From 6b2e29977518ec13ef3022f234ff8f3014c243da Mon Sep 17 00:00:00 2001 From: Lakshmi Sowjanya D Date: Mon, 13 May 2024 16:08:02 +0530 Subject: timekeeping: Provide infrastructure for converting to/from a base clock Hardware time stamps like provided by PTP clock implementations are based on a clock which feeds both the PCIe device and the system clock. For further processing the underlying hardwarre clock timestamp must be converted to the system clock. Right now this requires drivers to invoke an architecture specific conversion function, e.g. to convert the ART (Always Running Timer) timestamp to a TSC timestamp. As the system clock is aware of the underlying base clock, this can be moved to the core code by providing a base clock property for the system clock which contains the conversion factors and assigning a clocksource ID to the base clock. Add the required data structures and the conversion infrastructure in the core code to prepare for converting X86 and the related PTP drivers over. [ tglx: Added a missing READ_ONCE(). Massaged change log ] Co-developed-by: Thomas Gleixner Signed-off-by: Thomas Gleixner Co-developed-by: Christopher S. Hall Signed-off-by: Christopher S. Hall Signed-off-by: Lakshmi Sowjanya D Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240513103813.5666-2-lakshmi.sowjanya.d@intel.com --- include/linux/clocksource.h | 27 +++++++++++++++++++++++++++ include/linux/timekeeping.h | 2 ++ 2 files changed, 29 insertions(+) (limited to 'include/linux') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 0ad8b550bb4b..d35b677b08fe 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -21,6 +21,7 @@ #include #include +struct clocksource_base; struct clocksource; struct module; @@ -50,6 +51,7 @@ struct module; * multiplication * @name: Pointer to clocksource name * @list: List head for registration (internal) + * @freq_khz: Clocksource frequency in khz. * @rating: Rating value for selection (higher is better) * To avoid rating inflation the following * list should give you a guide as to how @@ -70,6 +72,8 @@ struct module; * validate the clocksource from which the snapshot was * taken. * @flags: Flags describing special properties + * @base: Hardware abstraction for clock on which a clocksource + * is based * @enable: Optional function to enable the clocksource * @disable: Optional function to disable the clocksource * @suspend: Optional suspend function for the clocksource @@ -107,10 +111,12 @@ struct clocksource { u64 max_cycles; const char *name; struct list_head list; + u32 freq_khz; int rating; enum clocksource_ids id; enum vdso_clock_mode vdso_clock_mode; unsigned long flags; + struct clocksource_base *base; int (*enable)(struct clocksource *cs); void (*disable)(struct clocksource *cs); @@ -306,4 +312,25 @@ static inline unsigned int clocksource_get_max_watchdog_retry(void) void clocksource_verify_percpu(struct clocksource *cs); +/** + * struct clocksource_base - hardware abstraction for clock on which a clocksource + * is based + * @id: Defaults to CSID_GENERIC. The id value is used for conversion + * functions which require that the current clocksource is based + * on a clocksource_base with a particular ID in certain snapshot + * functions to allow callers to validate the clocksource from + * which the snapshot was taken. + * @freq_khz: Nominal frequency of the base clock in kHz + * @offset: Offset between the base clock and the clocksource + * @numerator: Numerator of the clock ratio between base clock and the clocksource + * @denominator: Denominator of the clock ratio between base clock and the clocksource + */ +struct clocksource_base { + enum clocksource_ids id; + u32 freq_khz; + u64 offset; + u32 numerator; + u32 denominator; +}; + #endif /* _LINUX_CLOCKSOURCE_H */ diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 