Hi,
arm and arm64 topology.c share a lot of code related to parsing of capacity
information. This is v4 of a solution [1] (based on Will's, Catalin's and
Mark's off-line suggestions) to move such common code in a single place:
drivers/base/arch_topology.c (by creating such file and conditionally compiling
it for arm and arm64 only).
First 4 patches are actually fixes for the current code.
Patch 5 is the actual refactoring.
Patch 6 removes one of the extern symbols by changing a bit the now common
code.
Patch 7 removes the remaining externs (as required by Russell during v1 review)
by creating a new header file include/linux/arch_topology.h and including that
from arm, arm64 and drivers.
Last patch addresses Dietmar's comments to v1 and adds a 'atd_' prefix to
interfaces exported by drivers code and used by arch (and potentially others in
the future).
Changes from v3:
- rebase on top of 4.11-rc7
- addressed Vincent's comment on patch 3/8
- removed v3 6/9 as discussed with Russell
- added Russell and Catalin's Acked-by
The set is based on top of linux/master (4.11-rc7 f61143c45077) and it is also
available from:
git://linux-arm.org/linux-jl.git upstream/default_caps_factorize-v4
Best,
- Juri
[1] v1 - https://marc.info/?l=linux-kernel&m=148483680119355&w=2
v2 - https://marc.info/?l=linux-kernel&m=148663344018205&w=2
v3 - http://marc.info/?l=linux-kernel&m=149062080701399&w=2
Juri Lelli (8):
Documentation: arm: fix wrong reference number in DT definition
Documentation/ABI: add information about cpu_capacity
arm: fix return value of parse_cpu_capacity
arm: remove wrong CONFIG_PROC_SYSCTL ifdef
arm, arm64: factorize common cpu capacity default code
arm,arm64,drivers: reduce scope of cap_parsing_failed
arm,arm64,drivers: move externs in a new header file
arm,arm64,drivers: add a prefix to drivers arch_topology interfaces
Documentation/ABI/testing/sysfs-devices-system-cpu | 7 +
Documentation/devicetree/bindings/arm/cpus.txt | 4 +-
arch/arm/Kconfig | 1 +
arch/arm/kernel/topology.c | 221 +------------------
arch/arm64/Kconfig | 1 +
arch/arm64/kernel/topology.c | 226 +------------------
drivers/base/Kconfig | 8 +
drivers/base/Makefile | 1 +
drivers/base/arch_topology.c | 243 +++++++++++++++++++++
include/linux/arch_topology.h | 17 ++
10 files changed, 290 insertions(+), 439 deletions(-)
create mode 100644 drivers/base/arch_topology.c
create mode 100644 include/linux/arch_topology.h
--
2.10.0
Reference to cpu capacity binding has a wrong number. Fix it.
Reported-by: Lorenzo Pieralisi <[email protected]>
Signed-off-by: Juri Lelli <[email protected]>
Acked-by: Rob Herring <[email protected]>
Acked-by: Russell King <[email protected]>
---
Documentation/devicetree/bindings/arm/cpus.txt | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/arm/cpus.txt b/Documentation/devicetree/bindings/arm/cpus.txt
index 698ad1f097fa..83ec3fa0a05e 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -248,7 +248,7 @@ nodes to be present and contain the properties described below.
Usage: Optional
Value type: <u32>
Definition:
- # u32 value representing CPU capacity [3] in
+ # u32 value representing CPU capacity [4] in
DMIPS/MHz, relative to highest capacity-dmips-mhz
in the system.
@@ -475,5 +475,5 @@ cpus {
[2] arm/msm/qcom,kpss-acc.txt
[3] ARM Linux kernel documentation - idle states bindings
Documentation/devicetree/bindings/arm/idle-states.txt
-[3] ARM Linux kernel documentation - cpu capacity bindings
+[4] ARM Linux kernel documentation - cpu capacity bindings
Documentation/devicetree/bindings/arm/cpu-capacity.txt
--
2.10.0
parse_cpu_capacity() has to return 0 on failure, but it currently returns
1 instead if raw_capacity kcalloc failed.
Fix it (by directly returning 0).
