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| author | Nathan Lynch <ntl@pobox.com> | 2008-07-27 15:24:54 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2008-07-28 16:30:52 +1000 |
| commit | e9efed3b80a83e44b98fc626f3268ae072550b84 (patch) | |
| tree | cbe7cc897dc112e2eb93f9bbded5aa3a8e6e0bf3 /arch | |
| parent | 440a0857e32a05979fb01fc59ea454a723e80e4b (diff) | |
| download | linux-e9efed3b80a83e44b98fc626f3268ae072550b84.tar.gz linux-e9efed3b80a83e44b98fc626f3268ae072550b84.tar.bz2 linux-e9efed3b80a83e44b98fc626f3268ae072550b84.zip | |
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 <ntl@pobox.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index f7a2f81b5b7d..5337ca7bb649 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. */ |