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Message-Id: <20191219121905.26905-11-cristian.marussi@arm.com>
Date: Thu, 19 Dec 2019 12:19:03 +0000
From: Cristian Marussi <cristian.marussi@....com>
To: linux-kernel@...r.kernel.org
Cc: linux-arch@...r.kernel.org, mark.rutland@....com,
peterz@...radead.org, catalin.marinas@....com,
takahiro.akashi@...aro.org, james.morse@....com,
hidehiro.kawai.ez@...achi.com, tglx@...utronix.de, will@...nel.org,
linux-arm-kernel@...ts.infradead.org, mingo@...hat.com,
x86@...nel.org, dzickus@...hat.com, ehabkost@...hat.com,
linux@...linux.org.uk, davem@...emloft.net,
sparclinux@...r.kernel.org, hch@...radead.org
Subject: [RFC PATCH v3 10/12] arm: smp: use generic SMP stop common code
Make arm use the generic SMP-stop logic provided by common code
unified smp_send_stop() function.
Signed-off-by: Cristian Marussi <cristian.marussi@....com>
---
v2 --> v3
- conflicts
- added missing barriers
---
arch/arm/Kconfig | 1 +
arch/arm/kernel/smp.c | 22 ++++++----------------
2 files changed, 7 insertions(+), 16 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ba75e3661a41..40f6961c449c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -35,6 +35,7 @@ config ARM
select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
select ARCH_WANT_IPC_PARSE_VERSION
+ select ARCH_USE_COMMON_SMP_STOP
select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
select BUILDTIME_EXTABLE_SORT if MMU
select CLONE_BACKWARDS
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 46e1be9e57a8..f03e9bbf4116 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -598,6 +598,8 @@ static void ipi_cpu_stop(unsigned int cpu)
}
set_cpu_online(cpu, false);
+ /* ensure all writes are globally visible before cpu parks */
+ wmb();
local_fiq_disable();
local_irq_disable();
@@ -705,23 +707,9 @@ void smp_send_reschedule(int cpu)
smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
}
-void smp_send_stop(void)
+void arch_smp_stop_call(cpumask_t *cpus, unsigned int __unused)
{
- unsigned long timeout;
- struct cpumask mask;
-
- cpumask_copy(&mask, cpu_online_mask);
- cpumask_clear_cpu(smp_processor_id(), &mask);
- if (!cpumask_empty(&mask))
- smp_cross_call(&mask, IPI_CPU_STOP);
-
- /* Wait up to one second for other CPUs to stop */
- timeout = USEC_PER_SEC;
- while (num_online_cpus() > 1 && timeout--)
- udelay(1);
-
- if (num_online_cpus() > 1)
- pr_warn("SMP: failed to stop secondary CPUs\n");
+ smp_cross_call(cpus, IPI_CPU_STOP);
}
/* In case panic() and panic() called at the same time on CPU1 and CPU2,
@@ -735,6 +723,8 @@ void panic_smp_self_stop(void)
pr_debug("CPU %u will stop doing anything useful since another CPU has paniced\n",
smp_processor_id());
set_cpu_online(smp_processor_id(), false);
+ /* ensure all writes visible before parking */
+ wmb();
while (1)
cpu_relax();
}
--
2.17.1
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