Cc: Russell King <[email protected]>
Reported-by: Morten Rasmussen <[email protected]>
Fixes: 06073ee26775 ('ARM: 8621/3: parse cpu capacity-dmips-mhz from DT')
Signed-off-by: Juri Lelli <[email protected]>
Acked-by: Russell King <[email protected]>
---
Changes from v3:
- directly return 0 on failure (as pointed out by Vincent)
---
arch/arm/kernel/topology.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index f8a3ab82e77f..1b8ec3054642 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -166,7 +166,7 @@ static int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
if (!raw_capacity) {
pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
cap_parsing_failed = true;
- return !ret;
+ return 0;
}
}
capacity_scale = max(cpu_capacity, capacity_scale);
--
2.10.0
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 <[email protected]>
Suggested-by: Mark Rutland <[email protected]>
Suggested-by: Catalin Marinas <[email protected]>
Cc: Russell King <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Juri Lelli <[email protected]>
Acked-by: Russell King <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
---
Changes from v2:
- make capacity_scale and raw_capacity static
- added SPDX header
- improved indent
- misc. whitespaces/newlines fixes
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 | 242 +++++++++++++++++++++++++++++++++++++++++++
7 files changed, 262 insertions(+), 423 deletions(-)
create mode 100644 drivers/base/arch_topology.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0d4e71b42c77..cd61154bb6d0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -25,6 +25,7 @@ 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 40dd35aa46d0..49ef025ffaa0 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -44,75 +44,10 @@
* 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 {
@@ -141,145 +76,9 @@ 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 0;
- }
- }
- 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 3741859765cf..e36fb12afad6 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -40,6 +40,7 @@ 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 08243533e5ee..c5bc31eb97e8 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>
@@ -23,226 +22,14 @@
#include <linux/sched/topology.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..f046d21de57d 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..097834f0fcd7
--- /dev/null
+++ b/drivers/base/arch_topology.c
@@ -0,0 +1,242 @@
+/*
+ * 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.
+ *
+ * Released under the GPLv2 only.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#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/sched/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;
+ int i;
+ unsigned long new_capacity;
+ ssize_t ret;
+
+ if (!count)
+ return 0;
+
+ 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;
+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 0;
+ }
+ }
+ 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
Now that some functions that deal with arch topology information live
under drivers, there is a clash of naming that might create confusion.
Tidy things up by creating a drivers namespace for interfaces used by
arch code; achieve this by prepending a 'atd_' (arch topology driver)
prefix to driver interfaces.
Signed-off-by: Juri Lelli <[email protected]>
Acked-by: Russell King <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
---
arch/arm/kernel/topology.c | 8 ++++----
arch/arm64/kernel/topology.c | 4 ++--
drivers/base/arch_topology.c | 20 ++++++++++----------
include/linux/arch_topology.h | 8 ++++----
4 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 557be4f1d2d7..e53391026c1b 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -111,7 +111,7 @@ static void __init parse_dt_topology(void)
continue;
}
- if (parse_cpu_capacity(cn, cpu)) {
+ if (atd_parse_cpu_capacity(cn, cpu)) {
of_node_put(cn);
continue;
}
@@ -160,7 +160,7 @@ static void __init parse_dt_topology(void)
>> (SCHED_CAPACITY_SHIFT-1)) + 1;
if (cap_from_dt)
- normalize_cpu_capacity();
+ atd_normalize_cpu_capacity();
}
/*
