Pull timer updates from Thomas Gleixner: "Updates for the time(r) subsystem: Core: - Make the clocksource watchdog more robust by better validation checks of the measurement. Drivers: - New drivers for MStar and SSD20xd SOCs - The usual cleanups and improvements all over the place" * tag 'timers-core-2022-01-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: dt-bindings: timer: Add Mstar MSC313e timer devicetree bindings documentation clocksource/drivers/msc313e: Add support for ssd20xd-based platforms clocksource/drivers: Add MStar MSC313e timer support clocksource/drivers/pistachio: Fix -Wunused-but-set-variable warning clocksource/drivers/timer-imx-sysctr: Set cpumask to cpu_possible_mask clocksource/drivers/imx-sysctr: Mark two variable with __ro_after_init clocksource/drivers/renesas,ostm: Make RENESAS_OSTM symbol visible clocksource/drivers/renesas-ostm: Add RZ/G2L OSTM support dt-bindings: timer: renesas: ostm: Document Renesas RZ/G2L OSTM clocksource/drivers/exynos_mct: Fix silly typo resulting in checkpatch warning clocksource: Reduce the default clocksource_watchdog() retries to 2 clocksource: Avoid accidental unstable marking of clocksources dt-bindings: timer: tpm-timer: Add imx8ulp compatible string reset: Add of_reset_control_get_optional_exclusive() clocksource/drivers/exynos_mct: Refactor resources allocation dt-bindings: timer: remove rockchip,rk3066-timer compatible string from rockchip,rk-timer.yaml dt-bindings: timer: cadence_ttc: Add power-domains
Showing the changes to kernel (1 of 16 files). Show all
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| @@ -107,7 +107,7 @@ static u64 suspend_start; · 106 unmodified lines | |||
| 107 | * This delay could be due to SMIs, NMIs, or to VCPU preemptions. Used as | 107 | * This delay could be due to SMIs, NMIs, or to VCPU preemptions. Used as |
| 108 | * a lower bound for cs->uncertainty_margin values when registering clocks. | 108 | * a lower bound for cs->uncertainty_margin values when registering clocks. |
| 109 | */ | 109 | */ |
| 110 | #define WATCHDOG_MAX_SKEW (50 * NSEC_PER_USEC) | 110 | #define WATCHDOG_MAX_SKEW (100 * NSEC_PER_USEC) |
| 111 | 111 | ||
| 112 | #ifdef CONFIG_CLOCKSOURCE_WATCHDOG | 112 | #ifdef CONFIG_CLOCKSOURCE_WATCHDOG |
| 113 | static void clocksource_watchdog_work(struct work_struct *work); | 113 | static void clocksource_watchdog_work(struct work_struct *work); |
| @@ -199,23 +199,30 @@ void clocksource_mark_unstable(struct clocksource *cs) · 85 unmodified lines | |||
| 199 | spin_unlock_irqrestore(&watchdog_lock, flags); | 199 | spin_unlock_irqrestore(&watchdog_lock, flags); |
| 200 | } | 200 | } |
| 201 | 201 | ||
| 202 | ulong max_cswd_read_retries = 3; | 202 | ulong max_cswd_read_retries = 2; |
| 203 | module_param(max_cswd_read_retries, ulong, 0644); | 203 | module_param(max_cswd_read_retries, ulong, 0644); |
| 204 | EXPORT_SYMBOL_GPL(max_cswd_read_retries); | 204 | EXPORT_SYMBOL_GPL(max_cswd_read_retries); |
| 205 | static int verify_n_cpus = 8; | 205 | static int verify_n_cpus = 8; |
| 206 | module_param(verify_n_cpus, int, 0644); | 206 | module_param(verify_n_cpus, int, 0644); |
| 207 | 207 | ||
| 208 | static bool cs_watchdog_read(struct clocksource *cs, u64 *csnow, u64 *wdnow) | 208 | enum wd_read_status { |
| 209 | WD_READ_SUCCESS, | ||
| 210 | WD_READ_UNSTABLE, | ||
| 211 | WD_READ_SKIP | ||
| 212 | }; | ||
| 213 | |||
| 214 | static enum wd_read_status cs_watchdog_read(struct clocksource *cs, u64 *csnow, u64 *wdnow) | ||
| 209 | { | 215 | { |
| 210 | unsigned int nretries; | 216 | unsigned int nretries; |
| 211 | u64 wd_end, wd_delta; | 217 | u64 wd_end, wd_end2, wd_delta; |
| 212 | int64_t wd_delay; | 218 | int64_t wd_delay, wd_seq_delay; |
| 213 | 219 | ||
| 214 | for (nretries = 0; nretries <= max_cswd_read_retries; nretries++) { | 220 | for (nretries = 0; nretries <= max_cswd_read_retries; nretries++) { |
