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 cycle_t 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 /* 29 * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, 30 * yielding a 64-bit result. 31 */ 32 static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift) 33 { 34 u64 product; 35 #ifdef __i386__ 36 u32 tmp1, tmp2; 37 #else 38 ulong tmp; 39 #endif 40 41 if (shift < 0) 42 delta >>= -shift; 43 else 44 delta <<= shift; 45 46 #ifdef __i386__ 47 __asm__ ( 48 "mul %5 ; " 49 "mov %4,%%eax ; " 50 "mov %%edx,%4 ; " 51 "mul %5 ; " 52 "xor %5,%5 ; " 53 "add %4,%%eax ; " 54 "adc %5,%%edx ; " 55 : "=A" (product), "=r" (tmp1), "=r" (tmp2) 56 : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) ); 57 #elif defined(__x86_64__) 58 __asm__ ( 59 "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" 60 : [lo]"=a"(product), 61 [hi]"=d"(tmp) 62 : "0"(delta), 63 [mul_frac]"rm"((u64)mul_frac)); 64 #else 65 #error implement me! 66 #endif 67 68 return product; 69 } 70 71 static __always_inline 72 unsigned __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, 73 cycle_t *cycles, u8 *flags) 74 { 75 unsigned version; 76 cycle_t offset; 77 u64 delta; 78 79 version = src->version; 80 /* Make the latest version visible */ 81 smp_rmb(); 82 83 delta = rdtsc_ordered() - src->tsc_timestamp; 84 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul, 85 src->tsc_shift); 86 *cycles = src->system_time + offset; 87 *flags = src->flags; 88 return version; 89 } 90 91 struct pvclock_vsyscall_time_info { 92 struct pvclock_vcpu_time_info pvti; 93 } __attribute__((__aligned__(SMP_CACHE_BYTES))); 94 95 #define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info) 96 97 #endif /* _ASM_X86_PVCLOCK_H */ 98