diff options
| author | Marc Zyngier <marc.zyngier@arm.com> | 2017-02-20 18:34:48 +0000 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2017-04-07 11:22:09 +0100 |
| commit | 6acc71ccac7187fc0ef85f10bd09c2058f21fab5 (patch) | |
| tree | fa55e6e16bdd8b41537ba1d27abefb2c1b2a96ee /arch/arm64 | |
| parent | 8c64621bf9501902a3086a5e38135344b3161128 (diff) | |
arm64: arch_timer: Allows a CPU-specific erratum to only affect a subset of CPUs
Instead of applying a CPU-specific workaround to all CPUs in the system,
allow it to only affect a subset of them (typical big-little case).
This is done by turning the erratum pointer into a per-CPU variable.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/arch_timer.h | 31 |
1 files changed, 20 insertions, 11 deletions
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 01917b4c65ca..6bd1a9a1573a 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -25,6 +25,7 @@ #include <linux/bug.h> #include <linux/init.h> #include <linux/jump_label.h> +#include <linux/smp.h> #include <linux/types.h> #include <clocksource/arm_arch_timer.h> @@ -55,17 +56,25 @@ struct arch_timer_erratum_workaround { int (*set_next_event_virt)(unsigned long, struct clock_event_device *); }; -extern const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround; - -#define arch_timer_reg_read_stable(reg) \ -({ \ - u64 _val; \ - if (needs_unstable_timer_counter_workaround() && \ - timer_unstable_counter_workaround->read_##reg) \ - _val = timer_unstable_counter_workaround->read_##reg(); \ - else \ - _val = read_sysreg(reg); \ - _val; \ +DECLARE_PER_CPU(const struct arch_timer_erratum_workaround *, + timer_unstable_counter_workaround); + +#define arch_timer_reg_read_stable(reg) \ +({ \ + u64 _val; \ + if (needs_unstable_timer_counter_workaround()) { \ + const struct arch_timer_erratum_workaround *wa; \ + preempt_disable(); \ + wa = __this_cpu_read(timer_unstable_counter_workaround); \ + if (wa && wa->read_##reg) \ + _val = wa->read_##reg(); \ + else \ + _val = read_sysreg(reg); \ + preempt_enable(); \ + } else { \ + _val = read_sysreg(reg); \ + } \ + _val; \ }) /* |