xref: /openbmc/linux/block/blk-mq.h (revision 1c2dd16a)
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 
24 	struct request_queue	*queue;
25 	struct kobject		kobj;
26 } ____cacheline_aligned_in_smp;
27 
28 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
29 void blk_mq_freeze_queue(struct request_queue *q);
30 void blk_mq_free_queue(struct request_queue *q);
31 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
32 void blk_mq_wake_waiters(struct request_queue *q);
33 bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *);
34 void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
35 bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx);
36 bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
37 				bool wait);
38 
39 /*
40  * Internal helpers for allocating/freeing the request map
41  */
42 void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
43 		     unsigned int hctx_idx);
44 void blk_mq_free_rq_map(struct blk_mq_tags *tags);
45 struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
46 					unsigned int hctx_idx,
47 					unsigned int nr_tags,
48 					unsigned int reserved_tags);
49 int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
50 		     unsigned int hctx_idx, unsigned int depth);
51 
52 /*
53  * Internal helpers for request insertion into sw queues
54  */
55 void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
56 				bool at_head);
57 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
58 				struct list_head *list);
59 /*
60  * CPU hotplug helpers
61  */
62 void blk_mq_enable_hotplug(void);
63 void blk_mq_disable_hotplug(void);
64 
65 /*
66  * CPU -> queue mappings
67  */
68 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
69 
70 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
71 		int cpu)
72 {
73 	return q->queue_hw_ctx[q->mq_map[cpu]];
74 }
75 
76 /*
77  * sysfs helpers
78  */
79 extern void blk_mq_sysfs_init(struct request_queue *q);
80 extern void blk_mq_sysfs_deinit(struct request_queue *q);
81 extern int __blk_mq_register_dev(struct device *dev, 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);
91 void blk_mq_debugfs_unregister(struct request_queue *q);
92 int blk_mq_debugfs_register_mq(struct request_queue *q);
93 void blk_mq_debugfs_unregister_mq(struct request_queue *q);
94 #else
95 static inline int blk_mq_debugfs_register(struct request_queue *q)
96 {
97 	return 0;
98 }
99 
100 static inline void blk_mq_debugfs_unregister(struct request_queue *q)
101 {
102 }
103 
104 static inline int blk_mq_debugfs_register_mq(struct request_queue *q)
105 {
106 	return 0;
107 }
108 
109 static inline void blk_mq_debugfs_unregister_mq(struct request_queue *q)
110 {
111 }
112 #endif
113 
114 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
115 
116 void blk_mq_release(struct request_queue *q);
117 
118 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
119 					   unsigned int cpu)
120 {
121 	return per_cpu_ptr(q->queue_ctx, cpu);
122 }
123 
124 /*
125  * This assumes per-cpu software queueing queues. They could be per-node
126  * as well, for instance. For now this is hardcoded as-is. Note that we don't
127  * care about preemption, since we know the ctx's are persistent. This does
128  * mean that we can't rely on ctx always matching the currently running CPU.
129  */
130 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
131 {
132 	return __blk_mq_get_ctx(q, get_cpu());
133 }
134 
135 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
136 {
137 	put_cpu();
138 }
139 
140 struct blk_mq_alloc_data {
141 	/* input parameter */
142 	struct request_queue *q;
143 	unsigned int flags;
144 	unsigned int shallow_depth;
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