blk-mq: abstract tag allocation out into sbitmap library
[linux-2.6-block.git] / include / linux / blk-mq.h
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1#ifndef BLK_MQ_H
2#define BLK_MQ_H
3
4#include <linux/blkdev.h>
88459642 5#include <linux/sbitmap.h>
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6
7struct blk_mq_tags;
f70ced09 8struct blk_flush_queue;
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9
10struct blk_mq_cpu_notifier {
11 struct list_head list;
12 void *data;
e814e71b 13 int (*notify)(void *data, unsigned long action, unsigned int cpu);
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14};
15
16struct blk_mq_hw_ctx {
17 struct {
18 spinlock_t lock;
19 struct list_head dispatch;
8d354f13 20 unsigned long state; /* BLK_MQ_S_* flags */
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21 } ____cacheline_aligned_in_smp;
22
27489a3c 23 struct work_struct run_work;
e4043dcf 24 cpumask_var_t cpumask;
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25 int next_cpu;
26 int next_cpu_batch;
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27
28 unsigned long flags; /* BLK_MQ_F_* flags */
29
30 struct request_queue *queue;
f70ced09 31 struct blk_flush_queue *fq;
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32
33 void *driver_data;
34
88459642 35 struct sbitmap ctx_map;
1429d7c9 36
4bb659b1 37 struct blk_mq_ctx **ctxs;
8d354f13 38 unsigned int nr_ctx;
4bb659b1 39
8537b120 40 atomic_t wait_index;
320ae51f 41
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42 struct blk_mq_tags *tags;
43
44 unsigned long queued;
45 unsigned long run;
8d354f13 46#define BLK_MQ_MAX_DISPATCH_ORDER 7
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47 unsigned long dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
48
320ae51f 49 unsigned int numa_node;
17ded320 50 unsigned int queue_num;
320ae51f 51
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52 atomic_t nr_active;
53
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54 struct delayed_work delay_work;
55
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56 struct blk_mq_cpu_notifier cpu_notifier;
57 struct kobject kobj;
05229bee 58
6e219353 59 unsigned long poll_considered;
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60 unsigned long poll_invoked;
61 unsigned long poll_success;
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62};
63
24d2f903 64struct blk_mq_tag_set {
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65 struct blk_mq_ops *ops;
66 unsigned int nr_hw_queues;
e3a2b3f9 67 unsigned int queue_depth; /* max hw supported */
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68 unsigned int reserved_tags;
69 unsigned int cmd_size; /* per-request extra data */
70 int numa_node;
71 unsigned int timeout;
72 unsigned int flags; /* BLK_MQ_F_* */
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73 void *driver_data;
74
75 struct blk_mq_tags **tags;
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76
77 struct mutex tag_list_lock;
78 struct list_head tag_list;
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79};
80
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81struct blk_mq_queue_data {
82 struct request *rq;
83 struct list_head *list;
84 bool last;
85};
86
87typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data *);
320ae51f 88typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int);
0152fb6b 89typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
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90typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
91typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
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92typedef int (init_request_fn)(void *, struct request *, unsigned int,
93 unsigned int, unsigned int);
94typedef void (exit_request_fn)(void *, struct request *, unsigned int,
95 unsigned int);
486cf989 96typedef int (reinit_request_fn)(void *, struct request *);
320ae51f 97
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98typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
99 bool);
f26cdc85 100typedef void (busy_tag_iter_fn)(struct request *, void *, bool);
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101typedef int (poll_fn)(struct blk_mq_hw_ctx *, unsigned int);
102
81481eb4 103
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104struct blk_mq_ops {
105 /*
106 * Queue request
107 */
108 queue_rq_fn *queue_rq;
109
110 /*
111 * Map to specific hardware queue
112 */
113 map_queue_fn *map_queue;
114
115 /*
116 * Called on request timeout
117 */
0152fb6b 118 timeout_fn *timeout;
320ae51f 119
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120 /*
121 * Called to poll for completion of a specific tag.
122 */
123 poll_fn *poll;
124
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125 softirq_done_fn *complete;
126
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127 /*
128 * Called when the block layer side of a hardware queue has been
129 * set up, allowing the driver to allocate/init matching structures.
130 * Ditto for exit/teardown.
131 */
132 init_hctx_fn *init_hctx;
133 exit_hctx_fn *exit_hctx;
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134
135 /*
136 * Called for every command allocated by the block layer to allow
137 * the driver to set up driver specific data.
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138 *
139 * Tag greater than or equal to queue_depth is for setting up
140 * flush request.
141 *
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142 * Ditto for exit/teardown.
