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4d05a28d KRW |
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 | ||
5a577e38 KRW |
27 | #ifndef __XEN_BLKIF__BACKEND__COMMON_H__ |
28 | #define __XEN_BLKIF__BACKEND__COMMON_H__ | |
4d05a28d | 29 | |
4d05a28d KRW |
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> | |
5489377c | 36 | #include <linux/io.h> |
4d05a28d KRW |
37 | #include <asm/setup.h> |
38 | #include <asm/pgalloc.h> | |
4d05a28d | 39 | #include <asm/hypervisor.h> |
88122933 | 40 | #include <xen/grant_table.h> |
4d05a28d | 41 | #include <xen/xenbus.h> |
452a6b2b KRW |
42 | #include <xen/interface/io/ring.h> |
43 | #include <xen/interface/io/blkif.h> | |
44 | #include <xen/interface/io/protocols.h> | |
4d05a28d | 45 | |
22b20f2d | 46 | #define DRV_PFX "xen-blkback:" |
1afbd730 | 47 | #define DPRINTK(fmt, args...) \ |
1bc05b0a | 48 | pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \ |
1afbd730 | 49 | __func__, __LINE__, ##args) |
4d05a28d | 50 | |
452a6b2b KRW |
51 | |
52 | /* Not a real protocol. Used to generate ring structs which contain | |
53 | * the elements common to all protocols only. This way we get a | |
54 | * compiler-checkable way to use common struct elements, so we can | |
55 | * avoid using switch(protocol) in a number of places. */ | |
56 | struct blkif_common_request { | |
57 | char dummy; | |
58 | }; | |
59 | struct blkif_common_response { | |
60 | char dummy; | |
61 | }; | |
62 | ||
b3cb0d6a | 63 | struct blkif_x86_32_request_rw { |
97e36834 KRW |
64 | uint8_t nr_segments; /* number of segments */ |
65 | blkif_vdev_t handle; /* only for read/write requests */ | |
66 | uint64_t id; /* private guest value, echoed in resp */ | |
b3cb0d6a LD |
67 | blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ |
68 | struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; | |
97e36834 | 69 | } __attribute__((__packed__)); |
b3cb0d6a LD |
70 | |
71 | struct blkif_x86_32_request_discard { | |
5ea42986 | 72 | uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */ |
97e36834 KRW |
73 | blkif_vdev_t _pad1; /* was "handle" for read/write requests */ |
74 | uint64_t id; /* private guest value, echoed in resp */ | |
b3cb0d6a | 75 | blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ |
97e36834 KRW |
76 | uint64_t nr_sectors; |
77 | } __attribute__((__packed__)); | |
b3cb0d6a | 78 | |
452a6b2b KRW |
79 | struct blkif_x86_32_request { |
80 | uint8_t operation; /* BLKIF_OP_??? */ | |
b3cb0d6a LD |
81 | union { |
82 | struct blkif_x86_32_request_rw rw; | |
83 | struct blkif_x86_32_request_discard discard; | |
84 | } u; | |
97e36834 KRW |
85 | } __attribute__((__packed__)); |
86 | ||
87 | /* i386 protocol version */ | |
88 | #pragma pack(push, 4) | |
452a6b2b KRW |
89 | struct blkif_x86_32_response { |
90 | uint64_t id; /* copied from request */ | |
91 | uint8_t operation; /* copied from request */ | |
92 | int16_t status; /* BLKIF_RSP_??? */ | |
93 | }; | |
452a6b2b | 94 | #pragma pack(pop) |
452a6b2b | 95 | /* x86_64 protocol version */ |
b3cb0d6a LD |
96 | |
97 | struct blkif_x86_64_request_rw { | |
97e36834 KRW |
98 | uint8_t nr_segments; /* number of segments */ |
99 | blkif_vdev_t handle; /* only for read/write requests */ | |
100 | uint32_t _pad1; /* offsetof(blkif_reqest..,u.rw.id)==8 */ | |
101 | uint64_t id; | |
b3cb0d6a LD |
102 | blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ |
103 | struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; | |
97e36834 | 104 | } __attribute__((__packed__)); |
b3cb0d6a LD |
105 | |
106 | struct blkif_x86_64_request_discard { | |
5ea42986 | 107 | uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */ |
97e36834 KRW |
108 | blkif_vdev_t _pad1; /* was "handle" for read/write requests */ |
109 | uint32_t _pad2; /* offsetof(blkif_..,u.discard.id)==8 */ | |
