diff --git a/include/linux/sched_energy.h b/include/linux/sched_energy.h new file mode 100644 index 000000000000..a3f1627ac609 --- /dev/null +++ b/include/linux/sched_energy.h @@ -0,0 +1,36 @@ +#ifndef _LINUX_SCHED_ENERGY_H +#define _LINUX_SCHED_ENERGY_H + +#include +#include + +/* + * There doesn't seem to be an NR_CPUS style max number of sched domain + * levels so here's an arbitrary constant one for the moment. + * + * The levels alluded to here correspond to entries in struct + * sched_domain_topology_level that are meant to be populated by arch + * specific code (topology.c). + */ +#define NR_SD_LEVELS 8 + +#define SD_LEVEL0 0 +#define SD_LEVEL1 1 +#define SD_LEVEL2 2 +#define SD_LEVEL3 3 +#define SD_LEVEL4 4 +#define SD_LEVEL5 5 +#define SD_LEVEL6 6 +#define SD_LEVEL7 7 + +/* + * Convenience macro for iterating through said sd levels. + */ +#define for_each_possible_sd_level(level) \ + for (level = 0; level < NR_SD_LEVELS; level++) + +extern struct sched_group_energy *sge_array[NR_CPUS][NR_SD_LEVELS]; + +void init_sched_energy_costs(void); + +#endif diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 67687973ce80..a541b5ce1dcc 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -12,7 +12,7 @@ CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer endif obj-y += core.o loadavg.o clock.o cputime.o -obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o +obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o energy.o obj-y += wait.o completion.o idle.o obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o diff --git a/kernel/sched/energy.c b/kernel/sched/energy.c new file mode 100644 index 000000000000..b0656b7a93e3 --- /dev/null +++ b/kernel/sched/energy.c @@ -0,0 +1,124 @@ +/* + * Obtain energy cost data from DT and populate relevant scheduler data + * structures. + * + * Copyright (C) 2015 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#define pr_fmt(fmt) "sched-energy: " fmt + +#define DEBUG + +#include +#include +#include +#include +#include +#include + +struct sched_group_energy *sge_array[NR_CPUS][NR_SD_LEVELS]; + +static void free_resources(void) +{ + int cpu, sd_level; + struct sched_group_energy *sge; + + for_each_possible_cpu(cpu) { + for_each_possible_sd_level(sd_level) { + sge = sge_array[cpu][sd_level]; + if (sge) { + kfree(sge->cap_states); + kfree(sge->idle_states); + kfree(sge); + } + } + } +} + +void init_sched_energy_costs(void) +{ + struct device_node *cn, *cp; + struct capacity_state *cap_states; + struct idle_state *idle_states; + struct sched_group_energy *sge; + const struct property *prop; + int sd_level, i, nstates, cpu; + const __be32 *val; + + for_each_possible_cpu(cpu) { + cn = of_get_cpu_node(cpu, NULL); + if (!cn) { + pr_warn("CPU device node missing for CPU %d\n", cpu); + return; + } + + if (!of_find_property(cn, "sched-energy-costs", NULL)) { + pr_warn("CPU device node has no sched-energy-costs\n"); + return; + } + + for_each_possible_sd_level(sd_level) { + cp = of_parse_phandle(cn, "sched-energy-costs", sd_level); + if (!cp) + break; + + prop = of_find_property(cp, "busy-cost-data", NULL); + if (!prop || !prop->value) { + pr_warn("No busy-cost data, skipping sched_energy init\n"); + goto out; + } + + sge = kcalloc(1, sizeof(struct sched_group_energy), + GFP_NOWAIT); + + nstates = (prop->length / sizeof(u32)) / 2; + cap_states = kcalloc(nstates, + sizeof(struct capacity_state), + GFP_NOWAIT); + + for (i = 0, val = prop->value; i < nstates; i++) { + cap_states[i].cap = be32_to_cpup(val++); + cap_states[i].power = be32_to_cpup(val++); + } + + sge->nr_cap_states = nstates; + sge->cap_states = cap_states; + + prop = of_find_property(cp, "idle-cost-data", NULL); + if (!prop || !prop->value) { + pr_warn("No idle-cost data, skipping sched_energy init\n"); + goto out; + } + + nstates = (prop->length / sizeof(u32)); + idle_states = kcalloc(nstates, + sizeof(struct idle_state), + GFP_NOWAIT); + + for (i = 0, val = prop->value; i < nstates; i++) + idle_states[i].power = be32_to_cpup(val++); + + sge->nr_idle_states = nstates; + sge->idle_states = idle_states; + + sge_array[cpu][sd_level] = sge; + } + } + + pr_info("Sched-energy-costs installed from DT\n"); + return; + +out: + free_resources(); +}