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Message-Id: <20170209092525.6654-7-juri.lelli@arm.com>
Date: Thu, 9 Feb 2017 09:25:22 +0000
From: Juri Lelli <juri.lelli@....com>
To: linux-kernel@...r.kernel.org
Cc: linux-pm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
devicetree@...r.kernel.org, peterz@...radead.org,
vincent.guittot@...aro.org, robh+dt@...nel.org,
mark.rutland@....com, linux@....linux.org.uk, sudeep.holla@....com,
lorenzo.pieralisi@....com, catalin.marinas@....com,
will.deacon@....com, morten.rasmussen@....com,
dietmar.eggemann@....com, juri.lelli@....com, broonie@...nel.org,
gregkh@...uxfoundation.org, Russell King <linux@...linux.org.uk>
Subject: [PATCH v2 6/9] arm, arm64: factorize common cpu capacity default code
arm and arm64 share lot of code relative to parsing CPU capacity
information from DT, using that information for appropriate scaling and
exposing a sysfs interface for chaging such values at runtime.
Factorize such code in a common place (driver/base/arch_topology.c) in
preparation for further additions.
Suggested-by: Will Deacon <will.deacon@....com>
Suggested-by: Mark Rutland <mark.rutland@....com>
Suggested-by: Catalin Marinas <catalin.marinas@....com>
Cc: Russell King <linux@...linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Juri Lelli <juri.lelli@....com>
---
Changes from v1:
- keep the original GPLv2 header
---
arch/arm/Kconfig | 1 +
arch/arm/kernel/topology.c | 213 ++------------------------------------
arch/arm64/Kconfig | 1 +
arch/arm64/kernel/topology.c | 219 +--------------------------------------
drivers/base/Kconfig | 8 ++
drivers/base/Makefile | 1 +
drivers/base/arch_topology.c | 237 +++++++++++++++++++++++++++++++++++++++++++
7 files changed, 257 insertions(+), 423 deletions(-)
create mode 100644 drivers/base/arch_topology.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 186c4c214e0a..6dd5736c1e3c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -19,6 +19,7 @@ config ARM
select EDAC_SUPPORT
select EDAC_ATOMIC_SCRUB
select GENERIC_ALLOCATOR
+ select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
select GENERIC_EARLY_IOREMAP
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index c760a321935b..51e9ed6439f1 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -43,75 +43,10 @@
* to run the rebalance_domains for all idle cores and the cpu_capacity can be
* updated during this sequence.
*/
-static DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
-static DEFINE_MUTEX(cpu_scale_mutex);
-unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
-{
- return per_cpu(cpu_scale, cpu);
-}
-
-static void set_capacity_scale(unsigned int cpu, unsigned long capacity)
-{
- per_cpu(cpu_scale, cpu) = capacity;
-}
-
-static ssize_t cpu_capacity_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct cpu *cpu = container_of(dev, struct cpu, dev);
-
- return sprintf(buf, "%lu\n",
- arch_scale_cpu_capacity(NULL, cpu->dev.id));
-}
-
-static ssize_t cpu_capacity_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf,
- size_t count)
-{
- struct cpu *cpu = container_of(dev, struct cpu, dev);
- int this_cpu = cpu->dev.id, i;
- unsigned long new_capacity;
- ssize_t ret;
-
- if (count) {
- ret = kstrtoul(buf, 0, &new_capacity);
- if (ret)
- return ret;
- if (new_capacity > SCHED_CAPACITY_SCALE)
- return -EINVAL;
-
- mutex_lock(&cpu_scale_mutex);
- for_each_cpu(i, &cpu_topology[this_cpu].core_sibling)
- set_capacity_scale(i, new_capacity);
- mutex_unlock(&cpu_scale_mutex);
- }
-
- return count;
-}
-
-static DEVICE_ATTR_RW(cpu_capacity);
-
-static int register_cpu_capacity_sysctl(void)
-{
- int i;
- struct device *cpu;
-
