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-rw-r--r--arch/arm/kernel/topology.c210
1 files changed, 70 insertions, 140 deletions
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index c5a59546a256..2336ee2aa44a 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -11,7 +11,9 @@
* for more details.
*/
+#include <linux/arch_topology.h>
#include <linux/cpu.h>
+#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/export.h>
#include <linux/init.h>
@@ -20,37 +22,29 @@
#include <linux/nodemask.h>
#include <linux/of.h>
#include <linux/sched.h>
+#include <linux/sched/topology.h>
#include <linux/slab.h>
+#include <linux/string.h>
+#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/topology.h>
/*
- * cpu power scale management
+ * cpu capacity scale management
*/
/*
- * cpu power table
+ * cpu capacity table
* This per cpu data structure describes the relative capacity of each core.
* On a heteregenous system, cores don't have the same computation capacity
- * and we reflect that difference in the cpu_power field so the scheduler can
- * take this difference into account during load balance. A per cpu structure
- * is preferred because each CPU updates its own cpu_power field during the
- * load balance except for idle cores. One idle core is selected to run the
- * rebalance_domains for all idle cores and the cpu_power can be updated
- * during this sequence.
+ * and we reflect that difference in the cpu_capacity field so the scheduler
+ * can take this difference into account during load balance. A per cpu
+ * structure is preferred because each CPU updates its own cpu_capacity field
+ * during the load balance except for idle cores. One idle core is selected
+ * to run the sched_balance_domains for all idle cores and the cpu_capacity can be
+ * updated during this sequence.
*/
-static DEFINE_PER_CPU(unsigned long, cpu_scale);
-
-unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu)
-{
- return per_cpu(cpu_scale, cpu);
-}
-
-static void set_power_scale(unsigned int cpu, unsigned long power)
-{
- per_cpu(cpu_scale, cpu) = power;
-}
#ifdef CONFIG_OF
struct cpu_efficiency {
@@ -62,53 +56,61 @@ struct cpu_efficiency {
* Table of relative efficiency of each processors
* The efficiency value must fit in 20bit and the final
* cpu_scale value must be in the range
- * 0 < cpu_scale < 3*SCHED_POWER_SCALE/2
+ * 0 < cpu_scale < 3*SCHED_CAPACITY_SCALE/2
* in order to return at most 1 when DIV_ROUND_CLOSEST
* is used to compute the capacity of a CPU.
* Processors that are not defined in the table,
- * use the default SCHED_POWER_SCALE value for cpu_scale.
+ * use the default SCHED_CAPACITY_SCALE value for cpu_scale.
*/
-struct cpu_efficiency table_efficiency[] = {
+static const struct cpu_efficiency table_efficiency[] = {
{"arm,cortex-a15", 3891},
{"arm,cortex-a7", 2048},
{NULL, },
};
-struct cpu_capacity {
- unsigned long hwid;
- unsigned long capacity;
-};
+static unsigned long *__cpu_capacity;
+#define cpu_capacity(cpu) __cpu_capacity[cpu]
-struct cpu_capacity *cpu_capacity;
-
-unsigned long middle_capacity = 1;
+static unsigned long middle_capacity = 1;
+static bool cap_from_dt = true;
/*
* Iterate all CPUs' descriptor in DT and compute the efficiency
* (as per table_efficiency). Also calculate a middle efficiency
* as close as possible to (max{eff_i} - min{eff_i}) / 2
- * This is later used to scale the cpu_power field such that an
- * 'average' CPU is of middle power. Also see the comments near
- * table_efficiency[] and update_cpu_power().
+ * This is later used to scale the cpu_capacity field such that an
+ * 'average' CPU is of middle capacity. Also see the comments near
+ * table_efficiency[] and update_cpu_capacity().
