Root/block/blk-mq.h

1#ifndef INT_BLK_MQ_H
2#define INT_BLK_MQ_H
3
4struct blk_mq_tag_set;
5
6struct 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
28void __blk_mq_complete_request(struct request *rq);
29void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
30void blk_mq_init_flush(struct request_queue *q);
31void blk_mq_drain_queue(struct request_queue *q);
32void blk_mq_free_queue(struct request_queue *q);
33void blk_mq_clone_flush_request(struct request *flush_rq,
34        struct request *orig_rq);
35int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
36
37/*
38 * CPU hotplug helpers
39 */
40struct blk_mq_cpu_notifier;
41void blk_mq_init_cpu_notifier(struct blk_mq_cpu_notifier *notifier,
42                  int (*fn)(void *, unsigned long, unsigned int),
43                  void *data);
44void blk_mq_register_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
45void blk_mq_unregister_cpu_notifier(struct blk_mq_cpu_notifier *notifier);
46void blk_mq_cpu_init(void);
47void blk_mq_enable_hotplug(void);
48void blk_mq_disable_hotplug(void);
49
50/*
51 * CPU -> queue mappings
52 */
53extern unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set);
54extern int blk_mq_update_queue_map(unsigned int *map, unsigned int nr_queues);
55extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
56
57/*
58 * sysfs helpers
59 */
60extern int blk_mq_sysfs_register(struct request_queue *q);
61extern 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 */
67struct blk_align_bitmap {
68    unsigned long word;
69    unsigned long depth;
70} ____cacheline_aligned_in_smp;
71
72static 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 */
84static 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
89static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
90{
91    put_cpu();
92}
93
94struct 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
105static 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

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