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-rw-r--r--meta-eas/recipes-kernel/linux/linux-renesas/0032-arm64-add-sysfs-cpu_capacity-attribute.patch130
1 files changed, 130 insertions, 0 deletions
diff --git a/meta-eas/recipes-kernel/linux/linux-renesas/0032-arm64-add-sysfs-cpu_capacity-attribute.patch b/meta-eas/recipes-kernel/linux/linux-renesas/0032-arm64-add-sysfs-cpu_capacity-attribute.patch
new file mode 100644
index 0000000..83f9e38
--- /dev/null
+++ b/meta-eas/recipes-kernel/linux/linux-renesas/0032-arm64-add-sysfs-cpu_capacity-attribute.patch
@@ -0,0 +1,130 @@
+From 4454a804e1015b7699441e42d36dd8be8b0ee897 Mon Sep 17 00:00:00 2001
+From: Juri Lelli <juri.lelli@arm.com>
+Date: Wed, 14 Oct 2015 12:02:05 +0100
+Subject: [PATCH 32/92] arm64: add sysfs cpu_capacity attribute
+
+Add a sysfs cpu_capacity attribute with which it is possible to read and
+write (thus over-writing default values) CPUs capacity. This might be
+useful in situations where values needs changing after boot.
+
+The new attribute shows up as:
+
+ /sys/devices/system/cpu/cpu*/cpu_capacity
+
+Cc: Catalin Marinas <catalin.marinas@arm.com>
+Cc: Will Deacon <will.deacon@arm.com>
+Cc: Mark Brown <broonie@kernel.org>
+Cc: Sudeep Holla <sudeep.holla@arm.com>
+Signed-off-by: Juri Lelli <juri.lelli@arm.com>
+---
+ arch/arm64/kernel/topology.c | 73 ++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 73 insertions(+)
+
+diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
+index b75b0ba..cff34cc 100644
+--- a/arch/arm64/kernel/topology.c
++++ b/arch/arm64/kernel/topology.c
+@@ -26,6 +26,7 @@
+ #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)
+ {
+@@ -37,6 +38,76 @@ static void set_capacity_scale(unsigned int cpu, unsigned long capacity)
+ per_cpu(cpu_scale, cpu) = capacity;
+ }
+
++#ifdef CONFIG_PROC_SYSCTL
++#include <asm/cpu.h>
++#include <linux/string.h>
++static ssize_t show_cpu_capacity(struct device *dev,
++ struct device_attribute *attr,
++ char *buf)
++{
++ struct cpu *cpu = container_of(dev, struct cpu, dev);
++ ssize_t rc;
++ int cpunum = cpu->dev.id;
++ unsigned long capacity = arch_scale_cpu_capacity(NULL, cpunum);
++
++ rc = sprintf(buf, "%lu\n", capacity);
++
++ return rc;
++}
++
++static ssize_t store_cpu_capacity(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) {
++ char *p = (char *) buf;
++
++ ret = kstrtoul(p, 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(cpu_capacity,
++ 0644,
++ show_cpu_capacity,
++ store_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;
++}
++late_initcall(register_cpu_capacity_sysctl);
++#endif
++
+ static u32 capacity_scale;
+ static u32 *raw_capacity;
+ static bool cap_parsing_failed;
+@@ -87,6 +158,7 @@ static void normalize_cpu_capacity(void)
+ 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]);
+@@ -96,6 +168,7 @@ static void normalize_cpu_capacity(void)
+ 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
+--
+1.9.1
+