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authorBen Horgan <ben.horgan@arm.com>2026-03-06 21:27:17 +0300
committerWill Deacon <will@kernel.org>2026-03-13 17:17:30 +0300
commitc1376f1ff3f016a4b84e8030ed69df82e018d231 (patch)
tree3efa0adf44b12ddf12f5aaf490f9328b3de96568
parent4ad79c874e53ebb7fe3b8ae7ac6c858a2121f415 (diff)
downloadlinux-c1376f1ff3f016a4b84e8030ed69df82e018d231.tar.xz
arm_mpam: Disable preemption when making accesses to fake MSC in kunit test
Accesses to MSC must be made from a cpu that is affine to that MSC and the driver checks this in __mpam_write_reg() using smp_processor_id(). A fake in-memory MSC is used for testing. When using that, it doesn't matter which cpu we access it from but calling smp_processor_id() from a preemptible context gives warnings when running with CONFIG_DEBUG_PREEMPT. Add a test helper that wraps mpam_reset_msc_bitmap() with preemption disabled to ensure all (fake) MSC accesses are made with preemption disabled. Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
-rw-r--r--drivers/resctrl/test_mpam_devices.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/resctrl/test_mpam_devices.c b/drivers/resctrl/test_mpam_devices.c
index 3e8d564a0c64..75bd41bcc395 100644
--- a/drivers/resctrl/test_mpam_devices.c
+++ b/drivers/resctrl/test_mpam_devices.c
@@ -322,6 +322,14 @@ static void test_mpam_enable_merge_features(struct kunit *test)
mutex_unlock(&mpam_list_lock);
}
+static void __test_mpam_reset_msc_bitmap(struct mpam_msc *msc, u16 reg, u16 wd)
+{
+ /* Avoid warnings when running with CONFIG_DEBUG_PREEMPT */
+ guard(preempt)();
+
+ mpam_reset_msc_bitmap(msc, reg, wd);
+}
+
static void test_mpam_reset_msc_bitmap(struct kunit *test)
{
char __iomem *buf = kunit_kzalloc(test, SZ_16K, GFP_KERNEL);
@@ -341,31 +349,31 @@ static void test_mpam_reset_msc_bitmap(struct kunit *test)
test_result = (u32 *)(buf + MPAMCFG_CPBM);
- mpam_reset_msc_bitmap(&fake_msc, MPAMCFG_CPBM, 0);
+ __test_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);
+ __test_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);
+ __test_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);
+ __test_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);
+ __test_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;