From 02b73e2e9c288cbbb6ec96bef628cf08e29824c4 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 6 Jun 2011 15:49:23 +0100 Subject: [PATCH] ARM: stop: execute platform callback from cpu_stop code Sending IPI_CPU_STOP to a CPU causes it to execute a busy cpu_relax loop forever. This makes it impossible to kexec successfully on an SMP system since the secondary CPUs do not reset. This patch adds a callback to platform_cpu_kill, defined when CONFIG_HOTPLUG_CPU=y, from the ipi_cpu_stop handling code. This function currently just returns 1 on all platforms that define it but allows them to do something more sophisticated in the future. Signed-off-by: Will Deacon --- arch/arm/Kconfig | 2 +- arch/arm/kernel/smp.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 4b01d71bdbd1..abba5b8c9d74 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2001,7 +2001,7 @@ config XIP_PHYS_ADDR config KEXEC bool "Kexec system call (EXPERIMENTAL)" - depends on EXPERIMENTAL + depends on EXPERIMENTAL && (!SMP || HOTPLUG_CPU) help kexec is a system call that implements the ability to shutdown your current kernel, and to start another kernel. It is like a reboot diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 76ff28d87bf3..57db122a4f62 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -522,6 +522,10 @@ static void ipi_cpu_stop(unsigned int cpu) local_fiq_disable(); local_irq_disable(); +#ifdef CONFIG_HOTPLUG_CPU + platform_cpu_kill(cpu); +#endif + while (1) cpu_relax(); } -- 2.20.1