diff options
Diffstat (limited to 'arch/arm64/include/asm/arch_timer.h')
-rw-r--r-- | arch/arm64/include/asm/arch_timer.h | 82 |
1 files changed, 55 insertions, 27 deletions
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index fbe0ca31a99c..eaa5bbe3fa87 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -20,13 +20,55 @@ #define __ASM_ARCH_TIMER_H #include <asm/barrier.h> +#include <asm/sysreg.h> #include <linux/bug.h> #include <linux/init.h> +#include <linux/jump_label.h> #include <linux/types.h> #include <clocksource/arm_arch_timer.h> +#if IS_ENABLED(CONFIG_FSL_ERRATUM_A008585) +extern struct static_key_false arch_timer_read_ool_enabled; +#define needs_fsl_a008585_workaround() \ + static_branch_unlikely(&arch_timer_read_ool_enabled) +#else +#define needs_fsl_a008585_workaround() false +#endif + +u32 __fsl_a008585_read_cntp_tval_el0(void); +u32 __fsl_a008585_read_cntv_tval_el0(void); +u64 __fsl_a008585_read_cntvct_el0(void); + +/* + * The number of retries is an arbitrary value well beyond the highest number + * of iterations the loop has been observed to take. + */ +#define __fsl_a008585_read_reg(reg) ({ \ + u64 _old, _new; \ + int _retries = 200; \ + \ + do { \ + _old = read_sysreg(reg); \ + _new = read_sysreg(reg); \ + _retries--; \ + } while (unlikely(_old != _new) && _retries); \ + \ + WARN_ON_ONCE(!_retries); \ + _new; \ +}) + +#define arch_timer_reg_read_stable(reg) \ +({ \ + u64 _val; \ + if (needs_fsl_a008585_workaround()) \ + _val = __fsl_a008585_read_##reg(); \ + else \ + _val = read_sysreg(reg); \ + _val; \ +}) + /* * These register accessors are marked inline so the compiler can * nicely work out which register we want, and chuck away the rest of @@ -38,19 +80,19 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val) if (access == ARCH_TIMER_PHYS_ACCESS) { switch (reg) { case ARCH_TIMER_REG_CTRL: - asm volatile("msr cntp_ctl_el0, %0" : : "r" (val)); + write_sysreg(val, cntp_ctl_el0); break; case ARCH_TIMER_REG_TVAL: - asm volatile("msr cntp_tval_el0, %0" : : "r" (val)); + write_sysreg(val, cntp_tval_el0); break; } } else if (access == ARCH_TIMER_VIRT_ACCESS) { switch (reg) { case ARCH_TIMER_REG_CTRL: - asm volatile("msr cntv_ctl_el0, %0" : : "r" (val)); + write_sysreg(val, cntv_ctl_el0); break; case ARCH_TIMER_REG_TVAL: - asm volatile("msr cntv_tval_el0, %0" : : "r" (val)); + write_sysreg(val, cntv_tval_el0); break; } } @@ -61,48 +103,38 @@ void arch_timer_reg_write_cp15(int access, enum arch_timer_reg reg, u32 val) static __always_inline u32 arch_timer_reg_read_cp15(int access, enum arch_timer_reg reg) { - u32 val; - if (access == ARCH_TIMER_PHYS_ACCESS) { switch (reg) { case ARCH_TIMER_REG_CTRL: - asm volatile("mrs %0, cntp_ctl_el0" : "=r" (val)); - break; + return read_sysreg(cntp_ctl_el0); case ARCH_TIMER_REG_TVAL: - asm volatile("mrs %0, cntp_tval_el0" : "=r" (val)); - break; + return arch_timer_reg_read_stable(cntp_tval_el0); } } else if (access == ARCH_TIMER_VIRT_ACCESS) { switch (reg) { case ARCH_TIMER_REG_CTRL: - asm volatile("mrs %0, cntv_ctl_el0" : "=r" (val)); - break; + return read_sysreg(cntv_ctl_el0); case ARCH_TIMER_REG_TVAL: - asm volatile("mrs %0, cntv_tval_el0" : "=r" (val)); - break; + return arch_timer_reg_read_stable(cntv_tval_el0); } } - return val; + BUG(); } static inline u32 arch_timer_get_cntfrq(void) { - u32 val; - asm volatile("mrs %0, cntfrq_el0" : "=r" (val)); - return val; + return read_sysreg(cntfrq_el0); } static inline u32 arch_timer_get_cntkctl(void) { - u32 cntkctl; - asm volatile("mrs %0, cntkctl_el1" : "=r" (cntkctl)); - return cntkctl; + return read_sysreg(cntkctl_el1); } static inline void arch_timer_set_cntkctl(u32 cntkctl) { - asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl)); + write_sysreg(cntkctl, cntkctl_el1); } static inline u64 arch_counter_get_cntpct(void) @@ -116,12 +148,8 @@ static inline u64 arch_counter_get_cntpct(void) static inline u64 arch_counter_get_cntvct(void) { - u64 cval; - isb(); - asm volatile("mrs %0, cntvct_el0" : "=r" (cval)); - - return cval; + return arch_timer_reg_read_stable(cntvct_el0); } static inline int arch_timer_arch_init(void) |