selftests/powerpc: Add cycles test with MMCR2 handling

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 93 insertions, 1 deletions

diff --git a/tools/testing/selftests/powerpc/pmu/ebb/Makefile b/tools/testing/selftests/powerpc/pmu/ebb/Makefile
index 251447eafe49..3dc4332698cb 100644
--- a/tools/testing/selftests/powerpc/pmu/ebb/Makefile
+++ b/tools/testing/selftests/powerpc/pmu/ebb/Makefile
@@ -13,7 +13,8 @@ PROGS := reg_access_test event_attributes_test cycles_test	\
          close_clears_pmcc_test instruction_count_test          \
          fork_cleanup_test ebb_on_child_test                    \
          ebb_on_willing_child_test back_to_back_ebbs_test       \
-         lost_exception_test no_handler_test
+         lost_exception_test no_handler_test                    \
+         cycles_with_mmcr2_test
 
 all: $(PROGS)
 
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c b/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c
new file mode 100644
index 000000000000..d43029b0800c
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c
@@ -0,0 +1,91 @@
+/*
+ * 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 manipulating the user accessible bits in MMCR2.
+ */
+
+/* We use two values because the first freezes PMC1 and so we would get no EBBs */
+#define MMCR2_EXPECTED_1 0x4020100804020000UL /* (FC1P|FC2P|FC3P|FC4P|FC5P|FC6P) */
+#define MMCR2_EXPECTED_2 0x0020100804020000UL /* (     FC2P|FC3P|FC4P|FC5P|FC6P) */
+
+
+int cycles_with_mmcr2(void)
+{
+        struct event event;
+        uint64_t val, expected[2], actual;
+        int i;
+        bool bad_mmcr2;
+
+        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));
+
+        ebb_enable_pmc_counting(1);
+        setup_ebb_handler(standard_ebb_callee);
+        ebb_global_enable();
+
+        FAIL_IF(ebb_event_enable(&event));
+
+        mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
+
+        /* XXX Set of MMCR2 must be after enable */
+        expected[0] = MMCR2_EXPECTED_1;
+        expected[1] = MMCR2_EXPECTED_2;
+        i = 0;
+        bad_mmcr2 = false;
+
+        /* Make sure we loop until we take at least one EBB */
+        while ((ebb_state.stats.ebb_count < 20 && !bad_mmcr2) ||
+                ebb_state.stats.ebb_count < 1)
+        {
+                mtspr(SPRN_MMCR2, expected[i % 2]);
+
+                FAIL_IF(core_busy_loop());
+
+                val = mfspr(SPRN_MMCR2);
+                if (val != expected[i % 2]) {
+                        bad_mmcr2 = true;
+                        actual = val;
+                }
+
+                i++;
+        }
+
+        ebb_global_disable();
+        ebb_freeze_pmcs();
+
+        count_pmc(1, sample_period);
+
+        dump_ebb_state();
+
+        event_close(&event);
+
+        FAIL_IF(ebb_state.stats.ebb_count == 0);
+
+        if (bad_mmcr2)
+                printf("Bad MMCR2 value seen is 0x%lx\n", actual);
+
+        FAIL_IF(bad_mmcr2);
+
+        return 0;
+}
+
+int main(void)
+{
+        return test_harness(cycles_with_mmcr2, "cycles_with_mmcr2");
+}