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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-09-25 22:18:45 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-09-25 22:18:45 +0200
commiteeb1aa5f78caf8d5ec1ef651c09bde34370321d8 (patch)
treecc641b7dad3bff3bf1527a99c5d88d1f23d0a563 /drivers/cpuidle
parent9133664097dd4aca0bed4882a86f0bfccbf07e53 (diff)
parentd2e5c871ed8a250f7ee1fe34dd52ed5757363fba (diff)
downloadop-kernel-dev-eeb1aa5f78caf8d5ec1ef651c09bde34370321d8.zip
op-kernel-dev-eeb1aa5f78caf8d5ec1ef651c09bde34370321d8.tar.gz
Merge branch 'cpuidle/3.18' of https://git.linaro.org/people/daniel.lezcano/linux into pm-cpuidle
Pull ARM cpuidle changes for v3.18 from Daniel Lezcano: "this pull request contains the following changes: * Lorenzo Pieralisi implemented a framework to initialize the ARM cpuidle drivers with the DT. As an example, it provided a couple of drivers using it: arm64 and big little. The former one is a new driver while the latter is a change. There was also a patch for Exynos allowing to use this framework but as it depends on a change in Samsung's tree, I postponed this patch until the change is visible after the merge. The set of changes depends on some other changes made in the ARM64 tree, for this reason a shared branch is used. This is why there is a merge from arm64 in my pull request. I believe we already used this procedure. * Kevin Hilman added the compatible string for the exynos 5800 in the DT" * 'cpuidle/3.18' of https://git.linaro.org/people/daniel.lezcano/linux: drivers: cpuidle: initialize big.LITTLE driver through DT drivers: cpuidle: CPU idle ARM64 driver drivers: cpuidle: implement DT based idle states infrastructure cpuidle: big.LITTLE: add Exynos5800 compatible string arm64: add PSCI CPU_SUSPEND based cpu_suspend support arm64: kernel: introduce cpu_init_idle CPU operation arm64: kernel: refactor the CPU suspend API for retention states Documentation: arm: define DT idle states bindings
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/Kconfig8
-rw-r--r--drivers/cpuidle/Kconfig.arm1
-rw-r--r--drivers/cpuidle/Kconfig.arm6414
-rw-r--r--drivers/cpuidle/Makefile5
-rw-r--r--drivers/cpuidle/cpuidle-arm64.c133
-rw-r--r--drivers/cpuidle/cpuidle-big_little.c20
-rw-r--r--drivers/cpuidle/dt_idle_states.c213
-rw-r--r--drivers/cpuidle/dt_idle_states.h7
8 files changed, 401 insertions, 0 deletions
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index 32748c3..c5029c1 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -25,11 +25,19 @@ config CPU_IDLE_GOV_MENU
bool "Menu governor (for tickless system)"
default y
+config DT_IDLE_STATES
+ bool
+
menu "ARM CPU Idle Drivers"
depends on ARM
source "drivers/cpuidle/Kconfig.arm"
endmenu
+menu "ARM64 CPU Idle Drivers"
+depends on ARM64
+source "drivers/cpuidle/Kconfig.arm64"
+endmenu
+
menu "MIPS CPU Idle Drivers"
depends on MIPS
source "drivers/cpuidle/Kconfig.mips"
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index 38cff69..e339c7f 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -7,6 +7,7 @@ config ARM_BIG_LITTLE_CPUIDLE
depends on MCPM
select ARM_CPU_SUSPEND
select CPU_IDLE_MULTIPLE_DRIVERS
+ select DT_IDLE_STATES
help
Select this option to enable CPU idle driver for big.LITTLE based
ARM systems. Driver manages CPUs coordination through MCPM and
diff --git a/drivers/cpuidle/Kconfig.arm64 b/drivers/cpuidle/Kconfig.arm64
new file mode 100644
index 0000000..d0a08ed
--- /dev/null
+++ b/drivers/cpuidle/Kconfig.arm64
@@ -0,0 +1,14 @@
+#
+# ARM64 CPU Idle drivers
+#
+
+config ARM64_CPUIDLE
+ bool "Generic ARM64 CPU idle Driver"
+ select ARM64_CPU_SUSPEND
+ select DT_IDLE_STATES
+ help
+ Select this to enable generic cpuidle driver for ARM64.
