From ec45d1cfd3cb65121fc52f39efc17d832f4f7b91 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 17 Jan 2013 12:31:45 +0000 Subject: arm64: mm: update CONTEXTIDR register to contain PID of current process This patch is a port of 575320d62 ("ARM: 7445/1: mm: update CONTEXTIDR register to contain PID of current process") from ARM that introduces a new Kconfig option which, when enabled, causes the kernel to write the PID of the current task into the CONTEXTIDR register on context switch. This is useful when analysing hardware trace, since writes to this register can be configured to emit an event into the trace stream. Signed-off-by: Will Deacon [catalin.marinas@arm.com: contextidr_thread_switch() moved to mmu_context.h] Signed-off-by: Catalin Marinas --- arch/arm64/kernel/process.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm64/kernel/process.c') diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index cb0956bc96ed..a8fbd7eaa2ed 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -45,9 +45,10 @@ #include #include +#include +#include #include #include -#include static void setup_restart(void) { @@ -319,6 +320,7 @@ struct task_struct *__switch_to(struct task_struct *prev, /* the actual thread switch */ last = cpu_switch_to(prev, next); + contextidr_thread_switch(next); return last; } -- cgit