In general, the set/clr registers should always be used in their
write form, never in a RMW form (imagine an interrupt disabling
a counter between the read and the write...).
The current implementation of [enable|disable]_counter both use the RMW
form, fix them by directly write to the set/clr registers.
At the same time, it also fix the buggy disable_counter() which would
end up disabling all the counters.
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Signed-off-by: Shaoqin Huang <shahuang@xxxxxxxxxx>
---
tools/testing/selftests/kvm/include/aarch64/vpmu.h | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/aarch64/vpmu.h b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
index e0cc1ca1c4b7..644dae3814b5 100644
--- a/tools/testing/selftests/kvm/include/aarch64/vpmu.h
+++ b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
@@ -78,17 +78,13 @@ static inline void write_sel_evtyper(int sel, unsigned long val)
static inline void enable_counter(int idx)
{
- uint64_t v = read_sysreg(pmcntenset_el0);
-
- write_sysreg(BIT(idx) | v, pmcntenset_el0);
+ write_sysreg(BIT(idx), pmcntenset_el0);
isb();
}
static inline void disable_counter(int idx)
{
- uint64_t v = read_sysreg(pmcntenset_el0);
-
- write_sysreg(BIT(idx) | v, pmcntenclr_el0);
+ write_sysreg(BIT(idx), pmcntenclr_el0);
isb();
}
--
2.40.1
