diff options
Diffstat (limited to 'drivers/clocksource/arm_arch_timer.c')
| -rw-r--r-- | drivers/clocksource/arm_arch_timer.c | 243 |
1 files changed, 147 insertions, 96 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index be6d741d404c..9a04eacc4412 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -44,23 +44,29 @@ #define CNTACR_RWVT BIT(4) #define CNTACR_RWPT BIT(5) -#define CNTVCT_LO 0x08 -#define CNTVCT_HI 0x0c +#define CNTVCT_LO 0x00 +#define CNTPCT_LO 0x08 #define CNTFRQ 0x10 -#define CNTP_TVAL 0x28 +#define CNTP_CVAL_LO 0x20 #define CNTP_CTL 0x2c -#define CNTV_TVAL 0x38 +#define CNTV_CVAL_LO 0x30 #define CNTV_CTL 0x3c -static unsigned arch_timers_present __initdata; +/* + * The minimum amount of time a generic counter is guaranteed to not roll over + * (40 years) + */ +#define MIN_ROLLOVER_SECS (40ULL * 365 * 24 * 3600) -static void __iomem *arch_counter_base __ro_after_init; +static unsigned arch_timers_present __initdata; struct arch_timer { void __iomem *base; struct clock_event_device evt; }; +static struct arch_timer *arch_timer_mem __ro_after_init; + #define to_arch_timer(e) container_of(e, struct arch_timer, evt) static u32 arch_timer_rate __ro_after_init; @@ -96,32 +102,57 @@ static int __init early_evtstrm_cfg(char *buf) early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg); /* + * Makes an educated guess at a valid counter width based on the Generic Timer + * specification. Of note: + * 1) the system counter is at least 56 bits wide + * 2) a roll-over time of not less than 40 years + * + * See 'ARM DDI 0487G.a D11.1.2 ("The system counter")' for more details. + */ +static int arch_counter_get_width(void) +{ + u64 min_cycles = MIN_ROLLOVER_SECS * arch_timer_rate; + + /* guarantee the returned width is within the valid range */ + return clamp_val(ilog2(min_cycles - 1) + 1, 56, 64); +} + +/* * Architected system timer support. */ static __always_inline -void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val, +void arch_timer_reg_write(int access, enum arch_timer_reg reg, u64 val, struct clock_event_device *clk) { if (access == ARCH_TIMER_MEM_PHYS_ACCESS) { struct arch_timer *timer = to_arch_timer(clk); switch (reg) { case ARCH_TIMER_REG_CTRL: - writel_relaxed(val, timer->base + CNTP_CTL); + writel_relaxed((u32)val, timer->base + CNTP_CTL); break; - case ARCH_TIMER_REG_TVAL: - writel_relaxed(val, timer->base + CNTP_TVAL); + case ARCH_TIMER_REG_CVAL: + /* + * Not guaranteed to be atomic, so the timer + * must be disabled at this point. + */ + writeq_relaxed(val, timer->base + CNTP_CVAL_LO); break; + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) { struct arch_timer *timer = to_arch_timer(clk); switch (reg) { case ARCH_TIMER_REG_CTRL: - writel_relaxed(val, timer->base + CNTV_CTL); + writel_relaxed((u32)val, timer->base + CNTV_CTL); break; - case ARCH_TIMER_REG_TVAL: - writel_relaxed(val, timer->base + CNTV_TVAL); + case ARCH_TIMER_REG_CVAL: + /* Same restriction as above */ + writeq_relaxed(val, timer->base + CNTV_CVAL_LO); break; + default: + BUILD_BUG(); } } else { arch_timer_reg_write_cp15(access, reg, val); @@ -140,9 +171,8 @@ u32 arch_timer_reg_read(int access, enum arch_timer_reg reg, case ARCH_TIMER_REG_CTRL: val = readl_relaxed(timer->base + CNTP_CTL); break; - case ARCH_TIMER_REG_TVAL: - val = readl_relaxed(timer->base + CNTP_TVAL); - break; + default: + BUILD_BUG(); } } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) { struct arch_timer *timer = to_arch_timer(clk); @@ -150,9 +180,8 @@ u32 arch_timer_reg_read(int access, enum arch_timer_reg reg, case ARCH_TIMER_REG_CTRL: val = readl_relaxed(timer->base + CNTV_CTL); break; - case ARCH_TIMER_REG_TVAL: - val = readl_relaxed(timer->base + CNTV_TVAL); - break; + default: + BUILD_BUG(); } } else { val = arch_timer_reg_read_cp15(access, reg); @@ -205,13 +234,11 @@ static struct clocksource clocksource_counter = { .id = CSID_ARM_ARCH_COUNTER, .rating = 400, .read = arch_counter_read, - .mask = CLOCKSOURCE_MASK(56), .