143 */
144 init_request_fn *init_request;
145 exit_request_fn *exit_request;
486cf989 146 reinit_request_fn *reinit_request;
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147};
148
149enum {
150 BLK_MQ_RQ_QUEUE_OK = 0, /* queued fine */
151 BLK_MQ_RQ_QUEUE_BUSY = 1, /* requeue IO for later */
152 BLK_MQ_RQ_QUEUE_ERROR = 2, /* end IO with error */
153
154 BLK_MQ_F_SHOULD_MERGE = 1 << 0,
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155 BLK_MQ_F_TAG_SHARED = 1 << 1,
156 BLK_MQ_F_SG_MERGE = 1 << 2,
e167dfb5 157 BLK_MQ_F_DEFER_ISSUE = 1 << 4,
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158 BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
159 BLK_MQ_F_ALLOC_POLICY_BITS = 1,
320ae51f 160
5d12f905 161 BLK_MQ_S_STOPPED = 0,
0d2602ca 162 BLK_MQ_S_TAG_ACTIVE = 1,
320ae51f 163
a4391c64 164 BLK_MQ_MAX_DEPTH = 10240,
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165
166 BLK_MQ_CPU_WORK_BATCH = 8,
320ae51f 167};
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168#define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
169 ((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
170 ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
171#define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
172 ((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
173 << BLK_MQ_F_ALLOC_POLICY_START_BIT)
320ae51f 174
24d2f903 175struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
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176struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
177 struct request_queue *q);
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178int blk_mq_register_disk(struct gendisk *);
179void blk_mq_unregister_disk(struct gendisk *);
320ae51f 180
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181int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
182void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
183
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184void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
185
feb71dae 186void blk_mq_insert_request(struct request *, bool, bool, bool);
320ae51f 187void blk_mq_free_request(struct request *rq);
7c7f2f2b 188void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *, struct request *rq);
320ae51f 189bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
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190
191enum {
192 BLK_MQ_REQ_NOWAIT = (1 << 0), /* return when out of requests */
193 BLK_MQ_REQ_RESERVED = (1 << 1), /* allocate from reserved pool */
194};
195
4ce01dd1 196struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
6f3b0e8b 197 unsigned int flags);
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198struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int op,
199 unsigned int flags, unsigned int hctx_idx);
0e62f51f 200struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
f26cdc85 201struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags);
320ae51f 202
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203enum {
204 BLK_MQ_UNIQUE_TAG_BITS = 16,
205 BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
206};
207
208u32 blk_mq_unique_tag(struct request *rq);
209
210static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
211{
212 return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
213}
214
215static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
216{
217 return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
218}
219
320ae51f 220struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
320ae51f 221
973c0191 222int blk_mq_request_started(struct request *rq);
e2490073 223void blk_mq_start_request(struct request *rq);
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224void blk_mq_end_request(struct request *rq, int error);
225void __blk_mq_end_request(struct request *rq, int error);
320ae51f 226
ed0791b2 227void blk_mq_requeue_request(struct request *rq);
6fca6a61 228void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
c68ed59f 229void blk_mq_cancel_requeue_work(struct request_queue *q);
6fca6a61 230void blk_mq_kick_requeue_list(struct request_queue *q);
2849450a 231void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
1885b24d 232void blk_mq_abort_requeue_list(struct request_queue *q);
f4829a9b 233void blk_mq_complete_request(struct request *rq, int error);
30a91cb4 234
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235void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
236void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
280d45f6 237void blk_mq_stop_hw_queues(struct request_queue *q);
2f268556 238void blk_mq_start_hw_queues(struct request_queue *q);
1b4a3258 239void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
b94ec296 240void blk_mq_run_hw_queues(struct request_queue *q, bool async);
70f4db63 241void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
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242void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
243 busy_tag_iter_fn *fn, void *priv);
c761d96b 244void blk_mq_freeze_queue(struct request_queue *q);
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245void blk_mq_unfreeze_queue(struct request_queue *q);
246void blk_mq_freeze_queue_start(struct request_queue *q);
486cf989 247int blk_mq_reinit_tagset(struct blk_mq_tag_set *set);
320ae51f 248
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249void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
250
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251/*
252 * Driver command data is immediately after the request. So subtract request
2963e3f7 253 * size to get back to the original request, add request size to get the PDU.
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254 */
255static inline struct request *blk_mq_rq_from_pdu(void *pdu)
256{
257 return pdu - sizeof(struct request);
258}
259static inline void *blk_mq_rq_to_pdu(struct request *rq)
260{
2963e3f7 261 return rq + 1;
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262}
263
320ae51f 264#define queue_for_each_hw_ctx(q, hctx, i) \
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265 for ((i) = 0; (i) < (q)->nr_hw_queues && \
266 ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
320ae51f 267
320ae51f 268#define hctx_for_each_ctx(hctx, ctx, i) \
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269 for ((i) = 0; (i) < (hctx)->nr_ctx && \
270 ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
320ae51f 271
320ae51f 272#endif