1#ifndef _ASM_X86_PVCLOCK_H 2#define _ASM_X86_PVCLOCK_H 3 4#include <linux/clocksource.h> 5#include <asm/pvclock-abi.h> 6 7/* some helper functions for xen and kvm pv clock sources */ 8cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); 9u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); 10void pvclock_set_flags(u8 flags); 11unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); 12void pvclock_read_wallclock(struct pvclock_wall_clock *wall, 13 struct pvclock_vcpu_time_info *vcpu, 14 struct timespec *ts); 15void pvclock_resume(void); 16 17void pvclock_touch_watchdogs(void); 18 19/* 20 * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, 21 * yielding a 64-bit result. 22 */ 23static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) 24{ 25 u64 product; 26#ifdef __i386__ 27 u32 tmp1, tmp2; 28#else 29 ulong tmp; 30#endif 31 32 if (shift < 0) 33 delta >>= -shift; 34 else 35 delta <<= shift; 36 37#ifdef __i386__ 38 __asm__ ( 39 "mul %5 ; " 40 "mov %4,%%eax ; " 41 "mov %%edx,%4 ; " 42 "mul %5 ; " 43 "xor %5,%5 ; " 44 "add %4,%%eax ; " 45 "adc %5,%%edx ; " 46 : "=A" (product), "=r" (tmp1), "=r" (tmp2) 47 : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); 48#elif defined(__x86_64__) 49 __asm__ ( 50 "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" 51 : [lo]"=a"(product), 52 [hi]"=d"(tmp) 53 : "0"(delta), 54 [mul_frac]"rm"((u64)mul_frac)); 55#else 56#error implement me! 57#endif 58 59 return product; 60} 61 62static __always_inline 63u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src) 64{ 65 u64 delta = __native_read_tsc() - src->tsc_timestamp; 66 return pvclock_scale_delta(delta, src->tsc_to_system_mul, 67 src->tsc_shift); 68} 69 70static __always_inline 71unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, 72 cycle_t *cycles, u8 *flags) 73{ 74 unsigned version; 75 cycle_t ret, offset; 76 u8 ret_flags; 77 78 version = src->version; 79 /* Note: emulated platforms which do not advertise SSE2 support 80 * result in kvmclock not using the necessary RDTSC barriers. 81 * Without barriers, it is possible that RDTSC instruction reads from 82 * the time stamp counter outside rdtsc_barrier protected section 83 * below, resulting in violation of monotonicity. 84 */ 85 rdtsc_barrier(); 86 offset = pvclock_get_nsec_offset(src); 87 ret = src->system_time + offset; 88 ret_flags = src->flags; 89 rdtsc_barrier(); 90 91 *cycles = ret; 92 *flags = ret_flags; 93 return version; 94} 95 96struct pvclock_vsyscall_time_info { 97 struct pvclock_vcpu_time_info pvti; 98} __attribute__((__aligned__(SMP_CACHE_BYTES))); 99 100#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info) 101#define PVCLOCK_VSYSCALL_NR_PAGES (((NR_CPUS-1)/(PAGE_SIZE/PVTI_SIZE))+1) 102 103int __init pvclock_init_vsyscall(struct pvclock_vsyscall_time_info *i, 104 int size); 105struct pvclock_vcpu_time_info *pvclock_get_vsyscall_time_info(int cpu); 106 107#endif /* _ASM_X86_PVCLOCK_H */ 108