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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/s390/include/asm/timex.h |
Initial import
Diffstat (limited to 'arch/s390/include/asm/timex.h')
-rw-r--r-- | arch/s390/include/asm/timex.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h new file mode 100644 index 000000000..98eb2a579 --- /dev/null +++ b/arch/s390/include/asm/timex.h @@ -0,0 +1,163 @@ +/* + * S390 version + * Copyright IBM Corp. 1999 + * + * Derived from "include/asm-i386/timex.h" + * Copyright (C) 1992, Linus Torvalds + */ + +#ifndef _ASM_S390_TIMEX_H +#define _ASM_S390_TIMEX_H + +#include <asm/lowcore.h> + +/* The value of the TOD clock for 1.1.1970. */ +#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL + +/* Inline functions for clock register access. */ +static inline int set_tod_clock(__u64 time) +{ + int cc; + + asm volatile( + " sck %1\n" + " ipm %0\n" + " srl %0,28\n" + : "=d" (cc) : "Q" (time) : "cc"); + return cc; +} + +static inline int store_tod_clock(__u64 *time) +{ + int cc; + + asm volatile( + " stck %1\n" + " ipm %0\n" + " srl %0,28\n" + : "=d" (cc), "=Q" (*time) : : "cc"); + return cc; +} + +static inline void set_clock_comparator(__u64 time) +{ + asm volatile("sckc %0" : : "Q" (time)); +} + +static inline void store_clock_comparator(__u64 *time) +{ + asm volatile("stckc %0" : "=Q" (*time)); +} + +void clock_comparator_work(void); + +static inline unsigned long long local_tick_disable(void) +{ + unsigned long long old; + + old = S390_lowcore.clock_comparator; + S390_lowcore.clock_comparator = -1ULL; + set_clock_comparator(S390_lowcore.clock_comparator); + return old; +} + +static inline void local_tick_enable(unsigned long long comp) +{ + S390_lowcore.clock_comparator = comp; + set_clock_comparator(S390_lowcore.clock_comparator); +} + +#define CLOCK_TICK_RATE 1193180 /* Underlying HZ */ +#define STORE_CLOCK_EXT_SIZE 16 /* stcke writes 16 bytes */ + +typedef unsigned long long cycles_t; + +static inline void get_tod_clock_ext(char *clk) +{ + typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype; + + asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc"); +} + +static inline unsigned long long get_tod_clock(void) +{ + unsigned char clk[STORE_CLOCK_EXT_SIZE]; + + get_tod_clock_ext(clk); + return *((unsigned long long *)&clk[1]); +} + +static inline unsigned long long get_tod_clock_fast(void) +{ +#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES + unsigned long long clk; + + asm volatile("stckf %0" : "=Q" (clk) : : "cc"); + return clk; +#else + return get_tod_clock(); +#endif +} + +static inline cycles_t get_cycles(void) +{ + return (cycles_t) get_tod_clock() >> 2; +} + +int get_sync_clock(unsigned long long *clock); +void init_cpu_timer(void); +unsigned long long monotonic_clock(void); + +void tod_to_timeval(__u64, struct timespec *); + +static inline +void stck_to_timespec(unsigned long long stck, struct timespec *ts) +{ + tod_to_timeval(stck - TOD_UNIX_EPOCH, ts); +} + +extern u64 sched_clock_base_cc; + +/** + * get_clock_monotonic - returns current time in clock rate units + * + * The caller must ensure that preemption is disabled. + * The clock and sched_clock_base get changed via stop_machine. + * Therefore preemption must be disabled when calling this + * function, otherwise the returned value is not guaranteed to + * be monotonic. + */ +static inline unsigned long long get_tod_clock_monotonic(void) +{ + return get_tod_clock() - sched_clock_base_cc; +} + +/** + * tod_to_ns - convert a TOD format value to nanoseconds + * @todval: to be converted TOD format value + * Returns: number of nanoseconds that correspond to the TOD format value + * + * Converting a 64 Bit TOD format value to nanoseconds means that the value + * must be divided by 4.096. In order to achieve that we multiply with 125 + * and divide by 512: + * + * ns = (todval * 125) >> 9; + * + * In order to avoid an overflow with the multiplication we can rewrite this. + * With a split todval == 2^32 * th + tl (th upper 32 bits, tl lower 32 bits) + * we end up with + * + * ns = ((2^32 * th + tl) * 125 ) >> 9; + * -> ns = (2^23 * th * 125) + ((tl * 125) >> 9); + * + */ +static inline unsigned long long tod_to_ns(unsigned long long todval) +{ + unsigned long long ns; + + ns = ((todval >> 32) << 23) * 125; + ns += ((todval & 0xffffffff) * 125) >> 9; + return ns; +} + +#endif |