- for_each_possible_cpu(i) {
- cpu = get_cpu_device(i);
- if (!cpu) {
- pr_err("%s: too early to get CPU%d device!\n",
- __func__, i);
- continue;
- }
- device_create_file(cpu, &dev_attr_cpu_capacity);
- }
-
- return 0;
-}
-subsys_initcall(register_cpu_capacity_sysctl);
+extern unsigned long
+arch_scale_cpu_capacity(struct sched_domain *sd, int cpu);
+extern void set_capacity_scale(unsigned int cpu, unsigned long capacity);
#ifdef CONFIG_OF
struct cpu_efficiency {
@@ -140,145 +75,9 @@ static unsigned long *__cpu_capacity;
static unsigned long middle_capacity = 1;
static bool cap_from_dt = true;
-static u32 *raw_capacity;
-static bool cap_parsing_failed;
-static u32 capacity_scale;
-
-static int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
-{
- int ret = 1;
- u32 cpu_capacity;
-
- if (cap_parsing_failed)
- return !ret;
-
- ret = of_property_read_u32(cpu_node,
- "capacity-dmips-mhz",
- &cpu_capacity);
- if (!ret) {
- if (!raw_capacity) {
- raw_capacity = kcalloc(num_possible_cpus(),
- sizeof(*raw_capacity),
- GFP_KERNEL);
- if (!raw_capacity) {
- pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
- cap_parsing_failed = true;
- return ret;
- }
- }
- capacity_scale = max(cpu_capacity, capacity_scale);
- raw_capacity[cpu] = cpu_capacity;
- pr_debug("cpu_capacity: %s cpu_capacity=%u (raw)\n",
- cpu_node->full_name, raw_capacity[cpu]);
- } else {
- if (raw_capacity) {
- pr_err("cpu_capacity: missing %s raw capacity\n",
- cpu_node->full_name);
- pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
- }
- cap_parsing_failed = true;
- kfree(raw_capacity);
- }
-
- return !ret;
-}
-
-static void normalize_cpu_capacity(void)
-{
- u64 capacity;
- int cpu;
-
- if (!raw_capacity || cap_parsing_failed)
- return;
-
- pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
- mutex_lock(&cpu_scale_mutex);
- for_each_possible_cpu(cpu) {
- capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
- / capacity_scale;
- set_capacity_scale(cpu, capacity);
- pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
- cpu, arch_scale_cpu_capacity(NULL, cpu));
- }
- mutex_unlock(&cpu_scale_mutex);
-}
-
-#ifdef CONFIG_CPU_FREQ
-static cpumask_var_t cpus_to_visit;
-static bool cap_parsing_done;
-static void parsing_done_workfn(struct work_struct *work);
-static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
-
-static int
-init_cpu_capacity_callback(struct notifier_block *nb,
- unsigned long val,
- void *data)
-{
- struct cpufreq_policy *policy = data;
- int cpu;
-
- if (cap_parsing_failed || cap_parsing_done)
- return 0;
-
- switch (val) {
- case CPUFREQ_NOTIFY:
- pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
- cpumask_pr_args(policy->related_cpus),
- cpumask_pr_args(cpus_to_visit));
- cpumask_andnot(cpus_to_visit,
- cpus_to_visit,
- policy->related_cpus);
- for_each_cpu(cpu, policy->related_cpus) {
- raw_capacity[cpu] = arch_scale_cpu_capacity(NULL, cpu) *
- policy->cpuinfo.max_freq / 1000UL;
- capacity_scale = max(raw_capacity[cpu], capacity_scale);
- }
- if (cpumask_empty(cpus_to_visit)) {
- normalize_cpu_capacity();
- kfree(raw_capacity);
- pr_debug("cpu_capacity: parsing done\n");
- cap_parsing_done = true;
- schedule_work(&parsing_done_work);
- }
- }
- return 0;
-}
-
-static struct notifier_block init_cpu_capacity_notifier = {
- .notifier_call = init_cpu_capacity_callback,
-};
-
-static int __init register_cpufreq_notifier(void)
-{
- if (cap_parsing_failed)
- return -EINVAL;
-
- if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) {
- pr_err("cpu_capacity: failed to allocate memory for cpus_to_visit\n");
- return -ENOMEM;
- }
- cpumask_copy(cpus_to_visit, cpu_possible_mask);
-
