Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e9efed...
Commit: e9efed3b80a83e44b98fc626f3268ae072550b84
Parent: 440a0857e32a05979fb01fc59ea454a723e80e4b
Author: Nathan Lynch <ntl@pobox.com>
AuthorDate: Sun Jul 27 15:24:54 2008 +1000
Committer: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CommitDate: Mon Jul 28 16:30:52 2008 +1000
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>
---
arch/powerpc/kernel/smp.c | 23 +++++++++++++++++++++++
include/asm-powerpc/smp.h | 1 +
include/asm-powerpc/topology.h | 1 +
3 files changed, 25 insertions(+), 0 deletions(-)
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
@@ ...
