Commit dd9233d0 authored Mar 07, 2014 by Paul Burton

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 <paul.burton@imgtec.com>

parent 0f4d3d11

arch/mips/kernel/smp-cps.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -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);