[PATCH v5 0/7] Fix issues and factorize arm/arm64 capacity information code

[PATCH v5 0/7] Fix issues and factorize arm/arm64 capacity information code

[Juri Lelli]

Hi,

arm and arm64 topology.c share a lot of code related to parsing of capacity
information. This is v5 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 3 patches are actually fixes for the current code.

Patch 4 is the actual refactoring.

Patch 5 removes one of the extern symbols by changing a bit the now common
code.

Patch 6 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 Greg, Dietmar and Morten's comments to v4 by adding a
'topology_' prefix to interfaces exported by drivers code and used by arch (and
potentially others in the future). It also rename function names to make them
better reflect what the functions really do.

Changes from v4:

 - rebase on top of 4.12-rc3 (3f173bde7e43)
 - addressed Greg, Dietmar and Morten's comment on patch 7/7
 - added Vincent and Greg's Acked-by

The set is based on top of linux/master (4.12-rc3 3f173bde7e43) and it is also
available from:

 git://linux-arm.org/linux-jl.git upstream/default_caps_factorize-v5

Greg, if 7/7 looks now OK to you, could you please take the set so that it will
be ready for 4.13 merge window?

Thanks,

- 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
    v4 - https://marc.info/?l=linux-kernel&m=149269955206646&w=2

Juri Lelli (7):
  Documentation: arm: fix wrong reference number in DT definition
  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/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 ++
 9 files changed, 283 insertions(+), 439 deletions(-)
 create mode 100644 drivers/base/arch_topology.c
 create mode 100644 include/linux/arch_topology.h

-- 
2.11.0

[PATCH v5 1/7] Documentation: arm: fix wrong reference number in DT definition

[Juri Lelli]

Reference to cpu capacity binding has a wrong number. Fix it.

Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 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 1030f5f50207..2713aadb7411 100644
--- a/Documentation/devicetree/bindings/arm/cpus.txt
+++ b/Documentation/devicetree/bindings/arm/cpus.txt
@@ -249,7 +249,7 @@ 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.
 
@@ -476,5 +476,5 @@ 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
-- 
2.11.0

[PATCH v5 2/7] arm: fix return value of parse_cpu_capacity

[Juri Lelli]

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 <linux@arm.linux.org.uk>
Reported-by: Morten Rasmussen <morten.rasmussen@arm.com>
Fixes: 06073ee26775 ('ARM: 8621/3: parse cpu capacity-dmips-mhz from DT')
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Vincent Guittot <vincent.guittot@linaor.org>
---
 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);
-- 
2.11.0

[PATCH v5 3/7] arm: remove wrong CONFIG_PROC_SYSCTL ifdef

[Juri Lelli]

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 <linux@arm.linux.org.uk>
Reported-and-suggested-by: Sudeep Holla <sudeep.holla@arm.com>
Fixes: 7e5930aaef5d ('ARM: 8622/3: add sysfs cpu_capacity attribute')
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 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 {
-- 
2.11.0

[PATCH v5 4/7] arm, arm64: factorize common cpu capacity default code

[Juri Lelli]

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@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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 4c1a35f15838..7ef16700cb88 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_CPU_AUTOPROBE
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 3dcd7ec69bca..1ce760d259b6 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -41,6 +41,7 @@ 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
-- 
2.11.0

[PATCH v5 5/7] arm,arm64,drivers: reduce scope of cap_parsing_failed

[Juri Lelli]

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 <morten.rasmussen@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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)) {
-- 
2.11.0

[PATCH v5 6/7] arm,arm64,drivers: move externs in a new header file

[Juri Lelli]

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 <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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_ */
-- 
2.11.0

[PATCH v5 7/7] arm, arm64, drivers: add a prefix to drivers arch_topology interfaces

[Juri Lelli]

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 topology namespace for interfaces used by
arch code; achieve this by prepending a 'topology_' prefix to driver
interfaces.

Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
---

Changes from v4:

 - as per discussion with Greg, Dietmar and Morten (off-line)
   the interface function have been renamed as

   s/atd_normalize_cpu_capacity/topology_normalize_cpu_scale/
   s/atd_parse_cpu_capacity/topology_parse_cpu_capacity/
   s/atd_scale_cpu_capacity/topology_get_cpu_scale/
   s/atd_set_capacity_scale/topology_set_cpu_scale/

   which seems to better reflect their purpose and creates a saner
   "topology_" scope
---
 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..bf949a763dbe 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 (topology_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();
+		topology_normalize_cpu_scale();
 }
 
 /*
@@ -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);
+	topology_set_cpu_scale(cpu, cpu_capacity(cpu) / middle_capacity);
 
 	pr_info("CPU%u: update cpu_capacity %lu\n",
-		cpu, arch_scale_cpu_capacity(NULL, cpu));
+		cpu, topology_get_cpu_scale(NULL, cpu));
 }
 
 #else
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 255230c3e835..79244c75eaec 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);
+			topology_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();
+	topology_normalize_cpu_scale();
 
 	/*
 	 * 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..d1c33a85059e 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 topology_get_cpu_scale(struct sched_domain *sd, int cpu)
 {
 	return per_cpu(cpu_scale, cpu);
 }
 
-void set_capacity_scale(unsigned int cpu, unsigned long capacity)
+void topology_set_cpu_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));
+			topology_get_cpu_scale(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);
+		topology_set_cpu_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 topology_normalize_cpu_scale(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);
+		topology_set_cpu_scale(cpu, capacity);
 		pr_debug("cpu_capacity: CPU%d cpu_capacity=%lu\n",
-			cpu, arch_scale_cpu_capacity(NULL, cpu));
+			cpu, topology_get_cpu_scale(NULL, cpu));
 	}
 	mutex_unlock(&cpu_scale_mutex);
 }
 
-int __init parse_cpu_capacity(struct device_node *cpu_node, int cpu)
+int __init topology_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] = topology_get_cpu_scale(NULL, cpu) *
 					    policy->cpuinfo.max_freq / 1000UL;
 			capacity_scale = max(raw_capacity[cpu], capacity_scale);
 		}
 		if (cpumask_empty(cpus_to_visit)) {
-			normalize_cpu_capacity();
+			topology_normalize_cpu_scale();
 			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..9af3c174c03a 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 topology_normalize_cpu_scale(void);
 
 struct device_node;
-int parse_cpu_capacity(struct device_node *cpu_node, int cpu);
+int topology_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 topology_get_cpu_scale(struct sched_domain *sd, int cpu);
 
-void set_capacity_scale(unsigned int cpu, unsigned long capacity);
+void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity);
 
 #endif /* _LINUX_ARCH_TOPOLOGY_H_ */
-- 
2.11.0

Re: [PATCH v5 2/7] arm: fix return value of parse_cpu_capacity

[Russell King - ARM Linux]

On Wed, May 31, 2017 at 05:59:26PM +0100, Juri Lelli 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 <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>

You can drop these Cc's now.  Thanks.

> Reported-by: Morten Rasmussen <morten.rasmussen-5wv7dgnIgG8@public.gmane.org>
> Fixes: 06073ee26775 ('ARM: 8621/3: parse cpu capacity-dmips-mhz from DT')
> Signed-off-by: Juri Lelli <juri.lelli-5wv7dgnIgG8@public.gmane.org>
> Acked-by: Russell King <rmk+kernel-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org>
> Acked-by: Vincent Guittot <vincent.guittot-nDFRoQF+wuAdnm+yROfE0A@public.gmane.org>
> ---
>  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);
> -- 
> 2.11.0
> 

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