xref: /linux/block/blk-mq.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9) 
1 #ifndef INT_BLK_MQ_H
2 #define INT_BLK_MQ_H
3 
4 #include "blk-stat.h"
5 
6 struct blk_mq_tag_set;
7 
8 struct blk_mq_ctx {
9 	struct {
10 		spinlock_t		lock;
11 		struct list_head	rq_list;
12 	}  ____cacheline_aligned_in_smp;
13 
14 	unsigned int		cpu;
15 	unsigned int		index_hw;
16 
17 	/* incremented at dispatch time */
18 	unsigned long		rq_dispatched[2];
19 	unsigned long		rq_merged;
20 
21 	/* incremented at completion time */
22 	unsigned long		____cacheline_aligned_in_smp rq_completed[2];
23 	struct blk_rq_stat	stat[2];
24 
25 	struct request_queue	*queue;
26 	struct kobject		kobj;
27 } ____cacheline_aligned_in_smp;
28 
29 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
30 void blk_mq_freeze_queue(struct request_queue *q);
31 void blk_mq_free_queue(struct request_queue *q);
32 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
33 void blk_mq_wake_waiters(struct request_queue *q);
34 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *);
35 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
36 bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx);
37 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
38 				bool wait);
39 
40 /*
41  * Internal helpers for allocating/freeing the request map
42  */
43 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
44 		     unsigned int hctx_idx);
45 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
46 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
47 					unsigned int hctx_idx,
48 					unsigned int nr_tags,
49 					unsigned int reserved_tags);
50 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
51 		     unsigned int hctx_idx, unsigned int depth);
52 
53 /*
54  * Internal helpers for request insertion into sw queues
55  */
56 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
57 				bool at_head);
58 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
59 				struct list_head *list);
60 /*
61  * CPU hotplug helpers
62  */
63 void blk_mq_enable_hotplug(void);
64 void blk_mq_disable_hotplug(void);
65 
66 /*
67  * CPU -> queue mappings
68  */
69 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
70 
71 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
72 		int cpu)
73 {
74 	return q->queue_hw_ctx[q->mq_map[cpu]];
75 }
76 
77 /*
78  * sysfs helpers
79  */
80 extern void blk_mq_sysfs_init(struct request_queue *q);
81 extern void blk_mq_sysfs_deinit(struct request_queue *q);
82 extern int blk_mq_sysfs_register(struct request_queue *q);
83 extern void blk_mq_sysfs_unregister(struct request_queue *q);
84 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
85 
86 /*
87  * debugfs helpers
88  */
89 #ifdef CONFIG_BLK_DEBUG_FS
90 int blk_mq_debugfs_register(struct request_queue *q, const char *name);
91 void blk_mq_debugfs_unregister(struct request_queue *q);
92 int blk_mq_debugfs_register_hctxs(struct request_queue *q);
93 void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);
94 #else
95 static inline int blk_mq_debugfs_register(struct request_queue *q,
96 					  const char *name)
97 {
98 	return 0;
99 }
100 
101 static inline void blk_mq_debugfs_unregister(struct request_queue *q)
102 {
103 }
104 
105 static inline int blk_mq_debugfs_register_hctxs(struct request_queue *q)
106 {
107 	return 0;
108 }
109 
110 static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
111 {
112 }
113 #endif
114 
115 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
116 
117 void blk_mq_release(struct request_queue *q);
118 
119 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
120 					   unsigned int cpu)
121 {
122 	return per_cpu_ptr(q->queue_ctx, cpu);
123 }
124 
125 /*
126  * This assumes per-cpu software queueing queues. They could be per-node
127  * as well, for instance. For now this is hardcoded as-is. Note that we don't
128  * care about preemption, since we know the ctx's are persistent. This does
129  * mean that we can't rely on ctx always matching the currently running CPU.
130  */
131 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
132 {
133 	return __blk_mq_get_ctx(q, get_cpu());
134 }
135 
136 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
137 {
138 	put_cpu();
139 }
140 
141 struct blk_mq_alloc_data {
142 	/* input parameter */
143 	struct request_queue *q;
144 	unsigned int flags;
145 
146 	/* input & output parameter */
147 	struct blk_mq_ctx *ctx;
148 	struct blk_mq_hw_ctx *hctx;
149 };
150 
151 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
152 {
153 	if (data->flags & BLK_MQ_REQ_INTERNAL)
154 		return data->hctx->sched_tags;
155 
156 	return data->hctx->tags;
157 }
158 
159 /*
160  * Internal helpers for request allocation/init/free
161  */
162 void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
163 			struct request *rq, unsigned int op);
164 void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
165 				struct request *rq);
166 void blk_mq_finish_request(struct request *rq);
167 struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
168 					unsigned int op);
169 
170 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
171 {
172 	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
173 }
174 
175 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
176 {
177 	return hctx->nr_ctx && hctx->tags;
178 }
179 
180 #endif
181