110 | uint64_t id; | |
b3cb0d6a | 111 | blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */ |
97e36834 KRW |
112 | uint64_t nr_sectors; |
113 | } __attribute__((__packed__)); | |
b3cb0d6a | 114 | |
452a6b2b KRW |
115 | struct blkif_x86_64_request { |
116 | uint8_t operation; /* BLKIF_OP_??? */ | |
b3cb0d6a LD |
117 | union { |
118 | struct blkif_x86_64_request_rw rw; | |
119 | struct blkif_x86_64_request_discard discard; | |
120 | } u; | |
97e36834 KRW |
121 | } __attribute__((__packed__)); |
122 | ||
452a6b2b KRW |
123 | struct blkif_x86_64_response { |
124 | uint64_t __attribute__((__aligned__(8))) id; | |
125 | uint8_t operation; /* copied from request */ | |
126 | int16_t status; /* BLKIF_RSP_??? */ | |
127 | }; | |
452a6b2b KRW |
128 | |
129 | DEFINE_RING_TYPES(blkif_common, struct blkif_common_request, | |
130 | struct blkif_common_response); | |
131 | DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request, | |
132 | struct blkif_x86_32_response); | |
133 | DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request, | |
134 | struct blkif_x86_64_response); | |
135 | ||
136 | union blkif_back_rings { | |
137 | struct blkif_back_ring native; | |
138 | struct blkif_common_back_ring common; | |
139 | struct blkif_x86_32_back_ring x86_32; | |
140 | struct blkif_x86_64_back_ring x86_64; | |
141 | }; | |
142 | ||
143 | enum blkif_protocol { | |
144 | BLKIF_PROTOCOL_NATIVE = 1, | |
145 | BLKIF_PROTOCOL_X86_32 = 2, | |
146 | BLKIF_PROTOCOL_X86_64 = 3, | |
147 | }; | |
148 | ||
3d814731 | 149 | struct xen_vbd { |
01f37f2d KRW |
150 | /* What the domain refers to this vbd as. */ |
151 | blkif_vdev_t handle; | |
152 | /* Non-zero -> read-only */ | |
153 | unsigned char readonly; | |
154 | /* VDISK_xxx */ | |
155 | unsigned char type; | |
156 | /* phys device that this vbd maps to. */ | |
157 | u32 pdevice; | |
158 | struct block_device *bdev; | |
159 | /* Cached size parameter. */ | |
160 | sector_t size; | |
161 | bool flush_support; | |
5ea42986 | 162 | bool discard_secure; |
4d05a28d KRW |
163 | }; |
164 | ||
165 | struct backend_info; | |
166 | ||
30fd1502 | 167 | struct xen_blkif { |
4d05a28d | 168 | /* Unique identifier for this interface. */ |
01f37f2d KRW |
169 | domid_t domid; |
170 | unsigned int handle; | |
4d05a28d | 171 | /* Physical parameters of the comms window. */ |
01f37f2d | 172 | unsigned int irq; |
4d05a28d | 173 | /* Comms information. */ |
01f37f2d KRW |
174 | enum blkif_protocol blk_protocol; |
175 | union blkif_back_rings blk_rings; | |
2d073846 | 176 | void *blk_ring; |
4d05a28d | 177 | /* The VBD attached to this interface. */ |
3d814731 | 178 | struct xen_vbd vbd; |
4d05a28d | 179 | /* Back pointer to the backend_info. */ |
01f37f2d | 180 | struct backend_info *be; |
4d05a28d | 181 | /* Private fields. */ |
01f37f2d KRW |
182 | spinlock_t blk_ring_lock; |
183 | atomic_t refcnt; | |
4d05a28d | 184 | |
01f37f2d | 185 | wait_queue_head_t wq; |
29bde093 KRW |
186 | /* for barrier (drain) requests */ |
187 | struct completion drain_complete; | |
188 | atomic_t drain; | |
a1397fa3 | 189 | /* One thread per one blkif. */ |
01f37f2d KRW |
190 | struct task_struct *xenblkd; |
191 | unsigned int waiting_reqs; | |
4d05a28d KRW |
192 | |
193 | /* statistics */ | |
01f37f2d KRW |
194 | unsigned long st_print; |
195 | int st_rd_req; | |
196 | int st_wr_req; | |
197 | int st_oo_req; | |
198 | int st_f_req; | |
b3cb0d6a | 199 | int st_ds_req; |
01f37f2d KRW |
200 | int st_rd_sect; |
201 | int st_wr_sect; | |
202 | ||
203 | wait_queue_head_t waiting_to_free; | |
5489377c | 204 | }; |
4d05a28d | 205 | |
42c7841d KRW |
206 | |
207 | #define vbd_sz(_v) ((_v)->bdev->bd_part ? \ | |
208 | (_v)->bdev->bd_part->nr_sects : \ | |
209 | get_capacity((_v)->bdev->bd_disk)) | |
4d05a28d | 210 | |
8b6bf747 KRW |
