xref: /openbmc/linux/block/blk-mq.h (revision d2999e1b)
1 #ifndef INT_BLK_MQ_H
2 #define INT_BLK_MQ_H
3 
4 struct blk_mq_tag_set;
5 
6 struct blk_mq_ctx {
7 	struct {
8 		spinlock_t		lock;
9 		struct list_head	rq_list;
10 	}  ____cacheline_aligned_in_smp;
11 
12 	unsigned int		cpu;
13 	unsigned int		index_hw;
14 
15 	unsigned int		last_tag ____cacheline_aligned_in_smp;
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_complete_request(struct request *rq);
29 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
30 void blk_mq_init_flush(struct request_queue *q);
31 void blk_mq_drain_queue(struct request_queue *q);
32 void blk_mq_free_queue(struct request_queue *q);
33 void blk_mq_clone_flush_request(struct request *flush_rq,
34 		struct request *orig_rq);
35 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
36 
37 /*
38  * CPU hotplug helpers
39  */
40 struct blk_mq_cpu_notifier;
41 void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
42 			      int (*fn)(void *, unsigned long, unsigned int),
43 			      void *data);
44 void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
45 void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
46 void blk_mq_cpu_init(void);
47 void blk_mq_enable_hotplug(void);
48 void blk_mq_disable_hotplug(void);
49 
50 /*
51  * CPU -> queue mappings
52  */
53 extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
54 extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
55 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
56 
57 /*
58  * sysfs helpers
59  */
60 extern int blk_mq_sysfs_register(struct request_queue *q);
61 extern void blk_mq_sysfs_unregister(struct request_queue *q);
62 
63 /*
64  * Basic implementation of sparser bitmap, allowing the user to spread
65  * the bits over more cachelines.
66  */
67 struct blk_align_bitmap {
68 	unsigned long word;
69 	unsigned long depth;
70 } ____cacheline_aligned_in_smp;
71 
72 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
73 					   unsigned int cpu)
74 {
75 	return per_cpu_ptr(q->queue_ctx, cpu);
76 }
77 
78 /*
79  * This assumes per-cpu software queueing queues. They could be per-node
80  * as well, for instance. For now this is hardcoded as-is. Note that we don't
81  * care about preemption, since we know the ctx's are persistent. This does
82  * mean that we can't rely on ctx always matching the currently running CPU.
83  */
84 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
85 {
86 	return __blk_mq_get_ctx(q, get_cpu());
87 }
88 
89 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
90 {
91 	put_cpu();
92 }
93 
94 struct blk_mq_alloc_data {
95 	/* input parameter */
96 	struct request_queue *q;
97 	gfp_t gfp;
98 	bool reserved;
99 
100 	/* input & output parameter */
101 	struct blk_mq_ctx *ctx;
102 	struct blk_mq_hw_ctx *hctx;
103 };
104 
105 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
106 		struct request_queue *q, gfp_t gfp, bool reserved,
107 		struct blk_mq_ctx *ctx,
108 		struct blk_mq_hw_ctx *hctx)
109 {
110 	data->q = q;
111 	data->gfp = gfp;
112 	data->reserved = reserved;
113 	data->ctx = ctx;
114 	data->hctx = hctx;
115 }
116 
117 #endif
118