ARM: Factor out common psci_get_cpu_id
Will be required for obtaining the ID of the current CPU in shared PSCI
functions. The default implementation requires a dense ID space and only
supports a single cluster. Therefore, the functions can be overloaded in
cases where these assumptions do not hold.
CC: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Tested-by: Ian Campbell <ijc@hellion.org.uk>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S
index bf11a34..12ad09b 100644
--- a/arch/arm/cpu/armv7/psci.S
+++ b/arch/arm/cpu/armv7/psci.S
@@ -99,4 +99,12 @@
pop {r4-r7, lr}
movs pc, lr @ Return to the kernel
+@ Requires dense and single-cluster CPU ID space
+ENTRY(psci_get_cpu_id)
+ mrc p15, 0, r0, c0, c0, 5 /* read MPIDR */
+ and r0, r0, #0xff /* return CPU ID in cluster */
+ bx lr
+ENDPROC(psci_get_cpu_id)
+.weak psci_get_cpu_id
+
.popsection