[PATCH 4.19 025/205] MIPS: kexec: Mark CPU offline before disabling local IRQ

Greg Kroah-Hartman
2018-11-19T16:32:57Z

From: Dengcheng Zhu <dzhu@wavecomp.com>

[ Upstream commit dc57aaf95a516f70e2d527d8287a0332c481a226 ]

After changing CPU online status, it will not be sent any IPIs such as in
__flush_cache_all() on software coherency systems. Do this before disabling
local IRQ.

Signed-off-by: Dengcheng Zhu <dzhu@wavecomp.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20571/
Cc: pburton@wavecomp.com
Cc: ralf@linux-mips.org
Cc: linux-mips@linux-mips.org
Cc: rachel.mozes@intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/mips/kernel/crash.c | 3 +++
arch/mips/kernel/machine_kexec.c | 3 +++
2 files changed, 6 insertions(+)

--- a/arch/mips/kernel/crash.c
+++ b/arch/mips/kernel/crash.c
@@ -36,6 +36,9 @@ static void crash_shutdown_secondary(voi
if (!cpu_online(cpu))
return;

+ /* We won't be sent IPIs any more. */
+ set_cpu_online(cpu, false);
+
local_irq_disable();
if (!cpumask_test_cpu(cpu, &cpus_in_crash))
crash_save_cpu(regs, cpu);
--- a/arch/mips/kernel/machine_kexec.c
+++ b/arch/mips/kernel/machine_kexec.c
@@ -118,6 +118,9 @@ machine_kexec(struct kimage *image)
*ptr = (unsigned long) phys_to_virt(*ptr);
}

+ /* Mark offline BEFORE disabling local irq. */
+ set_cpu_online(smp_processor_id(), false);
+
/*
* we do not want to be bothered.
*/