linux-kernel - [PATCH AUTOSEL 4.4 10/15] MIPS: kexec: Mark CPU offline before disabling local IRQ

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Message-Id: <20181104135417.88671-10-sashal@kernel.org>
Date:   Sun,  4 Nov 2018 08:54:12 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     stable@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Dengcheng Zhu <dzhu@...ecomp.com>,
        Paul Burton <paul.burton@...s.com>, pburton@...ecomp.com,
        ralf@...ux-mips.org, linux-mips@...ux-mips.org,
        rachel.mozes@...el.com, Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 4.4 10/15] MIPS: kexec: Mark CPU offline before disabling local IRQ

From: Dengcheng Zhu <dzhu@...ecomp.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@...ecomp.com>
Signed-off-by: Paul Burton <paul.burton@...s.com>
Patchwork: https://patchwork.linux-mips.org/patch/20571/
Cc: pburton@...ecomp.com
Cc: ralf@...ux-mips.org
Cc: linux-mips@...ux-mips.org
Cc: rachel.mozes@...el.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 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 610f0f3bdb34..93c46c9cebb7 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 50980bf3983e..92bc066e47a3 100644
--- a/arch/mips/kernel/machine_kexec.c
+++ b/arch/mips/kernel/machine_kexec.c
@@ -95,6 +95,9 @@ 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