xref: /linux-6.15/include/linux/blk-mq.h (revision 02bdf9da)
1 #ifndef BLK_MQ_H
2 #define BLK_MQ_H
3 
4 #include <linux/blkdev.h>
5 #include <linux/sbitmap.h>
6 #include <linux/srcu.h>
7 
8 struct blk_mq_tags;
9 struct blk_flush_queue;
10 
11 struct blk_mq_hw_ctx {
12 	struct {
13 		spinlock_t		lock;
14 		struct list_head	dispatch;
15 		unsigned long		state;		/* BLK_MQ_S_* flags */
16 	} ____cacheline_aligned_in_smp;
17 
18 	struct delayed_work	run_work;
19 	cpumask_var_t		cpumask;
20 	int			next_cpu;
21 	int			next_cpu_batch;
22 
23 	unsigned long		flags;		/* BLK_MQ_F_* flags */
24 
25 	void			*sched_data;
26 	struct request_queue	*queue;
27 	struct blk_flush_queue	*fq;
28 
29 	void			*driver_data;
30 
31 	struct sbitmap		ctx_map;
32 
33 	struct blk_mq_ctx	**ctxs;
34 	unsigned int		nr_ctx;
35 
36 	wait_queue_entry_t		dispatch_wait;
37 	atomic_t		wait_index;
38 
39 	struct blk_mq_tags	*tags;
40 	struct blk_mq_tags	*sched_tags;
41 
42 	unsigned long		queued;
43 	unsigned long		run;
44 #define BLK_MQ_MAX_DISPATCH_ORDER	7
45 	unsigned long		dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
46 
47 	unsigned int		numa_node;
48 	unsigned int		queue_num;
49 
50 	atomic_t		nr_active;
51 
52 	struct hlist_node	cpuhp_dead;
53 	struct kobject		kobj;
54 
55 	unsigned long		poll_considered;
56 	unsigned long		poll_invoked;
57 	unsigned long		poll_success;
58 
59 #ifdef CONFIG_BLK_DEBUG_FS
60 	struct dentry		*debugfs_dir;
61 	struct dentry		*sched_debugfs_dir;
62 #endif
63 
64 	/* Must be the last member - see also blk_mq_hw_ctx_size(). */
65 	struct srcu_struct	queue_rq_srcu[0];
66 };
67 
68 struct blk_mq_tag_set {
69 	unsigned int		*mq_map;
70 	const struct blk_mq_ops	*ops;
71 	unsigned int		nr_hw_queues;
72 	unsigned int		queue_depth;	/* max hw supported */
73 	unsigned int		reserved_tags;
74 	unsigned int		cmd_size;	/* per-request extra data */
75 	int			numa_node;
76 	unsigned int		timeout;
77 	unsigned int		flags;		/* BLK_MQ_F_* */
78 	void			*driver_data;
79 
80 	struct blk_mq_tags	**tags;
81 
82 	struct mutex		tag_list_lock;
83 	struct list_head	tag_list;
84 };
85 
86 struct blk_mq_queue_data {
87 	struct request *rq;
88 	bool last;
89 };
90 
91 typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *,
92 		const struct blk_mq_queue_data *);
93 typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool);
94 typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int);
95 typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int);
96 typedef int (init_request_fn)(struct blk_mq_tag_set *set, struct request *,
97 		unsigned int, unsigned int);
98 typedef void (exit_request_fn)(struct blk_mq_tag_set *set, struct request *,
99 		unsigned int);
100 typedef int (reinit_request_fn)(void *, struct request *);
101 
102 typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
103 		bool);
104 typedef void (busy_tag_iter_fn)(struct request *, void *, bool);
105 typedef int (poll_fn)(struct blk_mq_hw_ctx *, unsigned int);
106 typedef int (map_queues_fn)(struct blk_mq_tag_set *set);
107 
108 
109 struct blk_mq_ops {
110 	/*
111 	 * Queue request
112 	 */
113 	queue_rq_fn		*queue_rq;
114 
115 	/*
116 	 * Called on request timeout
117 	 */
118 	timeout_fn		*timeout;
119 
120 	/*
121 	 * Called to poll for completion of a specific tag.
122 	 */
123 	poll_fn			*poll;
124 
125 	softirq_done_fn		*complete;
126 
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;
134 
135 	/*
136 	 * Called for every command allocated by the block layer to allow
137 	 * the driver to set up driver specific data.
138 	 *
139 	 * Tag greater than or equal to queue_depth is for setting up
140 	 * flush request.
141 	 *
142 	 * Ditto for exit/teardown.
143 	 */
144 	init_request_fn		*init_request;
145 	exit_request_fn		*exit_request;
146 	reinit_request_fn	*reinit_request;
147 	/* Called from inside blk_get_request() */
148 	void (*initialize_rq_fn)(struct request *rq);
149 
150 	map_queues_fn		*map_queues;
151 
152 #ifdef CONFIG_BLK_DEBUG_FS
153 	/*
154 	 * Used by the debugfs implementation to show driver-specific
155 	 * information about a request.