+ It provides a generic idle driver whose idle states are configured
+ at run-time through DT nodes. The CPUidle suspend backend is
+ initialized by calling the CPU operations init idle hook
+ provided by architecture code.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 11edb31..4d177b9 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -4,6 +4,7 @@
obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
+obj-$(CONFIG_DT_IDLE_STATES) += dt_idle_states.o
##################################################################################
# ARM SoC drivers
@@ -22,6 +23,10 @@ obj-$(CONFIG_ARM_EXYNOS_CPUIDLE) += cpuidle-exynos.o
obj-$(CONFIG_MIPS_CPS_CPUIDLE) += cpuidle-cps.o
###############################################################################
+# ARM64 drivers
+obj-$(CONFIG_ARM64_CPUIDLE) += cpuidle-arm64.o
+
+###############################################################################
# POWERPC drivers
obj-$(CONFIG_PSERIES_CPUIDLE) += cpuidle-pseries.o
obj-$(CONFIG_POWERNV_CPUIDLE) += cpuidle-powernv.o
diff --git a/drivers/cpuidle/cpuidle-arm64.c b/drivers/cpuidle/cpuidle-arm64.c
new file mode 100644
index 0000000..50997ea
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-arm64.c
@@ -0,0 +1,133 @@
+/*
+ * ARM64 generic CPU idle driver.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "CPUidle arm64: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <asm/cpuidle.h>
+#include <asm/suspend.h>
+
+#include "dt_idle_states.h"
+
+/*
+ * arm64_enter_idle_state - Programs CPU to enter the specified state
+ *
+ * dev: cpuidle device
+ * drv: cpuidle driver
+ * idx: state index
+ *
+ * Called from the CPUidle framework to program the device to the
+ * specified target state selected by the governor.
+ */
+static int arm64_enter_idle_state(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int idx)
+{
+ int ret;
+
+ if (!idx) {
+ cpu_do_idle();
+ return idx;
+ }
+
+ ret = cpu_pm_enter();
+ if (!ret) {
+ /*
+ * Pass idle state index to cpu_suspend which in turn will
+ * call the CPU ops suspend protocol with idle index as a
+ * parameter.
+ */
+ ret = cpu_suspend(idx);
+
+ cpu_pm_exit();
+ }
+
+ return ret ? -1 : idx;
+}
+
+static struct cpuidle_driver arm64_idle_driver = {
+ .name = "arm64_idle",
+ .owner = THIS_MODULE,
+ /*
+ * State at index 0 is standby wfi and considered standard
+ * on all ARM platforms. If in some platforms simple wfi
+ * can't be used as "state 0", DT bindings must be implemented
+ * to work around this issue and allow installing a special
+ * handler for idle state index 0.
+ */
+ .states[0] = {
+ .enter = arm64_enter_idle_state,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .power_usage = UINT_MAX,
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .name = "WFI",
+ .desc = "ARM64 WFI",
+ }
+};
+
+static const struct of_device_id arm64_idle_state_match[] __initconst = {
+ { .compatible = "arm,idle-state",
+ .data = arm64_enter_idle_state },
+ { },
+};
+
+/*
+ * arm64_idle_init
+ *
+ * Registers the arm64 specific cpuidle driver with the cpuidle
+ * framework. It relies on core code to parse the idle states
+ * and initialize them using driver data structures accordingly.
+ */
+static int __init arm64_idle_init(void)
+{
+ int cpu, ret;
+ struct cpuidle_driver *drv = &arm64_idle_driver;
+
+ /*
+ * Initialize idle states data, starting at index 1.
+ * This driver is DT only, if no DT idle states are detected (ret == 0)
+ * let the driver initialization fail accordingly since there is no
+ * reason to initialize the idle driver if only wfi is supported.
