diff options
Diffstat (limited to 'include/linux/clocksource.h')
| -rw-r--r-- | include/linux/clocksource.h | 102 |
1 files changed, 0 insertions, 102 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index abcafaa20b86..9c78d15d33e4 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h | |||
| @@ -18,8 +18,6 @@ | |||
| 18 | #include <asm/div64.h> | 18 | #include <asm/div64.h> |
| 19 | #include <asm/io.h> | 19 | #include <asm/io.h> |
| 20 | 20 | ||
| 21 | /* clocksource cycle base type */ | ||
| 22 | typedef u64 cycle_t; | ||
| 23 | struct clocksource; | 21 | struct clocksource; |
| 24 | struct module; | 22 | struct module; |
| 25 | 23 | ||
| @@ -28,106 +26,6 @@ struct module; | |||
| 28 | #endif | 26 | #endif |
| 29 | 27 | ||
| 30 | /** | 28 | /** |
| 31 | * struct cyclecounter - hardware abstraction for a free running counter | ||
| 32 | * Provides completely state-free accessors to the underlying hardware. | ||
| 33 | * Depending on which hardware it reads, the cycle counter may wrap | ||
| 34 | * around quickly. Locking rules (if necessary) have to be defined | ||
| 35 | * by the implementor and user of specific instances of this API. | ||
| 36 | * | ||
| 37 | * @read: returns the current cycle value | ||
| 38 | * @mask: bitmask for two's complement | ||
| 39 | * subtraction of non 64 bit counters, | ||
| 40 | * see CLOCKSOURCE_MASK() helper macro | ||
| 41 | * @mult: cycle to nanosecond multiplier | ||
| 42 | * @shift: cycle to nanosecond divisor (power of two) | ||
| 43 | */ | ||
| 44 | struct cyclecounter { | ||
| 45 | cycle_t (*read)(const struct cyclecounter *cc); | ||
| 46 | cycle_t mask; | ||
| 47 | u32 mult; | ||
| 48 | u32 shift; | ||
| 49 | }; | ||
| 50 | |||
| 51 | /** | ||
| 52 | * struct timecounter - layer above a %struct cyclecounter which counts nanoseconds | ||
| 53 | * Contains the state needed by timecounter_read() to detect | ||
| 54 | * cycle counter wrap around. Initialize with | ||
| 55 | * timecounter_init(). Also used to convert cycle counts into the | ||
| 56 | * corresponding nanosecond counts with timecounter_cyc2time(). Users | ||
| 57 | * of this code are responsible for initializing the underlying | ||
| 58 | * cycle counter hardware, locking issues and reading the time | ||
| 59 | * more often than the cycle counter wraps around. The nanosecond | ||
| 60 | * counter will only wrap around after ~585 years. | ||
| 61 | * | ||
| 62 | * @cc: the cycle counter used by this instance | ||
| 63 | * @cycle_last: most recent cycle counter value seen by | ||
| 64 | * timecounter_read() | ||
| 65 | * @nsec: continuously increasing count | ||
| 66 | */ | ||
| 67 | struct timecounter { | ||
| 68 | const struct cyclecounter *cc; | ||
| 69 | cycle_t cycle_last; | ||
| 70 | u64 nsec; | ||
| 71 | }; | ||
| 72 | |||
| 73 | /** | ||
| 74 | * cyclecounter_cyc2ns - converts cycle counter cycles to nanoseconds | ||
| 75 | * @cc: Pointer to cycle counter. | ||
| 76 | * @cycles: Cycles | ||
| 77 | * | ||
| 78 | * XXX - This could use some mult_lxl_ll() asm optimization. Same code | ||
| 79 | * as in cyc2ns, but with unsigned result. | ||
| 80 | */ | ||
| 81 | static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc, | ||
| 82 | cycle_t cycles) | ||
| 83 | { | ||
| 84 | u64 ret = (u64)cycles; | ||
| 85 | ret = (ret * cc->mult) >> cc->shift; | ||
| 86 | return ret; | ||
| 87 | } | ||
| 88 | |||
| 89 | /** | ||
| 90 | * timecounter_init - initialize a time counter | ||
| 91 | * @tc: Pointer to time counter which is to be initialized/reset | ||
| 92 | * @cc: A cycle counter, ready to be used. | ||
| 93 | * @start_tstamp: Arbitrary initial time stamp. | ||
| 94 | * | ||
| 95 | * After this call the current cycle register (roughly) corresponds to | ||
| 96 | * the initial time stamp. Every call to timecounter_read() increments | ||
| 97 | * the time stamp counter by the number of elapsed nanoseconds. | ||
| 98 | */ | ||
| 99 | extern void timecounter_init(struct timecounter *tc, | ||
| 100 | const struct cyclecounter *cc, | ||
| 101 | u64 start_tstamp); | ||
| 102 | |||
| 103 | /** | ||
| 104 | * timecounter_read - return nanoseconds elapsed since timecounter_init() | ||
| 105 | * plus the initial time stamp | ||
| 106 | * @tc: Pointer to time counter. | ||
| 107 | * | ||
| 108 | * In other words, keeps track of time since the same epoch as | ||
| 109 | * the function which generated the initial time stamp. | ||
| 110 | */ | ||
| 111 | extern u64 timecounter_read(struct timecounter *tc); | ||
| 112 | |||
| 113 | /** | ||
| 114 | * timecounter_cyc2time - convert a cycle counter to same | ||
| 115 | * time base as values returned by | ||
| 116 | * timecounter_read() | ||
| 117 | * @tc: Pointer to time counter. | ||
| 118 | * @cycle_tstamp: a value returned by tc->cc->read() | ||
| 119 | * | ||
| 120 | * Cycle counts that are converted correctly as long as they | ||
| 121 | * fall into the interval [-1/2 max cycle count, +1/2 max cycle count], | ||
| 122 | * with "max cycle count" == cs->mask+1. | ||
| 123 | * | ||
| 124 | * This allows conversion of cycle counter values which were generated | ||
| 125 | * in the past. | ||
| 126 | */ | ||
| 127 | extern u64 timecounter_cyc2time(struct timecounter *tc, | ||
| 128 | cycle_t cycle_tstamp); | ||
| 129 | |||
| 130 | /** | ||
| 131 | * struct clocksource - hardware abstraction for a free running counter | 29 | * struct clocksource - hardware abstraction for a free running counter |
| 132 | * Provides mostly state-free accessors to the underlying hardware. | 30 | * Provides mostly state-free accessors to the underlying hardware. |
| 133 | * This is the structure used for system time. | 31 | * This is the structure used for system time. |
