diff options
| -rw-r--r-- | Documentation/devicetree/bindings/arm/global_timer.txt | 24 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/timer/marvell,orion-timer.txt | 17 | ||||
| -rw-r--r-- | drivers/clocksource/Kconfig | 18 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clocksource/arm_global_timer.c | 321 | ||||
| -rw-r--r-- | drivers/clocksource/time-orion.c | 150 | ||||
| -rw-r--r-- | include/linux/nmi.h | 2 | ||||
| -rw-r--r-- | kernel/sysctl.c | 4 | ||||
| -rw-r--r-- | kernel/time/tick-broadcast.c | 5 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 15 | ||||
| -rw-r--r-- | kernel/watchdog.c | 113 |
11 files changed, 608 insertions, 63 deletions
diff --git a/Documentation/devicetree/bindings/arm/global_timer.txt b/Documentation/devicetree/bindings/arm/global_timer.txt new file mode 100644 index 0000000..1e54898 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/global_timer.txt @@ -0,0 +1,24 @@ + +* ARM Global Timer + Cortex-A9 are often associated with a per-core Global timer. + +** Timer node required properties: + +- compatible : Should be "arm,cortex-a9-global-timer" + Driver supports versions r2p0 and above. + +- interrupts : One interrupt to each core + +- reg : Specify the base address and the size of the GT timer + register window. + +- clocks : Should be phandle to a clock. + +Example: + + timer@2c000600 { + compatible = "arm,cortex-a9-global-timer"; + reg = <0x2c000600 0x20>; + interrupts = <1 13 0xf01>; + clocks = <&arm_periph_clk>; + }; diff --git a/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt b/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt new file mode 100644 index 0000000..62bb826 --- /dev/null +++ b/Documentation/devicetree/bindings/timer/marvell,orion-timer.txt @@ -0,0 +1,17 @@ +Marvell Orion SoC timer + +Required properties: +- compatible: shall be "marvell,orion-timer" +- reg: base address of the timer register starting with TIMERS CONTROL register +- interrupt-parent: phandle of the bridge interrupt controller +- interrupts: should contain the interrupts for Timer0 and Timer1 +- clocks: phandle of timer reference clock (tclk) + +Example: + timer: timer { + compatible = "marvell,orion-timer"; + reg = <0x20300 0x20>; + interrupt-parent = <&bridge_intc>; + interrupts = <1>, <2>; + clocks = <&core_clk 0>; + }; diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 81465c2..b7b9b04 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -27,6 +27,11 @@ config DW_APB_TIMER_OF config ARMADA_370_XP_TIMER bool +config ORION_TIMER + select CLKSRC_OF + select CLKSRC_MMIO + bool + config SUN4I_TIMER bool @@ -69,6 +74,19 @@ config ARM_ARCH_TIMER bool select CLKSRC_OF if OF +config ARM_GLOBAL_TIMER + bool + select CLKSRC_OF if OF + help + This options enables support for the ARM global timer unit + +config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK + bool + depends on ARM_GLOBAL_TIMER + default y + help + Use ARM global timer clock source as sched_clock + config CLKSRC_METAG_GENERIC def_bool y if METAG help diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 9ba8b4d..8b00c5c 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o obj-$(CONFIG_CLKSRC_NOMADIK_MTU) += nomadik-mtu.o obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o +obj-$(CONFIG_ORION_TIMER) += time-orion.o obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o obj-$(CONFIG_ARCH_MARCO) += timer-marco.o obj-$(CONFIG_ARCH_MXS) += mxs_timer.o @@ -30,5 +31,6 @@ obj-$(CONFIG_CLKSRC_SAMSUNG_PWM) += samsung_pwm_timer.o obj-$(CONFIG_VF_PIT_TIMER) += vf_pit_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o +obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c new file mode 100644 index 0000000..db8afc7 --- /dev/null +++ b/drivers/clocksource/arm_global_timer.c @@ -0,0 +1,321 @@ +/* + * drivers/clocksource/arm_global_timer.c + * + * Copyright (C) 2013 STMicroelectronics (R&D) Limited. + * Author: Stuart Menefy <stuart.menefy@st.com> + * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com> + * + * 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. + */ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/cpu.