+ */
+ ret = dt_init_idle_driver(drv, arm64_idle_state_match, 1);
+ if (ret <= 0) {
+ if (ret)
+ pr_err("failed to initialize idle states\n");
+ return ret ? : -ENODEV;
+ }
+
+ /*
+ * Call arch CPU operations in order to initialize
+ * idle states suspend back-end specific data
+ */
+ for_each_possible_cpu(cpu) {
+ ret = cpu_init_idle(cpu);
+ if (ret) {
+ pr_err("CPU %d failed to init idle CPU ops\n", cpu);
+ return ret;
+ }
+ }
+
+ ret = cpuidle_register(drv, NULL);
+ if (ret) {
+ pr_err("failed to register cpuidle driver\n");
+ return ret;
+ }
+
+ return 0;
+}
+device_initcall(arm64_idle_init);
diff --git a/drivers/cpuidle/cpuidle-big_little.c b/drivers/cpuidle/cpuidle-big_little.c
index ef94c3b..fbc00a1 100644
--- a/drivers/cpuidle/cpuidle-big_little.c
+++ b/drivers/cpuidle/cpuidle-big_little.c
@@ -24,6 +24,8 @@
#include <asm/smp_plat.h>
#include <asm/suspend.h>
+#include "dt_idle_states.h"
+
static int bl_enter_powerdown(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int idx);
@@ -73,6 +75,12 @@ static struct cpuidle_driver bl_idle_little_driver = {
.state_count = 2,
};
+static const struct of_device_id bl_idle_state_match[] __initconst = {
+ { .compatible = "arm,idle-state",
+ .data = bl_enter_powerdown },
+ { },
+};
+
static struct cpuidle_driver bl_idle_big_driver = {
.name = "big_idle",
.owner = THIS_MODULE,
@@ -159,6 +167,7 @@ static int __init bl_idle_driver_init(struct cpuidle_driver *drv, int part_id)
static const struct of_device_id compatible_machine_match[] = {
{ .compatible = "arm,vexpress,v2p-ca15_a7" },
{ .compatible = "samsung,exynos5420" },
+ { .compatible = "samsung,exynos5800" },
{},
};
@@ -190,6 +199,17 @@ static int __init bl_idle_init(void)
if (ret)
goto out_uninit_little;
+ /* Start at index 1, index 0 standard WFI */
+ ret = dt_init_idle_driver(&bl_idle_big_driver, bl_idle_state_match, 1);
+ if (ret < 0)
+ goto out_uninit_big;
+
+ /* Start at index 1, index 0 standard WFI */
+ ret = dt_init_idle_driver(&bl_idle_little_driver,
+ bl_idle_state_match, 1);
+ if (ret < 0)
+ goto out_uninit_big;
+
ret = cpuidle_register(&bl_idle_little_driver, NULL);
if (ret)
goto out_uninit_big;
diff --git a/drivers/cpuidle/dt_idle_states.c b/drivers/cpuidle/dt_idle_states.c
new file mode 100644
index 0000000..52f4d11
--- /dev/null
+++ b/drivers/cpuidle/dt_idle_states.c
@@ -0,0 +1,213 @@
+/*
+ * DT idle states parsing code.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "DT idle-states: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include "dt_idle_states.h"
+
+static int init_state_node(struct cpuidle_state *idle_state,
+ const struct of_device_id *matches,
+ struct device_node *state_node)
+{
+ int err;
+ const struct of_device_id *match_id;
+
+ match_id = of_match_node(matches, state_node);
+ if (!match_id)
+ return -ENODEV;
+ /*
+ * CPUidle drivers are expected to initialize the const void *data
+ * pointer of the passed in struct of_device_id array to the idle
+ * state enter function.
+ */
+ idle_state->enter = match_id->data;
+
+ err = of_property_read_u32(state_node, "wakeup-latency-us",
+ &idle_state->exit_latency);
+ if (err) {
+ u32 entry_latency, exit_latency;
+
+ err = of_property_read_u32(state_node, "entry-latency-us",
+ &entry_latency);
+ if (err) {
+ pr_debug(" * %s missing entry-latency-us property\n",
+ state_node->full_name);
+ return -EINVAL;
+ }
+
+ err = of_property_read_u32(state_node, "exit-latency-us",
+ &exit_latency);
+ if (err) {
+ pr_debug(" * %s missing exit-latency-us property\n",
+ state_node->full_name);
+ return -EINVAL;
+ }
+ /*
+ * If wakeup-latency-us is missing, default to entry+exit
+ * latencies as defined in idle states bindings
+ */
+ idle_state->exit_latency = entry_latency + exit_latency;
+ }
+
+ err = of_property_read_u32(state_node, "min-residency-us",
+ &idle_state->target_residency);
+ if (err) {
+ pr_debug(" * %s missing min-residency-us property\n",
+ state_node->full_name);
+ return -EINVAL;
+ }
+
+ idle_state->flags = CPUIDLE_FLAG_TIME_VALID;
+ if (of_property_read_bool(state_node, "local-timer-stop"))
+ idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;
+ /*
+ * TODO:
+ * replace with kstrdup and pointer assignment when name
+ * and desc become string pointers
+ */
+ strncpy(idle_state->name, state_node->name, CPUIDLE_NAME_LEN - 1);
+ strncpy(idle_state->desc, state_node->name, CPUIDLE_DESC_LEN - 1);
+ return 0;
+}
+
+/*
+ * Check that the idle state is uniform across all CPUs in the CPUidle driver
+ * cpumask
+ */
+static bool idle_state_valid(struct device_node *state_node, unsigned int idx,
+ const cpumask_t *cpumask)
+{
+ int cpu;
+ struct device_node *cpu_node, *curr_state_node;
+ bool valid = true;
+
+ /*
+ * Compare idle state phandles for index idx on all CPUs in the
+ * CPUidle driver cpumask. Start from next logical cpu following
+ * cpumask_first(cpumask) since that's the CPU state_node was
+ * retrieved from. If a mismatch is found bail out straight
+ * away since we certainly hit a firmware misconfiguration.
