xref: /openbmc/linux/block/blk-mq.h (revision 6f52b16c5b29b89d92c0e7236f4655dc8491ad70)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef INT_BLK_MQ_H
3 #define INT_BLK_MQ_H
4 
5 #include "blk-stat.h"
6 
7 struct blk_mq_tag_set;
8 
9 struct blk_mq_ctx {
10 	struct {
11 		spinlock_t		lock;
12 		struct list_head	rq_list;
13 	}  ____cacheline_aligned_in_smp;
14 
15 	unsigned int		cpu;
16 	unsigned int		index_hw;
17 
18 	/* incremented at dispatch time */
19 	unsigned long		rq_dispatched[2];
20 	unsigned long		rq_merged;
21 
22 	/* incremented at completion time */
23 	unsigned long		____cacheline_aligned_in_smp rq_completed[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_request_bypass_insert(struct request *rq);
59 void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
60 				struct list_head *list);
61 
62 /*
63  * CPU -> queue mappings
64  */
65 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
66 
67 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
68 		int cpu)
69 {
70 	return q->queue_hw_ctx[q->mq_map[cpu]];
71 }
72 
73 /*
74  * sysfs helpers
75  */
76 extern void blk_mq_sysfs_init(struct request_queue *q);
77 extern void blk_mq_sysfs_deinit(struct request_queue *q);
78 extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
79 extern int blk_mq_sysfs_register(struct request_queue *q);
80 extern void blk_mq_sysfs_unregister(struct request_queue *q);
81 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
82 
83 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
84 
85 void blk_mq_release(struct request_queue *q);
86 
87 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
88 					   unsigned int cpu)
89 {
90 	return per_cpu_ptr(q->queue_ctx, cpu);
91 }
92 
93 /*
94  * This assumes per-cpu software queueing queues. They could be per-node
95  * as well, for instance. For now this is hardcoded as-is. Note that we don't
96  * care about preemption, since we know the ctx's are persistent. This does
97  * mean that we can't rely on ctx always matching the currently running CPU.
98  */
99 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
100 {
101 	return __blk_mq_get_ctx(q, get_cpu());
102 }
103 
104 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
105 {
106 	put_cpu();
107 }
108 
109 struct blk_mq_alloc_data {
110 	/* input parameter */
111 	struct request_queue *q;
112 	unsigned int flags;
113 	unsigned int shallow_depth;
114 
115 	/* input & output parameter */
116 	struct blk_mq_ctx *ctx;
117 	struct blk_mq_hw_ctx *hctx;
118 };
119 
120 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
121 {
122 	if (data->flags & BLK_MQ_REQ_INTERNAL)
123 		return data->hctx->sched_tags;
124 
125 	return data->hctx->tags;
126 }
127 
128 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
129 {
130 	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
131 }
132 
133 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
134 {
135 	return hctx->nr_ctx && hctx->tags;
136 }
137 
138 void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
139 			unsigned int inflight[2]);
140 
141 #endif
142