Beginning with a simple sanity check of the control register, add a unit test for the ARM Performance Monitors Unit (PMU).
Signed-off-by: Christopher Covington <c...@codeaurora.org> --- arm/pmu.c | 82 ++++++++++++++++++++++++++++++++++++++++++++ arm/unittests.cfg | 5 +++ config/config-arm-common.mak | 4 ++- 3 files changed, 90 insertions(+), 1 deletion(-) create mode 100644 arm/pmu.c diff --git a/arm/pmu.c b/arm/pmu.c new file mode 100644 index 0000000..42d0ee1 --- /dev/null +++ b/arm/pmu.c @@ -0,0 +1,82 @@ +/* + * Test the ARM Performance Monitors Unit (PMU). + * + * Copyright 2015 The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU Lesser General Public License version 2.1 and + * only version 2.1 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License + * for more details. + */ +#include "libcflat.h" + +#if defined(__arm__) +static inline uint32_t get_pmcr(void) +{ + uint32_t ret; + + asm volatile("mrc p15, 0, %0, c9, c12, 0" : "=r" (ret)); + return ret; +} +#elif defined(__aarch64__) +static inline uint32_t get_pmcr(void) +{ + uint32_t ret; + + asm volatile("mrs %0, pmcr_el0" : "=r" (ret)); + return ret; +} +#endif + +struct pmu_data { + union { + uint32_t pmcr_el0; + struct { + uint32_t enable:1; + uint32_t event_counter_reset:1; + uint32_t cycle_counter_reset:1; + uint32_t cycle_counter_clock_divider:1; + uint32_t event_counter_export:1; + uint32_t cycle_counter_disable_when_prohibited:1; + uint32_t cycle_counter_long:1; + uint32_t reserved:4; + uint32_t counters:5; + uint32_t identification_code:8; + uint32_t implementer:8; + }; + }; +}; + +/* + * As a simple sanity check on the PMCR_EL0, ensure the implementer field isn't + * null. Also print out a couple other interesting fields for diagnostic + * purposes. For example, as of fall 2015, QEMU TCG mode doesn't implement + * event counters and therefore reports zero event counters, but hopefully + * support for at least the instructions event will be added in the future and + * the reported number of event counters will become nonzero. + */ +static bool check_pmcr(void) +{ + struct pmu_data pmu; + + pmu.pmcr_el0 = get_pmcr(); + + printf("PMU implementer: %c\n", pmu.implementer); + printf("Identification code: 0x%x\n", pmu.identification_code); + printf("Event counters: %d\n", pmu.counters); + + return pmu.implementer != 0; +} + +int main(void) +{ + report_prefix_push("pmu"); + + report("Control register", check_pmcr()); + + return report_summary(); +} diff --git a/arm/unittests.cfg b/arm/unittests.cfg index e068a0c..fd94adb 100644 --- a/arm/unittests.cfg +++ b/arm/unittests.cfg @@ -35,3 +35,8 @@ file = selftest.flat smp = `getconf _NPROCESSORS_CONF` extra_params = -append 'smp' groups = selftest + +# Test PMU support without -icount +[pmu] +file = pmu.flat +groups = pmu diff --git a/config/config-arm-common.mak b/config/config-arm-common.mak index 698555d..b34d04c 100644 --- a/config/config-arm-common.mak +++ b/config/config-arm-common.mak @@ -11,7 +11,8 @@ endif tests-common = \ $(TEST_DIR)/selftest.flat \ - $(TEST_DIR)/spinlock-test.flat + $(TEST_DIR)/spinlock-test.flat \ + $(TEST_DIR)/pmu.flat all: test_cases @@ -70,3 +71,4 @@ test_cases: $(generated_files) $(tests-common) $(tests) $(TEST_DIR)/selftest.elf: $(cstart.o) $(TEST_DIR)/selftest.o $(TEST_DIR)/spinlock-test.elf: $(cstart.o) $(TEST_DIR)/spinlock-test.o +$(TEST_DIR)/pmu.elf: $(cstart.o) $(TEST_DIR)/pmu.o -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html