+ */
+ for (cpu = cpumask_next(cpumask_first(cpumask), cpumask);
+ cpu < nr_cpu_ids; cpu = cpumask_next(cpu, cpumask)) {
+ cpu_node = of_cpu_device_node_get(cpu);
+ curr_state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
+ idx);
+ if (state_node != curr_state_node)
+ valid = false;
+
+ of_node_put(curr_state_node);
+ of_node_put(cpu_node);
+ if (!valid)
+ break;
+ }
+
+ return valid;
+}
+
+/**
+ * dt_init_idle_driver() - Parse the DT idle states and initialize the
+ * idle driver states array
+ * @drv: Pointer to CPU idle driver to be initialized
+ * @matches: Array of of_device_id match structures to search in for
+ * compatible idle state nodes. The data pointer for each valid
+ * struct of_device_id entry in the matches array must point to
+ * a function with the following signature, that corresponds to
+ * the CPUidle state enter function signature:
+ *
+ * int (*)(struct cpuidle_device *dev,
+ * struct cpuidle_driver *drv,
+ * int index);
+ *
+ * @start_idx: First idle state index to be initialized
+ *
+ * If DT idle states are detected and are valid the state count and states
+ * array entries in the cpuidle driver are initialized accordingly starting
+ * from index start_idx.
+ *
+ * Return: number of valid DT idle states parsed, <0 on failure
+ */
+int dt_init_idle_driver(struct cpuidle_driver *drv,
+ const struct of_device_id *matches,
+ unsigned int start_idx)
+{
+ struct cpuidle_state *idle_state;
+ struct device_node *state_node, *cpu_node;
+ int i, err = 0;
+ const cpumask_t *cpumask;
+ unsigned int state_idx = start_idx;
+
+ if (state_idx >= CPUIDLE_STATE_MAX)
+ return -EINVAL;
+ /*
+ * We get the idle states for the first logical cpu in the
+ * driver mask (or cpu_possible_mask if the driver cpumask is not set)
+ * and we check through idle_state_valid() if they are uniform
+ * across CPUs, otherwise we hit a firmware misconfiguration.
+ */
+ cpumask = drv->cpumask ? : cpu_possible_mask;
+ cpu_node = of_cpu_device_node_get(cpumask_first(cpumask));
+
+ for (i = 0; ; i++) {
+ state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
+ if (!state_node)
+ break;
+
+ if (!idle_state_valid(state_node, i, cpumask)) {
+ pr_warn("%s idle state not valid, bailing out\n",
+ state_node->full_name);
+ err = -EINVAL;
+ break;
+ }
+
+ if (state_idx == CPUIDLE_STATE_MAX) {
+ pr_warn("State index reached static CPU idle driver states array size\n");
+ break;
+ }
+
+ idle_state = &drv->states[state_idx++];
+ err = init_state_node(idle_state, matches, state_node);
+ if (err) {
+ pr_err("Parsing idle state node %s failed with err %d\n",
+ state_node->full_name, err);
+ err = -EINVAL;
+ break;
+ }
+ of_node_put(state_node);
+ }
+
+ of_node_put(state_node);
+ of_node_put(cpu_node);
+ if (err)
+ return err;
+ /*
+ * Update the driver state count only if some valid DT idle states
+ * were detected
+ */
+ if (i)
+ drv->state_count = state_idx;
+
+ /*
+ * Return the number of present and valid DT idle states, which can
+ * also be 0 on platforms with missing DT idle states or legacy DT
+ * configuration predating the DT idle states bindings.
+ */
+ return i;
+}
+EXPORT_SYMBOL_GPL(dt_init_idle_driver);
diff --git a/drivers/cpuidle/dt_idle_states.h b/drivers/cpuidle/dt_idle_states.h
new file mode 100644
index 0000000..4818134
--- /dev/null
+++ b/drivers/cpuidle/dt_idle_states.h
@@ -0,0 +1,7 @@
+#ifndef __DT_IDLE_STATES
+#define __DT_IDLE_STATES
+
+int dt_init_idle_driver(struct cpuidle_driver *drv,
+ const struct of_device_id *matches,
+ unsigned int start_idx);
+#endif
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