diff options
| author | Ben Horgan <ben.horgan@arm.com> | 2026-01-12 16:58:29 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2026-01-16 12:04:20 +0000 |
| commit | b9f5c38e4af1a094384650d2fc79fb992d6d5e64 (patch) | |
| tree | 1d7833277d766258e9f8f33546101b0957704a71 | |
| parent | b5a69c4869211a6ab61a95f5cc987b25f383dbc3 (diff) | |
arm_mpam: Use non-atomic bitops when modifying feature bitmap
In the test__props_mismatch() kunit test we rely on the struct mpam_props
being packed to ensure memcmp doesn't consider packing. Making it packed
reduces the alignment of the features bitmap and so breaks a requirement
for the use of atomics. As we don't rely on the set/clear of these bits
being atomic, just make them non-atomic.
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports")
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | drivers/resctrl/mpam_internal.h | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h index 17cdc3080d58..e8971842b124 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -200,8 +200,12 @@ struct mpam_props { } PACKED_FOR_KUNIT; #define mpam_has_feature(_feat, x) test_bit(_feat, (x)->features) -#define mpam_set_feature(_feat, x) set_bit(_feat, (x)->features) -#define mpam_clear_feature(_feat, x) clear_bit(_feat, (x)->features) +/* + * The non-atomic get/set operations are used because if struct mpam_props is + * packed, the alignment requirements for atomics aren't met. + */ +#define mpam_set_feature(_feat, x) __set_bit(_feat, (x)->features) +#define mpam_clear_feature(_feat, x) __clear_bit(_feat, (x)->features) /* The values for MSMON_CFG_MBWU_FLT.RWBW */ enum mon_filter_options { |