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-rw-r--r--meta-eas/recipes-kernel/linux/linux-renesas/0024-arm-parse-cpu-capacity-dmips-mhz-from-DT.patch210
1 files changed, 210 insertions, 0 deletions
diff --git a/meta-eas/recipes-kernel/linux/linux-renesas/0024-arm-parse-cpu-capacity-dmips-mhz-from-DT.patch b/meta-eas/recipes-kernel/linux/linux-renesas/0024-arm-parse-cpu-capacity-dmips-mhz-from-DT.patch
new file mode 100644
index 0000000..0a841b6
--- /dev/null
+++ b/meta-eas/recipes-kernel/linux/linux-renesas/0024-arm-parse-cpu-capacity-dmips-mhz-from-DT.patch
@@ -0,0 +1,210 @@
+From c9441760c1171936fc561e364111866457fde987 Mon Sep 17 00:00:00 2001
+From: Juri Lelli <juri.lelli@arm.com>
+Date: Wed, 11 Nov 2015 16:21:27 +0000
+Subject: [PATCH 24/92] arm: parse cpu capacity-dmips-mhz from DT
+
+With the introduction of cpu capacity-dmips-mhz bindings, CPU capacities
+can now be calculated from values extracted from DT and information
+coming from cpufreq. Add parsing of DT information at boot time, and
+complement it with cpufreq information. We keep code that can produce
+same information, based on different DT properties and hard-coded
+values, as fall-back for backward compatibility.
+
+Caveat: the information provided by this patch will start to be used in
+the future. We need to #define arch_scale_cpu_capacity to something
+provided in arch, so that scheduler's default implementation (which gets
+used if arch_scale_cpu_capacity is not defined) is overwritten.
+
+Cc: Russell King <linux@arm.linux.org.uk>
+Signed-off-by: Juri Lelli <juri.lelli@arm.com>
+---
+ arch/arm/kernel/topology.c | 145 ++++++++++++++++++++++++++++++++++++++++++++-
+ 1 file changed, 144 insertions(+), 1 deletion(-)
+
+diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
+index ec279d1..b22868a 100644
+--- a/arch/arm/kernel/topology.c
++++ b/arch/arm/kernel/topology.c
+@@ -78,6 +78,134 @@ struct cpu_efficiency {
+ #define cpu_capacity(cpu) __cpu_capacity[cpu]
+
+ 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);
++ 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));
++ }
++}
++
++#ifdef CONFIG_CPU_FREQ
++static cpumask_var_t cpus_to_visit;
++static bool cap_parsing_done;
++
++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;
++ }
++ }
++ 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);
++#else
++static int __init free_raw_capacity(void)
++{
++ kfree(raw_capacity);
++
++ return 0;
++}
++core_initcall(free_raw_capacity);
++#endif
+
+ /*
+ * Iterate all CPUs' descriptor in DT and compute the efficiency
+@@ -99,6 +227,12 @@ static void __init parse_dt_topology(void)
+ __cpu_capacity = kcalloc(nr_cpu_ids, sizeof(*__cpu_capacity),
+ GFP_NOWAIT);
+
++ cn = of_find_node_by_path("/cpus");
++ if (!cn) {
++ pr_err("No CPU information found in DT\n");
++ return;
++ }
++
+ for_each_possible_cpu(cpu) {
+ const u32 *rate;
+ int len;
+@@ -110,6 +244,13 @@ static void __init parse_dt_topology(void)
+ continue;
+ }
+
++ if (parse_cpu_capacity(cn, cpu)) {
++ of_node_put(cn);
++ continue;
++ }
++
++ cap_from_dt = false;
++
+ for (cpu_eff = table_efficiency; cpu_eff->compatible; cpu_eff++)
+ if (of_device_is_compatible(cn, cpu_eff->compatible))
+ break;
+@@ -151,6 +292,8 @@ static void __init parse_dt_topology(void)
+ middle_capacity = ((max_capacity / 3)
+ >> (SCHED_CAPACITY_SHIFT-1)) + 1;
+
++ if (cap_from_dt && !cap_parsing_failed)
++ normalize_cpu_capacity();
+ }
+
+ /*
+@@ -160,7 +303,7 @@ static void __init parse_dt_topology(void)
+ */
+ static void update_cpu_capacity(unsigned int cpu)
+ {
+- if (!cpu_capacity(cpu))
++ if (!cpu_capacity(cpu) || cap_from_dt)
+ return;
+
+ set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity);
+--
+1.9.1
+