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> +#include <linux/sched_clock.h> + +#include <asm/cputype.h> + +#define GT_COUNTER0 0x00 +#define GT_COUNTER1 0x04 + +#define GT_CONTROL 0x08 +#define GT_CONTROL_TIMER_ENABLE BIT(0) /* this bit is NOT banked */ +#define GT_CONTROL_COMP_ENABLE BIT(1) /* banked */ +#define GT_CONTROL_IRQ_ENABLE BIT(2) /* banked */ +#define GT_CONTROL_AUTO_INC BIT(3) /* banked */ + +#define GT_INT_STATUS 0x0c +#define GT_INT_STATUS_EVENT_FLAG BIT(0) + +#define GT_COMP0 0x10 +#define GT_COMP1 0x14 +#define GT_AUTO_INC 0x18 + +/* + * We are expecting to be clocked by the ARM peripheral clock. + * + * Note: it is assumed we are using a prescaler value of zero, so this is + * the units for all operations. + */ +static void __iomem *gt_base; +static unsigned long gt_clk_rate; +static int gt_ppi; +static struct clock_event_device __percpu *gt_evt; + +/* + * To get the value from the Global Timer Counter register proceed as follows: + * 1. Read the upper 32-bit timer counter register + * 2. Read the lower 32-bit timer counter register + * 3. Read the upper 32-bit timer counter register again. If the value is + * different to the 32-bit upper value read previously, go back to step 2. + * Otherwise the 64-bit timer counter value is correct. + */ +static u64 gt_counter_read(void) +{ + u64 counter; + u32 lower; + u32 upper, old_upper; + + upper = readl_relaxed(gt_base + GT_COUNTER1); + do { + old_upper = upper; + lower = readl_relaxed(gt_base + GT_COUNTER0); + upper = readl_relaxed(gt_base + GT_COUNTER1); + } while (upper != old_upper); + + counter = upper; + counter <<= 32; + counter |= lower; + return counter; +} + +/** + * To ensure that updates to comparator value register do not set the + * Interrupt Status Register proceed as follows: + * 1. Clear the Comp Enable bit in the Timer Control Register. + * 2. Write the lower 32-bit Comparator Value Register. + * 3. Write the upper 32-bit Comparator Value Register. + * 4. Set the Comp Enable bit and, if necessary, the IRQ enable bit. + */ +static void gt_compare_set(unsigned long delta, int periodic) +{ + u64 counter = gt_counter_read(); + unsigned long ctrl; + + counter += delta; + ctrl = GT_CONTROL_TIMER_ENABLE; + writel(ctrl, gt_base + GT_CONTROL); + writel(lower_32_bits(counter), gt_base + GT_COMP0); + writel(upper_32_bits(counter), gt_base + GT_COMP1); + + if (periodic) { + writel(delta, gt_base + GT_AUTO_INC); + ctrl |= GT_CONTROL_AUTO_INC; + } + + ctrl |= GT_CONTROL_COMP_ENABLE | GT_CONTROL_IRQ_ENABLE; + writel(ctrl, gt_base + GT_CONTROL); +} + +static void gt_clockevent_set_mode(enum clock_event_mode mode, + struct clock_event_device *clk) +{ + unsigned long ctrl; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + gt_compare_set(DIV_ROUND_CLOSEST(gt_clk_rate, HZ), 1); + break; + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + ctrl = readl(gt_base + GT_CONTROL); + ctrl &= ~(GT_CONTROL_COMP_ENABLE | + GT_CONTROL_IRQ_ENABLE | GT_CONTROL_AUTO_INC); + writel(ctrl, gt_base + GT_CONTROL); + break; + default: + break; + } +} + +static int gt_clockevent_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + gt_compare_set(evt, 0); + return 0; +} + +static irqreturn_t gt_clockevent_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + if (!