@@ -173,10 +173,10 @@ static void update_cpu_capacity(unsigned int cpu)
if (!cpu_capacity(cpu) || cap_from_dt)
return;
- set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity);
+ atd_set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity);
pr_info("CPU%u: update cpu_capacity %lu\n",
- cpu, arch_scale_cpu_capacity(NULL, cpu));
+ cpu, atd_scale_cpu_capacity(NULL, cpu));
}
#else
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 255230c3e835..5f24faa09c05 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -39,7 +39,7 @@ static int __init get_cpu_for_node(struct device_node *node)
for_each_possible_cpu(cpu) {
if (of_get_cpu_node(cpu, NULL) == cpu_node) {
- parse_cpu_capacity(cpu_node, cpu);
+ atd_parse_cpu_capacity(cpu_node, cpu);
of_node_put(cpu_node);
return cpu;
}
@@ -191,7 +191,7 @@ static int __init parse_dt_topology(void)
if (ret != 0)
goto out_map;
- normalize_cpu_capacity();
+ atd_normalize_cpu_capacity();
/*
* Check that all cores are in the topology; the SMP code will
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 76c19aa0d82f..f04999e3ff75 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -25,12 +25,12 @@
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)
+unsigned long atd_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)
+void atd_set_capacity_scale(unsigned int cpu, unsigned long capacity)
{
per_cpu(cpu_scale, cpu) = capacity;
}
@@ -42,7 +42,7 @@ static ssize_t cpu_capacity_show(struct device *dev,
struct cpu *cpu = container_of(dev, struct cpu, dev);
return sprintf(buf, "%lu\n",
- arch_scale_cpu_capacity(NULL, cpu->dev.id));
+ atd_scale_cpu_capacity(NULL, cpu->dev.id));
}
static ssize_t cpu_capacity_store(struct device *dev,
@@ -67,7 +67,7 @@ static ssize_t cpu_capacity_store(struct device *dev,
mutex_lock(&cpu_scale_mutex);
for_each_cpu(i, &cpu_topology[this_cpu].core_sibling)
- set_capacity_scale(i, new_capacity);
+ atd_set_capacity_scale(i, new_capacity);
mutex_unlock(&cpu_scale_mutex);
return count;
@@ -98,7 +98,7 @@ static u32 capacity_scale;
static u32 *raw_capacity;
static bool cap_parsing_failed;
-void normalize_cpu_capacity(void)
+void atd_normalize_cpu_capacity(void)
{
u64 capacity;
int cpu;
@@ -113,14 +113,14 @@ void normalize_cpu_capacity(void)
cpu, raw_capacity[cpu]);
capacity = (raw_capacity[cpu] << SCHED_CAPACITY_SHIFT)
/ capacity_scale;
- set_capacity_scale(cpu, capacity);
+ atd_set_capacity_scale(cpu, capacity);
pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
- cpu, arch_scale_cpu_capacity(NULL, cpu));
+ cpu, atd_scale_cpu_capacity(NULL, cpu));
}
mutex_unlock(&cpu_scale_mutex);
}
-int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
+int __init atd_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
{
int ret = 1;
u32 cpu_capacity;
@@ -185,12 +185,12 @@ init_cpu_capacity_callback(struct notifier_block *nb,
cpus_to_visit,
policy->related_cpus);
for_each_cpu(cpu, policy->related_cpus) {
- raw_capacity[cpu] = arch_scale_cpu_capacity(NULL, cpu) *
+ raw_capacity[cpu] = atd_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();
+ atd_normalize_cpu_capacity();
kfree(raw_capacity);
pr_debug("cpu_capacity: parsing done\n");
cap_parsing_done = true;
diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h
index 4edae9fe8cdd..e25458d7ee9a 100644
--- a/include/linux/arch_topology.h
+++ b/include/linux/arch_topology.h
@@ -4,14 +4,14 @@
#ifndef _LINUX_ARCH_TOPOLOGY_H_
#define _LINUX_ARCH_TOPOLOGY_H_
-void normalize_cpu_capacity(void);
+void atd_normalize_cpu_capacity(void);
struct device_node;
-int parse_cpu_capacity(struct device_node *cpu_node, int cpu);
+int atd_parse_cpu_capacity(struct device_node *cpu_node, int cpu);
struct sched_domain;
-unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu);
+unsigned long atd_scale_cpu_capacity(struct sched_domain *sd, int cpu);
-void set_capacity_scale(unsigned int cpu, unsigned long capacity);
+void atd_set_capacity_scale(unsigned int cpu, unsigned long capacity);
#endif /* _LINUX_ARCH_TOPOLOGY_H_ */
--
2.10.0
Reduce the scope of cap_parsing_failed (making it static in
drivers/base/arch_topology.c) by slightly changing {arm,arm64} DT
parsing code.
