From 5aae8a53708025d4e718f0d2e7c2f766779ddc71 Mon Sep 17 00:00:00 2001 From: "K.Prasad" Date: Tue, 15 Jun 2010 11:35:19 +0530 Subject: powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors Implement perf-events based hw-breakpoint interfaces for PowerPC 64-bit server (Book III S) processors. This allows access to a given location to be used as an event that can be counted or profiled by the perf_events subsystem. This is done using the DABR (data breakpoint register), which can also be used for process debugging via ptrace. When perf_event hw_breakpoint support is configured in, the perf_event subsystem manages the DABR and arbitrates access to it, and ptrace then creates a perf_event when it is requested to set a data breakpoint. [Adopted suggestions from Paul Mackerras to - emulate_step() all system-wide breakpoints and single-step only the per-task breakpoints - perform arch-specific cleanup before unregistration through arch_unregister_hw_breakpoint() ] Signed-off-by: K.Prasad Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/machine_kexec_64.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/powerpc/kernel/machine_kexec_64.c') diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c index 26f9900f773c..6c7c546aa1be 100644 --- a/arch/powerpc/kernel/machine_kexec_64.c +++ b/arch/powerpc/kernel/machine_kexec_64.c @@ -25,6 +25,7 @@ #include /* _end */ #include #include +#include int default_machine_kexec_prepare(struct kimage *image) { @@ -165,6 +166,7 @@ static void kexec_smp_down(void *arg) while(kexec_all_irq_disabled == 0) cpu_relax(); mb(); /* make sure all irqs are disabled before this */ + hw_breakpoint_disable(); /* * Now every CPU has IRQs off, we can clear out any pending * IPIs and be sure that no more will come in after this. @@ -180,6 +182,7 @@ static void kexec_prepare_cpus_wait(int wait_state) { int my_cpu, i, notified=-1; + hw_breakpoint_disable(); my_cpu = get_cpu(); /* Make sure each CPU has atleast made it to the state we need */ for (i=0; i < NR_CPUS; i++) { -- cgit v1.2.1