1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/blk-cgroup.h>
4 #include <linux/ioprio.h>
5
6 #include "mq-deadline-cgroup.h"
7
8 static struct blkcg_policy dd_blkcg_policy;
9
dd_cpd_alloc(gfp_t gfp)10 static struct blkcg_policy_data *dd_cpd_alloc(gfp_t gfp)
11 {
12 struct dd_blkcg *pd;
13
14 pd = kzalloc(sizeof(*pd), gfp);
15 if (!pd)
16 return NULL;
17 pd->stats = alloc_percpu_gfp(typeof(*pd->stats),
18 GFP_KERNEL | __GFP_ZERO);
19 if (!pd->stats) {
20 kfree(pd);
21 return NULL;
22 }
23 return &pd->cpd;
24 }
25
dd_cpd_free(struct blkcg_policy_data * cpd)26 static void dd_cpd_free(struct blkcg_policy_data *cpd)
27 {
28 struct dd_blkcg *dd_blkcg = container_of(cpd, typeof(*dd_blkcg), cpd);
29
30 free_percpu(dd_blkcg->stats);
31 kfree(dd_blkcg);
32 }
33
dd_blkcg_from_pd(struct blkg_policy_data * pd)34 static struct dd_blkcg *dd_blkcg_from_pd(struct blkg_policy_data *pd)
35 {
36 return container_of(blkcg_to_cpd(pd->blkg->blkcg, &dd_blkcg_policy),
37 struct dd_blkcg, cpd);
38 }
39
40 /*
41 * Convert an association between a block cgroup and a request queue into a
42 * pointer to the mq-deadline information associated with a (blkcg, queue) pair.
43 */
dd_blkcg_from_bio(struct bio * bio)44 struct dd_blkcg *dd_blkcg_from_bio(struct bio *bio)
45 {
46 struct blkg_policy_data *pd;
47
48 pd = blkg_to_pd(bio->bi_blkg, &dd_blkcg_policy);
49 if (!pd)
50 return NULL;
51
52 return dd_blkcg_from_pd(pd);
53 }
54
dd_pd_stat(struct blkg_policy_data * pd,char * buf,size_t size)55 static size_t dd_pd_stat(struct blkg_policy_data *pd, char *buf, size_t size)
56 {
57 static const char *const prio_class_name[] = {
58 [IOPRIO_CLASS_NONE] = "NONE",
59 [IOPRIO_CLASS_RT] = "RT",
60 [IOPRIO_CLASS_BE] = "BE",
61 [IOPRIO_CLASS_IDLE] = "IDLE",
62 };
63 struct dd_blkcg *blkcg = dd_blkcg_from_pd(pd);
64 int res = 0;
65 u8 prio;
66
67 for (prio = 0; prio < ARRAY_SIZE(blkcg->stats->stats); prio++)
68 res += scnprintf(buf + res, size - res,
69 " [%s] dispatched=%u inserted=%u merged=%u",
70 prio_class_name[prio],
71 ddcg_sum(blkcg, dispatched, prio) +
72 ddcg_sum(blkcg, merged, prio) -
73 ddcg_sum(blkcg, completed, prio),
74 ddcg_sum(blkcg, inserted, prio) -
75 ddcg_sum(blkcg, completed, prio),
76 ddcg_sum(blkcg, merged, prio));
77
78 return res;
79 }
80
dd_pd_alloc(gfp_t gfp,struct request_queue * q,struct blkcg * blkcg)81 static struct blkg_policy_data *dd_pd_alloc(gfp_t gfp, struct request_queue *q,
82 struct blkcg *blkcg)
83 {
84 struct dd_blkg *pd;
85
86 pd = kzalloc(sizeof(*pd), gfp);
87 if (!pd)
88 return NULL;
89 return &pd->pd;
90 }
91
dd_pd_free(struct blkg_policy_data * pd)92 static void dd_pd_free(struct blkg_policy_data *pd)
93 {
94 struct dd_blkg *dd_blkg = container_of(pd, typeof(*dd_blkg), pd);
95
96 kfree(dd_blkg);
97 }
98
99 static struct blkcg_policy dd_blkcg_policy = {
100 .cpd_alloc_fn = dd_cpd_alloc,
101 .cpd_free_fn = dd_cpd_free,
102
103 .pd_alloc_fn = dd_pd_alloc,
104 .pd_free_fn = dd_pd_free,
105 .pd_stat_fn = dd_pd_stat,
106 };
107
dd_activate_policy(struct request_queue * q)108 int dd_activate_policy(struct request_queue *q)
109 {
110 return blkcg_activate_policy(q, &dd_blkcg_policy);
111 }
112
dd_deactivate_policy(struct request_queue * q)113 void dd_deactivate_policy(struct request_queue *q)
114 {
115 blkcg_deactivate_policy(q, &dd_blkcg_policy);
116 }
117
dd_blkcg_init(void)118 int __init dd_blkcg_init(void)
119 {
120 return blkcg_policy_register(&dd_blkcg_policy);
121 }
122
dd_blkcg_exit(void)123 void __exit dd_blkcg_exit(void)
124 {
125 blkcg_policy_unregister(&dd_blkcg_policy);
126 }
127