1 /*
2 * Obtain energy cost data from DT and populate relevant scheduler data
3 * structures.
4 *
5 * Copyright (C) 2015 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19 #define pr_fmt(fmt) "sched-energy: " fmt
20
21 #define DEBUG
22
23 #include <linux/gfp.h>
24 #include <linux/of.h>
25 #include <linux/printk.h>
26 #include <linux/sched.h>
27 #include <linux/sched_energy.h>
28 #include <linux/stddef.h>
29
30 struct sched_group_energy *sge_array[NR_CPUS][NR_SD_LEVELS];
31
free_resources(void)32 static void free_resources(void)
33 {
34 int cpu, sd_level;
35 struct sched_group_energy *sge;
36
37 for_each_possible_cpu(cpu) {
38 for_each_possible_sd_level(sd_level) {
39 sge = sge_array[cpu][sd_level];
40 if (sge) {
41 kfree(sge->cap_states);
42 kfree(sge->idle_states);
43 kfree(sge);
44 }
45 }
46 }
47 }
48
init_sched_energy_costs(void)49 void init_sched_energy_costs(void)
50 {
51 struct device_node *cn, *cp;
52 struct capacity_state *cap_states;
53 struct idle_state *idle_states;
54 struct sched_group_energy *sge;
55 const struct property *prop;
56 int sd_level, i, nstates, cpu;
57 const __be32 *val;
58
59 for_each_possible_cpu(cpu) {
60 cn = of_get_cpu_node(cpu, NULL);
61 if (!cn) {
62 pr_warn("CPU device node missing for CPU %d\n", cpu);
63 return;
64 }
65
66 if (!of_find_property(cn, "sched-energy-costs", NULL)) {
67 pr_warn("CPU device node has no sched-energy-costs\n");
68 return;
69 }
70
71 for_each_possible_sd_level(sd_level) {
72 cp = of_parse_phandle(cn, "sched-energy-costs", sd_level);
73 if (!cp)
74 break;
75
76 prop = of_find_property(cp, "busy-cost-data", NULL);
77 if (!prop || !prop->value) {
78 pr_warn("No busy-cost data, skipping sched_energy init\n");
79 goto out;
80 }
81
82 sge = kcalloc(1, sizeof(struct sched_group_energy),
83 GFP_NOWAIT);
84
85 nstates = (prop->length / sizeof(u32)) / 2;
86 cap_states = kcalloc(nstates,
87 sizeof(struct capacity_state),
88 GFP_NOWAIT);
89
90 for (i = 0, val = prop->value; i < nstates; i++) {
91 cap_states[i].cap = be32_to_cpup(val++);
92 cap_states[i].power = be32_to_cpup(val++);
93 }
94
95 sge->nr_cap_states = nstates;
96 sge->cap_states = cap_states;
97
98 prop = of_find_property(cp, "idle-cost-data", NULL);
99 if (!prop || !prop->value) {
100 pr_warn("No idle-cost data, skipping sched_energy init\n");
101 goto out;
102 }
103
104 nstates = (prop->length / sizeof(u32));
105 idle_states = kcalloc(nstates,
106 sizeof(struct idle_state),
107 GFP_NOWAIT);
108
109 for (i = 0, val = prop->value; i < nstates; i++)
110 idle_states[i].power = be32_to_cpup(val++);
111
112 sge->nr_idle_states = nstates;
113 sge->idle_states = idle_states;
114
115 sge_array[cpu][sd_level] = sge;
116 }
117 }
118
119 pr_info("Sched-energy-costs installed from DT\n");
120 return;
121
122 out:
123 free_resources();
124 }
125