powerpc/perf: move perf irq/nmi handling details into traps.c

This is required in order to allow more significant differences between
NMI type interrupt handlers and regular asynchronous handlers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-20-npiggin@gmail.com

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 4349b25..6da3a36 100644 (file)
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1892,11 +1892,40 @@ void vsx_unavailable_tm(struct pt_regs *regs)
 }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
-void performance_monitor_exception(struct pt_regs *regs)
+static void performance_monitor_exception_nmi(struct pt_regs *regs)
+{
+       nmi_enter();
+
+       __this_cpu_inc(irq_stat.pmu_irqs);
+
+       perf_irq(regs);
+
+       nmi_exit();
+}
+
+static void performance_monitor_exception_async(struct pt_regs *regs)
 {
+       irq_enter();
+
        __this_cpu_inc(irq_stat.pmu_irqs);
 
        perf_irq(regs);
+
+       irq_exit();
+}
+
+void performance_monitor_exception(struct pt_regs *regs)
+{
+       /*
+        * On 64-bit, if perf interrupts hit in a local_irq_disable
+        * (soft-masked) region, we consider them as NMIs. This is required to
+        * prevent hash faults on user addresses when reading callchains (and
+        * looks better from an irq tracing perspective).
+        */
+       if (IS_ENABLED(CONFIG_PPC64) && unlikely(arch_irq_disabled_regs(regs)))
+               performance_monitor_exception_nmi(regs);
+       else
+               performance_monitor_exception_async(regs);
 }
 
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 28206b1..9fd0601 100644 (file)
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -110,10 +110,6 @@ static inline void perf_read_regs(struct pt_regs *regs)
 {
        regs->result = 0;
 }
-static inline int perf_intr_is_nmi(struct pt_regs *regs)
-{
-       return 0;
-}
 
 static inline int siar_valid(struct pt_regs *regs)
 {
@@ -353,15 +349,6 @@ static inline void perf_read_regs(struct pt_regs *regs)
        regs->result = use_siar;
 }
 
-/*
- * 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 & IRQS_DISABLED);
-}
-
 /*
  * On processors like P7+ that have the SIAR-Valid bit, marked instructions
  * must be sampled only if the SIAR-valid bit is set.
@@ -2279,7 +2266,6 @@ static void __perf_event_interrupt(struct pt_regs *regs)
        struct perf_event *event;
        unsigned long val[8];
        int found, active;
-       int nmi;
 
        if (cpuhw->n_limited)
                freeze_limited_counters(cpuhw, mfspr(SPRN_PMC5),
@@ -2287,18 +2273,6 @@ static void __perf_event_interrupt(struct pt_regs *regs)
 
        perf_read_regs(regs);
 
-       /*
-        * If perf interrupts hit in a local_irq_disable (soft-masked) region,
-        * we consider them as NMIs. This is required to prevent hash faults on
-        * user addresses when reading callchains. See the NMI test in
-        * do_hash_page.
-        */
-       nmi = perf_intr_is_nmi(regs);
-       if (nmi)
-               nmi_enter();
-       else
-               irq_enter();
-
        /* Read all the PMCs since we'll need them a bunch of times */
        for (i = 0; i < ppmu->n_counter; ++i)
                val[i] = read_pmc(i + 1);
@@ -2344,8 +2318,8 @@ static void __perf_event_interrupt(struct pt_regs *regs)
                        }
                }
        }
-       if (!found && !nmi && printk_ratelimit())
-               printk(KERN_WARNING "Can't find PMC that caused IRQ\n");
+       if (unlikely(!found) && !arch_irq_disabled_regs(regs))
+               printk_ratelimited(KERN_WARNING "Can't find PMC that caused IRQ\n");
 
        /*
         * Reset MMCR0 to its normal value.  This will set PMXE and
@@ -2355,11 +2329,6 @@ static void __perf_event_interrupt(struct pt_regs *regs)
         * we get back out of this interrupt.
         */
        write_mmcr0(cpuhw, cpuhw->mmcr.mmcr0);
-
-       if (nmi)
-               nmi_exit();
-       else
-               irq_exit();
 }
 
 static void perf_event_interrupt(struct pt_regs *regs)

diff --git a/arch/powerpc/perf/core-fsl-emb.c b/arch/powerpc/perf/core-fsl-emb.c
index e0e7e27..ee721f4 100644 (file)
--- a/arch/powerpc/perf/core-fsl-emb.c
+++ b/arch/powerpc/perf/core-fsl-emb.c
@@ -31,19 +31,6 @@ static atomic_t num_events;
 /* Used to avoid races in calling reserve/release_pmc_hardware */
 static DEFINE_MUTEX(pmc_reserve_mutex);
 
-/*
- * 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)
-{
-#ifdef __powerpc64__
-       return (regs->softe & IRQS_DISABLED);
-#else
-       return 0;
-#endif
-}
-
 static void perf_event_interrupt(struct pt_regs *regs);
 
 /*
@@ -659,13 +646,6 @@ static void perf_event_interrupt(struct pt_regs *regs)
        struct perf_event *event;
        unsigned long val;
        int found = 0;
-       int nmi;
-
-       nmi = perf_intr_is_nmi(regs);
-       if (nmi)
-               nmi_enter();
-       else
-               irq_enter();
 
        for (i = 0; i < ppmu->n_counter; ++i) {
                event = cpuhw->event[i];
@@ -690,11 +670,6 @@ static void perf_event_interrupt(struct pt_regs *regs)
        mtmsr(mfmsr() | MSR_PMM);
        mtpmr(PMRN_PMGC0, PMGC0_PMIE | PMGC0_FCECE);
        isync();
-
-       if (nmi)
-               nmi_exit();
-       else
-               irq_exit();
 }
 
 void hw_perf_event_setup(int cpu)