Commit 9736c615 authored Jul 07, 2016 by Matt Redfearn Committed by Ralf Baechle Jul 24, 2016

MIPS: smp-cps: Allow booting of CPU other than VP0 within a core



The boot_core function was hardcoded to always start VP0 when starting
a core via the CPC. When hotplugging a CPU this may not be the desired
behaviour.

Make boot_core receive the VP ID to start running on the core, such that
alternate VPs can be started via CPU hotplug.
Also ensure that all other VPs within the core are stopped before
bringing the core out of reset so that only the desired VP starts.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13750/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

parent 253aced6

arch/mips/kernel/smp-cps.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -206,7 +206,7 @@ static void __init cps_prepare_cpus(unsigned int max_cpus)
		}
		}

		static void boot_core(unsigned core)
		static void boot_core(unsigned int core, unsigned int vpe_id)
		{
		u32 access, stat, seq_state;
		unsigned timeout;
		@@ -233,8 +233,9 @@ static void boot_core(unsigned core)
		mips_cpc_lock_other(core);

		if (mips_cm_revision() >= CM_REV_CM3) {
		/* Run VP0 following the reset */
		write_cpc_co_vp_run(0x1);
		/* Run only the requested VP following the reset */
		write_cpc_co_vp_stop(0xf);
		write_cpc_co_vp_run(1 << vpe_id);

		/*
		* Ensure that the VP_RUN register is written before the
		@@ -306,7 +307,7 @@ static void cps_boot_secondary(int cpu, struct task_struct *idle)

		if (!test_bit(core, core_power)) {
		/* Boot a VPE on a powered down core */
		boot_core(core);
		boot_core(core, vpe_id);
		goto out;
		}