[PATCH AUTOSEL 4.9 14/21] MIPS: kexec: Mark CPU offline before disabling local IRQ

From: Sasha Levin
Date: Sun Nov 04 2018 - 08:54:15 EST


From: Dengcheng Zhu <dzhu@xxxxxxxxxxxx>

[ 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@xxxxxxxxxxxx>
Signed-off-by: Paul Burton <paul.burton@xxxxxxxx>
Patchwork: https://patchwork.linux-mips.org/patch/20571/
Cc: pburton@xxxxxxxxxxxx
Cc: ralf@xxxxxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: rachel.mozes@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/mips/kernel/crash.c | 3 +++
arch/mips/kernel/machine_kexec.c | 3 +++
2 files changed, 6 insertions(+)

diff --git a/arch/mips/kernel/crash.c b/arch/mips/kernel/crash.c
index 1723b1762297..e757f36cea6f 100644
--- a/arch/mips/kernel/crash.c
+++ b/arch/mips/kernel/crash.c
@@ -34,6 +34,9 @@ static void crash_shutdown_secondary(void *passed_regs)
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);
diff --git a/arch/mips/kernel/machine_kexec.c b/arch/mips/kernel/machine_kexec.c
index 59725204105c..32b567e88b02 100644
--- a/arch/mips/kernel/machine_kexec.c
+++ b/arch/mips/kernel/machine_kexec.c
@@ -96,6 +96,9 @@ 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.
*/
--
2.17.1