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 #ifdef CONFIG_KVM_GUEST 8 extern struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void); 9 #else 10 static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void) 11 { 12 return NULL; 13 } 14 #endif 15 16 /* some helper functions for xen and kvm pv clock sources */ 17 u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src); 18 u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src); 19 void pvclock_set_flags(u8 flags); 20 unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src); 21 void pvclock_read_wallclock(struct pvclock_wall_clock *wall, 22 struct pvclock_vcpu_time_info *vcpu, 23 struct timespec *ts); 24 void pvclock_resume(void); 25 26 void pvclock_touch_watchdogs(void); 27 28 static __always_inline 29 unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src) 30 { 31 unsigned version = src->version & ~1; 32 /* Make sure that the version is read before the data. */ 33 virt_rmb(); 34 return version; 35 } 36 37 static __always_inline 38 bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src, 39 unsigned version) 40 { 41 /* Make sure that the version is re-read after the data. */ 42 virt_rmb(); 43 return unlikely(version != src->version); 44 } 45 46 /* 47 * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, 48 * yielding a 64-bit result. 49 */ 50 static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) 51 { 52 u64 product; 53 #ifdef __i386__ 54 u32 tmp1, tmp2; 55 #else 56 ulong tmp; 57 #endif 58 59 if (shift < 0) 60 delta >>= -shift; 61 else 62 delta <<= shift; 63 64 #ifdef __i386__ 65 __asm__ ( 66 "mul %5 ; " 67 "mov %4,%%eax ; " 68 "mov %%edx,%4 ; " 69 "mul %5 ; " 70 "xor %5,%5 ; " 71 "add %4,%%eax ; " 72 "adc %5,%%edx ; " 73 : "=A" (product), "=r" (tmp1), "=r" (tmp2) 74 : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); 75 #elif defined(__x86_64__) 76 __asm__ ( 77 "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" 78 : [lo]"=a"(product), 79 [hi]"=d"(tmp) 80 : "0"(delta), 81 [mul_frac]"rm"((u64)mul_frac)); 82 #else 83 #error implement me! 84 #endif 85 86 return product; 87 } 88 89 static __always_inline 90 u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc) 91 { 92 u64 delta = tsc - src->tsc_timestamp; 93 u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul, 94 src->tsc_shift); 95 return src->system_time + offset; 96 } 97 98 struct pvclock_vsyscall_time_info { 99 struct pvclock_vcpu_time_info pvti; 100 } __attribute__((__aligned__(SMP_CACHE_BYTES))); 101 102 #define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info) 103 104 #endif /* _ASM_X86_PVCLOCK_H */ 105