For arm checking for !cap_parsing_failed before calling normalize_
cpu_capacity() is superfluous, as returning an error from parse_
cpu_capacity() (above) means cap_from _dt is set to false.
For arm64 we can simply check if raw_capacity points to something,
which is not if capacity parsing has failed.
Suggested-by: Morten Rasmussen <[email protected]>
Signed-off-by: Juri Lelli <[email protected]>
Acked-by: Russell King <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
---
arch/arm/kernel/topology.c | 3 +--
arch/arm64/kernel/topology.c | 5 +----
drivers/base/arch_topology.c | 4 ++--
3 files changed, 4 insertions(+), 8 deletions(-)
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 49ef025ffaa0..1e35a3265ddf 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -76,7 +76,6 @@ static unsigned long *__cpu_capacity;
static unsigned long middle_capacity = 1;
static bool cap_from_dt = true;
-extern bool cap_parsing_failed;
extern void normalize_cpu_capacity(void);
extern int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu);
@@ -165,7 +164,7 @@ static void __init parse_dt_topology(void)
middle_capacity = ((max_capacity / 3)
>> (SCHED_CAPACITY_SHIFT-1)) + 1;
- if (cap_from_dt && !cap_parsing_failed)
+ if (cap_from_dt)
normalize_cpu_capacity();
}
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index c5bc31eb97e8..7e1f6f75185b 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -27,7 +27,6 @@
#include <asm/cputype.h>
#include <asm/topology.h>
-extern bool cap_parsing_failed;
extern void normalize_cpu_capacity(void);
extern int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu);
@@ -187,10 +186,8 @@ static int __init parse_dt_topology(void)
* cluster with restricted subnodes.
*/
map = of_get_child_by_name(cn, "cpu-map");
- if (!map) {
- cap_parsing_failed = true;
+ if (!map)
goto out;
- }
ret = parse_cluster(map, 0);
if (ret != 0)
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 097834f0fcd7..acf99372c5cf 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -95,7 +95,7 @@ subsys_initcall(register_cpu_capacity_sysctl);
static u32 capacity_scale;
static u32 *raw_capacity;
-bool cap_parsing_failed;
+static bool cap_parsing_failed;
void normalize_cpu_capacity(void)
{
@@ -210,7 +210,7 @@ static int __init register_cpufreq_notifier(void)
* until we have the necessary code to parse the cpu capacity, so
* skip registering cpufreq notifier.
*/
- if (!acpi_disabled || cap_parsing_failed)
+ if (!acpi_disabled || !raw_capacity)
return -EINVAL;
if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) {
--
2.10.0
Create a new header file (include/linux/arch_topology.h) and put there
declarations of interfaces used by arm, arm64 and drivers code.
Signed-off-by: Juri Lelli <[email protected]>
Acked-by: Russell King <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
---
arch/arm/kernel/topology.c | 7 +------
arch/arm64/kernel/topology.c | 4 +---
drivers/base/arch_topology.c | 1 +
include/linux/arch_topology.h | 17 +++++++++++++++++
4 files changed, 20 insertions(+), 9 deletions(-)
create mode 100644 include/linux/arch_topology.h
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 1e35a3265ddf..557be4f1d2d7 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -11,6 +11,7 @@
* for more details.
*/
+#include <linux/arch_topology.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
@@ -45,10 +46,6 @@
* updated during this sequence.
*/
-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 {
const char *compatible;
@@ -76,8 +73,6 @@ static unsigned long *__cpu_capacity;
static unsigned long middle_capacity = 1;
static bool cap_from_dt = true;
-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/kernel/topology.c b/arch/arm64/kernel/topology.c
index 7e1f6f75185b..255230c3e835 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -11,6 +11,7 @@
* for more details.
