From e9efed3b80a83e44b98fc626f3268ae072550b84 Mon Sep 17 00:00:00 2001 From: Nathan Lynch Date: Sun, 27 Jul 2008 15:24:54 +1000 Subject: [PATCH] powerpc: Make core id information available to userspace Existing Open Firmware practice is to report each processor core as a separate node in the device tree. Report the value of the "reg" OF property corresponding to a logical CPU's device node as the core_id attribute in /sys/devices/system/cpu/cpu*/topology/core_id. Signed-off-by: Nathan Lynch Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/smp.c | 23 +++++++++++++++++++++++ include/asm-powerpc/smp.h | 1 + include/asm-powerpc/topology.h | 1 + 3 files changed, 25 insertions(+) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index f7a2f81..5337ca7 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -380,6 +380,29 @@ int __cpuinit __cpu_up(unsigned int cpu) return 0; } +/* Return the value of the reg property corresponding to the given + * logical cpu. + */ +int cpu_to_core_id(int cpu) +{ + struct device_node *np; + const int *reg; + int id = -1; + + np = of_get_cpu_node(cpu, NULL); + if (!np) + goto out; + + reg = of_get_property(np, "reg", NULL); + if (!reg) + goto out; + + id = *reg; +out: + of_node_put(np); + return id; +} + /* Must be called when no change can occur to cpu_present_map, * i.e. during cpu online or offline. */ diff --git a/include/asm-powerpc/smp.h b/include/asm-powerpc/smp.h index 32e9100..4d28e1e 100644 --- a/include/asm-powerpc/smp.h +++ b/include/asm-powerpc/smp.h @@ -63,6 +63,7 @@ extern int smp_hw_index[]; DECLARE_PER_CPU(cpumask_t, cpu_sibling_map); DECLARE_PER_CPU(cpumask_t, cpu_core_map); +extern int cpu_to_core_id(int cpu); /* 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 f00e8e5..c32da6f 100644 --- a/include/asm-powerpc/topology.h +++ b/include/asm-powerpc/topology.h @@ -109,6 +109,7 @@ static inline void sysfs_remove_device_from_node(struct sys_device *dev, #define topology_thread_siblings(cpu) (per_cpu(cpu_sibling_map, cpu)) #define topology_core_siblings(cpu) (per_cpu(cpu_core_map, cpu)) +#define topology_core_id(cpu) (cpu_to_core_id(cpu)) #endif #endif -- 2.7.4