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arm_mpam: Use non-atomic bitops when modifying feature bitmap

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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: 8c90dc68a5 ("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>
This commit is contained in:
Ben Horgan
2026-01-12 16:58:29 +00:00
committed by Catalin Marinas
parent b5a69c4869
commit b9f5c38e4a
1 changed files with 6 additions and 2 deletions
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8
drivers/resctrl/mpam_internal.h
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@@ -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 {