perf_counter: powerpc: Change how processor-specific back-ends get selected

At present, the powerpc generic (processor-independent) perf_counter
code has list of processor back-end modules, and at initialization,
it looks at the PVR (processor version register) and has a switch
statement to select a suitable processor-specific back-end.

This is going to become inconvenient as we add more processor-specific
back-ends, so this inverts the order: now each back-end checks whether
it applies to the current processor, and registers itself if so.
Furthermore, instead of looking at the PVR, back-ends now check the
cur_cpu_spec->oprofile_cpu_type string and match on that.

Lastly, each back-end now specifies a name for itself so the core can
print a nice message when a back-end registers itself.

This doesn't provide any support for unregistering back-ends, but that
wouldn't be hard to do and would allow back-ends to be modules.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linuxppc-dev@ozlabs.org
Cc: benh@kernel.crashing.org
LKML-Reference: <19000.55529.762227.518531@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/perf_counter.h b/arch/powerpc/include/asm/perf_counter.h
index 2ceb0fe..8ccd4e1 100644
--- a/arch/powerpc/include/asm/perf_counter.h
+++ b/arch/powerpc/include/asm/perf_counter.h
@@ -21,6 +21,7 @@
  * describe the PMU on a particular POWER-family CPU.
  */
 struct power_pmu {
+	const char	*name;
 	int		n_counter;
 	int		max_alternatives;
 	unsigned long	add_fields;
@@ -41,8 +42,6 @@ struct power_pmu {
 			       [PERF_COUNT_HW_CACHE_RESULT_MAX];
 };
 
-extern struct power_pmu *ppmu;
-
 /*
  * Values for power_pmu.flags
  */
@@ -56,6 +55,8 @@ extern struct power_pmu *ppmu;
 #define PPMU_LIMITED_PMC_REQD	2	/* have to put this on a limited PMC */
 #define PPMU_ONLY_COUNT_RUN	4	/* only counting in run state */
 
+extern int register_power_pmu(struct power_pmu *);
+
 struct pt_regs;
 extern unsigned long perf_misc_flags(struct pt_regs *regs);
 extern unsigned long perf_instruction_pointer(struct pt_regs *regs);