xref: /openbmc/linux/block/blk-mq.h (revision 9cfc5c90)
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_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 
34 /*
35  * CPU hotplug helpers
36  */
37 struct blk_mq_cpu_notifier;
38 void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
39 			      int (*fn)(void *, unsigned long, unsigned int),
40 			      void *data);
41 void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
42 void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
43 void blk_mq_cpu_init(void);
44 void blk_mq_enable_hotplug(void);
45 void blk_mq_disable_hotplug(void);
46 
47 /*
48  * CPU -> queue mappings
49  */
50 extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
51 extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues,
52 				   const struct cpumask *online_mask);
53 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
54 
55 /*
56  * sysfs helpers
57  */
58 extern int blk_mq_sysfs_register(struct request_queue *q);
59 extern void blk_mq_sysfs_unregister(struct request_queue *q);
60 
61 extern void blk_mq_rq_timed_out(struct request *req, bool reserved);
62 
63 void blk_mq_release(struct request_queue *q);
64 
65 /*
66  * Basic implementation of sparser bitmap, allowing the user to spread
67  * the bits over more cachelines.
68  */
69 struct blk_align_bitmap {
70 	unsigned long word;
71 	unsigned long depth;
72 } ____cacheline_aligned_in_smp;
73 
74 static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
75 					   unsigned int cpu)
76 {
77 	return per_cpu_ptr(q->queue_ctx, cpu);
78 }
79 
80 /*
81  * This assumes per-cpu software queueing queues. They could be per-node
82  * as well, for instance. For now this is hardcoded as-is. Note that we don't
83  * care about preemption, since we know the ctx's are persistent. This does
84  * mean that we can't rely on ctx always matching the currently running CPU.
85  */
86 static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
87 {
88 	return __blk_mq_get_ctx(q, get_cpu());
89 }
90 
91 static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
92 {
93 	put_cpu();
94 }
95 
96 struct blk_mq_alloc_data {
97 	/* input parameter */
98 	struct request_queue *q;
99 	gfp_t gfp;
100 	bool reserved;
101 
102 	/* input & output parameter */
103 	struct blk_mq_ctx *ctx;
104 	struct blk_mq_hw_ctx *hctx;
105 };
106 
107 static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
108 		struct request_queue *q, gfp_t gfp, bool reserved,
109 		struct blk_mq_ctx *ctx,
110 		struct blk_mq_hw_ctx *hctx)
111 {
112 	data->q = q;
113 	data->gfp = gfp;
114 	data->reserved = reserved;
115 	data->ctx = ctx;
116 	data->hctx = hctx;
117 }
118 
119 static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
120 {
121 	return hctx->nr_ctx && hctx->tags;
122 }
123 
124 #endif
125