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