From 9736c6152ef6fbb688c05c75b250304787fc9ff7 Mon Sep 17 00:00:00 2001 From: Matt Redfearn Date: Thu, 7 Jul 2016 08:50:38 +0100 Subject: [PATCH] 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 Reviewed-by: Paul Burton Cc: Matt Redfearn Cc: Qais Yousef Cc: Thomas Gleixner 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 --- arch/mips/kernel/smp-cps.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c index 4ed36f2..006e99d 100644 --- a/arch/mips/kernel/smp-cps.c +++ b/arch/mips/kernel/smp-cps.c @@ -206,7 +206,7 @@ err_out: } } -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; } -- 2.7.4