/* * linux/drivers/clocksource/arm_arch_timer.c * * Copyright (C) 2011 ARM Ltd. * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #define pr_fmt(fmt) "arm_arch_timer: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #undef pr_fmt #define pr_fmt(fmt) "arch_timer: " fmt #define CNTTIDR 0x08 #define CNTTIDR_VIRT(n) (BIT(1) << ((n) * 4)) #define CNTACR(n) (0x40 + ((n) * 4)) #define CNTACR_RPCT BIT(0) #define CNTACR_RVCT BIT(1) #define CNTACR_RFRQ BIT(2) #define CNTACR_RVOFF BIT(3) #define CNTACR_RWVT BIT(4) #define CNTACR_RWPT BIT(5) #define CNTVCT_LO 0x08 #define CNTVCT_HI 0x0c #define CNTFRQ 0x10 #define CNTP_TVAL 0x28 #define CNTP_CTL 0x2c #define CNTCVAL_LO 0x30 #define CNTCVAL_HI 0x34 #define CNTV_TVAL 0x38 #define CNTV_CTL 0x3c static unsigned arch_timers_present __initdata; static void __iomem *arch_counter_base; struct arch_timer { void __iomem *base; struct clock_event_device evt; }; #define to_arch_timer(e) container_of(e, struct arch_timer, evt) static u32 arch_timer_rate; static int arch_timer_ppi[ARCH_TIMER_MAX_TIMER_PPI]; static struct clock_event_device __percpu *arch_timer_evt; static enum arch_timer_ppi_nr arch_timer_uses_ppi = ARCH_TIMER_VIRT_PPI; static bool arch_timer_c3stop; static bool arch_timer_mem_use_virtual; static bool arch_counter_suspend_stop; static bool vdso_default = true; static cpumask_t evtstrm_available = CPU_MASK_NONE; static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM); static int __init early_evtstrm_cfg(char *buf) { return strtobool(buf, &evtstrm_enable); } early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg); /* * Architected system timer support. */ static __always_inline void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 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_no_log(val, timer->base + CNTP_CTL); break; case ARCH_TIMER_REG_TVAL: writel_relaxed_no_log(val, timer->base + CNTP_TVAL); break; } } 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_no_log(val, timer->base + CNTV_CTL); break; case ARCH_TIMER_REG_TVAL: writel_relaxed_no_log(val, timer->base + CNTV_TVAL); break; } } else { arch_timer_reg_write_cp15(access, reg, val); } } static __always_inline u32 arch_timer_reg_read(int access, enum arch_timer_reg reg, struct clock_event_device *clk) { u32 val; if (access == ARCH_TIMER_MEM_PHYS_ACCESS) { struct arch_timer *timer = to_arch_timer(clk); switch (reg) { case ARCH_TIMER_REG_CTRL: val = readl_relaxed_no_log(timer->base + CNTP_CTL); break; case ARCH_TIMER_REG_TVAL: val = readl_relaxed_no_log(timer->base + CNTP_TVAL); break; } } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) { struct arch_timer *timer = to_arch_timer(clk); switch (reg) { case ARCH_TIMER_REG_CTRL: val = readl_relaxed_no_log(timer->base + CNTV_CTL); break; case ARCH_TIMER_REG_TVAL: val = readl_relaxed_no_log(timer->base + CNTV_TVAL); break; } } else { val = arch_timer_reg_read_cp15(access, reg); } return val; } /* * Default to cp15 based access because arm64 uses this function for * sched_clock() before DT is probed and the cp15 method is guaranteed * to exist on arm64. arm doesn't use this before DT is probed so even * if we don't have the cp15 accessors we won't have a problem. */ u64 (*arch_timer_read_counter)(void) = arch_counter_get_cntvct; static u64 arch_counter_read(struct clocksource *cs) { return arch_timer_read_counter(); } static u64 arch_counter_read_cc(const struct cyclecounter *cc) { return arch_timer_read_counter(); } static struct clocksource clocksource_counter = { .name = "arch_sys_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 { char oem_id[ACPI_OEM_ID_SIZE + 1]; char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1]; u32 oem_revision; }; #ifdef CONFIG_FSL_ERRATUM_A008585 /* * 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) { 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_cntvct_el0(void) { return __fsl_a008585_read_reg(cntvct_el0); } #endif #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 __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_cntvct_el0(void) { return __hisi_161010101_read_reg(cntvct_el0); } static struct ate_acpi_oem_info hisi_161010101_oem_info[] = { /* * Note that trailing spaces are required to properly match * the OEM table information. */ { .oem_id = "HISI ", .oem_table_id = "HIP05 ", .oem_revision = 0, }, { .oem_id = "HISI ", .oem_table_id = "HIP06 ", .oem_revision = 0, }, { .oem_id = "HISI ", .oem_table_id = "HIP07 ", .oem_revision = 0, }, { /* Sentinel indicating the end of the OEM array */ }, }; #endif #ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND #ifdef CONFIG_ARM64_ERRATUM_858921 static u64 notrace arm64_858921_read_cntvct_el0(void) { u64 old, new; old = read_sysreg(cntvct_el0); new = read_sysreg(cntvct_el0); return (((old ^ new) >> 32) & 1) ? old : new; } #endif #ifdef CONFIG_ARM64_ERRATUM_1188873 static u64 notrace arm64_1188873_read_cntvct_el0(void) { return read_sysreg(cntvct_el0); } #endif DEFINE_PER_CPU(const struct arch_timer_erratum_workaround *, timer_unstable_counter_workaround); 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 void erratum_set_next_event_tval_generic(const int access, unsigned long evt, struct clock_event_device *clk) { unsigned long ctrl; u64 cval = evt + arch_counter_get_cntvct(); 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_PHYS_ACCESS) write_sysreg(cval, cntp_cval_el0); else write_sysreg(cval, cntv_cval_el0); arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk); } static __maybe_unused int erratum_set_next_event_tval_virt(unsigned long evt, struct clock_event_device *clk) { erratum_set_next_event_tval_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk); return 0; } static __maybe_unused int erratum_set_next_event_tval_phys(unsigned long evt, struct clock_event_device *clk) { erratum_set_next_event_tval_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk); return 0; } static const struct arch_timer_erratum_workaround ool_workarounds[] = { #ifdef CONFIG_FSL_ERRATUM_A008585 { .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_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, }, #endif #ifdef CONFIG_HISILICON_ERRATUM_161010101 { .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_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, }, { .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_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, }, #endif #ifdef CONFIG_ARM64_ERRATUM_858921 { .match_type = ate_match_local_cap_id, .id = (void *)ARM64_WORKAROUND_858921, .desc = "ARM erratum 858921", .read_cntvct_el0 = arm64_858921_read_cntvct_el0, }, #endif #ifdef CONFIG_ARM64_ERRATUM_1188873 { .match_type = ate_match_local_cap_id, .id = (void *)ARM64_WORKAROUND_1188873, .desc = "ARM erratum 1188873", .read_cntvct_el0 = arm64_1188873_read_cntvct_el0, }, #endif }; typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *, const void *); static bool arch_timer_check_dt_erratum(const struct arch_timer_erratum_workaround *wa, const void *arg) { const struct device_node *np = arg; return of_property_read_bool(np, wa->id); } static bool arch_timer_check_local_cap_erratum(const struct arch_timer_erratum_workaround *wa, const void *arg) { return this_cpu_has_cap((uintptr_t)wa->id); } static bool arch_timer_check_acpi_oem_erratum(const struct arch_timer_erratum_workaround *wa, const void *arg) { static const struct ate_acpi_oem_info empty_oem_info = {}; const struct ate_acpi_oem_info *info = wa->id; const struct acpi_table_header *table = arg; /* Iterate over the ACPI OEM info array, looking for a match */ while (memcmp(info, &empty_oem_info, sizeof(*info))) { if (!memcmp(info->oem_id, table->oem_id, ACPI_OEM_ID_SIZE) && !memcmp(info->oem_table_id, table->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) && info->oem_revision == table->oem_revision) return true; info++; } return false; } static const struct arch_timer_erratum_workaround * arch_timer_iterate_errata(enum arch_timer_erratum_match_type type, ate_match_fn_t match_fn, void *arg) { int i; for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) { if (ool_workarounds[i].match_type != type) continue; if (match_fn(&ool_workarounds[i], arg)) return &ool_workarounds[i]; } return NULL; } static void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa, bool local) { int i; if (local) { __this_cpu_write(timer_unstable_counter_workaround, wa); } else { for_each_possible_cpu(i) per_cpu(timer_unstable_counter_workaround, i) = wa; } /* * Use the locked version, as we're called from the CPU * hotplug framework. Otherwise, we end-up in deadlock-land. */ static_branch_enable_cpuslocked(&arch_timer_read_ool_enabled); /* * Don't use the vdso fastpath if errata require using the * out-of-line counter accessor. We may change our mind pretty * late in the game (with a per-CPU erratum, for example), so * change both the default value and the vdso itself. */ if (wa->read_cntvct_el0) { clocksource_counter.archdata.vdso_direct = false; vdso_default = false; } } static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type type, void *arg) { const struct arch_timer_erratum_workaround *wa; ate_match_fn_t match_fn = NULL; bool local = false; switch (type) { case ate_match_dt: match_fn = arch_timer_check_dt_erratum; break; case ate_match_local_cap_id: match_fn = arch_timer_check_local_cap_erratum; local = true; break; case ate_match_acpi_oem_info: match_fn = arch_timer_check_acpi_oem_erratum; break; default: WARN_ON(1); return; } wa = arch_timer_iterate_errata(type, match_fn, arg); if (!wa) return; if (needs_unstable_timer_counter_workaround()) { const struct arch_timer_erratum_workaround *__wa; __wa = __this_cpu_read(timer_unstable_counter_workaround); if (__wa && wa != __wa) pr_warn("Can't enable workaround for %s (clashes with %s\n)", wa->desc, __wa->desc); if (__wa) return; } arch_timer_enable_workaround(wa, local); pr_info("Enabling %s workaround for %s\n", local ? "local" : "global", wa->desc); } #define erratum_handler(fn, r, ...) \ ({ \ bool __val; \ if (needs_unstable_timer_counter_workaround()) { \ const struct arch_timer_erratum_workaround *__wa; \ __wa = __this_cpu_read(timer_unstable_counter_workaround); \ if (__wa && __wa->fn) { \ r = __wa->fn(__VA_ARGS__); \ __val = true; \ } else { \ __val = false; \ } \ } else { \ __val = false; \ } \ __val; \ }) static bool arch_timer_this_cpu_has_cntvct_wa(void) { const struct arch_timer_erratum_workaround *wa; wa = __this_cpu_read(timer_unstable_counter_workaround); return wa && wa->read_cntvct_el0; } #else #define arch_timer_check_ool_workaround(t,a) do { } while(0) #define erratum_set_next_event_tval_virt(...) ({BUG(); 0;}) #define erratum_set_next_event_tval_phys(...) ({BUG(); 0;}) #define erratum_handler(fn, r, ...) ({false;}) #define arch_timer_this_cpu_has_cntvct_wa() ({false;}) #endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */ static __always_inline irqreturn_t timer_handler(const int access, struct clock_event_device *evt) { unsigned long ctrl; ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, evt); if (ctrl & ARCH_TIMER_CTRL_IT_STAT) { ctrl |= ARCH_TIMER_CTRL_IT_MASK; arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, evt); evt->event_handler(evt); return IRQ_HANDLED; } return IRQ_NONE; } static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id) { struct clock_event_device *evt = dev_id; return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt); } static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id) { struct clock_event_device *evt = dev_id; return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt); } static irqreturn_t arch_timer_handler_phys_mem(int irq, void *dev_id) { struct clock_event_device *evt = dev_id; return timer_handler(ARCH_TIMER_MEM_PHYS_ACCESS, evt); } static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id) { struct clock_event_device *evt = dev_id; return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt); } static __always_inline int timer_shutdown(const int access, struct clock_event_device *clk) { unsigned long ctrl; ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk); ctrl &= ~ARCH_TIMER_CTRL_ENABLE; arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk); return 0; } static int arch_timer_shutdown_virt(struct clock_event_device *clk) { return timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk); } static int arch_timer_shutdown_phys(struct clock_event_device *clk) { return timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk); } static int arch_timer_shutdown_virt_mem(struct clock_event_device *clk) { return timer_shutdown(ARCH_TIMER_MEM_VIRT_ACCESS, clk); } static int arch_timer_shutdown_phys_mem(struct clock_event_device *clk) { return timer_shutdown(ARCH_TIMER_MEM_PHYS_ACCESS, clk); } static __always_inline void set_next_event(const int access, unsigned long evt, struct clock_event_device *clk) { unsigned long ctrl; 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); arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk); } static int arch_timer_set_next_event_virt(unsigned long evt, struct clock_event_device *clk) { int ret; if (erratum_handler(set_next_event_virt, ret, evt, clk)) return ret; set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk); return 0; } static int arch_timer_set_next_event_phys(unsigned long evt, struct clock_event_device *clk) { int ret; if (erratum_handler(set_next_event_phys, ret, evt, clk)) return ret; set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk); return 0; } 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); 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); return 0; } static void __arch_timer_setup(unsigned type, struct clock_event_device *clk) { clk->features = CLOCK_EVT_FEAT_ONESHOT; if (type == ARCH_TIMER_TYPE_CP15) { if (arch_timer_c3stop) clk->features |= CLOCK_EVT_FEAT_C3STOP; clk->name = "arch_sys_timer"; clk->rating = 450; clk->cpumask = cpumask_of(smp_processor_id()); clk->irq = arch_timer_ppi[arch_timer_uses_ppi]; switch (arch_timer_uses_ppi) { case ARCH_TIMER_VIRT_PPI: clk->set_state_shutdown = arch_timer_shutdown_virt; clk->set_state_oneshot_stopped = arch_timer_shutdown_virt; clk->set_next_event = arch_timer_set_next_event_virt; break; case ARCH_TIMER_PHYS_SECURE_PPI: case ARCH_TIMER_PHYS_NONSECURE_PPI: case ARCH_TIMER_HYP_PPI: clk->set_state_shutdown = arch_timer_shutdown_phys; clk->set_state_oneshot_stopped = arch_timer_shutdown_phys; clk->set_next_event = arch_timer_set_next_event_phys; break; default: BUG(); } arch_timer_check_ool_workaround(ate_match_local_cap_id, NULL); } else { clk->features |= CLOCK_EVT_FEAT_DYNIRQ; clk->name = "arch_mem_timer"; clk->rating = 400; clk->cpumask = cpu_all_mask; if (arch_timer_mem_use_virtual) { clk->set_state_shutdown = arch_timer_shutdown_virt_mem; clk->set_state_oneshot_stopped = arch_timer_shutdown_virt_mem; clk->set_next_event = arch_timer_set_next_event_virt_mem; } else { clk->set_state_shutdown = arch_timer_shutdown_phys_mem; clk->set_state_oneshot_stopped = arch_timer_shutdown_phys_mem; clk->set_next_event = arch_timer_set_next_event_phys_mem; } } clk->set_state_shutdown(clk); clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff); } static void arch_timer_evtstrm_enable(int divider) { u32 cntkctl = arch_timer_get_cntkctl(); cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK; /* Set the divider and enable virtual event stream */ cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT) | ARCH_TIMER_VIRT_EVT_EN; arch_timer_set_cntkctl(cntkctl); elf_hwcap |= HWCAP_EVTSTRM; #ifdef CONFIG_COMPAT compat_elf_hwcap |= COMPAT_HWCAP_EVTSTRM; #endif cpumask_set_cpu(smp_processor_id(), &evtstrm_available); } static void arch_timer_configure_evtstream(void) { int evt_stream_div, pos; /* Find the closest power of two to the divisor */ evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ; pos = fls(evt_stream_div); if (pos > 1 && !(evt_stream_div & (1 << (pos - 2)))) pos--; /* enable event stream */ arch_timer_evtstrm_enable(min(pos, 15)); } static void arch_counter_set_user_access(void) { u32 cntkctl = arch_timer_get_cntkctl(); /* Disable user access to the timers and both counters */ /* Also disable virtual event stream */ cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN | ARCH_TIMER_USR_VT_ACCESS_EN | ARCH_TIMER_USR_VCT_ACCESS_EN | ARCH_TIMER_VIRT_EVT_EN | ARCH_TIMER_USR_PCT_ACCESS_EN); /* * Enable user access to the virtual counter if it doesn't * need to be workaround. The vdso may have been already * disabled though. */ if (arch_timer_this_cpu_has_cntvct_wa()) pr_info("CPU%d: Trapping CNTVCT access\n", smp_processor_id()); else if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_VCT_ACCESS)) cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN; arch_timer_set_cntkctl(cntkctl); } static bool arch_timer_has_nonsecure_ppi(void) { return (arch_timer_uses_ppi == ARCH_TIMER_PHYS_SECURE_PPI && arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]); } static u32 check_ppi_trigger(int irq) { u32 flags = irq_get_trigger_type(irq); if (flags != IRQF_TRIGGER_HIGH && flags != IRQF_TRIGGER_LOW) { pr_warn("WARNING: Invalid trigger for IRQ%d, assuming level low\n", irq); pr_warn("WARNING: Please fix your firmware\n"); flags = IRQF_TRIGGER_LOW; } return flags; } static int arch_timer_starting_cpu(unsigned int cpu) { struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt); u32 flags; __arch_timer_setup(ARCH_TIMER_TYPE_CP15, clk); flags = check_ppi_trigger(arch_timer_ppi[arch_timer_uses_ppi]); enable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], flags); if (arch_timer_has_nonsecure_ppi()) { flags = check_ppi_trigger(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]); enable_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI], flags); } arch_counter_set_user_access(); if (evtstrm_enable) arch_timer_configure_evtstream(); return 0; } /* * For historical reasons, when probing with DT we use whichever (non-zero) * rate was probed first, and don't verify that others match. If the first node * probed has a clock-frequency property, this overrides the HW register. */ static void arch_timer_of_configure_rate(u32 rate, struct device_node *np) { /* Who has more than one independent system counter? */ if (arch_timer_rate) return; if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) arch_timer_rate = rate; /* Check the timer frequency. */ if (arch_timer_rate == 0) pr_warn("frequency not available\n"); } static void arch_timer_banner(unsigned type) { pr_info("%s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n", type & ARCH_TIMER_TYPE_CP15 ? "cp15" : "", type == (ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM) ? " and " : "", type & ARCH_TIMER_TYPE_MEM ? "mmio" : "", (unsigned long)arch_timer_rate / 1000000, (unsigned long)(arch_timer_rate / 10000) % 100, type & ARCH_TIMER_TYPE_CP15 ? (arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) ? "virt" : "phys" : "", type == (ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM) ? "/" : "", type & ARCH_TIMER_TYPE_MEM ? arch_timer_mem_use_virtual ? "virt" : "phys" : ""); } u32 arch_timer_get_rate(void) { return arch_timer_rate; } void arch_timer_mem_get_cval(u32 *lo, u32 *hi) { u32 ctrl; *lo = *hi = ~0U; if (!arch_counter_base) return; ctrl = readl_relaxed_no_log(arch_counter_base + CNTV_CTL); if (ctrl & ARCH_TIMER_CTRL_ENABLE) { *lo = readl_relaxed_no_log(arch_counter_base + CNTCVAL_LO); *hi = readl_relaxed_no_log(arch_counter_base + CNTCVAL_HI); } } bool arch_timer_evtstrm_available(void) { /* * We might get called from a preemptible context. This is fine * because availability of the event stream should be always the same * for a preemptible context and context where we might resume a task. */ return cpumask_test_cpu(raw_smp_processor_id(), &evtstrm_available); } static u64 arch_counter_get_cntvct_mem(void) { u32 vct_lo, vct_hi, tmp_hi; do { vct_hi = readl_relaxed_no_log(arch_counter_base + CNTVCT_HI); vct_lo = readl_relaxed_no_log(arch_counter_base + CNTVCT_LO); tmp_hi = readl_relaxed_no_log(arch_counter_base + CNTVCT_HI); } while (vct_hi != tmp_hi); return ((u64) vct_hi << 32) | vct_lo; } static struct arch_timer_kvm_info arch_timer_kvm_info; struct arch_timer_kvm_info *arch_timer_get_kvm_info(void) { return &arch_timer_kvm_info; } static void __init arch_counter_register(unsigned type) { u64 start_count; /* Register the CP15 based counter if we have one */ if (type & ARCH_TIMER_TYPE_CP15) { if (IS_ENABLED(CONFIG_ARM64) || arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) arch_timer_read_counter = arch_counter_get_cntvct; else arch_timer_read_counter = arch_counter_get_cntpct; clocksource_counter.archdata.vdso_direct = vdso_default; } else { arch_timer_read_counter = arch_counter_get_cntvct_mem; } if (!arch_counter_suspend_stop) clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP; start_count = arch_timer_read_counter(); clocksource_register_hz(&clocksource_counter, arch_timer_rate); cyclecounter.mult = clocksource_counter.mult; cyclecounter.shift = clocksource_counter.shift; 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); } static void arch_timer_stop(struct clock_event_device *clk) { pr_debug("disable IRQ%d cpu #%d\n", clk->irq, smp_processor_id()); disable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi]); if (arch_timer_has_nonsecure_ppi()) disable_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]); clk->set_state_shutdown(clk); } static int arch_timer_dying_cpu(unsigned int cpu) { struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt); cpumask_clear_cpu(smp_processor_id(), &evtstrm_available); arch_timer_stop(clk); return 0; } #ifdef CONFIG_CPU_PM static DEFINE_PER_CPU(unsigned long, saved_cntkctl); static int arch_timer_cpu_pm_notify(struct notifier_block *self, unsigned long action, void *hcpu) { if (action == CPU_PM_ENTER) { __this_cpu_write(saved_cntkctl, arch_timer_get_cntkctl()); cpumask_clear_cpu(smp_processor_id(), &evtstrm_available); } else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT) { arch_timer_set_cntkctl(__this_cpu_read(saved_cntkctl)); if (elf_hwcap & HWCAP_EVTSTRM) cpumask_set_cpu(smp_processor_id(), &evtstrm_available); } return NOTIFY_OK; } static struct notifier_block arch_timer_cpu_pm_notifier = { .notifier_call = arch_timer_cpu_pm_notify, }; static int __init arch_timer_cpu_pm_init(void) { return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier); } static void __init arch_timer_cpu_pm_deinit(void) { WARN_ON(cpu_pm_unregister_notifier(&arch_timer_cpu_pm_notifier)); } #else static int __init arch_timer_cpu_pm_init(void) { return 0; } static void __init arch_timer_cpu_pm_deinit(void) { } #endif static int __init arch_timer_register(void) { int err; int ppi; arch_timer_evt = alloc_percpu(struct clock_event_device); if (!arch_timer_evt) { err = -ENOMEM; goto out; } ppi = arch_timer_ppi[arch_timer_uses_ppi]; switch (arch_timer_uses_ppi) { case ARCH_TIMER_VIRT_PPI: err = request_percpu_irq(ppi, arch_timer_handler_virt, "arch_timer", arch_timer_evt); break; case ARCH_TIMER_PHYS_SECURE_PPI: case ARCH_TIMER_PHYS_NONSECURE_PPI: err = request_percpu_irq(ppi, arch_timer_handler_phys, "arch_timer", arch_timer_evt); if (!err && arch_timer_has_nonsecure_ppi()) { ppi = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]; err = request_percpu_irq(ppi, arch_timer_handler_phys, "arch_timer", arch_timer_evt); if (err) free_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI], arch_timer_evt); } break; case ARCH_TIMER_HYP_PPI: err = request_percpu_irq(ppi, arch_timer_handler_phys, "arch_timer", arch_timer_evt); break; default: BUG(); } if (err) { pr_err("can't register interrupt %d (%d)\n", ppi, err); goto out_free; } err = arch_timer_cpu_pm_init(); if (err) goto out_unreg_notify; /* Register and immediately configure the timer on the boot CPU */ err = cpuhp_setup_state(CPUHP_AP_ARM_ARCH_TIMER_STARTING, "clockevents/arm/arch_timer:starting", arch_timer_starting_cpu, arch_timer_dying_cpu); if (err) goto out_unreg_cpupm; return 0; out_unreg_cpupm: arch_timer_cpu_pm_deinit(); out_unreg_notify: free_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], arch_timer_evt); if (arch_timer_has_nonsecure_ppi()) free_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI], arch_timer_evt); out_free: free_percpu(arch_timer_evt); out: return err; } 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) return -ENOMEM; t->base = base; t->evt.irq = irq; __arch_timer_setup(ARCH_TIMER_TYPE_MEM, &t->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); if (ret) { pr_err("Failed to request mem timer irq\n"); kfree(t); } return ret; } static const struct of_device_id arch_timer_of_match[] __initconst = { { .compatible = "arm,armv7-timer", }, { .compatible = "arm,armv8-timer", }, {}, }; static const struct of_device_id arch_timer_mem_of_match[] __initconst = { { .compatible = "arm,armv7-timer-mem", }, {}, }; static bool __init arch_timer_needs_of_probing(void) { struct device_node *dn; bool needs_probing = false; unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM; /* We have two timers, and both device-tree nodes are probed. */ if ((arch_timers_present & mask) == mask) return false; /* * Only one type of timer is probed, * check if we have another type of timer node in device-tree. */ if (arch_timers_present & ARCH_TIMER_TYPE_CP15) dn = of_find_matching_node(NULL, arch_timer_mem_of_match); else dn = of_find_matching_node(NULL, arch_timer_of_match); if (dn && of_device_is_available(dn)) needs_probing = true; of_node_put(dn); return needs_probing; } static int __init arch_timer_common_init(void) { int ret; arch_timer_banner(arch_timers_present); arch_counter_register(arch_timers_present); ret = arch_timer_arch_init(); if (!ret) clocksource_select_force(); return ret; } /** * arch_timer_select_ppi() - Select suitable PPI for the current system. * * If HYP mode is available, we know that the physical timer * has been configured to be accessible from PL1. Use it, so * that a guest can use the virtual timer instead. * * On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE * accesses to CNTP_*_EL1 registers are silently redirected to * their CNTHP_*_EL2 counterparts, and use a different PPI * number. * * If no interrupt provided for virtual timer, we'll have to * stick to the physical timer. It'd better be accessible... * For arm64 we never use the secure interrupt. * * Return: a suitable PPI type for the current system. */ static enum arch_timer_ppi_nr __init arch_timer_select_ppi(void) { if (is_kernel_in_hyp_mode()) return ARCH_TIMER_HYP_PPI; if (!is_hyp_mode_available() && arch_timer_ppi[ARCH_TIMER_VIRT_PPI]) return ARCH_TIMER_VIRT_PPI; if (IS_ENABLED(CONFIG_ARM64)) return