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authorK.Prasad <prasad@linux.vnet.ibm.com>2010-06-15 11:35:19 +0530
committerPaul Mackerras <paulus@samba.org>2010-06-22 19:40:50 +1000
commit5aae8a53708025d4e718f0d2e7c2f766779ddc71 (patch)
treed151e2c29e78248cee620cf5094a15316abd17d2 /arch/powerpc/kernel/exceptions-64s.S
parentf7136c5150c29846d7a1d09109449d96b2f63445 (diff)
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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 <paulus@samba.org> 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 <prasad@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 3e423fb..f53029a 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -828,6 +828,7 @@ END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)
/* We have a data breakpoint exception - handle it */
handle_dabr_fault:
+ bl .save_nvgprs
ld r4,_DAR(r1)
ld r5,_DSISR(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
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