| 1 | /* test-async-tsc.c |
| 2 | * |
| 3 | * test async tsc on AMD. |
| 4 | */ |
| 5 | |
| 6 | |
| 7 | #include <asm/atomic.h> |
| 8 | #include <linux/module.h> |
| 9 | #include <asm/timex.h> |
| 10 | #include <asm/hpet.h> |
| 11 | #include <asm/io.h> |
| 12 | #include <linux/clocksource.h> |
| 13 | #include <linux/ltt.h> |
| 14 | #include <asm/cacheflush.h> |
| 15 | |
| 16 | //#define NR_LOOPS 10000 |
| 17 | #define NR_LOOPS 10 |
| 18 | |
| 19 | extern cycle_t read_hpet(void); |
| 20 | |
| 21 | static int __init test_init(void) |
| 22 | { |
| 23 | int i; |
| 24 | cycles_t time1, time2; |
| 25 | volatile unsigned long myval; |
| 26 | int sync_save; /* racy */ |
| 27 | |
| 28 | sync_save = ltt_tsc_is_sync; |
| 29 | ltt_tsc_is_sync = 0; |
| 30 | //ltt_tsc_is_sync = 1; |
| 31 | return -EPERM; //TEST ! |
| 32 | myval = ltt_get_timestamp64(); |
| 33 | time1 = get_cycles(); |
| 34 | for (i=0; i < NR_LOOPS; i++) { |
| 35 | //printk("time %llu\n", ltt_tsc_read()); |
| 36 | //get_cycles_barrier(); |
| 37 | //myval = get_cycles(); |
| 38 | //get_cycles_barrier(); |
| 39 | myval = read_hpet(); |
| 40 | //clflush(<t_last_tsc); |
| 41 | //myval = ltt_get_timestamp64(); |
| 42 | printk("val : %llu\n", (unsigned long long)myval); |
| 43 | } |
| 44 | time2 = get_cycles(); |
| 45 | printk("timediff %llu\n", (time2-time1)/NR_LOOPS); |
| 46 | ltt_tsc_is_sync = sync_save; |
| 47 | return -EPERM; |
| 48 | } |
| 49 | |
| 50 | static void __exit test_exit(void) |
| 51 | { |
| 52 | } |
| 53 | |
| 54 | module_init(test_init); |
| 55 | module_exit(test_exit); |
| 56 | |
| 57 | MODULE_LICENSE("GPL"); |
| 58 | MODULE_AUTHOR("Mathieu Desnoyers"); |
| 59 | MODULE_DESCRIPTION("sync async tsc"); |
| 60 | |