0ea7823b7f31..b2ee182d891e 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -310,10 +310,12 @@ struct system_device_crosststamp { * timekeeping code to verify comparability of two cycle values. * The default ID, CSID_GENERIC, does not identify a specific * clocksource. + * @use_nsecs: @cycles is in nanoseconds. */ struct system_counterval_t { u64 cycles; enum clocksource_ids cs_id; + bool use_nsecs; }; /* -- cgit v1.2.3 From 3a52886c8f972c3a5b70bfec330c71817cd7fc63 Mon Sep 17 00:00:00 2001 From: Lakshmi Sowjanya D Date: Mon, 13 May 2024 16:08:03 +0530 Subject: x86/tsc: Provide ART base clock information for TSC The core code provides a new mechanism to allow conversion between ART and TSC. This allows to replace the x86 specific ART/TSC conversion functions. Prepare for removal by filling in the base clock conversion information for ART and associating the base clock to the TSC clocksource. The existing conversion functions will be removed once the usage sites are converted over to the new model. [ tglx: Massaged change log ] Co-developed-by: Thomas Gleixner Signed-off-by: Thomas Gleixner Co-developed-by: Christopher S. Hall Signed-off-by: Christopher S. Hall Signed-off-by: Lakshmi Sowjanya D Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240513103813.5666-3-lakshmi.sowjanya.d@intel.com --- arch/x86/kernel/tsc.c | 42 +++++++++++++++++++++++------------------ include/linux/clocksource_ids.h | 1 + 2 files changed, 25 insertions(+), 18 deletions(-) (limited to 'include/linux') diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 06b170759e5b..d1888db5db91 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -50,9 +50,9 @@ int tsc_clocksource_reliable; static int __read_mostly tsc_force_recalibrate; -static u32 art_to_tsc_numerator; -static u32 art_to_tsc_denominator; -static u64 art_to_tsc_offset; +static struct clocksource_base art_base_clk = { + .id = CSID_X86_ART, +}; static bool have_art; struct cyc2ns { @@ -1074,7 +1074,7 @@ core_initcall(cpufreq_register_tsc_scaling); */ static void __init detect_art(void) { - unsigned int unused[2]; + unsigned int unused; if (boot_cpu_data.cpuid_level < ART_CPUID_LEAF) return; @@ -1089,13 +1089,14 @@ static void __init detect_art(void) tsc_async_resets) return; - cpuid(ART_CPUID_LEAF, &art_to_tsc_denominator, - &art_to_tsc_numerator, unused, unused+1); + cpuid(ART_CPUID_LEAF, &art_base_clk.denominator, + &art_base_clk.numerator, &art_base_clk.freq_khz, &unused); - if (art_to_tsc_denominator < ART_MIN_DENOMINATOR) + art_base_clk.freq_khz /= KHZ; + if (art_base_clk.denominator < ART_MIN_DENOMINATOR) return; - rdmsrl(MSR_IA32_TSC_ADJUST, art_to_tsc_offset); + rdmsrl(MSR_IA32_TSC_ADJUST, art_base_clk.offset); /* Make this sticky over multiple CPU init calls */ setup_force_cpu_cap(X86_FEATURE_ART); @@ -1303,13 +1304,13 @@ struct system_counterval_t convert_art_to_tsc(u64 art) { u64 tmp, res, rem; - rem = do_div(art, art_to_tsc_denominator); + rem = do_div(art, art_base_clk.denominator); - res = art * art_to_tsc_numerator; - tmp = rem * art_to_tsc_numerator; + res = art * art_base_clk.numerator; + tmp = rem * art_base_clk.numerator; - do_div(tmp, art_to_tsc_denominator); - res += tmp + art_to_tsc_offset; + do_div(tmp, art_base_clk.denominator); + res += tmp + art_base_clk.offset; return (struct system_counterval_t) { .cs_id = have_art ? CSID_X86_TSC : CSID_GENERIC, @@ -1356,7 +1357,6 @@ struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns) } EXPORT_SYMBOL(convert_art_ns_to_tsc); - static void tsc_refine_calibration_work(struct work_struct *work); static DECLARE_DELAYED_WORK(tsc_irqwork, tsc_refine_calibration_work); /** @@ -1458,8 +1458,10 @@ out: if (tsc_unstable) goto unreg; - if (boot_cpu_has(X86_FEATURE_ART)) + if (boot_cpu_has(X86_FEATURE_ART)) { have_art = true; + clocksource_tsc.base = &art_base_clk; + } clocksource_register_khz(&clocksource_tsc, tsc_khz); unreg: clocksource_unregister(&clocksource_tsc_early); @@ -1484,8 +1486,10 @@ static int __init init_tsc_clocksource(void) * the refined calibration and directly register it as a clocksource. */ if (boot_cpu_has(X86_FEATURE_TSC_KNOWN_FREQ)) { - if (boot_cpu_has(X86_FEATURE_ART)) + if (boot_cpu_has(X86_FEATURE_ART)) { have_art = true; + clocksource_tsc.base = &art_base_clk; + } clocksource_register_khz(&clocksource_tsc, tsc_khz); clocksource_unregister(&clocksource_tsc_early); @@ -1509,10 +1513,12 @@ static bool __init determine_cpu_tsc_frequencies(bool early) if (early) { cpu_khz = x86_platform.calibrate_cpu(); - if (tsc_early_khz) + if (tsc_early_khz) { tsc_khz = tsc_early_khz; - else + } else { tsc_khz = x86_platform.calibrate_tsc(); + clocksource_tsc.freq_khz = tsc_khz; + } } else { /* We should not be here with non-native cpu calibration */ WARN_ON(x86_platform.calibrate_cpu != native_calibrate_cpu); diff --git a/include/linux/clocksource_ids.h b/include/linux/clocksource_ids.h index a4fa3436940c..2bb4d8c2f1b0 100644 --- a/include/linux/clocksource_ids.h +++ b/include/linux/clocksource_ids.h @@ -9,6 +9,7 @@ enum clocksource_ids { CSID_X86_TSC_EARLY, CSID_X86_TSC, CSID_X86_KVM_CLK, + CSID_X86_ART, CSID_MAX, }; -- cgit v1.2.3 From 02ecee07ca30f76f2a0f1381661a688b8e501ab0 Mon Sep 17 00:00:00 2001 From: Lakshmi Sowjanya D Date: Mon, 13 May 2024 16:08:10 +0530 Subject: timekeeping: Add function to convert realtime to base clock PPS (Pulse Per Second) generates a hardware pulse every second based on CLOCK_REALTIME. This works fine when the pulse is generated in software from a hrtimer callback function. For hardware which generates the pulse by programming a timer it is required to convert CLOCK_REALTIME to the underlying hardware clock. The X86 Timed IO device is based on the Always Running Timer (ART), which is the base clock of the TSC, which is usually the system clocksource on X86. The core code already has functionality to convert base clock timestamps to system clocksource timestamps, but there is no support for converting the other way around. Provide the required functionality to support such devices in a generic way to avoid code duplication in drivers: 1) ktime_real_to_base_clock() to convert a CLOCK_REALTIME timestamp to a base clock timestamp 2) timekeeping_clocksource_has_base() to allow drivers to validate that the system clocksource is based on a particular clocksource ID. [ tglx: Simplify timekeeping_clocksource_has_base() and add missing READ_ONCE() ] Co-developed-by: Thomas Gleixner Signed-off-by: Thomas Gleixner Co-developed-by: Christopher S. Hall Signed-off-by: Christopher S. Hall Signed-off-by: Lakshmi Sowjanya D Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240513103813.5666-10-lakshmi.sowjanya.d@intel.com --- include/linux/timekeeping.h | 4 +++ kernel/time/timekeeping.c | 86 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 90 insertions(+) (limited to 'include/linux') diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index b2ee182d891e..fc12a9ba2c88 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -318,6 +318,10 @@ struct system_counterval_t { bool use_nsecs; }; +extern bool ktime_real_to_base_clock(ktime_t treal, + enum clocksource_ids base_id, u64 *cycles); +extern bool timekeeping_clocksource_has_base(enum clocksource_ids id); + /* * Get cross timestamp between system clock and device clock */ diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 3096e10e0a1d..da984a368a95 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1235,6 +1235,68 @@ static bool convert_base_to_cs(struct system_counterval_t *scv) return true; } +static bool convert_cs_to_base(u64 *cycles, enum clocksource_ids base_id) +{ + struct clocksource *cs = tk_core.timekeeper.tkr_mono.clock; + struct clocksource_base *base; + + /* + * Check whether base_id matches the base clock. Prevent the compiler from + * re-evaluating @base as the clocksource might change concurrently. + */ + base = READ_ONCE(cs->base); + if (!base || base->id != base_id) + return false; + + *cycles -= base->offset; + if (!convert_clock(cycles, base->denominator, base->numerator)) + return false; + return true; +} + +static bool convert_ns_to_cs(u64 *delta) +{ + struct tk_read_base *tkr = &tk_core.timekeeper.tkr_mono; + + if (BITS_TO_BYTES(fls64(*delta) + tkr->shift) >= sizeof(*delta)) + return false; + + *delta = div_u64((*delta << tkr->shift) - tkr->xtime_nsec, tkr->mult); + return true; +} + +/** + * ktime_real_to_base_clock() - Convert CLOCK_REALTIME timestamp to a base clock timestamp + * @treal: CLOCK_REALTIME timestamp to convert + * @base_id: base clocksource id + * @cycles: pointer to store the converted base clock timestamp + * + * Converts a supplied, future realtime clock value to the corresponding base clock value. + * + * Return: true if the conversion is successful, false otherwise. + */ +bool ktime_real_to_base_clock(ktime_t treal, enum clocksource_ids base_id, u64 *cycles) +{ + struct timekeeper *tk = &tk_core.timekeeper; + unsigned int seq; + u64 delta; + + do { + seq = read_seqcount_begin(&tk_core.seq); + if ((u64)treal < tk->tkr_mono.base_real) + return false; + delta = (u64)treal - tk->tkr_mono.base_real; + if (!convert_ns_to_cs(&delta)) + return false; + *cycles = tk->tkr_mono.cycle_last + delta; + if (!convert_cs_to_base(cycles, base_id)) + return false; + } while (read_seqcount_retry(&tk_core.seq, seq)); + + return true; +} +EXPORT_SYMBOL_GPL(ktime_real_to_base_clock); + /** * get_device_system_crosststamp - Synchronously capture system/device timestamp * @get_time_fn: Callback to get simultaneous device time and @@ -1346,6 +1408,30 @@ int get_device_system_crosststamp(int (*get_time_fn) } EXPORT_SYMBOL_GPL(get_device_system_crosststamp); +/** + * timekeeping_clocksource_has_base - Check whether the current clocksource + * is based on given a base clock + * @id: base clocksource ID + * + * Note: The return value is a snapshot which can become invalid right + * after the function returns. + * + * Return: true if the timekeeper clocksource has a base clock with @id, + * false otherwise + */ +bool timekeeping_clocksource_has_base(enum clocksource_ids id) +{ + /* + * This is a snapshot, so no point in using the sequence + * count. Just prevent the compiler from re-evaluating @base as the + * clocksource might change concurrently. + */ + struct clocksource_base *base = READ_ONCE(tk_core.timekeeper.tkr_mono.clock->base); + + return base ? base->id == id : false; +} +EXPORT_SYMBOL_GPL(timekeeping_clocksource_has_base); + /** * do_settimeofday64 - Sets the time of day. * @ts: pointer to the timespec64 variable containing the new time -- cgit v1.2.3 From 9403408e122628a6dc7154a95716f00dae3747c7 Mon Sep 17 00:00:00 2001 From: Christian Loehle Date: Mon, 17 Jun 2024 17:16:15 +0100 Subject: tick: Remove unnused tick_nohz_get_idle_calls() The function returns the idle calls counter for the current cpu and therefore usually isn't what the caller wants. It is unnused since commit 466a2b42d676 ("cpufreq: schedutil: Use idle_calls counter of the remote CPU") Signed-off-by: Christian Loehle Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240617161615.49309-1-christian.loehle@arm.com --- include/linux/tick.h | 1 - kernel/time/tick-sched.c | 14 -------------- 2 files changed, 15 deletions(-) (limited to 'include/linux') diff --git a/include/linux/tick.h b/include/linux/tick.h index 4924a33700b7..72744638c5b0 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -139,7 +139,6 @@ extern