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-rw-r--r--arch/arm/kernel/topology.c88
1 files changed, 57 insertions, 31 deletions
diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 0bc94b1fd1ae..e35d880f9773 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -26,30 +26,30 @@
#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 rebalance_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)
+unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
{
return per_cpu(cpu_scale, cpu);
}
-static void set_power_scale(unsigned int cpu, unsigned long power)
+static void set_capacity_scale(unsigned int cpu, unsigned long capacity)
{
- per_cpu(cpu_scale, cpu) = power;
+ per_cpu(cpu_scale, cpu) = capacity;
}
#ifdef CONFIG_OF
@@ -62,11 +62,11 @@ 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.
*/
static const struct cpu_efficiency table_efficiency[] = {
{"arm,cortex-a15", 3891},
@@ -83,21 +83,21 @@ static unsigned long middle_capacity = 1;
* 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)
{
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(*__cpu_capacity);
- __cpu_capacity = kzalloc(alloc_size, GFP_NOWAIT);
+ __cpu_capacity = kcalloc(nr_cpu_ids, sizeof(*__cpu_capacity),
+ GFP_NOWAIT);
for_each_possible_cpu(cpu) {
const u32 *rate;
@@ -141,15 +141,15 @@ static void __init parse_dt_topology(void)
* 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 (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;
}
@@ -158,20 +158,20 @@ 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.
*/
-static void update_cpu_power(unsigned int cpu)
+static void update_cpu_capacity(unsigned int cpu)
{
if (!cpu_capacity(cpu))
return;
- set_power_scale(cpu, cpu_capacity(cpu) / middle_capacity);
+ set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity);
- printk(KERN_INFO "CPU%u: update cpu_power %lu\n",
- cpu, arch_scale_freq_power(NULL, cpu));
+ printk(KERN_INFO "CPU%u: update cpu_capacity %lu\n",
+ cpu, arch_scale_freq_capacity(NULL, cpu));
}
#else
static inline void parse_dt_topology(void) {}
-static inline void update_cpu_power(unsigned int cpuid) {}
+static inline void update_cpu_capacity(unsigned int cpuid) {}
#endif
/*
@@ -185,6 +185,15 @@ const struct cpumask *cpu_coregroup_mask(int cpu)
return &cpu_topology[cpu].core_sibling;
}
+/*
+ * The current assumption is that we can power gate each core independently.
+ * This will be superseded by DT binding once available.
+ */
+const struct cpumask *cpu_corepower_mask(int cpu)
+{
+ return &cpu_topology[cpu].thread_sibling;
+}
+
static void update_siblings_masks(unsigned int cpuid)
{
struct cputopo_arm *cpu_topo, *cpuid_topo = &cpu_topology[cpuid];
@@ -258,7 +267,7 @@ void store_cpu_topology(unsigned int cpuid)
update_siblings_masks(cpuid);
- update_cpu_power(cpuid);
+ update_cpu_capacity(cpuid);
printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
cpuid, cpu_topology[cpuid].thread_id,
@@ -266,6 +275,20 @@ void store_cpu_topology(unsigned int cpuid)
cpu_topology[cpuid].socket_id, mpidr);
}
+static inline int cpu_corepower_flags(void)
+{
+ return SD_SHARE_PKG_RESOURCES | SD_SHARE_POWERDOMAIN;
+}
+
+static struct sched_domain_topology_level arm_topology[] = {
+#ifdef CONFIG_SCHED_MC
+ { cpu_corepower_mask, cpu_corepower_flags, SD_INIT_NAME(GMC) },
+ { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
+#endif
+ { cpu_cpu_mask, SD_INIT_NAME(DIE) },
+ { NULL, },
+};
+
/*
* init_cpu_topology is called at boot when only one cpu is running
* which prevent simultaneous write access to cpu_topology array
@@ -274,7 +297,7 @@ void __init init_cpu_topology(void)
{
unsigned int cpu;
- /* init core mask and power*/
+ /* init core mask and capacity */
for_each_possible_cpu(cpu) {
struct cputopo_arm *cpu_topo = &(cpu_topology[cpu]);
@@ -284,9 +307,12 @@ void __init init_cpu_topology(void)
cpumask_clear(&cpu_topo->core_sibling);
cpumask_clear(&cpu_topo->thread_sibling);
- set_power_scale(cpu, SCHED_POWER_SCALE);
+ set_capacity_scale(cpu, SCHED_CAPACITY_SCALE);
}
smp_wmb();
parse_dt_topology();
+
+ /* Set scheduler topology descriptor */
+ set_sched_topology(arm_topology);
}