- return cpufreq_register_notifier(&init_cpu_capacity_notifier,
- CPUFREQ_POLICY_NOTIFIER);
-}
-core_initcall(register_cpufreq_notifier);
-
-static void parsing_done_workfn(struct work_struct *work)
-{
- cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
- CPUFREQ_POLICY_NOTIFIER);
-}
-
-#else
-static int __init free_raw_capacity(void)
-{
- kfree(raw_capacity);
-
- return 0;
-}
-core_initcall(free_raw_capacity);
-#endif
+extern bool cap_parsing_failed;
+extern void normalize_cpu_capacity(void);
+extern int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu);
/*
* Iterate all CPUs' descriptor in DT and compute the efficiency
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 111742126897..7534bb41ee09 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -36,6 +36,7 @@ config ARM64
select EDAC_SUPPORT
select FRAME_POINTER
select GENERIC_ALLOCATOR
+ select GENERIC_ARCH_TOPOLOGY
select GENERIC_CLOCKEVENTS
select GENERIC_CLOCKEVENTS_BROADCAST
select GENERIC_CPU_AUTOPROBE
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 565dd69888cc..f629f7524d65 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -11,7 +11,6 @@
* for more details.
*/
-#include <linux/acpi.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/init.h>
@@ -22,226 +21,14 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
-#include <linux/cpufreq.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/topology.h>
-static DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
-static DEFINE_MUTEX(cpu_scale_mutex);
-
-unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
-{
- return per_cpu(cpu_scale, cpu);
-}
-
-static void set_capacity_scale(unsigned int cpu, unsigned long capacity)
-{
- per_cpu(cpu_scale, cpu) = capacity;
-}
-
-static ssize_t cpu_capacity_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct cpu *cpu = container_of(dev, struct cpu, dev);
-
- return sprintf(buf, "%lu\n",
- arch_scale_cpu_capacity(NULL, cpu->dev.id));
-}
-
-static ssize_t cpu_capacity_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf,
- size_t count)
-{
- struct cpu *cpu = container_of(dev, struct cpu, dev);
- int this_cpu = cpu->dev.id, i;
- unsigned long new_capacity;
- ssize_t ret;
-
- if (count) {
- ret = kstrtoul(buf, 0, &new_capacity);
- if (ret)
- return ret;
- if (new_capacity > SCHED_CAPACITY_SCALE)
- return -EINVAL;
-
- mutex_lock(&cpu_scale_mutex);
- for_each_cpu(i, &cpu_topology[this_cpu].core_sibling)
- set_capacity_scale(i, new_capacity);
- mutex_unlock(&cpu_scale_mutex);
- }
-
- return count;
-}
-
-static DEVICE_ATTR_RW(cpu_capacity);
-
-static int register_cpu_capacity_sysctl(void)
-{
- int i;
- struct device *cpu;
-
- for_each_possible_cpu(i) {
- cpu = get_cpu_device(i);
- if (!cpu) {
- pr_err("%s: too early to get CPU%d device!\n",
- __func__, i);
- continue;
- }
- device_create_file(cpu, &dev_attr_cpu_capacity);
- }
-
- return 0;
-}
-subsys_initcall(register_cpu_capacity_sysctl);
-
-static u32 capacity_scale;
-static u32 *raw_capacity;
-static bool cap_parsing_failed;
-
-static void __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
-{
- int ret;
- u32 cpu_capacity;
-
- if (cap_parsing_failed)
- return;
-
- ret = of_property_read_u32(cpu_node,
- "capacity-dmips-mhz",
- &cpu_capacity);
- if (!ret) {
- if (!raw_capacity) {
- raw_capacity = kcalloc(num_possible_cpus(),
- sizeof(*raw_capacity),
- GFP_KERNEL);
- if (!raw_capacity) {
- pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
- cap_parsing_failed = true;
- return;
- }
- }
- capacity_scale = max(cpu_capacity, capacity_scale);
- raw_capacity[cpu] = cpu_capacity;
- pr_debug("cpu_capacity: %s cpu_capacity=%u (raw)\n",
- cpu_node->full_name, raw_capacity[cpu]);