ARCH_TIMER_PHYS_NONSECURE_PPI; return ARCH_TIMER_PHYS_SECURE_PPI; } static int __init arch_timer_of_init(struct device_node *np) { int i, ret; u32 rate; if (arch_timers_present & ARCH_TIMER_TYPE_CP15) { pr_warn("multiple nodes in dt, skipping\n"); return 0; } arch_timers_present |= ARCH_TIMER_TYPE_CP15; for (i = ARCH_TIMER_PHYS_SECURE_PPI; i < ARCH_TIMER_MAX_TIMER_PPI; i++) arch_timer_ppi[i] = irq_of_parse_and_map(np, i); arch_timer_kvm_info.virtual_irq = arch_timer_ppi[ARCH_TIMER_VIRT_PPI]; rate = arch_timer_get_cntfrq(); arch_timer_of_configure_rate(rate, np); arch_timer_c3stop = !of_property_read_bool(np, "always-on"); /* Check for globally applicable workarounds */ arch_timer_check_ool_workaround(ate_match_dt, np); /* * If we cannot rely on firmware initializing the timer registers then * we should use the physical timers instead. */ if (IS_ENABLED(CONFIG_ARM) && of_property_read_bool(np, "arm,cpu-registers-not-fw-configured")) arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI; else arch_timer_uses_ppi = arch_timer_select_ppi(); if (!arch_timer_ppi[arch_timer_uses_ppi]) { pr_err("No interrupt available, giving up\n"); return -EINVAL; } /* On some systems, the counter stops ticking when in suspend. */ arch_counter_suspend_stop = of_property_read_bool(np, "arm,no-tick-in-suspend"); ret = arch_timer_register(); if (ret) return ret; if (arch_timer_needs_of_probing()) return 0; return arch_timer_common_init(); } TIMER_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init); TIMER_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init); static u32 __init arch_timer_mem_frame_get_cntfrq(struct arch_timer_mem_frame *frame) { void __iomem *base; u32 rate; base = ioremap(frame->cntbase, frame->size); if (!base) { pr_err("Unable to map frame @ %pa\n", &frame->cntbase); return 0; } rate = readl_relaxed(base + CNTFRQ); iounmap(base); return rate; } static struct arch_timer_mem_frame * __init arch_timer_mem_find_best_frame(struct arch_timer_mem *timer_mem) { struct arch_timer_mem_frame *frame, *best_frame = NULL; void __iomem *cntctlbase; u32 cnttidr; int i; cntctlbase = ioremap(timer_mem->cntctlbase, timer_mem->size); if (!cntctlbase) { pr_err("Can't map CNTCTLBase @ %pa\n", &timer_mem->cntctlbase); return NULL; } cnttidr = readl_relaxed_no_log(cntctlbase + CNTTIDR); /* * Try to find a virtual capable frame. Otherwise fall back to a * physical capable frame. */ for (i = 0; i < ARCH_TIMER_MEM_MAX_FRAMES; i++) { u32 cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT | CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT; frame = &timer_mem->frame[i]; if (!frame->valid) continue; /* Try enabling everything, and see what sticks */ writel_relaxed(cntacr, cntctlbase + CNTACR(i)); cntacr = readl_relaxed(cntctlbase + CNTACR(i)); if ((cnttidr & CNTTIDR_VIRT(i)) && !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) { best_frame = frame; arch_timer_mem_use_virtual = true; break; } if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT)) continue; best_frame = frame; } iounmap(cntctlbase); return best_frame; } static int __init arch_timer_mem_frame_register(struct arch_timer_mem_frame *frame) { void __iomem *base; int ret, irq = 0; if (arch_timer_mem_use_virtual) irq = frame->virt_irq; else irq = frame->phys_irq; if (!irq) { pr_err("Frame missing %s irq.\n", arch_timer_mem_use_virtual ? "virt" : "phys"); return -EINVAL; } if (!request_mem_region(frame->cntbase, frame->size, "arch_mem_timer")) return -EBUSY; base = ioremap(frame->cntbase, frame->size); if (!base) { pr_err("Can't map frame's registers\n"); return -ENXIO; } ret = arch_timer_mem_register(base, irq); if (ret) { iounmap(base); return ret; } arch_counter_base = base; arch_timers_present |= ARCH_TIMER_TYPE_MEM; return 0; } static int __init arch_timer_mem_of_init(struct device_node *np) { struct arch_timer_mem *timer_mem; struct arch_timer_mem_frame *frame; struct device_node *frame_node; struct resource res; int ret = -EINVAL; u32 rate; timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL); if (!timer_mem) return -ENOMEM; if (of_address_to_resource(np, 0, &res)) goto out; timer_mem->cntctlbase = res.start; timer_mem->size = resource_size(&res); for_each_available_child_of_node(np, frame_node) { u32 n; struct arch_timer_mem_frame *frame; if (of_property_read_u32(frame_node, "frame-number", &n)) { pr_err(FW_BUG "Missing frame-number.\n"); of_node_put(frame_node); goto out; } if (n >= ARCH_TIMER_MEM_MAX_FRAMES) { pr_err(FW_BUG "Wrong frame-number, only 0-%u are permitted.