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static struct cyclecounter cyclecounter __ro_after_init = { .read = arch_counter_read_cc, - .mask = CLOCKSOURCE_MASK(56), }; struct ate_acpi_oem_info { @@ -239,16 +266,6 @@ struct ate_acpi_oem_info { _new; \ }) -static u32 notrace fsl_a008585_read_cntp_tval_el0(void) -{ - return __fsl_a008585_read_reg(cntp_tval_el0); -} - -static u32 notrace fsl_a008585_read_cntv_tval_el0(void) -{ - return __fsl_a008585_read_reg(cntv_tval_el0); -} - static u64 notrace fsl_a008585_read_cntpct_el0(void) { return __fsl_a008585_read_reg(cntpct_el0); @@ -285,16 +302,6 @@ static u64 notrace fsl_a008585_read_cntvct_el0(void) _new; \ }) -static u32 notrace hisi_161010101_read_cntp_tval_el0(void) -{ - return __hisi_161010101_read_reg(cntp_tval_el0); -} - -static u32 notrace hisi_161010101_read_cntv_tval_el0(void) -{ - return __hisi_161010101_read_reg(cntv_tval_el0); -} - static u64 notrace hisi_161010101_read_cntpct_el0(void) { return __hisi_161010101_read_reg(cntpct_el0); @@ -379,16 +386,6 @@ static u64 notrace sun50i_a64_read_cntvct_el0(void) { return __sun50i_a64_read_reg(cntvct_el0); } - -static u32 notrace sun50i_a64_read_cntp_tval_el0(void) -{ - return read_sysreg(cntp_cval_el0) - sun50i_a64_read_cntpct_el0(); -} - -static u32 notrace sun50i_a64_read_cntv_tval_el0(void) -{ - return read_sysreg(cntv_cval_el0) - sun50i_a64_read_cntvct_el0(); -} #endif #ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND @@ -397,7 +394,7 @@ EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround); static atomic_t timer_unstable_counter_workaround_in_use = ATOMIC_INIT(0); -static void erratum_set_next_event_tval_generic(const int access, unsigned long evt, +static void erratum_set_next_event_generic(const int access, unsigned long evt, struct clock_event_device *clk) { unsigned long ctrl; @@ -418,17 +415,17 @@ static void erratum_set_next_event_tval_generic(const int access, unsigned long arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk); } -static __maybe_unused int erratum_set_next_event_tval_virt(unsigned long evt, +static __maybe_unused int erratum_set_next_event_virt(unsigned long evt, struct clock_event_device *clk) { - erratum_set_next_event_tval_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk); + erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk); return 0; } -static __maybe_unused int erratum_set_next_event_tval_phys(unsigned long evt, +static __maybe_unused int erratum_set_next_event_phys(unsigned long evt, struct clock_event_device *clk) { - erratum_set_next_event_tval_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk); + erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk); return 0; } @@ -438,12 +435,10 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = { .match_type = ate_match_dt, .id = "fsl,erratum-a008585", .desc = "Freescale erratum a005858", - .read_cntp_tval_el0 = fsl_a008585_read_cntp_tval_el0, - .read_cntv_tval_el0 = fsl_a008585_read_cntv_tval_el0, .read_cntpct_el0 = fsl_a008585_read_cntpct_el0, .read_cntvct_el0 = fsl_a008585_read_cntvct_el0, - .set_next_event_phys = erratum_set_next_event_tval_phys, - .set_next_event_virt = erratum_set_next_event_tval_virt, + .set_next_event_phys = erratum_set_next_event_phys, + .set_next_event_virt = erratum_set_next_event_virt, }, #endif #ifdef CONFIG_HISILICON_ERRATUM_161010101 @@ -451,23 +446,19 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = { .match_type = ate_match_dt, .id = "hisilicon,erratum-161010101", .desc = "HiSilicon erratum 161010101", - .read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0, - .read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0, .read_cntpct_el0 = hisi_161010101_read_cntpct_el0, .read_cntvct_el0 = hisi_161010101_read_cntvct_el0, - .set_next_event_phys = erratum_set_next_event_tval_phys, - .set_next_event_virt = erratum_set_next_event_tval_virt, + .set_next_event_phys = erratum_set_next_event_phys, + .set_next_event_virt = erratum_set_next_event_virt, }, { .match_type = ate_match_acpi_oem_info, .id = hisi_161010101_oem_info, .desc = "HiSilicon erratum 161010101", - .read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0, - .read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0, .read_cntpct_el0 = hisi_161010101_read_cntpct_el0, .read_cntvct_el0 = hisi_161010101_read_cntvct_el0, - .set_next_event_phys = erratum_set_next_event_tval_phys, - .set_next_event_virt = erratum_set_next_event_tval_virt, + .set_next_event_phys = erratum_set_next_event_phys, + .set_next_event_virt = erratum_set_next_event_virt, }, #endif #ifdef CONFIG_ARM64_ERRATUM_858921 @@ -484,12 +475,10 @@ static const struct arch_timer_erratum_workaround ool_workarounds[] = { .match_type = ate_match_dt, .id = "allwinner,erratum-unknown1", .desc = "Allwinner erratum UNKNOWN1", - .read_cntp_tval_el0 = sun50i_a64_read_cntp_tval_el0, - .read_cntv_tval_el0 = sun50i_a64_read_cntv_tval_el0, .read_cntpct_el0 = sun50i_a64_read_cntpct_el0, .read_cntvct_el0 = sun50i_a64_read_cntvct_el0, - .set_next_event_phys = erratum_set_next_event_tval_phys, - .set_next_event_virt = erratum_set_next_event_tval_virt, + .set_next_event_phys = erratum_set_next_event_phys, + .set_next_event_virt = erratum_set_next_event_virt, }, #endif #ifdef CONFIG_ARM64_ERRATUM_1418040 @@ -727,10 +716,18 @@ static __always_inline void set_next_event(const int access, unsigned long evt, struct clock_event_device *clk) { unsigned long ctrl; + u64 cnt; + ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk); ctrl |= ARCH_TIMER_CTRL_ENABLE; ctrl &= ~ARCH_TIMER_CTRL_IT_MASK; - arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt, clk); + + if (access == ARCH_TIMER_PHYS_ACCESS) + cnt = __arch_counter_get_cntpct(); + else + cnt = __arch_counter_get_cntvct(); + + arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk); arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk); } @@ -748,23 +745,79 @@ static int arch_timer_set_next_event_phys(unsigned long evt, return 0; } +static u64 arch_counter_get_cnt_mem(struct arch_timer *t, int offset_lo) +{ + u32 cnt_lo, cnt_hi, tmp_hi; + + do { + cnt_hi = readl_relaxed(t->base + offset_lo + 4); + cnt_lo = readl_relaxed(t->base + offset_lo); + tmp_hi = readl_relaxed(t->base + offset_lo + 4); + } while (cnt_hi != tmp_hi); + + return ((u64) cnt_hi << 32) | cnt_lo; +} + +static __always_inline void set_next_event_mem(const int access, unsigned long evt, + struct clock_event_device *clk) +{ + struct arch_timer *timer = to_arch_timer(clk); + unsigned long ctrl; + u64 cnt; + + ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk); + ctrl |= ARCH_TIMER_CTRL_ENABLE; + ctrl &= ~ARCH_TIMER_CTRL_IT_MASK; + + if (access == ARCH_TIMER_MEM_VIRT_ACCESS) + cnt = arch_counter_get_cnt_mem(timer, CNTVCT_LO); + else + cnt = arch_counter_get_cnt_mem(timer, CNTPCT_LO); + + arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk); + arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk); +} + static int arch_timer_set_next_event_virt_mem(unsigned long evt, struct clock_event_device *clk) { - set_next_event(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk); + set_next_event_mem(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk); return 0; } static int arch_timer_set_next_event_phys_mem(unsigned long evt, struct clock_event_device *clk) { - set_next_event(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk); + set_next_event_mem(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk); return 0; } +static u64 __arch_timer_check_delta(void) +{ +#ifdef CONFIG_ARM64 + const struct midr_range broken_cval_midrs[] = { + /* + * XGene-1 implements