*/
+#include <linux/arch_topology.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/init.h>
@@ -27,9 +28,6 @@
#include <asm/cputype.h>
#include <asm/topology.h>
-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)
{
struct device_node *cpu_node;
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index acf99372c5cf..76c19aa0d82f 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -13,6 +13,7 @@
*/
#include <linux/acpi.h>
+#include <linux/arch_topology.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/device.h>
diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h
new file mode 100644
index 000000000000..4edae9fe8cdd
--- /dev/null
+++ b/include/linux/arch_topology.h
@@ -0,0 +1,17 @@
+/*
+ * include/linux/arch_topology.h - arch specific cpu topology information
+ */
+#ifndef _LINUX_ARCH_TOPOLOGY_H_
+#define _LINUX_ARCH_TOPOLOGY_H_
+
+void normalize_cpu_capacity(void);
+
+struct device_node;
+int parse_cpu_capacity(struct device_node *cpu_node, int cpu);
+
+struct sched_domain;
+unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu);
+
+void set_capacity_scale(unsigned int cpu, unsigned long capacity);
+
+#endif /* _LINUX_ARCH_TOPOLOGY_H_ */
--
2.10.0
The sysfs cpu_capacity entry for each CPU has nothing to do with
PROC_FS, nor it's in /proc/sys path.
Remove such ifdef.
Cc: Russell King <[email protected]>
Reported-and-suggested-by: Sudeep Holla <[email protected]>
Fixes: 7e5930aaef5d ('ARM: 8622/3: add sysfs cpu_capacity attribute')
Signed-off-by: Juri Lelli <[email protected]>
Acked-by: Russell King <[email protected]>
---
arch/arm/kernel/topology.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 1b8ec3054642..40dd35aa46d0 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -57,7 +57,6 @@ static void set_capacity_scale(unsigned int cpu, unsigned long capacity)
per_cpu(cpu_scale, cpu) = capacity;
}
-#ifdef CONFIG_PROC_SYSCTL
static ssize_t cpu_capacity_show(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -114,7 +113,6 @@ static int register_cpu_capacity_sysctl(void)
return 0;
}
subsys_initcall(register_cpu_capacity_sysctl);
-#endif
#ifdef CONFIG_OF
struct cpu_efficiency {
--
2.10.0
/sys/devices/system/cpu/cpu#/cpu_capacity describe information about
CPUs heterogeneity (ref. to Documentation/devicetree/bindings/arm/
cpu-capacity.txt).
Add such description.
Signed-off-by: Juri Lelli <[email protected]>
Acked-by: Russell King <[email protected]>
---
Documentation/ABI/testing/sysfs-devices-system-cpu | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 2a4a423d08e0..f3d5817c4ef0 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -366,3 +366,10 @@ Contact: Linux ARM Kernel Mailing list <[email protected]>
Description: AArch64 CPU registers
'identification' directory exposes the CPU ID registers for
identifying model and revision of the CPU.
+
+What: /sys/devices/system/cpu/cpu#/cpu_capacity
+Date: December 2016
+Contact: Linux kernel mailing list <[email protected]>
+Description: information about CPUs heterogeneity.
+
+ cpu_capacity: capacity of cpu#.
--
2.10.0
On 20 April 2017 at 16:43, Juri Lelli <[email protected]> wrote:
> parse_cpu_capacity() has to return 0 on failure, but it currently returns
> 1 instead if raw_capacity kcalloc failed.
>
> Fix it (by directly returning 0).
>
> Cc: Russell King <[email protected]>
> Reported-by: Morten Rasmussen <[email protected]>
> Fixes: 06073ee26775 ('ARM: 8621/3: parse cpu capacity-dmips-mhz from DT')
> Signed-off-by: Juri Lelli <[email protected]>
> Acked-by: Russell King <[email protected]>
> ---
>
> Changes from v3:
>
> - directly return 0 on failure (as pointed out by Vincent)
> ---
> arch/arm/kernel/topology.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
> index f8a3ab82e77f..1b8ec3054642 100644
> --- a/arch/arm/kernel/topology.c
> +++ b/arch/arm/kernel/topology.c
> @@ -166,7 +166,7 @@ static int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
> if (!raw_capacity) {
> pr_err("cpu_capacity: failed to allocate memory for raw capacities\n");
> cap_parsing_failed = true;
> - return !ret;
> + return 0;
Acked-by: Vincent Guittot <[email protected]>
> }
> }
> capacity_scale = max(cpu_capacity, capacity_scale);
> --
> 2.10.0
>