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, 7 insertions, 37 deletions

diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c
index 9300638b8c26..25e656c14945 100644
--- a/arch/powerpc/kernel/perf_counter.c
+++ b/arch/powerpc/kernel/perf_counter.c
@@ -1214,42 +1214,14 @@ void hw_perf_counter_setup(int cpu)
         cpuhw->mmcr[0] = MMCR0_FC;
 }
 
-extern struct power_pmu power4_pmu;
-extern struct power_pmu ppc970_pmu;
-extern struct power_pmu power5_pmu;
-extern struct power_pmu power5p_pmu;
-extern struct power_pmu power6_pmu;
-extern struct power_pmu power7_pmu;
-
-static int init_perf_counters(void)
+int register_power_pmu(struct power_pmu *pmu)
 {
-        unsigned long pvr;
-
-        /* XXX should get this from cputable */
-        pvr = mfspr(SPRN_PVR);
-        switch (PVR_VER(pvr)) {
-        case PV_POWER4:
-        case PV_POWER4p:
-                ppmu = &power4_pmu;
-                break;
-        case PV_970:
-        case PV_970FX:
-        case PV_970MP:
-                ppmu = &ppc970_pmu;
-                break;
-        case PV_POWER5:
-                ppmu = &power5_pmu;
-                break;
-        case PV_POWER5p:
-                ppmu = &power5p_pmu;
-                break;
-        case 0x3e:
-                ppmu = &power6_pmu;
-                break;
-        case 0x3f:
-                ppmu = &power7_pmu;
-                break;
-        }
+        if (ppmu)
+                return -EBUSY;          /* something's already registered */
+
+        ppmu = pmu;
+        pr_info("%s performance monitor hardware support registered\n",
+                pmu->name);
 
         /*
          * Use FCHV to ignore kernel events if MSR.HV is set.
@@ -1259,5 +1231,3 @@ static int init_perf_counters(void)
 
         return 0;
 }
-
-arch_initcall(init_perf_counters);