xref: /openbmc/linux/block/blk-mq.h (revision 8730046c)
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 blk_mq_hw_ctx *, struct list_head *);
35 
36 /*
37  * CPU hotplug helpers
38  */
39 void blk_mq_enable_hotplug(void);
40 void blk_mq_disable_hotplug(void);
41 
42 /*
43  * CPU -> queue mappings
44  */
45 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
46 
47 static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
48 		int cpu)
49 {
50 	return q->queue_hw_ctx[q->mq_map[cpu]];
51 }
52 
53 /*
54  * sysfs helpers
55  */
56 extern int blk_mq_sysfs_register(struct request_queue *q);
57 extern void blk_mq_sysfs_unregister(struct request_queue *q);
58 extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
59 
60 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
61 
62 void blk_mq_release(struct request_queue *q);
63 
64 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
65 					   unsigned int cpu)
66 {
67 	return per_cpu_ptr(q->queue_ctx, cpu);
68 }
69 
70 /*
71  * This assumes per-cpu software queueing queues. They could be per-node
72  * as well, for instance. For now this is hardcoded as-is. Note that we don't
73  * care about preemption, since we know the ctx's are persistent. This does
74  * mean that we can't rely on ctx always matching the currently running CPU.
75  */
76 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
77 {
78 	return __blk_mq_get_ctx(q, get_cpu());
79 }
80 
81 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
82 {
83 	put_cpu();
84 }
85 
86 struct blk_mq_alloc_data {
87 	/* input parameter */
88 	struct request_queue *q;
89 	unsigned int flags;
90 
91 	/* input & output parameter */
92 	struct blk_mq_ctx *ctx;
93 	struct blk_mq_hw_ctx *hctx;
94 };
95 
96 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
97 		struct request_queue *q, unsigned int flags,
98 		struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
99 {
100 	data->q = q;
101 	data->flags = flags;
102 	data->ctx = ctx;
103 	data->hctx = hctx;
104 }
105 
106 static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
107 {
108 	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
109 }
110 
111 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
112 {
113 	return hctx->nr_ctx && hctx->tags;
114 }
115 
116 #endif
117