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 <[e-mail]>
Signed-off-by: Ben Horgan <[e-mail]>
Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports")
Reviewed-by: Gavin Shan <[e-mail]>
Tested-by: Shaopeng Tan <[e-mail]>
Tested-by: Peter Newman <[e-mail]>
Signed-off-by: Catalin Marinas <[e-mail]>

drivers/resctrl/mpam_internal.h

···
 } 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 {