Implement the notion of "core siblings" for powerpc. This makes
/sys/devices/system/cpu/cpu*/topology/core_siblings present sensible
values, indicating online CPUs which share an L2 cache.
Signed-off-by: Nathan Lynch <[EMAIL PROTECTED]>
---
arch/powerpc/kernel/smp.c | 71 ++++++++++++++++++++++++++++++++++++++++
include/asm-powerpc/smp.h | 1 +
include/asm-powerpc/topology.h | 1 +
3 files changed, 73 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 3c4d07e..e8bc6a0 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -63,10 +63,12 @@ struct thread_info *secondary_ti;
cpumask_t cpu_possible_map = CPU_MASK_NONE;
cpumask_t cpu_online_map = CPU_MASK_NONE;
DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
+DEFINE_PER_CPU(cpumask_t, cpu_core_map) = CPU_MASK_NONE;
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);
EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
+EXPORT_PER_CPU_SYMBOL(cpu_core_map);
/* SMP operations for this machine */
struct smp_ops_t *smp_ops;
@@ -230,6 +232,7 @@ void __devinit smp_prepare_boot_cpu(void)
cpu_set(boot_cpuid, cpu_online_map);
cpu_set(boot_cpuid, per_cpu(cpu_sibling_map, boot_cpuid));
+ cpu_set(boot_cpuid, per_cpu(cpu_core_map, boot_cpuid));
#ifdef CONFIG_PPC64
paca[boot_cpuid].__current = current;
#endif
@@ -377,11 +380,43 @@ int __cpuinit __cpu_up(unsigned int cpu)
return 0;
}
+/* Must be called when no change can occur to cpu_present_map,
+ * i.e. during cpu online or offline.
+ */
+static struct device_node *cpu_to_l2cache(int cpu)
+{
+ struct device_node *np;
+ const u32 *l2cache_phandle;
+
+ if (!cpu_present(cpu))
+ return NULL;
+
+ np = of_get_cpu_node(cpu, NULL);
+
+ l2cache_phandle = of_get_property(np, "l2-cache", NULL);
+
+ of_node_put(np);
+
+ if (!l2cache_phandle)
+ return NULL;
+
+ np = NULL;
+ for_each_node_by_type(np, "cache") {
+ const u32 *phandle = of_get_property(np, "ibm,phandle", NULL);
+ if (!phandle)
+ continue;
+ if (*phandle == *l2cache_phandle)
+ return np;
+ }
+
+ return NULL;
+}
/* Activate a secondary processor. */
int __devinit start_secondary(void *unused)
{
unsigned int cpu = smp_processor_id();
+ struct device_node *l2_cache;
int i, base;
atomic_inc(&init_mm.mm_count);
@@ -410,7 +445,26 @@ int __devinit start_secondary(void *unused)
continue;
cpu_set(cpu, per_cpu(cpu_sibling_map, base + i));
cpu_set(base + i, per_cpu(cpu_sibling_map, cpu));
+
+ /* cpu_core_map should be a superset of
+ * cpu_sibling_map even if we don't have cache
+ * information, so update the former here, too.
+ */
+ cpu_set(cpu, per_cpu(cpu_core_map, base +i));
+ cpu_set(base + i, per_cpu(cpu_core_map, cpu));
+ }
+ l2_cache = cpu_to_l2cache(cpu);
+ for_each_online_cpu(i) {
+ struct device_node *np = cpu_to_l2cache(i);
+ if (!np)
+ continue;
+ if (np == l2_cache) {
+ cpu_set(cpu, per_cpu(cpu_core_map, i));
+ cpu_set(i, per_cpu(cpu_core_map, cpu));
+ }
+ of_node_put(np);
}
+ of_node_put(l2_cache);
ipi_call_unlock();
local_irq_enable();
@@ -448,6 +502,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
#ifdef CONFIG_HOTPLUG_CPU
int __cpu_disable(void)
{
+ struct device_node *l2_cache;
int cpu = smp_processor_id();
int base, i;
int err;
@@ -464,8 +519,24 @@ int __cpu_disable(void)
for (i = 0; i < threads_per_core; i++) {
cpu_clear(cpu, per_cpu(cpu_sibling_map, base + i));
cpu_clear(base + i, per_cpu(cpu_sibling_map, cpu));
+ cpu_clear(cpu, per_cpu(cpu_core_map, base +i));
+ cpu_clear(base + i, per_cpu(cpu_core_map, cpu));
}
+ l2_cache = cpu_to_l2cache(cpu);
+ for_each_present_cpu(i) {
+ struct device_node *np = cpu_to_l2cache(i);
+ if (!np)
+ continue;
+ if (np == l2_cache) {
+ cpu_clear(cpu, per_cpu(cpu_core_map, i));
+ cpu_clear(i, per_cpu(cpu_core_map, cpu));
+ }
+ of_node_put(np);
+ }
+ of_node_put(l2_cache);
+
+
return 0;
}
diff --git a/include/asm-powerpc/smp.h b/include/asm-powerpc/smp.h
index 416d4c2..32e9100 100644
--- a/include/asm-powerpc/smp.h
+++ b/include/asm-powerpc/smp.h
@@ -62,6 +62,7 @@ extern int smp_hw_index[];
#endif
DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
+DECLARE_PER_CPU(cpumask_t, cpu_core_map);
/* Since OpenPIC has only 4 IPIs, we use slightly different message numbers.
*
diff --git a/include/asm-powerpc/topology.h b/include/asm-powerpc/topology.h
index 100c6fb..f00e8e5 100644
--- a/include/asm-powerpc/topology.h
+++ b/include/asm-powerpc/topology.h
@@ -108,6 +108,7 @@ static inline void sysfs_remove_device_from_node(struct
sys_device *dev,
#include <asm/smp.h>
#define topology_thread_siblings(cpu) (per_cpu(cpu_sibling_map, cpu))
+#define topology_core_siblings(cpu) (per_cpu(cpu_core_map, cpu))
#endif
#endif
--
1.5.6.2
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