\n", ARCH_TIMER_MEM_MAX_FRAMES - 1); of_node_put(frame_node); goto out; } frame = &timer_mem->frame[n]; if (frame->valid) { pr_err(FW_BUG "Duplicated frame-number.\n"); of_node_put(frame_node); goto out; } if (of_address_to_resource(frame_node, 0, &res)) { of_node_put(frame_node); goto out; } frame->cntbase = res.start; frame->size = resource_size(&res); frame->virt_irq = irq_of_parse_and_map(frame_node, ARCH_TIMER_VIRT_SPI); frame->phys_irq = irq_of_parse_and_map(frame_node, ARCH_TIMER_PHYS_SPI); frame->valid = true; } frame = arch_timer_mem_find_best_frame(timer_mem); if (!frame) { pr_err("Unable to find a suitable frame in timer @ %pa\n", &timer_mem->cntctlbase); ret = -EINVAL; goto out; } rate = arch_timer_mem_frame_get_cntfrq(frame); arch_timer_of_configure_rate(rate, np); ret = arch_timer_mem_frame_register(frame); if (!ret && !arch_timer_needs_of_probing()) ret = arch_timer_common_init(); get_pct_hook_init(); out: kfree(timer_mem); return ret; } TIMER_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem", arch_timer_mem_of_init); #ifdef CONFIG_ACPI_GTDT static int __init arch_timer_mem_verify_cntfrq(struct arch_timer_mem *timer_mem) { struct arch_timer_mem_frame *frame; u32 rate; int i; for (i = 0; i < ARCH_TIMER_MEM_MAX_FRAMES; i++) { frame = &timer_mem->frame[i]; if (!frame->valid) continue; rate = arch_timer_mem_frame_get_cntfrq(frame); if (rate == arch_timer_rate) continue; pr_err(FW_BUG "CNTFRQ mismatch: frame @ %pa: (0x%08lx), CPU: (0x%08lx)\n", &frame->cntbase, (unsigned long)rate, (unsigned long)arch_timer_rate); return -EINVAL; } return 0; } static int __init arch_timer_mem_acpi_init(int platform_timer_count) { struct arch_timer_mem *timers, *timer; struct arch_timer_mem_frame *frame, *best_frame = NULL; int timer_count, i, ret = 0; timers = kcalloc(platform_timer_count, sizeof(*timers), GFP_KERNEL); if (!timers) return -ENOMEM; ret = acpi_arch_timer_mem_init(timers, &timer_count); if (ret || !timer_count) goto out; /* * While unlikely, it's theoretically possible that none of the frames * in a timer expose the combination of feature we want. */ for (i = 0; i < timer_count; i++) { timer = &timers[i]; frame = arch_timer_mem_find_best_frame(timer); if (!best_frame) best_frame = frame; ret = arch_timer_mem_verify_cntfrq(timer); if (ret) { pr_err("Disabling MMIO timers due to CNTFRQ mismatch\n"); goto out; } if (!best_frame) /* implies !frame */ /* * Only complain about missing suitable frames if we * haven't already found one in a previous iteration. */ pr_err("Unable to find a suitable frame in timer @ %pa\n", &timer->cntctlbase); } if (best_frame) ret = arch_timer_mem_frame_register(best_frame); out: kfree(timers); return ret; } /* Initialize per-processor generic timer and memory-mapped timer(if present) */ static int __init arch_timer_acpi_init(struct acpi_table_header *table) { int ret, platform_timer_count; if (arch_timers_present & ARCH_TIMER_TYPE_CP15) { pr_warn("already initialized, skipping\n"); return -EINVAL; } arch_timers_present |= ARCH_TIMER_TYPE_CP15; ret = acpi_gtdt_init(table, &platform_timer_count); if (ret) { pr_err("Failed to init GTDT table.\n"); return ret; } arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI] = acpi_gtdt_map_ppi(ARCH_TIMER_PHYS_NONSECURE_PPI); arch_timer_ppi[ARCH_TIMER_VIRT_PPI] = acpi_gtdt_map_ppi(ARCH_TIMER_VIRT_PPI); arch_timer_ppi[ARCH_TIMER_HYP_PPI] = acpi_gtdt_map_ppi(ARCH_TIMER_HYP_PPI); arch_timer_kvm_info.virtual_irq = arch_timer_ppi[ARCH_TIMER_VIRT_PPI]; /* * When probing via ACPI, we have no mechanism to override the sysreg * CNTFRQ value. This *must* be correct. */ arch_timer_rate = arch_timer_get_cntfrq(); if (!arch_timer_rate) { pr_err(FW_BUG "frequency not available.\n"); return -EINVAL; } arch_timer_uses_ppi = arch_timer_select_ppi(); if (!arch_timer_ppi[arch_timer_uses_ppi]) { pr_err("No interrupt available, giving up\n"); return -EINVAL; } /* Always-on capability */ arch_timer_c3stop = acpi_gtdt_c3stop(arch_timer_uses_ppi); /* Check for globally applicable workarounds */ arch_timer_check_ool_workaround(ate_match_acpi_oem_info, table); ret = arch_timer_register(); if (ret) return ret; if (platform_timer_count && arch_timer_mem_acpi_init(platform_timer_count)) pr_err("Failed to initialize memory-mapped timer.\n"); return arch_timer_common_init(); } TIMER_ACPI_DECLARE(arch_timer, ACPI_SIG_GTDT, arch_timer_acpi_init); #endif