xref: /linux/include/linux/blk-mq.h (revision a13d7201d7deedcbb6ac6efa94a1a7d34d3d79ec)
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 typedef void (busy_tag_iter_fn)(struct request *, void *, bool);
100 
101 struct blk_mq_ops {
102 	/*
103 	 * Queue request
104 	 */
105 	queue_rq_fn		*queue_rq;
106 
107 	/*
108 	 * Map to specific hardware queue
109 	 */
110 	map_queue_fn		*map_queue;
111 
112 	/*
113 	 * Called on request timeout
114 	 */
115 	timeout_fn		*timeout;
116 
117 	softirq_done_fn		*complete;
118 
119 	/*
120 	 * Called when the block layer side of a hardware queue has been
121 	 * set up, allowing the driver to allocate/init matching structures.
122 	 * Ditto for exit/teardown.
123 	 */
124 	init_hctx_fn		*init_hctx;
125 	exit_hctx_fn		*exit_hctx;
126 
127 	/*
128 	 * Called for every command allocated by the block layer to allow
129 	 * the driver to set up driver specific data.
130 	 *
131 	 * Tag greater than or equal to queue_depth is for setting up
132 	 * flush request.
133 	 *
134 	 * Ditto for exit/teardown.
135 	 */
136 	init_request_fn		*init_request;
137 	exit_request_fn		*exit_request;
138 };
139 
140 enum {
141 	BLK_MQ_RQ_QUEUE_OK	= 0,	/* queued fine */
142 	BLK_MQ_RQ_QUEUE_BUSY	= 1,	/* requeue IO for later */
143 	BLK_MQ_RQ_QUEUE_ERROR	= 2,	/* end IO with error */
144 
145 	BLK_MQ_F_SHOULD_MERGE	= 1 << 0,
146 	BLK_MQ_F_TAG_SHARED	= 1 << 1,
147 	BLK_MQ_F_SG_MERGE	= 1 << 2,
148 	BLK_MQ_F_SYSFS_UP	= 1 << 3,
149 	BLK_MQ_F_DEFER_ISSUE	= 1 << 4,
150 	BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
151 	BLK_MQ_F_ALLOC_POLICY_BITS = 1,
152 
153 	BLK_MQ_S_STOPPED	= 0,
154 	BLK_MQ_S_TAG_ACTIVE	= 1,
155 
156 	BLK_MQ_MAX_DEPTH	= 10240,
157 
158 	BLK_MQ_CPU_WORK_BATCH	= 8,
159 };
160 #define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
161 	((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
162 		((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
163 #define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
164 	((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
165 		<< BLK_MQ_F_ALLOC_POLICY_START_BIT)
166 
167 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
168 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
169 						  struct request_queue *q);
170 void blk_mq_finish_init(struct request_queue *q);
171 int blk_mq_register_disk(struct gendisk *);
172 void blk_mq_unregister_disk(struct gendisk *);
173 
174 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
175 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
176 
177 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
178 
179 void blk_mq_insert_request(struct request *, bool, bool, bool);
180 void blk_mq_free_request(struct request *rq);
181 void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *, struct request *rq);
182 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
183 struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
184 		gfp_t gfp, bool reserved);
185 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
186 struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags);
187 
188 enum {
189 	BLK_MQ_UNIQUE_TAG_BITS = 16,
190 	BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
191 };
192 
193 u32 blk_mq_unique_tag(struct request *rq);
194 
195 static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
196 {
197 	return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
198 }
199 
200 static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
201 {
202 	return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
203 }
204 
205 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
206 struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
207 
208 int blk_mq_request_started(struct request *rq);
209 void blk_mq_start_request(struct request *rq);
210 void blk_mq_end_request(struct request *rq, int error);
211 void __blk_mq_end_request(struct request *rq, int error);
212 
213 void blk_mq_requeue_request(struct request *rq);
214 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
215 void blk_mq_cancel_requeue_work(struct request_queue *q);
216 void blk_mq_kick_requeue_list(struct request_queue *q);
217 void blk_mq_abort_requeue_list(struct request_queue *q);
218 void blk_mq_complete_request(struct request *rq);
219 
220 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
221 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
222 void blk_mq_stop_hw_queues(struct request_queue *q);
223 void blk_mq_start_hw_queues(struct request_queue *q);
224 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
225 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
226 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
227 void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
228 		void *priv);
229 void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
230 		void *priv);
231 void blk_mq_freeze_queue(struct request_queue *q);
232 void blk_mq_unfreeze_queue(struct request_queue *q);
233 void blk_mq_freeze_queue_start(struct request_queue *q);
234 
235 /*
236  * Driver command data is immediately after the request. So subtract request
237  * size to get back to the original request, add request size to get the PDU.
238  */
239 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
240 {
241 	return pdu - sizeof(struct request);
242 }
243 static inline void *blk_mq_rq_to_pdu(struct request *rq)
244 {
245 	return rq + 1;
246 }
247 
248 #define queue_for_each_hw_ctx(q, hctx, i)				\
249 	for ((i) = 0; (i) < (q)->nr_hw_queues &&			\
250 	     ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
251 
252 #define queue_for_each_ctx(q, ctx, i)					\
253 	for ((i) = 0; (i) < (q)->nr_queues &&				\
254 	     ({ ctx = per_cpu_ptr((q)->queue_ctx, (i)); 1; }); (i)++)
255 
256 #define hctx_for_each_ctx(hctx, ctx, i)					\
257 	for ((i) = 0; (i) < (hctx)->nr_ctx &&				\
258 	     ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
259 
260 #define blk_ctx_sum(q, sum)						\
261 ({									\
262 	struct blk_mq_ctx *__x;						\
263 	unsigned int __ret = 0, __i;					\
264 									\
265 	queue_for_each_ctx((q), __x, __i)				\
266 		__ret += sum;						\
267 	__ret;								\
268 })
269 
270 #endif
271