From 9736c6152ef6fbb688c05c75b250304787fc9ff7 Mon Sep 17 00:00:00 2001
From: Matt Redfearn <matt.redfearn@imgtec.com>
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 <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>
---
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 4ed36f288d646..006e99de170d3 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -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;
}
--
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