * feature-max-indirect-segments entry), so the frontend knows how
116 * many indirect segments the backend supports.
117 */
118 uint64_t _pad2; /* make it 64 byte aligned */
119} __attribute__((__packed__));
120
121struct blkif_x86_32_request {
122 uint8_t operation; /* BLKIF_OP_??? */
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/* x86_64 protocol version */
132
133struct blkif_x86_64_request_rw {
134 uint8_t nr_segments; /* number of segments */
135 blkif_vdev_t handle; /* only for read/write requests */
136 uint32_t _pad1; /* offsetof(blkif_reqest..,u.rw.id)==8 */
137 uint64_t id;
138 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
139 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
140} __attribute__((__packed__));
141
142struct blkif_x86_64_request_discard {
143 uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
144 blkif_vdev_t _pad1; /* was "handle" for read/write requests */
145 uint32_t _pad2; /* offsetof(blkif_..,u.discard.id)==8 */
146 uint64_t id;
147 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
148 uint64_t nr_sectors;
149} __attribute__((__packed__));
150
151struct blkif_x86_64_request_other {
152 uint8_t _pad1;
153 blkif_vdev_t _pad2;
154 uint32_t _pad3; /* offsetof(blkif_..,u.discard.id)==8 */
155 uint64_t id; /* private guest value, echoed in resp */
156} __attribute__((__packed__));
157
158struct blkif_x86_64_request_indirect {
159 uint8_t indirect_op;
160 uint16_t nr_segments;
161 uint32_t _pad1; /* offsetof(blkif_..,u.indirect.id)==8 */
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 * The maximum number of indirect segments (and pages) that will
169 * be used is determined by MAX_INDIRECT_SEGMENTS, this value
170 * is also exported to the guest (via xenstore
171 * feature-max-indirect-segments entry), so the frontend knows how
172 * many indirect segments the backend supports.
173 */
174 uint32_t _pad3; /* make it 64 byte aligned */
175} __attribute__((__packed__));
176
177struct blkif_x86_64_request {
178 uint8_t operation; /* BLKIF_OP_??? */
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
187DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
188 struct blkif_response);
189DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
190 struct blkif_response __packed);
191DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
192 struct blkif_response);
193
194union 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
201enum blkif_protocol {
202 BLKIF_PROTOCOL_NATIVE = 1,
203 BLKIF_PROTOCOL_X86_32 = 2,
204 BLKIF_PROTOCOL_X86_64 = 3,
205};
206
207/*
208 * Default protocol if the frontend doesn't specify one.
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
216struct xen_vbd {
217 /* What the domain refers to this vbd as. */
218 blkif_vdev_t handle;
219 /* Non-zero -> read-only */
220 unsigned char readonly;
221 /* VDISK_xxx */
222 unsigned char type;
223 /* phys device that this vbd maps to. */
224 u32 pdevice;
225 struct block_device *bdev;
226 /* Cached size parameter. */
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
234struct backend_info;
235
236/* Number of requests that we can fit in a ring */
237#define XEN_BLKIF_REQS_PER_PAGE 32
238
239struct 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/* Per-ring information. */
250struct xen_blkif_ring {
251 /* Physical parameters of the comms window. */
252 unsigned int irq;
253 union blkif_back_rings blk_rings;
254 void *blk_ring;
255 /* Private fields. */
256 spinlock_t blk_ring_lock;
257
258 wait_queue_head_t wq;
259 atomic_t inflight;
260 bool active;
261 /* One thread per blkif ring. */
262 struct task_struct *xenblkd;
263 unsigned int waiting_reqs;
264
265 /* List of all 'pending_req' available */
266 struct list_head pending_free;
267 /* And its spinlock. */
268 spinlock_t pending_free_lock;
269 wait_queue_head_t pending_free_wq;
270
271 /* Tree to store persistent grants. */
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 /* Statistics. */
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 /* Used by the kworker that offload work from the persistent purge. */
288 struct list_head persistent_purge_list;
289 struct work_struct persistent_purge_work;
290
291 /* Buffer of free pages to map grant refs. */
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 /* Thread shutdown wait queue. */
298 wait_queue_head_t shutdown_wq;
299 struct xen_blkif *blkif;
300};
301
302struct xen_blkif {
303 /* Unique identifier for this interface. */
304 domid_t domid;
305 unsigned int handle;
306 /* Comms information. */
307 enum blkif_protocol blk_protocol;
308 /* The VBD attached to this interface. */
309 struct xen_vbd vbd;
310 /* Back pointer to the backend_info. */
311 struct backend_info *be;
312 atomic_t refcnt;
313 /* for barrier (drain) requests */
314 struct completion drain_complete;
315 atomic_t drain;
316
317 struct work_struct free_work;
318 unsigned int nr_ring_pages;
319 /* All rings for this device. */
320 struct xen_blkif_ring *rings;
321 unsigned int nr_rings;
322};
323
324struct seg_buf {
325 unsigned long offset;
326 unsigned int nsec;
327};
328
329struct grant_page {
330 struct page *page;
331 struct persistent_gnt *persistent_gnt;
332 grant_handle_t handle;
333 grant_ref_t gref;
334};
335
336/*
337 * Each outstanding request that we've passed to the lower device layers has a
338 * 'pending_req' allocated to it. Each buffer_head that completes decrements
339 * the pendcnt towards zero. When it hits zero, the specified domain has a
340 * response queued for it, with the saved 'id' passed back.
341 */
342struct 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 /* Indirect descriptors */
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
372struct phys_req {
373 unsigned short dev;
374 blkif_sector_t nr_sects;
375 struct block_device *bdev;
376 blkif_sector_t sector_number;
377};
378int xen_blkif_interface_init(void);
379
380int xen_blkif_xenbus_init(void);
381
382irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
383int xen_blkif_schedule(void *arg);
384int xen_blkif_purge_persistent(void *arg);
385void xen_blkbk_free_caches(struct xen_blkif_ring *ring);
386
387int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
388 struct backend_info *be, int state);
389
390int xen_blkbk_barrier(struct xenbus_transaction xbt,
391 struct backend_info *be, int state);
392struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
393void xen_blkbk_unmap_purged_grants(struct work_struct *work);
394
395static 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 * Don't know how to translate this op. Only get the
436 * ID so failure can be reported to the frontend.
437 */
438 dst->u.other.id = src->u.other.id;
439 break;
440 }
441}
442
443static 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 * Don't know how to translate this op. Only get the
484 * ID so failure can be reported to the frontend.
485 */
486 dst->u.other.id = src->u.other.id;
487 break;
488 }
489}
490
491#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */