perf_counter: powerpc: Make powerpc perf_counter code safe for 32-bit kernels

This abstracts a few things in arch/powerpc/kernel/perf_counter.c
that are specific to 64-bit kernels, and provides definitions for
32-bit kernels.  In particular,

* Only 64-bit has MMCRA and the bits in it that give information
  about a PMU interrupt (sampled PR, HV, slot number etc.)
* Only 64-bit has the lppaca and the lppaca->pmcregs_in_use field
* Use of SDAR is confined to 64-bit for now
* Only 64-bit has soft/lazy interrupt disable and therefore
  pseudo-NMIs (interrupts that occur while interrupts are soft-disabled)
* Only 64-bit has PMC7 and PMC8
* Only 64-bit has the MSR_HV bit.

This also fixes the types used in a couple of places, where we were
using long types for things that need to be 64-bit.

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: <19000.55590.634126.876084@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 133 insertions, 60 deletions

diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c
index 25e656c14945..809fdf94b95f 100644
--- a/arch/powerpc/kernel/perf_counter.c
+++ b/arch/powerpc/kernel/perf_counter.c
@@ -46,6 +46,115 @@ struct power_pmu *ppmu;
  */
 static unsigned int freeze_counters_kernel = MMCR0_FCS;
 
+/*
+ * 32-bit doesn't have MMCRA but does have an MMCR2,
+ * and a few other names are different.
+ */
+#ifdef CONFIG_PPC32
+
+#define MMCR0_FCHV              0
+#define MMCR0_PMCjCE            MMCR0_PMCnCE
+
+#define SPRN_MMCRA              SPRN_MMCR2
+#define MMCRA_SAMPLE_ENABLE     0
+
+static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
+{
+        return 0;
+}
+static inline void perf_set_pmu_inuse(int inuse) { }
+static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp) { }
+static inline u32 perf_get_misc_flags(struct pt_regs *regs)
+{
+        return 0;
+}
+static inline void perf_read_regs(struct pt_regs *regs) { }
+static inline int perf_intr_is_nmi(struct pt_regs *regs)
+{
+        return 0;
+}
+
+#endif /* CONFIG_PPC32 */
+
+/*
+ * Things that are specific to 64-bit implementations.
+ */
+#ifdef CONFIG_PPC64
+
+static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
+{
+        unsigned long mmcra = regs->dsisr;
+
+        if ((mmcra & MMCRA_SAMPLE_ENABLE) && !(ppmu->flags & PPMU_ALT_SIPR)) {
+                unsigned long slot = (mmcra & MMCRA_SLOT) >> MMCRA_SLOT_SHIFT;
+                if (slot > 1)
+                        return 4 * (slot - 1);
+        }
+        return 0;
+}
+
+static inline void perf_set_pmu_inuse(int inuse)
+{
+        get_lppaca()->pmcregs_in_use = inuse;
+}
+
+/*
+ * The user wants a data address recorded.
+ * If we're not doing instruction sampling, give them the SDAR
+ * (sampled data address).  If we are doing instruction sampling, then
+ * only give them the SDAR if it corresponds to the instruction
+ * pointed to by SIAR; this is indicated by the [POWER6_]MMCRA_SDSYNC
+ * bit in MMCRA.
+ */
+static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp)
+{
+        unsigned long mmcra = regs->dsisr;
+        unsigned long sdsync = (ppmu->flags & PPMU_ALT_SIPR) ?
+                POWER6_MMCRA_SDSYNC : MMCRA_SDSYNC;
+
+        if (!(mmcra & MMCRA_SAMPLE_ENABLE) || (mmcra & sdsync))
+                *addrp = mfspr(SPRN_SDAR);
+}
+
+static inline u32 perf_get_misc_flags(struct pt_regs *regs)
+{
+        unsigned long mmcra = regs->dsisr;
+
+        if (TRAP(regs) != 0xf00)
+                return 0;       /* not a PMU interrupt */
+
+        if (ppmu->flags & PPMU_ALT_SIPR) {
+                if (mmcra & POWER6_MMCRA_SIHV)
+                        return PERF_EVENT_MISC_HYPERVISOR;
+                return (mmcra & POWER6_MMCRA_SIPR) ?
+                        PERF_EVENT_MISC_USER : PERF_EVENT_MISC_KERNEL;
+        }
+        if (mmcra & MMCRA_SIHV)
+                return PERF_EVENT_MISC_HYPERVISOR;
+        return (mmcra & MMCRA_SIPR) ? PERF_EVENT_MISC_USER :
+                PERF_EVENT_MISC_KERNEL;
+}
+
+/*
+ * Overload regs->dsisr to store MMCRA so we only need to read it once
+ * on each interrupt.
+ */
+static inline void perf_read_regs(struct pt_regs *regs)
+{
+        regs->dsisr = mfspr(SPRN_MMCRA);
+}
+
+/*
+ * If interrupts were soft-disabled when a PMU interrupt occurs, treat
+ * it as an NMI.
+ */
+static inline int perf_intr_is_nmi(struct pt_regs *regs)
+{
+        return !regs->softe;
+}
+
+#endif /* CONFIG_PPC64 */
+
 static void perf_counter_interrupt(struct pt_regs *regs);
 
 void perf_counter_print_debug(void)
@@ -78,12 +187,14 @@ static unsigned long read_pmc(int idx)
         case 6:
                 val = mfspr(SPRN_PMC6);
                 break;
+#ifdef CONFIG_PPC64
         case 7:
                 val = mfspr(SPRN_PMC7);
                 break;
         case 8:
                 val = mfspr(SPRN_PMC8);
                 break;
+#endif /* CONFIG_PPC64 */
         default:
                 printk(KERN_ERR "oops trying to read PMC%d\n", idx);
                 val = 0;
@@ -115,12 +226,14 @@ static void write_pmc(int idx, unsigned long val)
         case 6:
                 mtspr(SPRN_PMC6, val);
                 break;
+#ifdef CONFIG_PPC64
         case 7:
                 mtspr(SPRN_PMC7, val);
                 break;
         case 8:
                 mtspr(SPRN_PMC8, val);
                 break;
+#endif /* CONFIG_PPC64 */
         default:
                 printk(KERN_ERR "oops trying to write PMC%d\n", idx);
         }
@@ -283,7 +396,7 @@ static int check_excludes(struct perf_counter **ctrs, unsigned int cflags[],
 
 static void power_pmu_read(struct perf_counter *counter)
 {
-        long val, delta, prev;
+        s64 val, delta, prev;
 
         if (!counter->hw.idx)
                 return;
@@ -477,7 +590,7 @@ void hw_perf_enable(void)
                 mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE);
                 mtspr(SPRN_MMCR1, cpuhw->mmcr[1]);
                 if (cpuhw->n_counters == 0)
-                        get_lppaca()->pmcregs_in_use = 0;
+                        perf_set_pmu_inuse(0);
                 goto out_enable;
         }
 
@@ -510,7 +623,7 @@ void hw_perf_enable(void)
          * bit set and set the hardware counters to their initial values.
          * Then unfreeze the counters.
          */
-        get_lppaca()->pmcregs_in_use = 1;
+        perf_set_pmu_inuse(1);
         mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE);
         mtspr(SPRN_MMCR1, cpuhw->mmcr[1]);
         mtspr(SPRN_MMCR0, (cpuhw->mmcr[0] & ~(MMCR0_PMC1CE | MMCR0_PMCjCE))
@@ -1007,11 +1120,10 @@ const struct pmu *hw_perf_counter_init(struct perf_counter *counter)
  * things if requested.  Note that interrupts are hard-disabled
  * here so there is no possibility of being interrupted.
  */
-static void record_and_restart(struct perf_counter *counter, long val,
+static void record_and_restart(struct perf_counter *counter, unsigned long val,
                                struct pt_regs *regs, int nmi)
 {
         u64 period = counter->hw.sample_period;
-        unsigned long mmcra, sdsync;
         s64 prev, delta, left;
         int record = 0;
 
@@ -1033,8 +1145,8 @@ static void record_and_restart(struct perf_counter *counter, long val,
                                 left = period;
                         record = 1;
                 }
-                if (left < 0x80000000L)
-                        val = 0x80000000L - left;
+                if (left < 0x80000000LL)
+                        val = 0x80000000LL - left;
         }
 
         /*
@@ -1047,22 +1159,9 @@ static void record_and_restart(struct perf_counter *counter, long val,
                         .period = counter->hw.last_period,
                 };
 
-                if (counter->attr.sample_type & PERF_SAMPLE_ADDR) {
-                        /*
-                         * The user wants a data address recorded.
-                         * If we're not doing instruction sampling,
-                         * give them the SDAR (sampled data address).
-                         * If we are doing instruction sampling, then only
-                         * give them the SDAR if it corresponds to the
-                         * instruction pointed to by SIAR; this is indicated
-                         * by the [POWER6_]MMCRA_SDSYNC bit in MMCRA.
-                         */
-                        mmcra = regs->dsisr;
-                        sdsync = (ppmu->flags & PPMU_ALT_SIPR) ?
-                                POWER6_MMCRA_SDSYNC : MMCRA_SDSYNC;
-                        if (!(mmcra & MMCRA_SAMPLE_ENABLE) || (mmcra & sdsync))
-                                data.addr = mfspr(SPRN_SDAR);
-                }
+                if (counter->attr.sample_type & PERF_SAMPLE_ADDR)
+                        perf_get_data_addr(regs, &data.addr);
+
                 if (perf_counter_overflow(counter, nmi, &data)) {
                         /*
                          * Interrupts are coming too fast - throttle them
@@ -1088,25 +1187,12 @@ static void record_and_restart(struct perf_counter *counter, long val,
  */
 unsigned long perf_misc_flags(struct pt_regs *regs)
 {
-        unsigned long mmcra;
+        u32 flags = perf_get_misc_flags(regs);
 
-        if (TRAP(regs) != 0xf00) {
-                /* not a PMU interrupt */
-                return user_mode(regs) ? PERF_EVENT_MISC_USER :
-                        PERF_EVENT_MISC_KERNEL;
-        }
-
-        mmcra = regs->dsisr;
-        if (ppmu->flags & PPMU_ALT_SIPR) {
-                if (mmcra & POWER6_MMCRA_SIHV)
-                        return PERF_EVENT_MISC_HYPERVISOR;
-                return (mmcra & POWER6_MMCRA_SIPR) ? PERF_EVENT_MISC_USER :
-                        PERF_EVENT_MISC_KERNEL;
-        }
-        if (mmcra & MMCRA_SIHV)
-                return PERF_EVENT_MISC_HYPERVISOR;
-        return (mmcra & MMCRA_SIPR) ? PERF_EVENT_MISC_USER :
-                        PERF_EVENT_MISC_KERNEL;
+        if (flags)
+                return flags;
+        return user_mode(regs) ? PERF_EVENT_MISC_USER :
+                PERF_EVENT_MISC_KERNEL;
 }
 
 /*
@@ -1115,20 +1201,12 @@ unsigned long perf_misc_flags(struct pt_regs *regs)
  */
 unsigned long perf_instruction_pointer(struct pt_regs *regs)
 {
-        unsigned long mmcra;
         unsigned long ip;
-        unsigned long slot;
 
         if (TRAP(regs) != 0xf00)
                 return regs->nip;       /* not a PMU interrupt */
 
-        ip = mfspr(SPRN_SIAR);
-        mmcra = regs->dsisr;
-        if ((mmcra & MMCRA_SAMPLE_ENABLE) && !(ppmu->flags & PPMU_ALT_SIPR)) {
-                slot = (mmcra & MMCRA_SLOT) >> MMCRA_SLOT_SHIFT;
-                if (slot > 1)
-                        ip += 4 * (slot - 1);
-        }
+        ip = mfspr(SPRN_SIAR) + perf_ip_adjust(regs);
         return ip;
 }
 
@@ -1140,7 +1218,7 @@ static void perf_counter_interrupt(struct pt_regs *regs)
         int i;
         struct cpu_hw_counters *cpuhw = &__get_cpu_var(cpu_hw_counters);
         struct perf_counter *counter;
-        long val;
+        unsigned long val;
         int found = 0;
         int nmi;
 
@@ -1148,16 +1226,9 @@ static void perf_counter_interrupt(struct pt_regs *regs)
                 freeze_limited_counters(cpuhw, mfspr(SPRN_PMC5),
                                         mfspr(SPRN_PMC6));
 
-        /*
-         * Overload regs->dsisr to store MMCRA so we only need to read it once.
-         */
-        regs->dsisr = mfspr(SPRN_MMCRA);
+        perf_read_regs(regs);
 
-        /*
-         * If interrupts were soft-disabled when this PMU interrupt
-         * occurred, treat it as an NMI.
-         */
-        nmi = !regs->softe;
+        nmi = perf_intr_is_nmi(regs);
         if (nmi)
                 nmi_enter();
         else
@@ -1223,11 +1294,13 @@ int register_power_pmu(struct power_pmu *pmu)
         pr_info("%s performance monitor hardware support registered\n",
                 pmu->name);
 
+#ifdef MSR_HV
         /*
          * Use FCHV to ignore kernel events if MSR.HV is set.
          */
         if (mfmsr() & MSR_HV)
                 freeze_counters_kernel = MMCR0_FCHV;
+#endif /* CONFIG_PPC64 */
 
         return 0;
 }