diff options
Diffstat (limited to 'drivers/clocksource/arm_arch_timer.c')
| -rw-r--r-- | drivers/clocksource/arm_arch_timer.c | 153 |
1 files changed, 111 insertions, 42 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 4c8c3fb2e8b2..93aa1364376a 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -96,41 +96,107 @@ early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg); */ #ifdef CONFIG_FSL_ERRATUM_A008585 -DEFINE_STATIC_KEY_FALSE(arch_timer_read_ool_enabled); -EXPORT_SYMBOL_GPL(arch_timer_read_ool_enabled); - -static int fsl_a008585_enable = -1; - -static int __init early_fsl_a008585_cfg(char *buf) +/* + * 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; \ +}) + +static u32 notrace fsl_a008585_read_cntp_tval_el0(void) { - int ret; - bool val; + return __fsl_a008585_read_reg(cntp_tval_el0); +} - ret = strtobool(buf, &val); - if (ret) - return ret; +static u32 notrace fsl_a008585_read_cntv_tval_el0(void) +{ + return __fsl_a008585_read_reg(cntv_tval_el0); +} - fsl_a008585_enable = val; - return 0; +static u64 notrace fsl_a008585_read_cntvct_el0(void) +{ + return __fsl_a008585_read_reg(cntvct_el0); } -early_param("clocksource.arm_arch_timer.fsl-a008585", early_fsl_a008585_cfg); +#endif -u32 __fsl_a008585_read_cntp_tval_el0(void) +#ifdef CONFIG_HISILICON_ERRATUM_161010101 +/* + * Verify whether the value of the second read is larger than the first by + * less than 32 is the only way to confirm the value is correct, so clear the + * lower 5 bits to check whether the difference is greater than 32 or not. + * Theoretically the erratum should not occur more than twice in succession + * when reading the system counter, but it is possible that some interrupts + * may lead to more than twice read errors, triggering the warning, so setting + * the number of retries far beyond the number of iterations the loop has been + * observed to take. + */ +#define __hisi_161010101_read_reg(reg) ({ \ + u64 _old, _new; \ + int _retries = 50; \ + \ + do { \ + _old = read_sysreg(reg); \ + _new = read_sysreg(reg); \ + _retries--; \ + } while (unlikely((_new - _old) >> 5) && _retries); \ + \ + WARN_ON_ONCE(!_retries); \ + _new; \ +}) + +static u32 notrace hisi_161010101_read_cntp_tval_el0(void) { - return __fsl_a008585_read_reg(cntp_tval_el0); + return __hisi_161010101_read_reg(cntp_tval_el0); } -u32 __fsl_a008585_read_cntv_tval_el0(void) +static u32 notrace hisi_161010101_read_cntv_tval_el0(void) { - return __fsl_a008585_read_reg(cntv_tval_el0); + return __hisi_161010101_read_reg(cntv_tval_el0); } -u64 __fsl_a008585_read_cntvct_el0(void) +static u64 notrace hisi_161010101_read_cntvct_el0(void) { - return __fsl_a008585_read_reg(cntvct_el0); + return __hisi_161010101_read_reg(cntvct_el0); } -EXPORT_SYMBOL(__fsl_a008585_read_cntvct_el0); -#endif /* CONFIG_FSL_ERRATUM_A008585 */ +#endif + +#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND +const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround = NULL; +EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround); + +DEFINE_STATIC_KEY_FALSE(arch_timer_read_ool_enabled); +EXPORT_SYMBOL_GPL(arch_timer_read_ool_enabled); + +static const struct arch_timer_erratum_workaround ool_workarounds[] = { +#ifdef CONFIG_FSL_ERRATUM_A008585 + { + .id = "fsl,erratum-a008585", + .read_cntp_tval_el0 = fsl_a008585_read_cntp_tval_el0, + .read_cntv_tval_el0 = fsl_a008585_read_cntv_tval_el0, + .read_cntvct_el0 = fsl_a008585_read_cntvct_el0, + }, +#endif +#ifdef CONFIG_HISILICON_ERRATUM_161010101 + { + .id = "hisilicon,erratum-161010101", + .read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0, + .read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0, + .read_cntvct_el0 = hisi_161010101_read_cntvct_el0, + }, +#endif +}; +#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */ static __always_inline