(readl_relaxed(gt_base + GT_INT_STATUS) & + GT_INT_STATUS_EVENT_FLAG)) + return IRQ_NONE; + + /** + * ERRATA 740657( Global Timer can send 2 interrupts for + * the same event in single-shot mode) + * Workaround: + * Either disable single-shot mode. + * Or + * Modify the Interrupt Handler to avoid the + * offending sequence. This is achieved by clearing + * the Global Timer flag _after_ having incremented + * the Comparator register value to a higher value. + */ + if (evt->mode == CLOCK_EVT_MODE_ONESHOT) + gt_compare_set(ULONG_MAX, 0); + + writel_relaxed(GT_INT_STATUS_EVENT_FLAG, gt_base + GT_INT_STATUS); + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static int __cpuinit gt_clockevents_init(struct clock_event_device *clk) +{ + int cpu = smp_processor_id(); + + clk->name = "arm_global_timer"; + clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + clk->set_mode = gt_clockevent_set_mode; + clk->set_next_event = gt_clockevent_set_next_event; + clk->cpumask = cpumask_of(cpu); + clk->rating = 300; + clk->irq = gt_ppi; + clockevents_config_and_register(clk, gt_clk_rate, + 1, 0xffffffff); + enable_percpu_irq(clk->irq, IRQ_TYPE_NONE); + return 0; +} + +static void gt_clockevents_stop(struct clock_event_device *clk) +{ + gt_clockevent_set_mode(CLOCK_EVT_MODE_UNUSED, clk); + disable_percpu_irq(clk->irq); +} + +static cycle_t gt_clocksource_read(struct clocksource *cs) +{ + return gt_counter_read(); +} + +static struct clocksource gt_clocksource = { + .name = "arm_global_timer", + .rating = 300, + .read = gt_clocksource_read, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK +static u32 notrace gt_sched_clock_read(void) +{ + return gt_counter_read(); +} +#endif + +static void __init gt_clocksource_init(void) +{ + writel(0, gt_base + GT_CONTROL); + writel(0, gt_base + GT_COUNTER0); + writel(0, gt_base + GT_COUNTER1); + /* enables timer on all the cores */ + writel(GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL); + +#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK + setup_sched_clock(gt_sched_clock_read, 32, gt_clk_rate); +#endif + clocksource_register_hz(>_clocksource, gt_clk_rate); +} + +static int __cpuinit gt_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_STARTING: + gt_clockevents_init(this_cpu_ptr(gt_evt)); + break; + case CPU_DYING: + gt_clockevents_stop(this_cpu_ptr(gt_evt)); + break; + } + + return NOTIFY_OK; +} +static struct notifier_block gt_cpu_nb __cpuinitdata = { + .notifier_call = gt_cpu_notify, +}; + +static void __init global_timer_of_register(struct device_node *np) +{ + struct clk *gt_clk; + int err = 0; + + /* + * In r2p0 the comparators for each processor with the global timer + * fire when the timer value is greater than or equal to. In previous + * revisions the comparators fired when the timer value was equal to. + */ + if ((read_cpuid_id() & 0xf0000f) < 0x200000) { + pr_warn("global-timer: non support for this cpu version.\n"); + return; + } + + gt_ppi = irq_of_parse_and_map(np, 0); + if (!gt_ppi) { + pr_warn("global-timer: unable to parse irq\n"); + return; + } + + gt_base = of_iomap(np, 0); + if (!gt_base) { + pr_warn("global-timer: invalid base address\n"); + return; + } + + gt_clk = of_clk_get(np, 0); + if (!IS_ERR(gt_clk)) { + err = clk_prepare_enable(gt_clk); + if (err) + goto out_unmap; + } else { + pr_warn("global-timer: clk not found\n"); + err = -EINVAL; + goto out_unmap; + } + + gt_clk_rate = clk_get_rate(gt_clk); + gt_evt = alloc_percpu(struct clock_event_device); + if (!gt_evt) { + pr_warn("global-timer: can't allocate memory\n"); + err = -ENOMEM; + goto out_clk; + } + + err = request_percpu_irq(gt_ppi, gt_clockevent_interrupt, + "gt", gt_evt); + if (err) { + pr_warn("global-timer: can't register interrupt %d (%d)\n", + gt_ppi, err); + goto out_free; + } + + err = register_cpu_notifier(>_cpu_nb); + if (err) { + pr_warn("global-timer: unable to register cpu notifier.\n"); + goto out_irq; + } + + /* Immediately configure the timer on the boot CPU */ + gt_clocksource_init(); + gt_clockevents_init(this_cpu_ptr(gt_evt)); + + return; + +out_irq: + free_percpu_irq(gt_ppi, gt_evt); +out_free: + free_percpu(gt_evt); +out_clk: + clk_disable_unprepare(gt_clk); +out_unmap: + iounmap(gt_base); + WARN(err, "ARM Global timer register failed (%d)\n", err); +} + +/* Only tested on r2p2 and r3p0 */ +CLOCKSOURCE_OF_DECLARE(arm_gt, "arm,cortex-a9-global-timer", + global_timer_of_register); diff --git a/drivers/clocksource/time-orion.c b/drivers/clocksource/time-orion.c new file mode 100644 index 0000000..ecbeb68 --- /dev/null +++ b/drivers/clocksource/time-orion.c @@ -0,0 +1,150 @@ +/* + * Marvell Orion SoC timer handling. + * + * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + * + * Timer 0 is used as free-running clocksource, while timer 1 is + * used as clock_event_device. + */ + +#include <linux/kernel.h> +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/spinlock.h> +#include <asm/sched_clock.h> + +#define TIMER_CTRL 0x00 +#define TIMER0_EN BIT(0) +#define TIMER0_RELOAD_EN BIT(1) +#define TIMER1_EN BIT(2) +#define TIMER1_RELOAD_EN BIT(3) +#define TIMER0_RELOAD 0x10 +#define TIMER0_VAL 0x14 +#define TIMER1_RELOAD 0x18 +#define TIMER1_VAL 0x1c + +#define ORION_ONESHOT_MIN 1 +#define ORION_ONESHOT_MAX 0xfffffffe + +static void __iomem *timer_base; +static DEFINE_SPINLOCK(timer_ctrl_lock); + +/* + * Thread-safe access to TIMER_CTRL register + * (shared with watchdog timer) + */ +void orion_timer_ctrl_clrset(u32 clr, u32 set) +{ + spin_lock(&timer_ctrl_lock); + writel((readl(timer_base + TIMER_CTRL) & ~clr) | set, + timer_base + TIMER_CTRL); + spin_unlock(&timer_ctrl_lock); +} +EXPORT_SYMBOL(orion_timer_ctrl_clrset); + +/* + * Free-running clocksource handling. + */ +static u32 notrace orion_read_sched_clock(void) +{ + return ~readl(timer_base + TIMER0_VAL); +} + +/* + * Clockevent handling. + */ +static u32 ticks_per_jiffy; + +static int orion_clkevt_next_event(unsigned long delta, + struct clock_event_device *dev) +{ + /* setup and enable one-shot timer */ + writel(delta, timer_base + TIMER1_VAL); + orion_timer_ctrl_clrset(TIMER1_RELOAD_EN, TIMER1_EN); + + return 0; +} + +static void orion_clkevt_mode(enum clock_event_mode mode, + struct clock_event_device *dev) +{ + if (mode == CLOCK_EVT_MODE_PERIODIC) { + /* setup and enable periodic timer at 1/HZ intervals */ + writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD); + writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL); + orion_timer_ctrl_clrset(0, TIMER1_RELOAD_EN | TIMER1_EN); + } else { + /* disable timer */ + orion_timer_ctrl_clrset(TIMER1_RELOAD_EN | TIMER1_EN, 0); + } +} + +static struct clock_event_device orion_clkevt = { + .name = "orion_event", + .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, + .shift = 32, + .rating = 300, + .set_next_event = orion_clkevt_next_event, + .set_mode = orion_clkevt_mode, +}; + +static irqreturn_t orion_clkevt_irq_handler(int irq, void *dev_id) +{ + orion_clkevt.event_handler(&orion_clkevt); + return IRQ_HANDLED; +} + +static struct irqaction orion_clkevt_irq = { + .name = "orion_event", + .flags = IRQF_TIMER, + .handler = orion_clkevt_irq_handler, +}; + +static void __init orion_timer_init(struct device_node *np) +{ + struct clk *clk; + int irq; + + /* timer registers are shared with watchdog timer */ + timer_base = of_iomap(np, 0); + if (!timer_base) + panic("%s: unable to map resource\n", np->name); + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) + panic("%s: unable to get clk\n", np->name); + clk_prepare_enable(clk); + + /* we are only interested in timer1 irq */ + irq = irq_of_parse_and_map(np, 1); + if (irq <= 0) + panic("%s: unable to parse timer1 irq\n", np->name); + + /* setup timer0 as free-running clocksource */ + writel(~0, timer_base + TIMER0_VAL); + writel(~0, timer_base + TIMER0_RELOAD); + orion_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | TIMER0_EN); + clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource", + clk_get_rate(clk), 300, 32, + clocksource_mmio_readl_down); + setup_sched_clock(orion_read_sched_clock, 32, clk_get_rate(clk)); + + /* setup timer1 as clockevent timer */ + if (setup_irq(irq, &orion_clkevt_irq)) + panic("%s: unable to setup irq\n", np->name); + + ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ; + orion_clkevt.cpumask = cpumask_of(0); + orion_clkevt.irq = irq; + clockevents_config_and_register(&orion_clkevt, clk_get_rate(clk), + ORION_ONESHOT_MIN, ORION_ONESHOT_MAX); +} +CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init); diff --git a/include/linux/nmi.h b/include/linux/nmi.h index db50840..6a45fb5 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -46,7 +46,7 @@ static inline bool trigger_all_cpu_backtrace(void) #ifdef CONFIG_LOCKUP_DETECTOR int hw_nmi_is_cpu_stuck(struct pt_regs *); u64 hw_nmi_get_sample_period(int watchdog_thresh); -extern int watchdog_enabled; +extern int watchdog_user_enabled; extern int watchdog_thresh; struct ctl_table; extern int proc_dowatchdog(struct ctl_table *, int , diff --git a/kernel/sysctl.c b/kernel/sysctl.c index e5b31af..ac09d98 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -807,7 +807,7 @@ static struct ctl_table kern_table[] = { #if defined(CONFIG_LOCKUP_DETECTOR) { .procname = "watchdog", - .data = &watchdog_enabled, + .data = &watchdog_user_enabled, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dowatchdog, @@ -834,7 +834,7 @@ static struct ctl_table kern_table[] = { }, { .procname = "nmi_watchdog", - .data = &watchdog_enabled, + .data = &watchdog_user_enabled, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dowatchdog, diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 6d3f916..218bcb5 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -157,7 +157,10 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu) dev->event_handler = tick_handle_periodic; tick_device_setup_broadcast_func(dev); cpumask_set_cpu(cpu, tick_broadcast_mask); - tick_broadcast_start_periodic(bc); + if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) + tick_broadcast_start_periodic(bc); + else + tick_broadcast_setup_oneshot(bc); ret = 1; } else { /* diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 0cf1c14..6960172 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -178,6 +178,11 @@ static bool can_stop_full_tick(void) */ if (!sched_clock_stable) { trace_tick_stop(0, "unstable sched clock\n"); + /* + * Don't allow the user to think they can get + * full NO_HZ with this machine. + */ + WARN_ONCE(1, "NO_HZ FULL will not work with unstable sched clock"); return false; } #endif @@ -346,16 +351,6 @@ void __init tick_nohz_init(void) } cpu_notifier(tick_nohz_cpu_down_callback, 0); - - /* Make sure full dynticks CPU are also RCU nocbs */ - for_each_cpu(cpu, nohz_full_mask) { - if (!rcu_is_nocb_cpu(cpu)) { - pr_warning("NO_HZ: CPU %d is not RCU nocb: " - "cleared from nohz_full range", cpu); - cpumask_clear_cpu(cpu, nohz_full_mask); - } - } - cpulist_scnprintf(nohz_full_buf, sizeof(nohz_full_buf), nohz_full_mask); pr_info("NO_HZ: Full dynticks CPUs: %s.\n", nohz_full_buf); } diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 05039e3..1241d8c 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -29,9 +29,9 @@ #include <linux/kvm_para.h> #include <linux/perf_event.h> -int watchdog_enabled = 1; +int watchdog_user_enabled = 1; int __read_mostly watchdog_thresh = 10; -static int __read_mostly watchdog_disabled; +static int __read_mostly watchdog_running; static u64 __read_mostly sample_period; static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts); @@ -63,7 +63,7 @@ static int __init hardlockup_panic_setup(char *str) else if (!strncmp(str, "nopanic", 7)) hardlockup_panic = 0; else if (!strncmp(str, "0", 1)) - watchdog_enabled = 0; + watchdog_user_enabled = 0; return 1; } __setup("nmi_watchdog=", hardlockup_panic_setup); @@ -82,7 +82,7 @@ __setup("softlockup_panic=", softlockup_panic_setup); static int __init nowatchdog_setup(char *str) { - watchdog_enabled = 0; + watchdog_user_enabled = 0; return 1; } __setup("nowatchdog", nowatchdog_setup); @@ -90,7 +90,7 @@ __setup("nowatchdog", nowatchdog_setup); /* deprecated */ static int __init nosoftlockup_setup(char *str) { - watchdog_enabled = 0; + watchdog_user_enabled = 0; return 1; } __setup("nosoftlockup", nosoftlockup_setup); @@ -158,7 +158,7 @@ void touch_all_softlockup_watchdogs(void) #ifdef CONFIG_HARDLOCKUP_DETECTOR void touch_nmi_watchdog(void) { - if (watchdog_enabled) { + if (watchdog_user_enabled) { unsigned