From: Marc Zyngier marc.zyngier@arm.com
commit 0064030c6fd4ca6cfab42de037b2a89445beeead upstream.
Should we ever have a workaround for an erratum that is detected using a capability and affecting a particular CPU, it'd be nice to have a way to probe them directly.
Acked-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: James Morse james.morse@arm.com --- arch/arm64/include/asm/arch_timer.h | 1 + drivers/clocksource/arm_arch_timer.c | 28 ++++++++++++++++++++++++---- 2 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 5cd964e90d11..1b0d7e994e0c 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -39,6 +39,7 @@ extern struct static_key_false arch_timer_read_ool_enabled;
enum arch_timer_erratum_match_type { ate_match_dt, + ate_match_local_cap_id, };
struct arch_timer_erratum_workaround { diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 015b28e7f1f2..138dbfdfb413 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -162,6 +162,13 @@ bool arch_timer_check_dt_erratum(const struct arch_timer_erratum_workaround *wa, return of_property_read_bool(np, wa->id); }
+static +bool arch_timer_check_local_cap_erratum(const struct arch_timer_erratum_workaround *wa, + const void *arg) +{ + return this_cpu_has_cap((uintptr_t)wa->id); +} + static const struct arch_timer_erratum_workaround * arch_timer_iterate_errata(enum arch_timer_erratum_match_type type, ate_match_fn_t match_fn, @@ -192,14 +199,16 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type t { const struct arch_timer_erratum_workaround *wa; ate_match_fn_t match_fn = NULL; - - if (static_branch_unlikely(&arch_timer_read_ool_enabled)) - return; + bool local = false;
switch (type) { case ate_match_dt: match_fn = arch_timer_check_dt_erratum; break; + case ate_match_local_cap_id: + match_fn = arch_timer_check_local_cap_erratum; + local = true; + break; default: WARN_ON(1); return; @@ -209,8 +218,17 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type t if (!wa) return;
+ if (needs_unstable_timer_counter_workaround()) { + if (wa != timer_unstable_counter_workaround) + pr_warn("Can't enable workaround for %s (clashes with %s\n)", + wa->desc, + timer_unstable_counter_workaround->desc); + return; + } + arch_timer_enable_workaround(wa); - pr_info("Enabling global workaround for %s\n", wa->desc); + pr_info("Enabling %s workaround for %s\n", + local ? "local" : "global", wa->desc); }
#else @@ -470,6 +488,8 @@ static void __arch_timer_setup(unsigned type, BUG(); }
+ arch_timer_check_ool_workaround(ate_match_local_cap_id, NULL); + erratum_workaround_set_sne(clk); } else { clk->features |= CLOCK_EVT_FEAT_DYNIRQ;