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 <will.deacon@arm.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 4b01d71..abba5b8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2001,7 +2001,7 @@
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