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, 15 insertions, 1 deletions

diff --git a/arch/powerpc/kernel/ppc970-pmu.c b/arch/powerpc/kernel/ppc970-pmu.c
index 3ed88333412f..6637c87fe70e 100644
--- a/arch/powerpc/kernel/ppc970-pmu.c
+++ b/arch/powerpc/kernel/ppc970-pmu.c
@@ -10,7 +10,9 @@
  */
 #include <linux/string.h>
 #include <linux/perf_counter.h>
+#include <linux/string.h>
 #include <asm/reg.h>
+#include <asm/cputable.h>
 
 /*
  * Bits in event code for PPC970
@@ -470,7 +472,8 @@ static int ppc970_cache_events[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = {
         },
 };
 
-struct power_pmu ppc970_pmu = {
+static struct power_pmu ppc970_pmu = {
+        .name                   = "PPC970/FX/MP",
         .n_counter              = 8,
         .max_alternatives       = 2,
         .add_fields             = 0x001100005555ull,
@@ -483,3 +486,14 @@ struct power_pmu ppc970_pmu = {
         .generic_events         = ppc970_generic_events,
         .cache_events           = &ppc970_cache_events,
 };
+
+static int init_ppc970_pmu(void)
+{
+        if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/970")
+            && strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/970MP"))
+                return -ENODEV;
+
+        return register_power_pmu(&ppc970_pmu);
+}
+
+arch_initcall(init_ppc970_pmu);