- } else {
- if (raw_capacity) {
- pr_err("cpu_capacity: missing %s raw capacity\n",
- cpu_node->full_name);
- pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
- }
- cap_parsing_failed = true;
- kfree(raw_capacity);
- }
-}
-
-static void normalize_cpu_capacity(void)
-{
- u64 capacity;
- int cpu;
-
- if (!raw_capacity || cap_parsing_failed)
- return;
-
- pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
- mutex_lock(&cpu_scale_mutex);
- for_each_possible_cpu(cpu) {
- pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n",
- cpu, raw_capacity[cpu]);
- capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
- / capacity_scale;
- set_capacity_scale(cpu, capacity);
- pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
- cpu, arch_scale_cpu_capacity(NULL, cpu));
- }
- mutex_unlock(&cpu_scale_mutex);
-}
-
-#ifdef CONFIG_CPU_FREQ
-static cpumask_var_t cpus_to_visit;
-static bool cap_parsing_done;
-static void parsing_done_workfn(struct work_struct *work);
-static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
-
-static int
-init_cpu_capacity_callback(struct notifier_block *nb,
- unsigned long val,
- void *data)
-{
- struct cpufreq_policy *policy = data;
- int cpu;
-
- if (cap_parsing_failed || cap_parsing_done)
- return 0;
-
- switch (val) {
- case CPUFREQ_NOTIFY:
- pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
- cpumask_pr_args(policy->related_cpus),
- cpumask_pr_args(cpus_to_visit));
- cpumask_andnot(cpus_to_visit,
- cpus_to_visit,
- policy->related_cpus);
- for_each_cpu(cpu, policy->related_cpus) {
- raw_capacity[cpu] = arch_scale_cpu_capacity(NULL, cpu) *
- policy->cpuinfo.max_freq / 1000UL;
- capacity_scale = max(raw_capacity[cpu], capacity_scale);
- }
- if (cpumask_empty(cpus_to_visit)) {
- normalize_cpu_capacity();
- kfree(raw_capacity);
- pr_debug("cpu_capacity: parsing done\n");
- cap_parsing_done = true;
- schedule_work(&parsing_done_work);
- }
- }
- return 0;
-}
-
-static struct notifier_block init_cpu_capacity_notifier = {
- .notifier_call = init_cpu_capacity_callback,
-};
-
-static int __init register_cpufreq_notifier(void)
-{
- /*
- * on ACPI-based systems we need to use the default cpu capacity
- * until we have the necessary code to parse the cpu capacity, so
- * skip registering cpufreq notifier.
- */
- if (!acpi_disabled || cap_parsing_failed)
- return -EINVAL;
-
- if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) {
- pr_err("cpu_capacity: failed to allocate memory for cpus_to_visit\n");
- return -ENOMEM;
- }
- cpumask_copy(cpus_to_visit, cpu_possible_mask);
-
- return cpufreq_register_notifier(&init_cpu_capacity_notifier,
- CPUFREQ_POLICY_NOTIFIER);
-}
-core_initcall(register_cpufreq_notifier);
-
-static void parsing_done_workfn(struct work_struct *work)
-{
- cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
- CPUFREQ_POLICY_NOTIFIER);
-}
-
-#else
-static int __init free_raw_capacity(void)
-{
- kfree(raw_capacity);
-
- return 0;
-}
-core_initcall(free_raw_capacity);
-#endif
+extern bool cap_parsing_failed;
+extern void normalize_cpu_capacity(void);
+extern int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu);
static int __init get_cpu_for_node(struct device_node *node)
{
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index d718ae4b907a..307ea31187dd 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -339,4 +339,12 @@ config CMA_ALIGNMENT
endif
+config GENERIC_ARCH_TOPOLOGY
+ bool
+ help
+ Enable support for architectures common topology code: e.g., parsing
+ CPU capacity information from DT, usage of such information for
+ appropriate scaling, sysfs interface for changing capacity values at
+ runtime.
