[RFC PATCH 35/36] arm_mpam: Add kunit test for bitmap reset
From: James Morse <james.morse@arm.com>
Date: 2025-07-11 18:38:59
Also in:
lkml
Subsystem:
arm64 platform drivers, the rest · Maintainers:
Hans de Goede, Ilpo Järvinen, Linus Torvalds
The bitmap reset code has been a source of bugs. Add a unit test. This currently has to be built in, as the rest of the driver is builtin. Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: James Morse <james.morse@arm.com> --- drivers/platform/arm64/mpam/Kconfig | 13 ++++ drivers/platform/arm64/mpam/mpam_devices.c | 4 ++ .../platform/arm64/mpam/test_mpam_devices.c | 68 +++++++++++++++++++ 3 files changed, 85 insertions(+) create mode 100644 drivers/platform/arm64/mpam/test_mpam_devices.c
diff --git a/drivers/platform/arm64/mpam/Kconfig b/drivers/platform/arm64/mpam/Kconfig
index b63495d7da87..861e4b946ddc 100644
--- a/drivers/platform/arm64/mpam/Kconfig
+++ b/drivers/platform/arm64/mpam/Kconfig@@ -4,7 +4,20 @@ config ARM_CPU_RESCTRL bool depends on ARM64 +menu "ARM64 MPAM driver options" + config ARM64_MPAM_DRIVER_DEBUG bool "Enable debug messages from the MPAM driver." help Say yes here to enable debug messages from the MPAM driver. + +config MPAM_KUNIT_TEST + bool "KUnit tests for MPAM driver " if !KUNIT_ALL_TESTS + depends on KUNIT=y + default KUNIT_ALL_TESTS + help + Enable this option to run tests in the MPAM driver. + + If unsure, say N. + +endmenu
diff --git a/drivers/platform/arm64/mpam/mpam_devices.c b/drivers/platform/arm64/mpam/mpam_devices.c
index 470a3709670e..a7f301b0da84 100644
--- a/drivers/platform/arm64/mpam/mpam_devices.c
+++ b/drivers/platform/arm64/mpam/mpam_devices.c@@ -2904,3 +2904,7 @@ static int __init mpam_msc_driver_init(void) } /* Must occur after arm64_mpam_register_cpus() from arch_initcall() */ subsys_initcall(mpam_msc_driver_init); + +#ifdef CONFIG_MPAM_KUNIT_TEST +#include "test_mpam_devices.c" +#endif
diff --git a/drivers/platform/arm64/mpam/test_mpam_devices.c b/drivers/platform/arm64/mpam/test_mpam_devices.c
new file mode 100644
index 000000000000..8e9d6c88171c
--- /dev/null
+++ b/drivers/platform/arm64/mpam/test_mpam_devices.c@@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2024 Arm Ltd. +/* This file is intended to be included into mpam_devices.c */ + +#include <kunit/test.h> + +static void test_mpam_reset_msc_bitmap(struct kunit *test) +{ + char *buf = kunit_kzalloc(test, SZ_16K, GFP_KERNEL); + struct mpam_msc fake_msc; + u32 *test_result; + + if (!buf) + return; + + fake_msc.mapped_hwpage = buf; + fake_msc.mapped_hwpage_sz = SZ_16K; + cpumask_copy(&fake_msc.accessibility, cpu_possible_mask); + + mutex_init(&fake_msc.part_sel_lock); + mutex_lock(&fake_msc.part_sel_lock); + + test_result = (u32 *)(buf + MPAMCFG_CPBM); + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 0); + KUNIT_EXPECT_EQ(test, test_result[0], 0); + KUNIT_EXPECT_EQ(test, test_result[1], 0); + test_result[0] = 0; + test_result[1] = 0; + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 1); + KUNIT_EXPECT_EQ(test, test_result[0], 1); + KUNIT_EXPECT_EQ(test, test_result[1], 0); + test_result[0] = 0; + test_result[1] = 0; + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 16); + KUNIT_EXPECT_EQ(test, test_result[0], 0xffff); + KUNIT_EXPECT_EQ(test, test_result[1], 0); + test_result[0] = 0; + test_result[1] = 0; + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 32); + KUNIT_EXPECT_EQ(test, test_result[0], 0xffffffff); + KUNIT_EXPECT_EQ(test, test_result[1], 0); + test_result[0] = 0; + test_result[1] = 0; + + mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 33); + KUNIT_EXPECT_EQ(test, test_result[0], 0xffffffff); + KUNIT_EXPECT_EQ(test, test_result[1], 1); + test_result[0] = 0; + test_result[1] = 0; + + mutex_unlock(&fake_msc.part_sel_lock); +} + +static struct kunit_case mpam_devices_test_cases[] = { + KUNIT_CASE(test_mpam_reset_msc_bitmap), + {} +}; + +static struct kunit_suite mpam_devices_test_suite = { + .name = "mpam_devices_test_suite", + .test_cases = mpam_devices_test_cases, +}; + +kunit_test_suites(&mpam_devices_test_suite);
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2.39.5