cpu; for_each_present_cpu(cpu) { @@ -347,11 +347,6 @@ static void watchdog_enable(unsigned int cpu) hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); hrtimer->function = watchdog_timer_fn; - if (!watchdog_enabled) { - kthread_park(current); - return; - } - /* Enable the perf event */ watchdog_nmi_enable(cpu); @@ -374,6 +369,11 @@ static void watchdog_disable(unsigned int cpu) watchdog_nmi_disable(cpu); } +static void watchdog_cleanup(unsigned int cpu, bool online) +{ + watchdog_disable(cpu); +} + static int watchdog_should_run(unsigned int cpu) { return __this_cpu_read(hrtimer_interrupts) != @@ -475,28 +475,40 @@ static int watchdog_nmi_enable(unsigned int cpu) { return 0; } static void watchdog_nmi_disable(unsigned int cpu) { return; } #endif /* CONFIG_HARDLOCKUP_DETECTOR */ -/* prepare/enable/disable routines */ -/* sysctl functions */ -#ifdef CONFIG_SYSCTL -static void watchdog_enable_all_cpus(void) +static struct smp_hotplug_thread watchdog_threads = { + .store = &softlockup_watchdog, + .thread_should_run = watchdog_should_run, + .thread_fn = watchdog, + .thread_comm = "watchdog/%u", + .setup = watchdog_enable, + .cleanup = watchdog_cleanup, + .park = watchdog_disable, + .unpark = watchdog_enable, +}; + +static int watchdog_enable_all_cpus(void) { - unsigned int cpu; + int err = 0; - if (watchdog_disabled) { - watchdog_disabled = 0; - for_each_online_cpu(cpu) - kthread_unpark(per_cpu(softlockup_watchdog, cpu)); + if (!watchdog_running) { + err = smpboot_register_percpu_thread(&watchdog_threads); + if (err) + pr_err("Failed to create watchdog threads, disabled\n"); + else + watchdog_running = 1; } + + return err; } +/* prepare/enable/disable routines */ +/* sysctl functions */ +#ifdef CONFIG_SYSCTL static void watchdog_disable_all_cpus(void) { - unsigned int cpu; - - if (!watchdog_disabled) { - watchdog_disabled = 1; - for_each_online_cpu(cpu) - kthread_park(per_cpu(softlockup_watchdog, cpu)); + if (watchdog_running) { + watchdog_running = 0; + smpboot_unregister_percpu_thread(&watchdog_threads); } } @@ -507,45 +519,48 @@ static void watchdog_disable_all_cpus(void) int proc_dowatchdog(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret; + int err, old_thresh, old_enabled; - if (watchdog_disabled < 0) - return -ENODEV; + old_thresh = ACCESS_ONCE(watchdog_thresh); + old_enabled = ACCESS_ONCE(watchdog_user_enabled); - ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); - if (ret || !write) - return ret; + err = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + if (err || !write) + return err; set_sample_period(); /* * Watchdog threads shouldn't be enabled if they are - * disabled. The 'watchdog_disabled' variable check in + * disabled. The 'watchdog_running' variable check in * watchdog_*_all_cpus() function takes care of this. */ - if (watchdog_enabled && watchdog_thresh) - watchdog_enable_all_cpus(); + if (watchdog_user_enabled && watchdog_thresh) + err = watchdog_enable_all_cpus(); else watchdog_disable_all_cpus(); - return ret; + /* Restore old values on failure */ + if (err) { + watchdog_thresh = old_thresh; + watchdog_user_enabled = old_enabled; + } + + return err; } #endif /* CONFIG_SYSCTL */ -static struct smp_hotplug_thread watchdog_threads = { - .store = &softlockup_watchdog, - .thread_should_run = watchdog_should_run, - .thread_fn = watchdog, - .thread_comm = "watchdog/%u", - .setup = watchdog_enable, - .park = watchdog_disable, - .unpark = watchdog_enable, -}; - void __init lockup_detector_init(void) { set_sample_period(); - if (smpboot_register_percpu_thread(&watchdog_threads)) { - pr_err("Failed to create watchdog threads, disabled\n"); - watchdog_disabled = -ENODEV; + +#ifdef CONFIG_NO_HZ_FULL + if (watchdog_user_enabled) { + watchdog_user_enabled = 0; + pr_warning("Disabled lockup detectors by default for full dynticks\n"); + pr_warning("You can reactivate it with 'sysctl -w kernel.watchdog=1'\n"); } +#endif + + if (watchdog_user_enabled) + watchdog_enable_all_cpus(); } |