156 	 */
157 	void (*show_rq)(struct seq_file *m, struct request *rq);
158 #endif
159 };
160 
161 enum {
162 	BLK_MQ_F_SHOULD_MERGE	= 1 << 0,
163 	BLK_MQ_F_TAG_SHARED	= 1 << 1,
164 	BLK_MQ_F_SG_MERGE	= 1 << 2,
165 	BLK_MQ_F_BLOCKING	= 1 << 5,
166 	BLK_MQ_F_NO_SCHED	= 1 << 6,
167 	BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
168 	BLK_MQ_F_ALLOC_POLICY_BITS = 1,
169 
170 	BLK_MQ_S_STOPPED	= 0,
171 	BLK_MQ_S_TAG_ACTIVE	= 1,
172 	BLK_MQ_S_SCHED_RESTART	= 2,
173 	BLK_MQ_S_TAG_WAITING	= 3,
174 	BLK_MQ_S_START_ON_RUN	= 4,
175 
176 	BLK_MQ_MAX_DEPTH	= 10240,
177 
178 	BLK_MQ_CPU_WORK_BATCH	= 8,
179 };
180 #define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
181 	((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
182 		((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
183 #define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
184 	((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
185 		<< BLK_MQ_F_ALLOC_POLICY_START_BIT)
186 
187 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
188 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
189 						  struct request_queue *q);
190 int blk_mq_register_dev(struct device *, struct request_queue *);
191 void blk_mq_unregister_dev(struct device *, struct request_queue *);
192 
193 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
194 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
195 
196 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
197 
198 void blk_mq_free_request(struct request *rq);
199 bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
200 
201 enum {
202 	BLK_MQ_REQ_NOWAIT	= (1 << 0), /* return when out of requests */
203 	BLK_MQ_REQ_RESERVED	= (1 << 1), /* allocate from reserved pool */
204 	BLK_MQ_REQ_INTERNAL	= (1 << 2), /* allocate internal/sched tag */
205 };
206 
207 struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
208 		unsigned int flags);
209 struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
210 		unsigned int op, unsigned int flags, unsigned int hctx_idx);
211 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
212 
213 enum {
214 	BLK_MQ_UNIQUE_TAG_BITS = 16,
215 	BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
216 };
217 
218 u32 blk_mq_unique_tag(struct request *rq);
219 
220 static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
221 {
222 	return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
223 }
224 
225 static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
226 {
227 	return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
228 }
229 
230 
231 int blk_mq_request_started(struct request *rq);
232 void blk_mq_start_request(struct request *rq);
233 void blk_mq_end_request(struct request *rq, blk_status_t error);
234 void __blk_mq_end_request(struct request *rq, blk_status_t error);
235 
236 void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
237 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
238 				bool kick_requeue_list);
239 void blk_mq_kick_requeue_list(struct request_queue *q);
240 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
241 void blk_mq_complete_request(struct request *rq);
242 
243 bool blk_mq_queue_stopped(struct request_queue *q);
244 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
245 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
246 void blk_mq_stop_hw_queues(struct request_queue *q);
247 void blk_mq_start_hw_queues(struct request_queue *q);
248 void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
249 void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
250 void blk_mq_quiesce_queue(struct request_queue *q);
251 void blk_mq_unquiesce_queue(struct request_queue *q);
252 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
253 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
254 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
255 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
256 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
257 		busy_tag_iter_fn *fn, void *priv);
258 void blk_mq_freeze_queue(struct request_queue *q);
259 void blk_mq_unfreeze_queue(struct request_queue *q);
260 void blk_freeze_queue_start(struct request_queue *q);
261 void blk_mq_freeze_queue_wait(struct request_queue *q);
262 int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
263 				     unsigned long timeout);
264 int blk_mq_reinit_tagset(struct blk_mq_tag_set *set);
265 
266 int blk_mq_map_queues(struct blk_mq_tag_set *set);
267 void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
268 
269 void blk_mq_quiesce_queue_nowait(struct request_queue *q);
270 
271 /*
272  * Driver command data is immediately after the request. So subtract request
273  * size to get back to the original request, add request size to get the PDU.
274  */
275 static inline struct request *blk_mq_rq_from_pdu(void *pdu)
276 {
277 	return pdu - sizeof(struct request);
278 }
279 static inline void *blk_mq_rq_to_pdu(struct request *rq)
280 {
281 	return rq + 1;
282 }
283 
284 #define queue_for_each_hw_ctx(q, hctx, i)				\
285 	for ((i) = 0; (i) < (q)->nr_hw_queues &&			\
286 	     ({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
287 
288 #define hctx_for_each_ctx(hctx, ctx, i)					\
289 	for ((i) = 0; (i) < (hctx)->nr_ctx &&				\
290 	     ({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
291 
292 #endif
293