+
endmenu
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index f2816f6ff76a..397e5c344e6a 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_SOC_BUS) += soc.o
obj-$(CONFIG_PINCTRL) += pinctrl.o
obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
obj-$(CONFIG_GENERIC_MSI_IRQ_DOMAIN) += platform-msi.o
+obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o
obj-y += test/
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
new file mode 100644
index 000000000000..c1dd430adad2
--- /dev/null
+++ b/drivers/base/arch_topology.c
@@ -0,0 +1,237 @@
+/*
+ * driver/base/arch_topology.c - Arch specific cpu topology information
+ *
+ * Copyright (C) 2016, ARM Ltd.
+ * Written by: Juri Lelli, ARM Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/acpi.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/topology.h>
+
+static DEFINE_MUTEX(cpu_scale_mutex);
+static DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE;
+
+unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
+{
+ return per_cpu(cpu_scale, cpu);
+}
+
+void set_capacity_scale(unsigned int cpu, unsigned long capacity)
+{
+ per_cpu(cpu_scale, cpu) = capacity;
+}
+
+static ssize_t cpu_capacity_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct cpu *cpu = container_of(dev, struct cpu, dev);
+
+ return sprintf(buf, "%lu\n",
+ arch_scale_cpu_capacity(NULL, cpu->dev.id));
+}
+
+static ssize_t cpu_capacity_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ struct cpu *cpu = container_of(dev, struct cpu, dev);
+ int this_cpu = cpu->dev.id, i;
+ unsigned long new_capacity;
+ ssize_t ret;
+
+ if (count) {
+ ret = kstrtoul(buf, 0, &new_capacity);
+ if (ret)
+ return ret;
+ if (new_capacity > SCHED_CAPACITY_SCALE)
+ return -EINVAL;
+
+ mutex_lock(&cpu_scale_mutex);
+ for_each_cpu(i, &cpu_topology[this_cpu].core_sibling)
+ set_capacity_scale(i, new_capacity);
+ mutex_unlock(&cpu_scale_mutex);
+ }
+
+ return count;
+}
+
+static DEVICE_ATTR_RW(cpu_capacity);
+
+static int register_cpu_capacity_sysctl(void)
+{
+ int i;
+ struct device *cpu;
+
+ for_each_possible_cpu(i) {
+ cpu = get_cpu_device(i);
+ if (!cpu) {
+ pr_err("%s: too early to get CPU%d device!\n",
+ __func__, i);
+ continue;
+ }
+ device_create_file(cpu, &dev_attr_cpu_capacity);
+ }
+
+ return 0;
+}
+subsys_initcall(register_cpu_capacity_sysctl);
+
+u32 capacity_scale;
+u32 *raw_capacity;
+bool cap_parsing_failed;
+
+void normalize_cpu_capacity(void)
+{
+ u64 capacity;
+ int cpu;
+
+ if (!raw_capacity || cap_parsing_failed)
+ return;
+
+ pr_debug("cpu_capacity: capacity_scale=%u\n", capacity_scale);
+ mutex_lock(&cpu_scale_mutex);
+ for_each_possible_cpu(cpu) {
+ pr_debug("cpu_capacity: cpu=%d raw_capacity=%u\n",
+ cpu, raw_capacity[cpu]);
+ capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
+ / capacity_scale;
+ set_capacity_scale(cpu, capacity);
+ pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
+ cpu, arch_scale_cpu_capacity(NULL, cpu));
+ }
+ mutex_unlock(&cpu_scale_mutex);
+}
+
+int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
+{
+ int ret = 1;
+ u32 cpu_capacity;
+
