The core which the CPC core-other region relates to is based upon the
core-local core-other addressing register. As its name suggests this
register is shared between all VPEs within a core, and if there is a
possibility that multiple VPEs within a core will attempt to access
another core simultaneously then locking is required. This wasn't
previously a problem with the only user being cpu0 during boot, but will
be an issue once hotplug is implemented & may race with other users such
as cpuidle.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
arch/mips/kernel/smp-cps.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index 6da42f0..fd946c7 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -161,11 +161,10 @@ static void boot_core(unsigned core)
write_gcr_access(access);
if (mips_cpc_present()) {
- /* Select the appropriate core */
- write_cpc_cl_other(core << CPC_Cx_OTHER_CORENUM_SHF);
-
/* Reset the core */
+ mips_cpc_lock_other(core);
write_cpc_co_cmd(CPC_Cx_CMD_RESET);
+ mips_cpc_unlock_other();
} else {
/* Take the core out of reset */
write_gcr_co_reset_release(0);
--
1.8.5.3
