lkml.org 
[lkml]   [2016]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[kvm-unit-tests PATCH v10 1/3] arm: Add PMU test
    Date
    From: Christopher Covington <cov@codeaurora.org>

    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 <cov@codeaurora.org>
    Signed-off-by: Wei Huang <wei@redhat.com>
    Reviewed-by: Andrew Jones <drjones@redhat.com>
    ---
    arm/Makefile.common | 3 ++-
    arm/pmu.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++
    arm/unittests.cfg | 5 ++++
    3 files changed, 81 insertions(+), 1 deletion(-)
    create mode 100644 arm/pmu.c

    diff --git a/arm/Makefile.common b/arm/Makefile.common
    index f37b5c2..5da2fdd 100644
    --- a/arm/Makefile.common
    +++ b/arm/Makefile.common
    @@ -12,7 +12,8 @@ endif
    tests-common = \
    $(TEST_DIR)/selftest.flat \
    $(TEST_DIR)/spinlock-test.flat \
    - $(TEST_DIR)/pci-test.flat
    + $(TEST_DIR)/pci-test.flat \
    + $(TEST_DIR)/pmu.flat

    all: test_cases

    diff --git a/arm/pmu.c b/arm/pmu.c
    new file mode 100644
    index 0000000..9d9c53b
    --- /dev/null
    +++ b/arm/pmu.c
    @@ -0,0 +1,74 @@
    +/*
    + * Test the ARM Performance Monitors Unit (PMU).
    + *
    + * Copyright (c) 2015-2016, 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"
    +#include "asm/barrier.h"
    +
    +#define PMU_PMCR_N_SHIFT 11
    +#define PMU_PMCR_N_MASK 0x1f
    +#define PMU_PMCR_ID_SHIFT 16
    +#define PMU_PMCR_ID_MASK 0xff
    +#define PMU_PMCR_IMP_SHIFT 24
    +#define PMU_PMCR_IMP_MASK 0xff
    +
    +#if defined(__arm__)
    +static inline uint32_t pmcr_read(void)
    +{
    + uint32_t ret;
    +
    + asm volatile("mrc p15, 0, %0, c9, c12, 0" : "=r" (ret));
    + return ret;
    +}
    +#elif defined(__aarch64__)
    +static inline uint32_t pmcr_read(void)
    +{
    + uint32_t ret;
    +
    + asm volatile("mrs %0, pmcr_el0" : "=r" (ret));
    + return ret;
    +}
    +#endif
    +
    +/*
    + * 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 2016, 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)
    +{
    + uint32_t pmcr;
    +
    + pmcr = pmcr_read();
    +
    + printf("PMU implementer: %c\n",
    + (pmcr >> PMU_PMCR_IMP_SHIFT) & PMU_PMCR_IMP_MASK);
    + printf("Identification code: 0x%x\n",
    + (pmcr >> PMU_PMCR_ID_SHIFT) & PMU_PMCR_ID_MASK);
    + printf("Event counters: %d\n",
    + (pmcr >> PMU_PMCR_N_SHIFT) & PMU_PMCR_N_MASK);
    +
    + return ((pmcr >> PMU_PMCR_IMP_SHIFT) & PMU_PMCR_IMP_MASK) != 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 ae32a42..816f494 100644
    --- a/arm/unittests.cfg
    +++ b/arm/unittests.cfg
    @@ -58,3 +58,8 @@ groups = selftest
    [pci-test]
    file = pci-test.flat
    groups = pci
    +
    +# Test PMU support
    +[pmu]
    +file = pmu.flat
    +groups = pmu
    --
    1.8.3.1
    \
     
     \ /
      Last update: 2016-11-21 21:33    [W:3.433 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site