From: Jingyi Wang wangjingyi11@huawei.com

hulk inclusion category: feature bugzilla: NA CVE: NA

-------------------------------------------------

On aarch64, we can compile both SDEI_WATCHODG and PMU_WATCHDOG code instead of choosing one. SDEI_WATCHDOG is used by default, and if SDEI_WATCHDOG is disabled by kernel parameter "disable_sdei_nmi_watchdog", PMU_WATCHDOG is used instead.

Signed-off-by: Jingyi Wang wangjingyi11@huawei.com Signed-off-by: Wei Li liwei391@huawei.com Reviewed-by: Xiongfeng Wang wangxiongfeng2@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/arm64/kernel/watchdog_sdei.c | 23 +++++++++++++++++------ include/linux/nmi.h | 11 +++++++++++ kernel/watchdog.c | 29 ++++++++++++++++++++++------- lib/Kconfig.debug | 7 ++----- 4 files changed, 52 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/kernel/watchdog_sdei.c b/arch/arm64/kernel/watchdog_sdei.c index 6352b589e02a..05b9a9a223a7 100644 --- a/arch/arm64/kernel/watchdog_sdei.c +++ b/arch/arm64/kernel/watchdog_sdei.c @@ -24,7 +24,7 @@ static int sdei_watchdog_event_num; static bool disable_sdei_nmi_watchdog; static bool sdei_watchdog_registered;

-int watchdog_nmi_enable(unsigned int cpu) +int watchdog_sdei_enable(unsigned int cpu) { int ret;

@@ -47,7 +47,7 @@ int watchdog_nmi_enable(unsigned int cpu) return 0; }

-void watchdog_nmi_disable(unsigned int cpu) +void watchdog_sdei_disable(unsigned int cpu) { int ret;

@@ -92,13 +92,10 @@ void sdei_watchdog_clear_eoi(void) sdei_api_clear_eoi(SDEI_NMI_WATCHDOG_HWIRQ); }

-int __init watchdog_nmi_probe(void) +int __init watchdog_sdei_probe(void) { int ret;

- if (disable_sdei_nmi_watchdog) - return -EINVAL; - if (!is_hyp_mode_available()) { pr_err("Disable SDEI NMI Watchdog in VM\n"); return -EINVAL; @@ -135,3 +132,17 @@ int __init watchdog_nmi_probe(void)

return 0; } + +static struct watchdog_operations arch_watchdog_ops = { + .watchdog_nmi_stop = &watchdog_nmi_stop, + .watchdog_nmi_start = &watchdog_nmi_start, + .watchdog_nmi_probe = &watchdog_sdei_probe, + .watchdog_nmi_enable = &watchdog_sdei_enable, + .watchdog_nmi_disable = &watchdog_sdei_disable, +}; + +void watchdog_ops_init(void) +{ + if (!disable_sdei_nmi_watchdog) + nmi_watchdog_ops = arch_watchdog_ops; +} diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 84f324d65068..b931ae96e2d0 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -130,6 +130,17 @@ int watchdog_nmi_probe(void); int watchdog_nmi_enable(unsigned int cpu); void watchdog_nmi_disable(unsigned int cpu);

+struct watchdog_operations { + void (*watchdog_nmi_stop)(void); + void (*watchdog_nmi_start)(void); + int (*watchdog_nmi_probe)(void); + int (*watchdog_nmi_enable)(unsigned int cpu); + void (*watchdog_nmi_disable)(unsigned int cpu); +}; + +extern struct watchdog_operations nmi_watchdog_ops; +void watchdog_ops_init(void); + /** * touch_nmi_watchdog - restart NMI watchdog timeout. * diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 0dd17265dcbd..aa5e98b98d46 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -50,7 +50,16 @@ struct cpumask watchdog_allowed_mask __read_mostly; struct cpumask watchdog_cpumask __read_mostly; unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);

+struct watchdog_operations nmi_watchdog_ops = { + .watchdog_nmi_stop = &watchdog_nmi_stop, + .watchdog_nmi_start = &watchdog_nmi_start, + .watchdog_nmi_probe = &watchdog_nmi_probe, + .watchdog_nmi_enable = &watchdog_nmi_enable, + .watchdog_nmi_disable = &watchdog_nmi_disable, +}; + #ifdef CONFIG_HARDLOCKUP_DETECTOR + /* * Should we panic when a soft-lockup or hard-lockup occurs: */ @@ -496,7 +505,7 @@ static void watchdog_enable(unsigned int cpu) __touch_watchdog(); /* Enable the perf event */ if (watchdog_enabled & NMI_WATCHDOG_ENABLED) - watchdog_nmi_enable(cpu); + nmi_watchdog_ops.watchdog_nmi_enable(cpu); }

static void watchdog_disable(unsigned int cpu) @@ -510,7 +519,7 @@ static void watchdog_disable(unsigned int cpu) * between disabling the timer and disabling the perf event causes * the perf NMI to detect a false positive. */ - watchdog_nmi_disable(cpu); + nmi_watchdog_ops.watchdog_nmi_disable(cpu); hrtimer_cancel(hrtimer); wait_for_completion(this_cpu_ptr(&softlockup_completion)); } @@ -566,7 +575,7 @@ int lockup_detector_offline_cpu(unsigned int cpu) static void lockup_detector_reconfigure(void) { cpus_read_lock(); - watchdog_nmi_stop(); + nmi_watchdog_ops.watchdog_nmi_stop();

softlockup_stop_all(); set_sample_period(); @@ -574,7 +583,7 @@ static void lockup_detector_reconfigure(void) if (watchdog_enabled && watchdog_thresh) softlockup_start_all();

- watchdog_nmi_start(); + nmi_watchdog_ops.watchdog_nmi_start(); cpus_read_unlock(); /* * Must be called outside the cpus locked section to prevent @@ -612,9 +621,9 @@ static __init void lockup_detector_setup(void) static void lockup_detector_reconfigure(void) { cpus_read_lock(); - watchdog_nmi_stop(); + nmi_watchdog_ops.watchdog_nmi_stop(); lockup_detector_update_enable(); - watchdog_nmi_start(); + nmi_watchdog_ops.watchdog_nmi_start(); cpus_read_unlock(); } static inline void lockup_detector_setup(void) @@ -772,15 +781,21 @@ int proc_watchdog_cpumask(struct ctl_table *table, int write, } #endif /* CONFIG_SYSCTL */

+void __weak watchdog_ops_init(void) +{ +} + void __init lockup_detector_init(void) { + watchdog_ops_init(); + if (tick_nohz_full_enabled()) pr_info("Disabling watchdog on nohz_full cores by default\n");

cpumask_copy(&watchdog_cpumask, housekeeping_cpumask(HK_FLAG_TIMER));

- if (!watchdog_nmi_probe()) + if (!nmi_watchdog_ops.watchdog_nmi_probe()) nmi_watchdog_available = true; lockup_detector_setup(); } diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 47dca144782b..2d2c51cbf4bb 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -835,11 +835,8 @@ config HARDLOCKUP_DETECTOR_PERF bool select SOFTLOCKUP_DETECTOR

-choice - prompt "aarch64 NMI watchdog method" +menu "ARM64 NMI watchdog configuration" depends on ARM64 - help - Watchdog implementation method configuration.

config SDEI_WATCHDOG bool "SDEI NMI Watchdog support" @@ -852,7 +849,7 @@ config PMU_WATCHDOG depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI select HAVE_HARDLOCKUP_DETECTOR_PERF

-endchoice +endmenu # "ARM64 NMI watchdog configuration"

# # Enables a timestamp based low pass filter to compensate for perf based