From: Marc Zyngier maz@kernel.org
mainline inclusion from mainline-v5.16-rc1 commit db26f8f2da92 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4QCBG CVE: NA
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We currently handle synchronisation when workarounds are enabled by having an ISB in the __arch_counter_get_cnt?ct_stable() helpers.
While this works, this prevents us from relaxing this synchronisation.
Instead, move it closer to the point where the synchronisation is actually needed. Further patches will subsequently relax this.
Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20211017124225.3018098-14-maz@kernel.org Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- arch/arm64/include/asm/arch_timer.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index b05018c907d5..637bb985a330 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -32,7 +32,7 @@ ({ \ const struct arch_timer_erratum_workaround *__wa; \ __wa = __this_cpu_read(timer_unstable_counter_workaround); \ - (__wa && __wa->h) ? __wa->h : arch_timer_##h; \ + (__wa && __wa->h) ? ({ isb(); __wa->h;}) : arch_timer_##h; \ })
#else @@ -64,11 +64,13 @@ DECLARE_PER_CPU(const struct arch_timer_erratum_workaround *,
static inline notrace u64 arch_timer_read_cntpct_el0(void) { + isb(); return read_sysreg(cntpct_el0); }
static inline notrace u64 arch_timer_read_cntvct_el0(void) { + isb(); return read_sysreg(cntvct_el0); }
@@ -163,7 +165,6 @@ static __always_inline u64 __arch_counter_get_cntpct_stable(void) { u64 cnt;
- isb(); cnt = arch_timer_reg_read_stable(cntpct_el0); arch_counter_enforce_ordering(cnt); return cnt; @@ -183,7 +184,6 @@ static __always_inline u64 __arch_counter_get_cntvct_stable(void) { u64 cnt;
- isb(); cnt = arch_timer_reg_read_stable(cntvct_el0); arch_counter_enforce_ordering(cnt); return cnt;