From c814ca029e1015bb0ecec312f4bb9751ba1a711a Mon Sep 17 00:00:00 2001 From: Ashwin Chaugule Date: Wed, 7 May 2014 10:18:36 -0400 Subject: ARM: Check if a CPU has gone offline PSCIv0.2 adds a new function called AFFINITY_INFO, which can be used to query if a specified CPU has actually gone offline. Calling this function via cpu_kill ensures that a CPU has quiesced after a call to cpu_die. This helps prevent the CPU from doing arbitrary bad things when data or instructions are clobbered (as happens with kexec) in the window between a CPU announcing that it is dead and said CPU leaving the kernel. Signed-off-by: Ashwin Chaugule Signed-off-by: Mark Rutland Reviewed-by: Rob Herring Acked-by: Catalin Marinas --- arch/arm64/include/asm/cpu_ops.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm64/include/asm/cpu_ops.h') diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h index 152413076503..d7b4b38a8e86 100644 --- a/arch/arm64/include/asm/cpu_ops.h +++ b/arch/arm64/include/asm/cpu_ops.h @@ -39,6 +39,7 @@ struct device_node; * from the cpu to be killed. * @cpu_die: Makes a cpu leave the kernel. Must not fail. Called from the * cpu being killed. + * @cpu_kill: Ensures a cpu has left the kernel. Called from another cpu. * @cpu_suspend: Suspends a cpu and saves the required context. May fail owing * to wrong parameters or error conditions. Called from the * CPU being suspended. Must be called with IRQs disabled. @@ -52,6 +53,7 @@ struct cpu_operations { #ifdef CONFIG_HOTPLUG_CPU int (*cpu_disable)(unsigned int cpu); void (*cpu_die)(unsigned int cpu); + int (*cpu_kill)(unsigned int cpu); #endif #ifdef CONFIG_ARM64_CPU_SUSPEND int (*cpu_suspend)(unsigned long); -- cgit v1.2.3-59-g8ed1b