CVAL in terms of TVAL, meaning + * that the maximum timer range is 32bit. Shame on them. + */ + MIDR_ALL_VERSIONS(MIDR_CPU_MODEL(ARM_CPU_IMP_APM, + APM_CPU_PART_POTENZA)), + {}, + }; + + if (is_midr_in_range_list(read_cpuid_id(), broken_cval_midrs)) { + pr_warn_once("Broken CNTx_CVAL_EL1, limiting width to 32bits"); + return CLOCKSOURCE_MASK(32); + } +#endif + return CLOCKSOURCE_MASK(arch_counter_get_width()); +} + static void __arch_timer_setup(unsigned type, struct clock_event_device *clk) { + u64 max_delta; + clk->features = CLOCK_EVT_FEAT_ONESHOT; if (type == ARCH_TIMER_TYPE_CP15) { @@ -796,6 +849,7 @@ static void __arch_timer_setup(unsigned type, } clk->set_next_event = sne; + max_delta = __arch_timer_check_delta(); } else { clk->features |= CLOCK_EVT_FEAT_DYNIRQ; clk->name = "arch_mem_timer"; @@ -812,11 +866,13 @@ static void __arch_timer_setup(unsigned type, clk->set_next_event = arch_timer_set_next_event_phys_mem; } + + max_delta = CLOCKSOURCE_MASK(56); } clk->set_state_shutdown(clk); - clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff); + clockevents_config_and_register(clk, arch_timer_rate, 0xf, max_delta); } static void arch_timer_evtstrm_enable(int divider) @@ -986,15 +1042,7 @@ bool arch_timer_evtstrm_available(void) static u64 arch_counter_get_cntvct_mem(void) { - u32 vct_lo, vct_hi, tmp_hi; - - do { - vct_hi = readl_relaxed(arch_counter_base + CNTVCT_HI); - vct_lo = readl_relaxed(arch_counter_base + CNTVCT_LO); - tmp_hi = readl_relaxed(arch_counter_base + CNTVCT_HI); - } while (vct_hi != tmp_hi); - - return ((u64) vct_hi << 32) | vct_lo; + return arch_counter_get_cnt_mem(arch_timer_mem, CNTVCT_LO); } static struct arch_timer_kvm_info arch_timer_kvm_info; @@ -1007,6 +1055,7 @@ struct arch_timer_kvm_info *arch_timer_get_kvm_info(void) static void __init arch_counter_register(unsigned type) { u64 start_count; + int width; /* Register the CP15 based counter if we have one */ if (type & ARCH_TIMER_TYPE_CP15) { @@ -1031,6 +1080,10 @@ static void __init arch_counter_register(unsigned type) arch_timer_read_counter = arch_counter_get_cntvct_mem; } + width = arch_counter_get_width(); + clocksource_counter.mask = CLOCKSOURCE_MASK(width); + cyclecounter.mask = CLOCKSOURCE_MASK(width); + if (!arch_counter_suspend_stop) clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP; start_count = arch_timer_read_counter(); @@ -1040,8 +1093,7 @@ static void __init arch_counter_register(unsigned type) timecounter_init(&arch_timer_kvm_info.timecounter, &cyclecounter, start_count); - /* 56 bits minimum, so we assume worst case rollover */ - sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate); + sched_clock_register(arch_timer_read_counter, width, arch_timer_rate); } static void arch_timer_stop(struct clock_event_device *clk) @@ -1182,25 +1234,25 @@ static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq) { int ret; irq_handler_t func; - struct arch_timer *t; - t = kzalloc(sizeof(*t), GFP_KERNEL); - if (!t) + arch_timer_mem = kzalloc(sizeof(*arch_timer_mem), GFP_KERNEL); + if (!arch_timer_mem) return -ENOMEM; - t->base = base; - t->evt.irq = irq; - __arch_timer_setup(ARCH_TIMER_TYPE_MEM, &t->evt); + arch_timer_mem->base = base; + arch_timer_mem->evt.irq = irq; + __arch_timer_setup(ARCH_TIMER_TYPE_MEM, &arch_timer_mem->evt); if (arch_timer_mem_use_virtual) func = arch_timer_handler_virt_mem; else func = arch_timer_handler_phys_mem; - ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &t->evt); + ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &arch_timer_mem->evt); if (ret) { pr_err("Failed to request mem timer irq\n"); - kfree(t); + kfree(arch_timer_mem); + arch_timer_mem = NULL; } return ret; @@ -1458,7 +1510,6 @@ arch_timer_mem_frame_register(struct arch_timer_mem_frame *frame) return ret; } - arch_counter_base = base; arch_timers_present |= ARCH_TIMER_TYPE_MEM; return 0; |