*/
static void __init parse_dt_topology(void)
{
- struct cpu_efficiency *cpu_eff;
+ const struct cpu_efficiency *cpu_eff;
struct device_node *cn = NULL;
- unsigned long min_capacity = (unsigned long)(-1);
+ unsigned long min_capacity = ULONG_MAX;
unsigned long max_capacity = 0;
unsigned long capacity = 0;
- int alloc_size, cpu = 0;
+ int cpu = 0;
- alloc_size = nr_cpu_ids * sizeof(struct cpu_capacity);
- cpu_capacity = kzalloc(alloc_size, GFP_NOWAIT);
+ __cpu_capacity = kcalloc(nr_cpu_ids, sizeof(*__cpu_capacity),
+ GFP_NOWAIT);
- while ((cn = of_find_node_by_type(cn, "cpu"))) {
- const u32 *rate, *reg;
+ for_each_possible_cpu(cpu) {
+ const __be32 *rate;
int len;
- if (cpu >= num_possible_cpus())
- break;
+ /* too early to use cpu->of_node */
+ cn = of_get_cpu_node(cpu, NULL);
+ if (!cn) {
+ pr_err("missing device node for CPU %d\n", cpu);
+ continue;
+ }
+
+ if (topology_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))
@@ -119,14 +121,7 @@ static void __init parse_dt_topology(void)
rate = of_get_property(cn, "clock-frequency", &len);
if (!rate || len != 4) {
- pr_err("%s missing clock-frequency property\n",
- cn->full_name);
- continue;
- }
-
- reg = of_get_property(cn, "reg", &len);
- if (!reg || len != 4) {
- pr_err("%s missing reg property\n", cn->full_name);
+ pr_err("%pOF missing clock-frequency property\n", cn);
continue;
}
@@ -140,29 +135,25 @@ static void __init parse_dt_topology(void)
if (capacity > max_capacity)
max_capacity = capacity;
- cpu_capacity[cpu].capacity = capacity;
- cpu_capacity[cpu++].hwid = be32_to_cpup(reg);
+ cpu_capacity(cpu) = capacity;
}
- if (cpu < num_possible_cpus())
- cpu_capacity[cpu].hwid = (unsigned long)(-1);
-
/* If min and max capacities are equals, we bypass the update of the
* cpu_scale because all CPUs have the same capacity. Otherwise, we
* compute a middle_capacity factor that will ensure that the capacity
* of an 'average' CPU of the system will be as close as possible to
- * SCHED_POWER_SCALE, which is the default value, but with the
+ * SCHED_CAPACITY_SCALE, which is the default value, but with the
* constraint explained near table_efficiency[].
*/
- if (min_capacity == max_capacity)
- cpu_capacity[0].hwid = (unsigned long)(-1);
- else if (4*max_capacity < (3*(max_capacity + min_capacity)))
+ if (4*max_capacity < (3*(max_capacity + min_capacity)))
middle_capacity = (min_capacity + max_capacity)
- >> (SCHED_POWER_SHIFT+1);
+ >> (SCHED_CAPACITY_SHIFT+1);
else
middle_capacity = ((max_capacity / 3)
- >> (SCHED_POWER_SHIFT-1)) + 1;
+ >> (SCHED_CAPACITY_SHIFT-1)) + 1;
+ if (cap_from_dt)
+ topology_normalize_cpu_scale();
}
/*
@@ -170,70 +161,22 @@ static void __init parse_dt_topology(void)
* boot. The update of all CPUs is in O(n^2) for heteregeneous system but the
* function returns directly for SMP system.
