From: Paul Burton Date: Fri, 7 Mar 2014 10:42:52 +0000 (+0000) Subject: MIPS: smp-cps: use CPC core-other locking X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=dd9233d0470bb8b02b30982c1de0a2dbffb407d5;p=deliverable%2Flinux.git MIPS: smp-cps: use CPC core-other locking 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 --- diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c index c3661ca5f25c..b519c8510972 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);