+ if (cap_parsing_failed)
+ return !ret;
+
+ ret = of_property_read_u32(cpu_node,
+ "capacity-dmips-mhz",
+ &cpu_capacity);
+ if (!ret) {
+ if (!raw_capacity) {
+ raw_capacity = kcalloc(num_possible_cpus(),
+ sizeof(*raw_capacity),
+ GFP_KERNEL);
+ if (!raw_capacity) {
+ pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
+ cap_parsing_failed = true;
+ return ret;
+ }
+ }
+ capacity_scale = max(cpu_capacity, capacity_scale);
+ raw_capacity[cpu] = cpu_capacity;
+ pr_debug("cpu_capacity: %s cpu_capacity=%u (raw)\n",
+ cpu_node->full_name, raw_capacity[cpu]);
+ } else {
+ if (raw_capacity) {
+ pr_err("cpu_capacity: missing %s raw capacity\n",
+ cpu_node->full_name);
+ pr_err("cpu_capacity: partial information: fallback to 1024 for all CPUs\n");
+ }
+ cap_parsing_failed = true;
+ kfree(raw_capacity);
+ }
+
+ return !ret;
+}
+
+#ifdef CONFIG_CPU_FREQ
+static cpumask_var_t cpus_to_visit;
+static bool cap_parsing_done;
+static void parsing_done_workfn(struct work_struct *work);
+static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
+
+static int
+init_cpu_capacity_callback(struct notifier_block *nb,
+ unsigned long val,
+ void *data)
+{
+ struct cpufreq_policy *policy = data;
+ int cpu;
+
+ if (cap_parsing_failed || cap_parsing_done)
+ return 0;
+
+ switch (val) {
+ case CPUFREQ_NOTIFY:
+ pr_debug("cpu_capacity: init cpu capacity for CPUs [%*pbl] (to_visit=%*pbl)\n",
+ cpumask_pr_args(policy->related_cpus),
+ cpumask_pr_args(cpus_to_visit));
+ cpumask_andnot(cpus_to_visit,
+ cpus_to_visit,
+ policy->related_cpus);
+ for_each_cpu(cpu, policy->related_cpus) {
+ raw_capacity[cpu] = arch_scale_cpu_capacity(NULL, cpu) *
+ policy->cpuinfo.max_freq / 1000UL;
+ capacity_scale = max(raw_capacity[cpu], capacity_scale);
+ }
+ if (cpumask_empty(cpus_to_visit)) {
+ normalize_cpu_capacity();
+ kfree(raw_capacity);
+ pr_debug("cpu_capacity: parsing done\n");
+ cap_parsing_done = true;
+ schedule_work(&parsing_done_work);
+ }
+ }
+ return 0;
+}
+
+static struct notifier_block init_cpu_capacity_notifier = {
+ .notifier_call = init_cpu_capacity_callback,
+};
+
+static int __init register_cpufreq_notifier(void)
+{
+ /*
+ * on ACPI-based systems we need to use the default cpu capacity
+ * until we have the necessary code to parse the cpu capacity, so
+ * skip registering cpufreq notifier.
+ */
+ if (!acpi_disabled || cap_parsing_failed)
+ return -EINVAL;
+
+ if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) {
+ pr_err("cpu_capacity: failed to allocate memory for cpus_to_visit\n");
+ return -ENOMEM;
+ }
+
+ cpumask_copy(cpus_to_visit, cpu_possible_mask);
+
+ return cpufreq_register_notifier(&init_cpu_capacity_notifier,
+ CPUFREQ_POLICY_NOTIFIER);
+}
+core_initcall(register_cpufreq_notifier);
+
+static void parsing_done_workfn(struct work_struct *work)
+{
+ cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
+ CPUFREQ_POLICY_NOTIFIER);
+}
+
+#else
+static int __init free_raw_capacity(void)
+{
+ kfree(raw_capacity);
+
+ return 0;
+}
+core_initcall(free_raw_capacity);
+#endif
--
2.10.0
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