void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val, @@ -281,8 +347,8 @@ static __always_inline void set_next_event(const int access, unsigned long evt, arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk); } -#ifdef CONFIG_FSL_ERRATUM_A008585 -static __always_inline void fsl_a008585_set_next_event(const int access, +#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND +static __always_inline void erratum_set_next_event_generic(const int access, unsigned long evt, struct clock_event_device *clk) { unsigned long ctrl; @@ -300,20 +366,20 @@ static __always_inline void fsl_a008585_set_next_event(const int access, arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk); } -static int fsl_a008585_set_next_event_virt(unsigned long evt, +static int erratum_set_next_event_virt(unsigned long evt, struct clock_event_device *clk) { - fsl_a008585_set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk); + erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk); return 0; } -static int fsl_a008585_set_next_event_phys(unsigned long evt, +static int erratum_set_next_event_phys(unsigned long evt, struct clock_event_device *clk) { - fsl_a008585_set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk); + erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk); return 0; } -#endif /* CONFIG_FSL_ERRATUM_A008585 */ +#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */ static int arch_timer_set_next_event_virt(unsigned long evt, struct clock_event_device *clk) @@ -343,16 +409,16 @@ static int arch_timer_set_next_event_phys_mem(unsigned long evt, return 0; } -static void fsl_a008585_set_sne(struct clock_event_device *clk) +static void erratum_workaround_set_sne(struct clock_event_device *clk) { -#ifdef CONFIG_FSL_ERRATUM_A008585 +#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND if (!static_branch_unlikely(&arch_timer_read_ool_enabled)) return; if (arch_timer_uses_ppi == VIRT_PPI) - clk->set_next_event = fsl_a008585_set_next_event_virt; + clk->set_next_event = erratum_set_next_event_virt; else - clk->set_next_event = fsl_a008585_set_next_event_phys; + clk->set_next_event = erratum_set_next_event_phys; #endif } @@ -385,7 +451,7 @@ static void __arch_timer_setup(unsigned type, BUG(); } - fsl_a008585_set_sne(clk); + erratum_workaround_set_sne(clk); } else { clk->features |= CLOCK_EVT_FEAT_DYNIRQ; clk->name = "arch_mem_timer"; @@ -580,7 +646,7 @@ static struct clocksource clocksource_counter = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; -static struct cyclecounter cyclecounter = { +static struct cyclecounter cyclecounter __ro_after_init = { .read = arch_counter_read_cc, .mask = CLOCKSOURCE_MASK(56), }; @@ -605,7 +671,7 @@ static void __init arch_counter_register(unsigned type) clocksource_counter.archdata.vdso_direct = true; -#ifdef CONFIG_FSL_ERRATUM_A008585 +#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND /* * Don't use the vdso fastpath if errata require using * the out-of-line counter accessor. @@ -893,12 +959,15 @@ static int __init arch_timer_of_init(struct device_node *np) arch_timer_c3stop = !of_property_read_bool(np, "always-on"); -#ifdef CONFIG_FSL_ERRATUM_A008585 - if (fsl_a008585_enable < 0) - fsl_a008585_enable = of_property_read_bool(np, "fsl,erratum-a008585"); - if (fsl_a008585_enable) { - static_branch_enable(&arch_timer_read_ool_enabled); - pr_info("Enabling workaround for FSL erratum A-008585\n"); +#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND + for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) { + if (of_property_read_bool(np, ool_workarounds[i].id)) { + timer_unstable_counter_workaround = &ool_workarounds[i]; + static_branch_enable(&arch_timer_read_ool_enabled); + pr_info("arch_timer: Enabling workaround for %s\n", + timer_unstable_counter_workaround->id); + break; + } } #endif |