1 /*- 2 * Copyright (c) 2014, Bryan Venteicher <bryanv@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #ifndef X86_PVCLOCK 28 #define X86_PVCLOCK 29 30 #include <sys/types.h> 31 32 #ifdef _KERNEL 33 #include <sys/timetc.h> 34 #endif /* _KERNEL */ 35 36 #define PVCLOCK_CDEVNAME "pvclock" 37 38 struct pvclock_vcpu_time_info { 39 uint32_t version; 40 uint32_t pad0; 41 uint64_t tsc_timestamp; 42 uint64_t system_time; 43 uint32_t tsc_to_system_mul; 44 int8_t tsc_shift; 45 uint8_t flags; 46 uint8_t pad[2]; 47 }; 48 49 #define PVCLOCK_FLAG_TSC_STABLE 0x01 50 #define PVCLOCK_FLAG_GUEST_PASUED 0x02 51 52 /* 53 * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, 54 * yielding a 64-bit result. 55 */ 56 static inline uint64_t 57 pvclock_scale_delta(uint64_t delta, uint32_t mul_frac, int shift) 58 { 59 uint64_t product; 60 61 if (shift < 0) 62 delta >>= -shift; 63 else 64 delta <<= shift; 65 #if defined(__i386__) 66 { 67 uint32_t tmp1, tmp2; 68 69 /** 70 * For i386, the formula looks like: 71 * 72 * lower = (mul_frac * (delta & UINT_MAX)) >> 32 73 * upper = mul_frac * (delta >> 32) 74 * product = lower + upper 75 */ 76 __asm__ ( 77 "mul %5 ; " 78 "mov %4,%%eax ; " 79 "mov %%edx,%4 ; " 80 "mul %5 ; " 81 "xor %5,%5 ; " 82 "add %4,%%eax ; " 83 "adc %5,%%edx ; " 84 : "=A" (product), "=r" (tmp1), "=r" (tmp2) 85 : "a" ((uint32_t)delta), "1" ((uint32_t)(delta >> 32)), 86 "2" (mul_frac) ); 87 } 88 #elif defined(__amd64__) 89 { 90 unsigned long tmp; 91 92 __asm__ ( 93 "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" 94 : [lo]"=a" (product), [hi]"=d" (tmp) 95 : "0" (delta), [mul_frac]"rm"((uint64_t)mul_frac)); 96 } 97 #else 98 #error "pvclock: unsupported x86 architecture?" 99 #endif 100 return (product); 101 } 102 103 #ifdef _KERNEL 104 105 typedef struct pvclock_wall_clock *pvclock_get_wallclock_t(void *arg); 106 107 struct pvclock_wall_clock { 108 uint32_t version; 109 uint32_t sec; 110 uint32_t nsec; 111 }; 112 113 struct pvclock { 114 /* Public; initialized by the caller of 'pvclock_init()': */ 115 pvclock_get_wallclock_t *get_wallclock; 116 void *get_wallclock_arg; 117 struct pvclock_vcpu_time_info *timeinfos; 118 bool stable_flag_supported; 119 120 /* Private; initialized by the 'pvclock' API: */ 121 bool vdso_force_unstable; 122 bool vdso_enable_without_rdtscp; 123 struct timecounter tc; 124 struct cdev *cdev; 125 }; 126 127 /* 128 * NOTE: 'pvclock_get_timecount()' and 'pvclock_get_wallclock()' are purely 129 * transitional; they should be removed after 'dev/xen/timer/timer.c' has been 130 * migrated to the 'struct pvclock' API. 131 */ 132 void pvclock_resume(void); 133 uint64_t pvclock_tsc_freq(struct pvclock_vcpu_time_info *ti); 134 uint64_t pvclock_get_timecount(struct pvclock_vcpu_time_info *ti); 135 void pvclock_get_wallclock(struct pvclock_wall_clock *wc, 136 struct timespec *ts); 137 138 void pvclock_init(struct pvclock *pvc, device_t dev, 139 const char *tc_name, int tc_quality, u_int tc_flags); 140 void pvclock_gettime(struct pvclock *pvc, struct timespec *ts); 141 int pvclock_destroy(struct pvclock *pvc); 142 143 #endif /* _KERNEL */ 144 145 #endif 146