void tick_nohz_irq_exit(void); extern bool tick_nohz_idle_got_tick(void); extern ktime_t tick_nohz_get_next_hrtimer(void); extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next); -extern unsigned long tick_nohz_get_idle_calls(void); extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu); extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 71a792cd8936..43a6370a2ebc 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -1385,20 +1385,6 @@ unsigned long tick_nohz_get_idle_calls_cpu(int cpu) return ts->idle_calls; } -/** - * tick_nohz_get_idle_calls - return the current idle calls counter value - * - * Called from the schedutil frequency scaling governor in scheduler context. - * - * Return: the current idle calls counter value for the current CPU - */ -unsigned long tick_nohz_get_idle_calls(void) -{ - struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched); - - return ts->idle_calls; -} - static void tick_nohz_account_idle_time(struct tick_sched *ts, ktime_t now) { -- cgit v1.2.3 From 4bdc3eaa102b6bedb0800f76f53eca516d5cf20c Mon Sep 17 00:00:00 2001 From: Chris Packham Date: Wed, 10 Jul 2024 16:35:21 +1200 Subject: clocksource/drivers/realtek: Add timer driver for rtl-otto platforms The timer/counter block on the Realtek SoCs provides up to 5 timers. It also includes a watchdog timer which is handled by the realtek_otto_wdt.c driver. One timer will be used per CPU as a local clock event generator. An additional timer will be used as an overal stable clocksource. Signed-off-by: Markus Stockhausen Signed-off-by: Sander Vanheule Signed-off-by: Chris Packham Link: https://lore.kernel.org/r/20240710043524.1535151-8-chris.packham@alliedtelesis.co.nz Signed-off-by: Daniel Lezcano --- drivers/clocksource/Kconfig | 10 ++ drivers/clocksource/Makefile | 1 + drivers/clocksource/timer-rtl-otto.c | 291 +++++++++++++++++++++++++++++++++++ include/linux/cpuhotplug.h | 1 + 4 files changed, 303 insertions(+) create mode 100644 drivers/clocksource/timer-rtl-otto.c (limited to 'include/linux') diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 34faa0320ece..95dd4660b5b6 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -134,6 +134,16 @@ config RDA_TIMER help Enables the support for the RDA Micro timer driver. +config REALTEK_OTTO_TIMER + bool "Clocksource/timer for the Realtek Otto platform" if COMPILE_TEST + select TIMER_OF + help + This driver adds support for the timers found in the Realtek RTL83xx + and RTL93xx SoCs series. This includes chips such as RTL8380, RTL8381 + and RTL832, as well as chips from the RTL839x series, such as RTL8390 + RT8391, RTL8392, RTL8393 and RTL8396 and chips of the RTL930x series + such as RTL9301, RTL9302 or RTL9303. + config SUN4I_TIMER bool "Sun4i timer driver" if COMPILE_TEST depends on HAS_IOMEM diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 4bb856e4df55..22743785299e 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -59,6 +59,7 @@ obj-$(CONFIG_MILBEAUT_TIMER) += timer-milbeaut.o obj-$(CONFIG_SPRD_TIMER) += timer-sprd.o obj-$(CONFIG_NPCM7XX_TIMER) += timer-npcm7xx.o obj-$(CONFIG_RDA_TIMER) += timer-rda.o +obj-$(CONFIG_REALTEK_OTTO_TIMER) += timer-rtl-otto.o obj-$(CONFIG_ARC_TIMERS) += arc_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o diff --git a/drivers/clocksource/timer-rtl-otto.c b/drivers/clocksource/timer-rtl-otto.c new file mode 100644 index 000000000000..8a3068b36e75 --- /dev/null +++ b/drivers/clocksource/timer-rtl-otto.c @@ -0,0 +1,291 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "timer-of.h" + +#define RTTM_DATA 0x0 +#define RTTM_CNT 0x4 +#define RTTM_CTRL 0x8 +#define RTTM_INT 0xc + +#define RTTM_CTRL_ENABLE BIT(28) +#define RTTM_INT_PENDING BIT(16) +#define RTTM_INT_ENABLE BIT(20) + +/* + * The Otto platform provides multiple 28 bit timers/counters with the following + * operating logic. If enabled the timer counts up. Per timer one can set a + * maximum counter value as an end marker. If end marker is reached the timer + * fires an interrupt. If the timer "overflows" by reaching the end marker or + * by adding 1 to 0x0fffffff the counter is reset to 0. When this happens and + * the timer is in operating mode COUNTER it stops. In mode TIMER it will + * continue to count up. + */ +#define RTTM_CTRL_COUNTER 0 +#define RTTM_CTRL_TIMER BIT(24) + +#define RTTM_BIT_COUNT 28 +#define RTTM_MIN_DELTA 8 +#define RTTM_MAX_DELTA CLOCKSOURCE_MASK(28) + +/* + * Timers are derived from the LXB clock frequency. Usually this is a fixed + * multiple of the 25 MHz oscillator. The 930X SOC is an exception from that. + * Its LXB clock has only dividers and uses the switch PLL of 2.45 GHz as its + * base. The only meaningful frequencies we can achieve from that are 175.000 + * MHz and 153.125 MHz. The greatest common divisor of all explained possible + * speeds is 3125000. Pin the timers to this 3.125 MHz reference frequency. + */ +#define RTTM_TICKS_PER_SEC 3125000 + +struct rttm_cs { + struct timer_of to; + struct clocksource cs; +}; + +/* Simple internal register functions */ +static inline void rttm_set_counter(void __iomem *base, unsigned int counter) +{ + iowrite32(counter, base + RTTM_CNT); +} + +static inline unsigned int rttm_get_counter(void __iomem *base) +{ + return ioread32(base + RTTM_CNT); +} + +static inline void rttm_set_period(void __iomem *base, unsigned int period) +{ + iowrite32(period, base + RTTM_DATA); +} + +static inline void rttm_disable_timer(void __iomem *base) +{ + iowrite32(0, base + RTTM_CTRL); +} + +static inline void rttm_enable_timer(void __iomem *base, u32 mode, u32 divisor) +{ + iowrite32(RTTM_CTRL_ENABLE | mode | divisor, base + RTTM_CTRL); +} + +static inline void rttm_ack_irq(void __iomem *base) +{ + iowrite32(ioread32(base + RTTM_INT) | RTTM_INT_PENDING, base + RTTM_INT); +} + +static inline void rttm_enable_irq(void __iomem *base) +{ + iowrite32(RTTM_INT_ENABLE, base + RTTM_INT); +} + +static inline void rttm_disable_irq(void __iomem *base) +{ + iowrite32(0, base + RTTM_INT); +} + +/* Aggregated control functions for kernel clock framework */ +#define RTTM_DEBUG(base) \ + pr_debug("------------- %d %p\n", \ + smp_processor_id(), base) + +static irqreturn_t rttm_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *clkevt = dev_id; + struct timer_of *to = to_timer_of(clkevt); + + rttm_ack_irq(to->of_base.base); + RTTM_DEBUG(to->of_base.base); + clkevt->event_handler(clkevt); + + return IRQ_HANDLED; +} + +static void rttm_stop_timer(void __iomem *base) +{ + rttm_disable_timer(base); + rttm_ack_irq(base); +} + +static void rttm_start_timer(struct timer_of *to, u32 mode) +{ + rttm_set_counter(to->of_base.base, 0); + rttm_enable_timer(to->of_base.base, mode, to->of_clk.rate / RTTM_TICKS_PER_SEC); +} + +static int rttm_next_event(unsigned long delta, struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + RTTM_DEBUG(to->of_base.base); + rttm_stop_timer(to->of_base.base); + rttm_set_period(to->of_base.base, delta); + rttm_start_timer(to, RTTM_CTRL_COUNTER); + + return 0; +} + +static int rttm_state_oneshot(struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + RTTM_DEBUG(to->of_base.base); + rttm_stop_timer(to->of_base.base); + rttm_set_period(to->of_base.base, RTTM_TICKS_PER_SEC / HZ); + rttm_start_timer(to, RTTM_CTRL_COUNTER); + + return 0; +} + +static int rttm_state_periodic(struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + RTTM_DEBUG(to->of_base.base); + rttm_stop_timer(to->of_base.base); + rttm_set_period(to->of_base.base, RTTM_TICKS_PER_SEC / HZ); + rttm_start_timer(to, RTTM_CTRL_TIMER); + + return 0; +} + +static int rttm_state_shutdown(struct clock_event_device *clkevt) +{ + struct timer_of *to = to_timer_of(clkevt); + + RTTM_DEBUG(to->of_base.base); + rttm_stop_timer(to->of_base.base); + + return 0; +} + +static void rttm_setup_timer(void __iomem *base) +{ + RTTM_DEBUG(base); + rttm_stop_timer(base); + rttm_set_period(base, 0); +} + +static u64 rttm_read_clocksource(struct clocksource *cs) +{ + struct rttm_cs *rcs = container_of(cs, struct rttm_cs, cs); + + return rttm_get_counter(rcs->to.of_base.base); +} + +/* Module initialization part. */ +static DEFINE_PER_CPU(struct timer_of, rttm_to) = { + .flags = TIMER_OF_BASE | TIMER_OF_CLOCK | TIMER_OF_IRQ, + .of_irq = { + .flags = IRQF_PERCPU | IRQF_TIMER, + .handler = rttm_timer_interrupt, + }, + .clkevt = { + .rating = 400, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_state_periodic = rttm_state_periodic, + .set_state_shutdown = rttm_state_shutdown, + .set_state_oneshot = rttm_state_oneshot, + .set_next_event = rttm_next_event + }, +}; + +static int rttm_enable_clocksource(struct clocksource *cs) +{ + struct rttm_cs *rcs = container_of(cs, struct rttm_cs, cs); + + rttm_disable_irq(rcs->to.of_base.base); + rttm_setup_timer(rcs->to.of_base.base); + rttm_enable_timer(rcs->to.of_base.base, RTTM_CTRL_TIMER, + rcs->to.of_clk.rate / RTTM_TICKS_PER_SEC); + + return 0; +} + +struct rttm_cs rttm_cs = { + .to = { + .flags = TIMER_OF_BASE | TIMER_OF_CLOCK, + }, + .cs = { + .name = "realtek_otto_timer", + .rating = 400, + .mask = CLOCKSOURCE_MASK(RTTM_BIT_COUNT), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .read = rttm_read_clocksource, + } +}; + +static u64 notrace rttm_read_clock(void) +{ + return rttm_get_counter(rttm_cs.to.of_base.base); +} + +static int rttm_cpu_starting(unsigned int cpu) +{ + struct timer_of *to = per_cpu_ptr(&rttm_to, cpu); + + RTTM_DEBUG(to->of_base.base); + to->clkevt.cpumask = cpumask_of(cpu); + irq_force_affinity(to->of_irq.irq, to->clkevt.cpumask); + clockevents_config_and_register(&to->clkevt, RTTM_TICKS_PER_SEC, + RTTM_MIN_DELTA, RTTM_MAX_DELTA); + rttm_enable_irq(to->of_base.base); + + return 0; +} + +static int __init rttm_probe(struct device_node *np) +{ + unsigned int cpu, cpu_rollback; + struct timer_of *to; + unsigned int clkidx = num_possible_cpus(); + + /* Use the first n timers as per CPU clock event generators */ + for_each_possible_cpu(cpu) { + to = per_cpu_ptr(&rttm_to, cpu); + to->of_irq.index = to->of_base.index = cpu; + if (timer_of_init(np, to)) { + pr_err("setup of timer %d failed\n", cpu); + goto rollback; + } + rttm_setup_timer(to->of_base.base); + } + + /* Activate the n'th + 1 timer as a stable CPU clocksource. */ + to = &rttm_cs.to; + to->of_base.index = clkidx; + timer_of_init(np, to); + if (rttm_cs.to.of_base.base && rttm_cs.to.of_clk.rate) { + rttm_enable_clocksource(&rttm_cs.cs); + clocksource_register_hz(&rttm_cs.cs, RTTM_TICKS_PER_SEC); + sched_clock_register(rttm_read_clock, RTTM_BIT_COUNT, RTTM_TICKS_PER_SEC); + } else + pr_err(" setup of timer %d as clocksource failed", clkidx); + + return cpuhp_setup_state(CPUHP_AP_REALTEK_TIMER_STARTING, + "timer/realtek:online", + rttm_cpu_starting, NULL); +rollback: + pr_err("timer registration failed\n"); + for_each_possible_cpu(cpu_rollback) { + if (cpu_rollback == cpu) + break; + to = per_cpu_ptr(&rttm_to, cpu_rollback); + timer_of_cleanup(to); + } + + return -EINVAL; +} + +TIMER_OF_DECLARE(otto_timer, "realtek,otto-timer", rttm_probe); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 7a5785f405b6..56b744dc1317 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -171,6 +171,7 @@ enum cpuhp_state { CPUHP_AP_ARMADA_TIMER_STARTING, CPUHP_AP_MIPS_GIC_TIMER_STARTING, CPUHP_AP_ARC_TIMER_STARTING, + CPUHP_AP_REALTEK_TIMER_STARTING, CPUHP_AP_RISCV_TIMER_STARTING, CPUHP_AP_CLINT_TIMER_STARTING, CPUHP_AP_CSKY_TIMER_STARTING, -- cgit v1.2.3