blob: 8342de041e114750975c1405fc6504194eef57cd [file] [log] [blame]
/*
* 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 <http://www.gnu.org/licenses/>.
*/
#define pr_fmt(fmt) "sched-energy: " fmt
#include <linux/gfp.h>
#include <linux/of.h>
#include <linux/printk.h>
#include <linux/sched.h>
#include <linux/sched/topology.h>
#include <linux/sched/energy.h>
#include <linux/stddef.h>
#include <linux/arch_topology.h>
#include <linux/cpu.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include "sched.h"
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);
}
}
}
}
static bool sge_ready;
static bool freq_energy_model;
void check_max_cap_vs_cpu_scale(int cpu, struct sched_group_energy *sge)
{
unsigned long max_cap, cpu_scale;
max_cap = sge->cap_states[sge->nr_cap_states - 1].cap;
cpu_scale = topology_get_cpu_scale(NULL, cpu);
if (max_cap == cpu_scale)
return;
pr_warn("CPU%d max energy model capacity=%ld != cpu_scale=%ld\n", cpu,
max_cap, cpu_scale);
}
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;
}
/* Check if the energy model contains frequency/power values */
if (of_find_property(cn, "freq-energy-model", NULL))
freq_energy_model = true;
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++) {
if (freq_energy_model) {
/*
* Capacity values will be calculated later using
* frequency reported by OPP driver and cpu_uarch_scale
* values.
*/
cap_states[i].frequency = be32_to_cpup(val++);
cap_states[i].cap = 0;
} else {
cap_states[i].frequency = 0;
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;
}
if (!freq_energy_model)
check_max_cap_vs_cpu_scale(cpu, sge_array[cpu][SD_LEVEL0]);
}
sge_ready = true;
pr_info("Sched-energy-costs installed from DT\n");
return;
out:
free_resources();
}
static int sched_energy_probe(struct platform_device *pdev)
{
int cpu;
unsigned long *max_frequencies = NULL;
int ret;
if (!sge_ready)
return -EPROBE_DEFER;
if (!energy_aware() || !freq_energy_model)
return 0;
max_frequencies = kmalloc_array(nr_cpu_ids, sizeof(unsigned long),
GFP_KERNEL);
if (!max_frequencies) {
ret = -ENOMEM;
goto exit;
}
/*
* Find system max possible frequency and max frequencies for each
* CPUs.
*/
for_each_possible_cpu(cpu) {
struct device *cpu_dev;
struct dev_pm_opp *opp;
cpu_dev = get_cpu_device(cpu);
if (IS_ERR_OR_NULL(cpu_dev)) {
if (!cpu_dev)
ret = -EINVAL;
else
ret = PTR_ERR(cpu_dev);
goto exit;
}
max_frequencies[cpu] = ULONG_MAX;
opp = dev_pm_opp_find_freq_floor(cpu_dev,
&max_frequencies[cpu]);
if (IS_ERR_OR_NULL(opp)) {
if (!opp || PTR_ERR(opp) == -ENODEV)
ret = -EPROBE_DEFER;
else
ret = PTR_ERR(opp);
goto exit;
}
/* Convert HZ to KHZ */
max_frequencies[cpu] /= 1000;
}
/* update capacity in energy model */
for_each_possible_cpu(cpu) {
unsigned long cpu_max_cap;
struct sched_group_energy *sge_l0, *sge;
cpu_max_cap = topology_get_cpu_scale(NULL, cpu);
/*
* All the cap_states have same frequency table so use
* SD_LEVEL0's.
*/
sge_l0 = sge_array[cpu][SD_LEVEL0];
if (sge_l0 && sge_l0->nr_cap_states > 0) {
int i;
int ncapstates = sge_l0->nr_cap_states;
for (i = 0; i < ncapstates; i++) {
int sd_level;
unsigned long freq, cap;
/*
* Energy model can contain more frequency
* steps than actual for multiple speedbin
* support. Ceil the max capacity with actual
* one.
*/
freq = min(sge_l0->cap_states[i].frequency,
max_frequencies[cpu]);
cap = DIV_ROUND_UP(cpu_max_cap * freq,
max_frequencies[cpu]);
for_each_possible_sd_level(sd_level) {
sge = sge_array[cpu][sd_level];
if (!sge)
break;
sge->cap_states[i].cap = cap;
}
dev_dbg(&pdev->dev,
"cpu=%d freq=%ld cap=%ld power_d0=%ld\n",
cpu, freq, sge_l0->cap_states[i].cap,
sge_l0->cap_states[i].power);
}
dev_info(&pdev->dev,
"cpu=%d [freq=%ld cap=%ld power_d0=%ld] -> [freq=%ld cap=%ld power_d0=%ld]\n",
cpu,
sge_l0->cap_states[0].frequency,
sge_l0->cap_states[0].cap,
sge_l0->cap_states[0].power,
sge_l0->cap_states[ncapstates - 1].frequency,
sge_l0->cap_states[ncapstates - 1].cap,
sge_l0->cap_states[ncapstates - 1].power
);
}
}
kfree(max_frequencies);
dev_info(&pdev->dev, "Sched-energy-costs capacity updated\n");
return 0;
exit:
if (ret != -EPROBE_DEFER)
dev_err(&pdev->dev, "error=%d\n", ret);
kfree(max_frequencies);
return ret;
}
static struct platform_driver energy_driver = {
.driver = {
.name = "sched-energy",
},
.probe = sched_energy_probe,
};
static struct platform_device energy_device = {
.name = "sched-energy",
};
static int __init sched_energy_init(void)
{
int ret;
ret = platform_device_register(&energy_device);
if (ret)
pr_err("%s device_register failed:%d\n", __func__, ret);
ret = platform_driver_register(&energy_driver);
if (ret) {
pr_err("%s driver_register failed:%d\n", __func__, ret);
platform_device_unregister(&energy_device);
}
return ret;
}
subsys_initcall(sched_energy_init);