xref: /openbmc/linux/block/blk-mq.h (revision 609e478b)
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_freeze_queue(struct request_queue *q);
31 void blk_mq_free_queue(struct request_queue *q);
32 void blk_mq_clone_flush_request(struct request *flush_rq,
33 		struct request *orig_rq);
34 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
35 
36 /*
37  * CPU hotplug helpers
38  */
39 struct blk_mq_cpu_notifier;
40 void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
41 			      int (*fn)(void *, unsigned long, unsigned int),
42 			      void *data);
43 void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
44 void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
45 void blk_mq_cpu_init(void);
46 void blk_mq_enable_hotplug(void);
47 void blk_mq_disable_hotplug(void);
48 
49 /*
50  * CPU -> queue mappings
51  */
52 extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
53 extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
54 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
55 
56 /*
57  * sysfs helpers
58  */
59 extern int blk_mq_sysfs_register(struct request_queue *q);
60 extern void blk_mq_sysfs_unregister(struct request_queue *q);
61 
62 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
63 
64 /*
65  * Basic implementation of sparser bitmap, allowing the user to spread
66  * the bits over more cachelines.
67  */
68 struct blk_align_bitmap {
69 	unsigned long word;
70 	unsigned long depth;
71 } ____cacheline_aligned_in_smp;
72 
73 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
74 					   unsigned int cpu)
75 {
76 	return per_cpu_ptr(q->queue_ctx, cpu);
77 }
78 
79 /*
80  * This assumes per-cpu software queueing queues. They could be per-node
81  * as well, for instance. For now this is hardcoded as-is. Note that we don't
82  * care about preemption, since we know the ctx's are persistent. This does
83  * mean that we can't rely on ctx always matching the currently running CPU.
84  */
85 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
86 {
87 	return __blk_mq_get_ctx(q, get_cpu());
88 }
89 
90 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
91 {
92 	put_cpu();
93 }
94 
95 struct blk_mq_alloc_data {
96 	/* input parameter */
97 	struct request_queue *q;
98 	gfp_t gfp;
99 	bool reserved;
100 
101 	/* input & output parameter */
102 	struct blk_mq_ctx *ctx;
103 	struct blk_mq_hw_ctx *hctx;
104 };
105 
106 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
107 		struct request_queue *q, gfp_t gfp, bool reserved,
108 		struct blk_mq_ctx *ctx,
109 		struct blk_mq_hw_ctx *hctx)
110 {
111 	data->q = q;
112 	data->gfp = gfp;
113 	data->reserved = reserved;
114 	data->ctx = ctx;
115 	data->hctx = hctx;
116 }
117 
118 #endif
119