211 | #define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt)) |
212 | #define xen_blkif_put(_b) \ | |
4d05a28d KRW |
213 | do { \ |
214 | if (atomic_dec_and_test(&(_b)->refcnt)) \ | |
215 | wake_up(&(_b)->waiting_to_free);\ | |
216 | } while (0) | |
217 | ||
4d05a28d | 218 | struct phys_req { |
01f37f2d | 219 | unsigned short dev; |
b3cb0d6a | 220 | blkif_sector_t nr_sects; |
01f37f2d KRW |
221 | struct block_device *bdev; |
222 | blkif_sector_t sector_number; | |
4d05a28d | 223 | }; |
8b6bf747 | 224 | int xen_blkif_interface_init(void); |
4d05a28d | 225 | |
8b6bf747 | 226 | int xen_blkif_xenbus_init(void); |
4d05a28d | 227 | |
8b6bf747 KRW |
228 | irqreturn_t xen_blkif_be_int(int irq, void *dev_id); |
229 | int xen_blkif_schedule(void *arg); | |
4d05a28d | 230 | |
24f567f9 KRW |
231 | int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt, |
232 | struct backend_info *be, int state); | |
4d05a28d | 233 | |
29bde093 KRW |
234 | int xen_blkbk_barrier(struct xenbus_transaction xbt, |
235 | struct backend_info *be, int state); | |
8b6bf747 | 236 | struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be); |
98e036a3 | 237 | |
b0f80127 | 238 | static inline void blkif_get_x86_32_req(struct blkif_request *dst, |
68c88dd7 KRW |
239 | struct blkif_x86_32_request *src) |
240 | { | |
241 | int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
242 | dst->operation = src->operation; | |
b3cb0d6a LD |
243 | switch (src->operation) { |
244 | case BLKIF_OP_READ: | |
245 | case BLKIF_OP_WRITE: | |
246 | case BLKIF_OP_WRITE_BARRIER: | |
247 | case BLKIF_OP_FLUSH_DISKCACHE: | |
97e36834 KRW |
248 | dst->u.rw.nr_segments = src->u.rw.nr_segments; |
249 | dst->u.rw.handle = src->u.rw.handle; | |
250 | dst->u.rw.id = src->u.rw.id; | |
b3cb0d6a LD |
251 | dst->u.rw.sector_number = src->u.rw.sector_number; |
252 | barrier(); | |
97e36834 KRW |
253 | if (n > dst->u.rw.nr_segments) |
254 | n = dst->u.rw.nr_segments; | |
b3cb0d6a LD |
255 | for (i = 0; i < n; i++) |
256 | dst->u.rw.seg[i] = src->u.rw.seg[i]; | |
257 | break; | |
258 | case BLKIF_OP_DISCARD: | |
5ea42986 | 259 | dst->u.discard.flag = src->u.discard.flag; |
8c9ce606 | 260 | dst->u.discard.id = src->u.discard.id; |
b3cb0d6a LD |
261 | dst->u.discard.sector_number = src->u.discard.sector_number; |
262 | dst->u.discard.nr_sectors = src->u.discard.nr_sectors; | |
263 | break; | |
264 | default: | |
265 | break; | |
266 | } | |
68c88dd7 KRW |
267 | } |
268 | ||
b0f80127 | 269 | static inline void blkif_get_x86_64_req(struct blkif_request *dst, |
68c88dd7 KRW |
270 | struct blkif_x86_64_request *src) |
271 | { | |
272 | int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
273 | dst->operation = src->operation; | |
b3cb0d6a LD |
274 | switch (src->operation) { |
275 | case BLKIF_OP_READ: | |
276 | case BLKIF_OP_WRITE: | |
277 | case BLKIF_OP_WRITE_BARRIER: | |
278 | case BLKIF_OP_FLUSH_DISKCACHE: | |
97e36834 KRW |
279 | dst->u.rw.nr_segments = src->u.rw.nr_segments; |
280 | dst->u.rw.handle = src->u.rw.handle; | |
281 | dst->u.rw.id = src->u.rw.id; | |
b3cb0d6a LD |
282 | dst->u.rw.sector_number = src->u.rw.sector_number; |
283 | barrier(); | |
97e36834 KRW |
284 | if (n > dst->u.rw.nr_segments) |
285 | n = dst->u.rw.nr_segments; | |
b3cb0d6a LD |
286 | for (i = 0; i < n; i++) |
287 | dst->u.rw.seg[i] = src->u.rw.seg[i]; | |
288 | break; | |
289 | case BLKIF_OP_DISCARD: | |
5ea42986 | 290 | dst->u.discard.flag = src->u.discard.flag; |
8c9ce606 | 291 | dst->u.discard.id = src->u.discard.id; |
b3cb0d6a LD |
292 | dst->u.discard.sector_number = src->u.discard.sector_number; |
293 | dst->u.discard.nr_sectors = src->u.discard.nr_sectors; | |
294 | break; | |
295 | default: | |
296 | break; | |
297 | } | |
68c88dd7 KRW |
298 | } |
299 | ||
5a577e38 | 300 | #endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */ |