From 3bd142a46b561a12408e8db78cc6d62eb1c6b84e Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 7 Feb 2020 13:38:53 +0100 Subject: clocksource: Cleanup struct clocksource and documentation Reformat the struct definition, add missing member documentation. No functional change. Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino Link: https://lkml.kernel.org/r/20200207124402.825471920@linutronix.de --- include/linux/clocksource.h | 87 ++++++++++++++++++++++++--------------------- 1 file changed, 47 insertions(+), 40 deletions(-) (limited to 'include/linux/clocksource.h') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index b21db536fd52..2c4574b517d2 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -32,9 +32,19 @@ struct module; * Provides mostly state-free accessors to the underlying hardware. * This is the structure used for system time. * - * @name: ptr to clocksource name - * @list: list head for registration - * @rating: rating value for selection (higher is better) + * @read: Returns a cycle value, passes clocksource as argument + * @mask: Bitmask for two's complement + * subtraction of non 64 bit counters + * @mult: Cycle to nanosecond multiplier + * @shift: Cycle to nanosecond divisor (power of two) + * @max_idle_ns: Maximum idle time permitted by the clocksource (nsecs) + * @maxadj: Maximum adjustment value to mult (~11%) + * @archdata: Optional arch-specific data + * @max_cycles: Maximum safe cycle value which won't overflow on + * multiplication + * @name: Pointer to clocksource name + * @list: List head for registration (internal) + * @rating: Rating value for selection (higher is better) * To avoid rating inflation the following * list should give you a guide as to how * to assign your clocksource a rating @@ -49,27 +59,23 @@ struct module; * 400-499: Perfect * The ideal clocksource. A must-use where * available. - * @read: returns a cycle value, passes clocksource as argument - * @enable: optional function to enable the clocksource - * @disable: optional function to disable the clocksource - * @mask: bitmask for two's complement - * subtraction of non 64 bit counters - * @mult: cycle to nanosecond multiplier - * @shift: cycle to nanosecond divisor (power of two) - * @max_idle_ns: max idle time permitted by the clocksource (nsecs) - * @maxadj: maximum adjustment value to mult (~11%) - * @max_cycles: maximum safe cycle value which won't overflow on multiplication - * @flags: flags describing special properties - * @archdata: arch-specific data - * @suspend: suspend function for the clocksource, if necessary - * @resume: resume function for the clocksource, if necessary + * @flags: Flags describing special properties + * @enable: Optional function to enable the clocksource + * @disable: Optional function to disable the clocksource + * @suspend: Optional suspend function for the clocksource + * @resume: Optional resume function for the clocksource * @mark_unstable: Optional function to inform the clocksource driver that * the watchdog marked the clocksource unstable - * @owner: module reference, must be set by clocksource in modules + * @tick_stable: Optional function called periodically from the watchdog + * code to provide stable syncrhonization points + * @wd_list: List head to enqueue into the watchdog list (internal) + * @cs_last: Last clocksource value for clocksource watchdog + * @wd_last: Last watchdog value corresponding to @cs_last + * @owner: Module reference, must be set by clocksource in modules * * Note: This struct is not used in hotpathes of the timekeeping code * because the timekeeper caches the hot path fields in its own data - * structure, so no line cache alignment is required, + * structure, so no cache line alignment is required, * * The pointer to the clocksource itself is handed to the read * callback. If you need extra information there you can wrap struct @@ -78,35 +84,36 @@ struct module; * structure. */ struct clocksource { - u64 (*read)(struct clocksource *cs); - u64 mask; - u32 mult; - u32 shift; - u64 max_idle_ns; - u32 maxadj; + u64 (*read)(struct clocksource *cs); + u64 mask; + u32 mult; + u32 shift; + u64 max_idle_ns; + u32 maxadj; #ifdef CONFIG_ARCH_CLOCKSOURCE_DATA struct arch_clocksource_data archdata; #endif - u64 max_cycles; - const char *name; - struct list_head list; - int rating; - int (*enable)(struct clocksource *cs); - void (*disable)(struct clocksource *cs); - unsigned long flags; - void (*suspend)(struct clocksource *cs); - void (*resume)(struct clocksource *cs); - void (*mark_unstable)(struct clocksource *cs); - void (*tick_stable)(struct clocksource *cs); + u64 max_cycles; + const char *name; + struct list_head list; + int rating; + unsigned long flags; + + int (*enable)(struct clocksource *cs); + void (*disable)(struct clocksource *cs); + void (*suspend)(struct clocksource *cs); + void (*resume)(struct clocksource *cs); + void (*mark_unstable)(struct clocksource *cs); + void (*tick_stable)(struct clocksource *cs); /* private: */ #ifdef CONFIG_CLOCKSOURCE_WATCHDOG /* Watchdog related data, used by the framework */ - struct list_head wd_list; - u64 cs_last; - u64 wd_last; + struct list_head wd_list; + u64 cs_last; + u64 wd_last; #endif - struct module *owner; + struct module *owner; }; /* -- cgit v1.2.3 From 5d51bee725cc1497352d6b0b604e42a90c680540 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 7 Feb 2020 13:38:55 +0100 Subject: clocksource: Add common vdso clock mode storage All architectures which use the generic VDSO code have their own storage for the VDSO clock mode. That's pointless and just requires duplicate code. Provide generic storage for it. The new Kconfig symbol is intermediate and will be removed once all architectures are converted over. Signed-off-by: Thomas Gleixner Tested-by: Vincenzo Frascino Reviewed-by: Vincenzo Frascino Link: https://lkml.kernel.org/r/20200207124403.028046322@linutronix.de --- include/linux/clocksource.h | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'include/linux/clocksource.h') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 2c4574b517d2..6d5ed1b4d24d 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -23,10 +23,19 @@ struct clocksource; struct module; -#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA +#if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \ + defined(CONFIG_GENERIC_VDSO_CLOCK_MODE) #include #endif +enum vdso_clock_mode { + VDSO_CLOCKMODE_NONE, +#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE + VDSO_ARCH_CLOCKMODES, +#endif + VDSO_CLOCKMODE_MAX, +}; + /** * struct clocksource - hardware abstraction for a free running counter * Provides mostly state-free accessors to the underlying hardware. @@ -97,6 +106,7 @@ struct clocksource { const char *name; struct list_head list; int rating; + enum vdso_clock_mode vdso_clock_mode; unsigned long flags; int (*enable)(struct clocksource *cs); -- cgit v1.2.3 From f86fd32db706613fe8d0104057efa6e83e0d7e8f Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 7 Feb 2020 13:38:59 +0100 Subject: lib/vdso: Cleanup clock mode storage leftovers Now that all architectures are converted to use the generic storage the helpers and conditionals can be removed. Signed-off-by: Thomas Gleixner Tested-by: Vincenzo Frascino Reviewed-by: Vincenzo Frascino Link: https://lkml.kernel.org/r/20200207124403.470699892@linutronix.de --- include/linux/clocksource.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/clocksource.h') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 6d5ed1b4d24d..7fefe0b21a14 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -24,13 +24,13 @@ struct clocksource; struct module; #if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \ - defined(CONFIG_GENERIC_VDSO_CLOCK_MODE) + defined(CONFIG_GENERIC_GETTIMEOFDAY) #include #endif enum vdso_clock_mode { VDSO_CLOCKMODE_NONE, -#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE +#ifdef CONFIG_GENERIC_GETTIMEOFDAY VDSO_ARCH_CLOCKMODES, #endif VDSO_CLOCKMODE_MAX, -- cgit v1.2.3 From 2d6b01bd88ccabba06d342ef80eaab6b39d12497 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 7 Feb 2020 13:39:01 +0100 Subject: lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes Move the time namespace indicator clock mode to the other ones for consistency sake. Signed-off-by: Thomas Gleixner Reviewed-by: Vincenzo Frascino Link: https://lkml.kernel.org/r/20200207124403.656097274@linutronix.de --- include/linux/clocksource.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/clocksource.h') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 7fefe0b21a14..02e3282719bd 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -34,6 +34,9 @@ enum vdso_clock_mode { VDSO_ARCH_CLOCKMODES, #endif VDSO_CLOCKMODE_MAX, + + /* Indicator for time namespace VDSO */ + VDSO_CLOCKMODE_TIMENS = INT_MAX }; /** -- cgit v1.2.3 From 14ee2ac618e49e767c9af4aa007f951eb9e35153 Mon Sep 17 00:00:00 2001 From: Vincenzo Frascino Date: Fri, 20 Mar 2020 14:53:33 +0000 Subject: linux/clocksource.h: Extract common header for vDSO The vDSO library should only include the necessary headers required for a userspace library (UAPI and a minimal set of kernel headers). To make this possible it is necessary to isolate from the kernel headers the common parts that are strictly necessary to build the library. Split clocksource.h into linux and common headers to make the latter suitable for inclusion in the vDSO library. Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200320145351.32292-9-vincenzo.frascino@arm.com --- include/linux/clocksource.h | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) (limited to 'include/linux/clocksource.h') diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 02e3282719bd..86d143db6523 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -28,16 +28,7 @@ struct module; #include #endif -enum vdso_clock_mode { - VDSO_CLOCKMODE_NONE, -#ifdef CONFIG_GENERIC_GETTIMEOFDAY - VDSO_ARCH_CLOCKMODES, -#endif - VDSO_CLOCKMODE_MAX, - - /* Indicator for time namespace VDSO */ - VDSO_CLOCKMODE_TIMENS = INT_MAX -}; +#include /** * struct clocksource - hardware abstraction for a free running counter -- cgit v1.2.3