*/
-void update_cpu_power(unsigned int cpu, unsigned long hwid)
+static void update_cpu_capacity(unsigned int cpu)
{
- unsigned int idx = 0;
-
- /* look for the cpu's hwid in the cpu capacity table */
- for (idx = 0; idx < num_possible_cpus(); idx++) {
- if (cpu_capacity[idx].hwid == hwid)
- break;
-
- if (cpu_capacity[idx].hwid == -1)
- return;
- }
-
- if (idx == num_possible_cpus())
+ if (!cpu_capacity(cpu) || cap_from_dt)
return;
- set_power_scale(cpu, cpu_capacity[idx].capacity / middle_capacity);
+ topology_set_cpu_scale(cpu, cpu_capacity(cpu) / middle_capacity);
- printk(KERN_INFO "CPU%u: update cpu_power %lu\n",
- cpu, arch_scale_freq_power(NULL, cpu));
+ pr_info("CPU%u: update cpu_capacity %lu\n",
+ cpu, topology_get_cpu_scale(cpu));
}
#else
static inline void parse_dt_topology(void) {}
-static inline void update_cpu_power(unsigned int cpuid, unsigned int mpidr) {}
+static inline void update_cpu_capacity(unsigned int cpuid) {}
#endif
- /*
- * cpu topology table
- */
-struct cputopo_arm cpu_topology[NR_CPUS];
-EXPORT_SYMBOL_GPL(cpu_topology);
-
-const struct cpumask *cpu_coregroup_mask(int cpu)
-{
- return &cpu_topology[cpu].core_sibling;
-}
-
-void update_siblings_masks(unsigned int cpuid)
-{
- struct cputopo_arm *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
- int cpu;
-
- /* update core and thread sibling masks */
- for_each_possible_cpu(cpu) {
- cpu_topo = &cpu_topology[cpu];
-
- if (cpuid_topo->socket_id != cpu_topo->socket_id)
- continue;
-
- cpumask_set_cpu(cpuid, &cpu_topo->core_sibling);
- if (cpu != cpuid)
- cpumask_set_cpu(cpu, &cpuid_topo->core_sibling);
-
- if (cpuid_topo->core_id != cpu_topo->core_id)
- continue;
-
- cpumask_set_cpu(cpuid, &cpu_topo->thread_sibling);
- if (cpu != cpuid)
- cpumask_set_cpu(cpu, &cpuid_topo->thread_sibling);
- }
- smp_wmb();
-}
-
/*
* store_cpu_topology is called at boot when only one cpu is running
* and with the mutex cpu_hotplug.lock locked, when several cpus have booted,
@@ -241,12 +184,11 @@ void update_siblings_masks(unsigned int cpuid)
*/
void store_cpu_topology(unsigned int cpuid)
{
- struct cputopo_arm *cpuid_topo = &cpu_topology[cpuid];
+ struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
unsigned int mpidr;
- /* If the cpu topology has been already set, just return */
- if (cpuid_topo->core_id != -1)
- return;
+ if (cpuid_topo->package_id != -1)
+ goto topology_populated;
mpidr = read_cpuid_mpidr();
@@ -261,12 +203,12 @@ void store_cpu_topology(unsigned int cpuid)
/* core performance interdependency */
cpuid_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
- cpuid_topo->socket_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
+ cpuid_topo->package_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
} else {
/* largely independent cores */
cpuid_topo->thread_id = -1;
cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
- cpuid_topo->socket_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+ cpuid_topo->package_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
}
} else {
/*
@@ -276,17 +218,18 @@ void store_cpu_topology(unsigned int cpuid)
*/
cpuid_topo->thread_id = -1;
cpuid_topo->core_id = 0;
- cpuid_topo->socket_id = -1;
+ cpuid_topo->package_id = -1;
}
- update_siblings_masks(cpuid);
-
- update_cpu_power(cpuid, mpidr & MPIDR_HWID_BITMASK);
+ update_cpu_capacity(cpuid);
- printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
+ pr_info("CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
cpuid, cpu_topology[cpuid].thread_id,
cpu_topology[cpuid].core_id,
- cpu_topology[cpuid].socket_id, mpidr);
+ cpu_topology[cpuid].package_id, mpidr);
+
+topology_populated:
+ update_siblings_masks(cpuid);
}
/*
@@ -295,20 +238,7 @@ void store_cpu_topology(unsigned int cpuid)
*/
void __init init_cpu_topology(void)
{
- unsigned int cpu;
-
- /* init core mask and power*/
- for_each_possible_cpu(cpu) {
- struct cputopo_arm *cpu_topo = &(cpu_topology[cpu]);
-
- cpu_topo->thread_id = -1;
- cpu_topo->core_id = -1;
- cpu_topo->socket_id = -1;
- cpumask_clear(&cpu_topo->core_sibling);
- cpumask_clear(&cpu_topo->thread_sibling);
-
- set_power_scale(cpu, SCHED_POWER_SCALE);
- }
+ reset_cpu_topology();
smp_wmb();
parse_dt_topology();