| 215 | local_irq_disable(); | 221 | local_irq_disable(); |
| 216 | *wdnow = watchdog->read(watchdog); | 222 | *wdnow = watchdog->read(watchdog); |
| 217 | *csnow = cs->read(cs); | 223 | *csnow = cs->read(cs); |
| 218 | wd_end = watchdog->read(watchdog); | 224 | wd_end = watchdog->read(watchdog); |
| 225 | wd_end2 = watchdog->read(watchdog); | ||
| 219 | local_irq_enable(); | 226 | local_irq_enable(); |
| 220 | 227 | ||
| 221 | wd_delta = clocksource_delta(wd_end, *wdnow, watchdog->mask); | 228 | wd_delta = clocksource_delta(wd_end, *wdnow, watchdog->mask); |
| @@ -226,13 +233,34 @@ static bool cs_watchdog_read(struct clocksource *cs, u64 *csnow, u64 *wdnow) · 4 unmodified lines | |||
| 226 | pr_warn("timekeeping watchdog on CPU%d: %s retried %d times before success\n", | 233 | pr_warn("timekeeping watchdog on CPU%d: %s retried %d times before success\n", |
| 227 | smp_processor_id(), watchdog->name, nretries); | 234 | smp_processor_id(), watchdog->name, nretries); |
| 228 | } | 235 | } |
| 229 | return true; | 236 | return WD_READ_SUCCESS; |
| 230 | } | 237 | } |
| 238 | |||
| 239 | /* | ||
| 240 | * Now compute delay in consecutive watchdog read to see if | ||
| 241 | * there is too much external interferences that cause | ||
| 242 | * significant delay in reading both clocksource and watchdog. | ||
| 243 | * | ||
| 244 | * If consecutive WD read-back delay > WATCHDOG_MAX_SKEW/2, | ||
| 245 | * report system busy, reinit the watchdog and skip the current | ||
| 246 | * watchdog test. | ||
| 247 | */ | ||
| 248 | wd_delta = clocksource_delta(wd_end2, wd_end, watchdog->mask); | ||
| 249 | wd_seq_delay = clocksource_cyc2ns(wd_delta, watchdog->mult, watchdog->shift); | ||
| 250 | if (wd_seq_delay > WATCHDOG_MAX_SKEW/2) | ||
| 251 | goto skip_test; | ||
| 231 | } | 252 | } |
| 232 | 253 | ||
| 233 | pr_warn("timekeeping watchdog on CPU%d: %s read-back delay of %lldns, attempt %d, marking unstable\n", | 254 | pr_warn("timekeeping watchdog on CPU%d: %s read-back delay of %lldns, attempt %d, marking unstable\n", |
| 234 | smp_processor_id(), watchdog->name, wd_delay, nretries); | 255 | smp_processor_id(), watchdog->name, wd_delay, nretries); |
| 235 | return false; | 256 | return WD_READ_UNSTABLE; |
| 257 | |||
| 258 | skip_test: | ||
| 259 | pr_info("timekeeping watchdog on CPU%d: %s wd-wd read-back delay of %lldns\n", | ||
| 260 | smp_processor_id(), watchdog->name, wd_seq_delay); | ||
| 261 | pr_info("wd-%s-wd read-back delay of %lldns, clock-skew test skipped!\n", | ||
| 262 | cs->name, wd_delay); | ||
| 263 | return WD_READ_SKIP; | ||
| 236 | } | 264 | } |
| 237 | 265 | ||
| 238 | static u64 csnow_mid; | 266 | static u64 csnow_mid; |
| @@ -356,6 +384,7 @@ static void clocksource_watchdog(struct timer_list *unused) · 117 unmodified lines | |||
| 356 | int next_cpu, reset_pending; | 384 | int next_cpu, reset_pending; |
| 357 | int64_t wd_nsec, cs_nsec; | 385 | int64_t wd_nsec, cs_nsec; |
| 358 | struct clocksource *cs; | 386 | struct clocksource *cs; |
| 387 | enum wd_read_status read_ret; | ||
| 359 | u32 md; | 388 | u32 md; |
| 360 | 389 | ||
| 361 | spin_lock(&watchdog_lock); | 390 | spin_lock(&watchdog_lock); |
| @@ -373,9 +402,12 @@ static void clocksource_watchdog(struct timer_list *unused) · 11 unmodified lines | |||
| 373 | continue; | 402 | continue; |
| 374 | } | 403 | } |
| 375 | 404 | ||
| 376 | if (!cs_watchdog_read(cs, &csnow, &wdnow)) { | 405 | read_ret = cs_watchdog_read(cs, &csnow, &wdnow); |
| 377 | /* Clock readout unreliable, so give it up. */ | 406 | |
| 378 | __clocksource_unstable(cs); | 407 | if (read_ret != WD_READ_SUCCESS) { |
| 408 | if (read_ret == WD_READ_UNSTABLE) | ||
| 409 | /* Clock readout unreliable, so give it up. */ | ||
| 410 | __clocksource_unstable(cs); | ||
| 379 | continue; | 411 | continue; |
| 380 | } | 412 | } |
| 381 | 413 | ||