Merge branch 'WIP.x86-pti.base-for-linus' of git://git.kernel.org/pub/scm/linux/kerne...

[sfrench/cifs-2.6.git] / arch / arc / kernel / perf_event.c

diff --git a/arch/arc/kernel/perf_event.c b/arch/arc/kernel/perf_event.c
index 2ce24e74f87956af0bba1d9430200196353bdff8..8aec462d90fbe8f0aa88847272d02004a863f2db 100644 (file)
--- a/arch/arc/kernel/perf_event.c
+++ b/arch/arc/kernel/perf_event.c
@@ -336,15 +336,12 @@ static int arc_pmu_add(struct perf_event *event, int flags)
        struct hw_perf_event *hwc = &event->hw;
        int idx = hwc->idx;
 
-       if (__test_and_set_bit(idx, pmu_cpu->used_mask)) {
-               idx = find_first_zero_bit(pmu_cpu->used_mask,
-                                         arc_pmu->n_counters);
-               if (idx == arc_pmu->n_counters)
-                       return -EAGAIN;
-
-               __set_bit(idx, pmu_cpu->used_mask);
-               hwc->idx = idx;
-       }
+       idx = ffz(pmu_cpu->used_mask[0]);
+       if (idx == arc_pmu->n_counters)
+               return -EAGAIN;
+
+       __set_bit(idx, pmu_cpu->used_mask);
+       hwc->idx = idx;
 
        write_aux_reg(ARC_REG_PCT_INDEX, idx);
 
@@ -377,21 +374,22 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev)
        struct perf_sample_data data;
        struct arc_pmu_cpu *pmu_cpu = this_cpu_ptr(&arc_pmu_cpu);
        struct pt_regs *regs;
-       int active_ints;
+       unsigned int active_ints;
        int idx;
 
        arc_pmu_disable(&arc_pmu->pmu);
 
        active_ints = read_aux_reg(ARC_REG_PCT_INT_ACT);
+       if (!active_ints)
+               goto done;
 
        regs = get_irq_regs();
 
-       for (idx = 0; idx < arc_pmu->n_counters; idx++) {
-               struct perf_event *event = pmu_cpu->act_counter[idx];
+       do {
+               struct perf_event *event;
                struct hw_perf_event *hwc;
 
-               if (!(active_ints & (1 << idx)))
-                       continue;
+               idx = __ffs(active_ints);
 
                /* Reset interrupt flag by writing of 1 */
                write_aux_reg(ARC_REG_PCT_INT_ACT, 1 << idx);
@@ -404,19 +402,22 @@ static irqreturn_t arc_pmu_intr(int irq, void *dev)
                write_aux_reg(ARC_REG_PCT_INT_CTRL,
                        read_aux_reg(ARC_REG_PCT_INT_CTRL) | (1 << idx));
 
+               event = pmu_cpu->act_counter[idx];
                hwc = &event->hw;
 
                WARN_ON_ONCE(hwc->idx != idx);
 
                arc_perf_event_update(event, &event->hw, event->hw.idx);
                perf_sample_data_init(&data, 0, hwc->last_period);
-               if (!arc_pmu_event_set_period(event))
-                       continue;
+               if (arc_pmu_event_set_period(event)) {
+                       if (perf_event_overflow(event, &data, regs))
+                               arc_pmu_stop(event, 0);
+               }
 
-               if (perf_event_overflow(event, &data, regs))
-                       arc_pmu_stop(event, 0);
-       }
+               active_ints &= ~(1U << idx);
+       } while (active_ints);
 
+done:
        arc_pmu_enable(&arc_pmu->pmu);
 
        return IRQ_HANDLED;
@@ -461,6 +462,7 @@ static int arc_pmu_device_probe(struct platform_device *pdev)
                pr_err("This core does not have performance counters!\n");
                return -ENODEV;
        }
+       BUILD_BUG_ON(ARC_PERF_MAX_COUNTERS > 32);
        BUG_ON(pct_bcr.c > ARC_PERF_MAX_COUNTERS);
 
        READ_BCR(ARC_REG_CC_BUILD, cc_bcr);