Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / tools / testing / selftests / powerpc / pmu / ebb / cycles_with_freeze_test.c

diff --git a/kernel/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_freeze_test.c b/kernel/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_freeze_test.c
new file mode 100644 (file)
index 0000000..754b3f2
--- /dev/null
+++ b/kernel/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_freeze_test.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2014, Michael Ellerman, IBM Corp.
+ * Licensed under GPLv2.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "ebb.h"
+
+
+/*
+ * Test of counting cycles while using MMCR0_FC (freeze counters) to only count
+ * parts of the code. This is complicated by the fact that FC is set by the
+ * hardware when the event overflows. We may take the EBB after we have set FC,
+ * so we have to be careful about whether we clear FC at the end of the EBB
+ * handler or not.
+ */
+
+static bool counters_frozen = false;
+static int ebbs_while_frozen = 0;
+
+static void ebb_callee(void)
+{
+       uint64_t mask, val;
+
+       mask = MMCR0_PMAO | MMCR0_FC;
+
+       val = mfspr(SPRN_BESCR);
+       if (!(val & BESCR_PMEO)) {
+               ebb_state.stats.spurious++;
+               goto out;
+       }
+
+       ebb_state.stats.ebb_count++;
+       trace_log_counter(ebb_state.trace, ebb_state.stats.ebb_count);
+
+       val = mfspr(SPRN_MMCR0);
+       trace_log_reg(ebb_state.trace, SPRN_MMCR0, val);
+
+       if (counters_frozen) {
+               trace_log_string(ebb_state.trace, "frozen");
+               ebbs_while_frozen++;
+               mask &= ~MMCR0_FC;
+       }
+
+       count_pmc(1, sample_period);
+out:
+       reset_ebb_with_clear_mask(mask);
+}
+
+int cycles_with_freeze(void)
+{
+       struct event event;
+       uint64_t val;
+       bool fc_cleared;
+
+       event_init_named(&event, 0x1001e, "cycles");
+       event_leader_ebb_init(&event);
+
+       event.attr.exclude_kernel = 1;
+       event.attr.exclude_hv = 1;
+       event.attr.exclude_idle = 1;
+
+       FAIL_IF(event_open(&event));
+
+       setup_ebb_handler(ebb_callee);
+       ebb_global_enable();
+       FAIL_IF(ebb_event_enable(&event));
+
+       mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
+
+       fc_cleared = false;
+
+       /* Make sure we loop until we take at least one EBB */
+       while ((ebb_state.stats.ebb_count < 20 && !fc_cleared) ||
+               ebb_state.stats.ebb_count < 1)
+       {
+               counters_frozen = false;
+               mb();
+               mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_FC);
+
+               FAIL_IF(core_busy_loop());
+
+               counters_frozen = true;
+               mb();
+               mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) |  MMCR0_FC);
+
+               val = mfspr(SPRN_MMCR0);
+               if (! (val & MMCR0_FC)) {
+                       printf("Outside of loop, FC NOT set MMCR0 0x%lx\n", val);
+                       fc_cleared = true;
+               }
+       }
+
+       ebb_global_disable();
+       ebb_freeze_pmcs();
+
+       count_pmc(1, sample_period);
+
+       dump_ebb_state();
+
+       printf("EBBs while frozen %d\n", ebbs_while_frozen);
+
+       event_close(&event);
+
+       FAIL_IF(ebb_state.stats.ebb_count == 0);
+       FAIL_IF(fc_cleared);
+
+       return 0;
+}
+
+int main(void)
+{
+       return test_harness(cycles_with_freeze, "cycles_with_freeze");
+}