diff options
Diffstat (limited to 'arch/arm64/include/asm/arch_timer.h')
| -rw-r--r-- | arch/arm64/include/asm/arch_timer.h | 110 |
1 files changed, 47 insertions, 63 deletions
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 7ae54d7d333a..f5794d50f51d 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -15,7 +15,7 @@ #include <linux/bug.h> #include <linux/init.h> #include <linux/jump_label.h> -#include <linux/smp.h> +#include <linux/percpu.h> #include <linux/types.h> #include <clocksource/arm_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 @@ -52,47 +52,43 @@ struct arch_timer_erratum_workaround { enum arch_timer_erratum_match_type match_type; const void *id; const char *desc; - u32 (*read_cntp_tval_el0)(void); - u32 (*read_cntv_tval_el0)(void); u64 (*read_cntpct_el0)(void); u64 (*read_cntvct_el0)(void); int (*set_next_event_phys)(unsigned long, struct clock_event_device *); int (*set_next_event_virt)(unsigned long, struct clock_event_device *); + bool disable_compat_vdso; }; DECLARE_PER_CPU(const struct arch_timer_erratum_workaround *, timer_unstable_counter_workaround); -/* inline sysreg accessors that make erratum_handler() work */ -static inline notrace u32 arch_timer_read_cntp_tval_el0(void) +static inline notrace u64 arch_timer_read_cntpct_el0(void) { - return read_sysreg(cntp_tval_el0); -} + u64 cnt; -static inline notrace u32 arch_timer_read_cntv_tval_el0(void) -{ - return read_sysreg(cntv_tval_el0); -} + asm volatile(ALTERNATIVE("isb\n mrs %0, cntpct_el0", + "nop\n" __mrs_s("%0", SYS_CNTPCTSS_EL0), + ARM64_HAS_ECV) + : "=r" (cnt)); -static inline notrace u64 arch_timer_read_cntpct_el0(void) -{ - return read_sysreg(cntpct_el0); + return cnt; } static inline notrace u64 arch_timer_read_cntvct_el0(void) { - return read_sysreg(cntvct_el0); + u64 cnt; + + asm volatile(ALTERNATIVE("isb\n mrs %0, cntvct_el0", + "nop\n" __mrs_s("%0", SYS_CNTVCTSS_EL0), + ARM64_HAS_ECV) + : "=r" (cnt)); + + return cnt; } #define arch_timer_reg_read_stable(reg) \ ({ \ - u64 _val; \ - \ - preempt_disable_notrace(); \ - _val = erratum_handler(read_ ## reg)(); \ - preempt_enable_notrace(); \ - \ - _val; \ + erratum_handler(read_ ## reg)(); \ }) /* @@ -101,51 +97,58 @@ static inline notrace u64 arch_timer_read_cntvct_el0(void) * the code. */ static __always_inline -void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val) +void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u64 val) { if (access == ARCH_TIMER_PHYS_ACCESS) { switch (reg) { case ARCH_TIMER_REG_CTRL: write_sysreg(val, cntp_ctl_el0); + isb(); break; - case ARCH_TIMER_REG_TVAL: - write_sysreg(val, cntp_tval_el0); + case ARCH_TIMER_REG_CVAL: + write_sysreg(val, cntp_cval_el0); break; + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_VIRT_ACCESS) { switch (reg) { case ARCH_TIMER_REG_CTRL: write_sysreg(val, cntv_ctl_el0); + isb(); break; - case ARCH_TIMER_REG_TVAL: - write_sysreg(val, cntv_tval_el0); + case ARCH_TIMER_REG_CVAL: + write_sysreg(val, cntv_cval_el0); break; + default: + BUILD_BUG(); } + } else { + BUILD_BUG(); } - - isb(); } static __always_inline -u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) +u64 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) { if (access == ARCH_TIMER_PHYS_ACCESS) { switch (reg) { case ARCH_TIMER_REG_CTRL: return read_sysreg(cntp_ctl_el0); - case ARCH_TIMER_REG_TVAL: - return arch_timer_reg_read_stable(cntp_tval_el0); + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_VIRT_ACCESS) { switch (reg) { case ARCH_TIMER_REG_CTRL: return read_sysreg(cntv_ctl_el0); - case ARCH_TIMER_REG_TVAL: - return arch_timer_reg_read_stable(cntv_tval_el0); + default: + BUILD_BUG(); } } - BUG(); + BUILD_BUG(); + unreachable(); } static inline u32 arch_timer_get_cntfrq(void) @@ -164,30 +167,10 @@ static inline void arch_timer_set_cntkctl(u32 cntkctl) isb(); } -/* - * Ensure that reads of the counter are treated the same as memory reads - * for the purposes of ordering by subsequent memory barriers. - * - * This insanity brought to you by speculative system register reads, - * out-of-order memory accesses, sequence locks and Thomas Gleixner. - * - * http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/631195.html - */ -#define arch_counter_enforce_ordering(val) do { \ - u64 tmp, _val = (val); \ - \ - asm volatile( \ - " eor %0, %1, %1\n" \ - " add %0, sp, %0\n" \ - " ldr xzr, [%0]" \ - : "=r" (tmp) : "r" (_val)); \ -} while (0) - 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; @@ -197,8 +180,10 @@ static __always_inline u64 __arch_counter_get_cntpct(void) { u64 cnt; - isb(); - cnt = read_sysreg(cntpct_el0); + asm volatile(ALTERNATIVE("isb\n mrs %0, cntpct_el0", + "nop\n" __mrs_s("%0", SYS_CNTPCTSS_EL0), + ARM64_HAS_ECV) + : "=r" (cnt)); arch_counter_enforce_ordering(cnt); return cnt; } @@ -207,7 +192,6 @@ 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; @@ -217,14 +201,14 @@ static __always_inline u64 __arch_counter_get_cntvct(void) { u64 cnt; - isb(); - cnt = read_sysreg(cntvct_el0); + asm volatile(ALTERNATIVE("isb\n mrs %0, cntvct_el0", + "nop\n" __mrs_s("%0", SYS_CNTVCTSS_EL0), + ARM64_HAS_ECV) + : "=r" (cnt)); arch_counter_enforce_ordering(cnt); return cnt; } -#undef arch_counter_enforce_ordering - static inline int arch_timer_arch_init(void) { return 0; |