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 * $FreeBSD$ 27 */ 28 29 #ifndef X86_PVCLOCK 30 #define X86_PVCLOCK 31 32 #include <sys/types.h> 33 34 #ifdef _KERNEL 35 #include <sys/timetc.h> 36 #endif /* _KERNEL */ 37 38 #define PVCLOCK_CDEVNAME "pvclock" 39 40 struct pvclock_vcpu_time_info { 41 uint32_t version; 42 uint32_t pad0; 43 uint64_t tsc_timestamp; 44 uint64_t system_time; 45 uint32_t tsc_to_system_mul; 46 int8_t tsc_shift; 47 uint8_t flags; 48 uint8_t pad[2]; 49 }; 50 51 #define PVCLOCK_FLAG_TSC_STABLE 0x01 52 #define PVCLOCK_FLAG_GUEST_PASUED 0x02 53 54 /* 55 * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, 56 * yielding a 64-bit result. 57 */ 58 static inline uint64_t 59 pvclock_scale_delta(uint64_t delta, uint32_t mul_frac, int shift) 60 { 61 uint64_t product; 62 63 if (shift < 0) 64 delta >>= -shift; 65 else 66 delta <<= shift; 67 #if defined(__i386__) 68 { 69 uint32_t tmp1, tmp2; 70 71 /** 72 * For i386, the formula looks like: 73 * 74 * lower = (mul_frac * (delta & UINT_MAX)) >> 32 75 * upper = mul_frac * (delta >> 32) 76 * product = lower + upper 77 */ 78 __asm__ ( 79 "mul %5 ; " 80 "mov %4,%%eax ; " 81 "mov %%edx,%4 ; " 82 "mul %5 ; " 83 "xor %5,%5 ; " 84 "add %4,%%eax ; " 85 "adc %5,%%edx ; " 86 : "=A" (product), "=r" (tmp1), "=r" (tmp2) 87 : "a" ((uint32_t)delta), "1" ((uint32_t)(delta >> 32)), 88 "2" (mul_frac) ); 89 } 90 #elif defined(__amd64__) 91 { 92 unsigned long tmp; 93 94 __asm__ ( 95 "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]" 96 : [lo]"=a" (product), [hi]"=d" (tmp) 97 : "0" (delta), [mul_frac]"rm"((uint64_t)mul_frac)); 98 } 99 #else 100 #error "pvclock: unsupported x86 architecture?" 101 #endif 102 return (product); 103 } 104 105 #ifdef _KERNEL 106 107 typedef struct pvclock_wall_clock *pvclock_get_wallclock_t(void *arg); 108 109 struct pvclock_wall_clock { 110 uint32_t version; 111 uint32_t sec; 112 uint32_t nsec; 113 }; 114 115 struct pvclock { 116 /* Public; initialized by the caller of 'pvclock_init()': */ 117 pvclock_get_wallclock_t *get_wallclock; 118 void *get_wallclock_arg; 119 struct pvclock_vcpu_time_info *timeinfos; 120 bool stable_flag_supported; 121 122 /* Private; initialized by the 'pvclock' API: */ 123 bool vdso_force_unstable; 124 struct timecounter tc; 125 struct cdev *cdev; 126 }; 127 128 /* 129 * NOTE: 'pvclock_get_timecount()' and 'pvclock_get_wallclock()' are purely 130 * transitional; they should be removed after 'dev/xen/timer/timer.c' has been 131 * migrated to the 'struct pvclock' API. 132 */ 133 void pvclock_resume(void); 134 uint64_t pvclock_tsc_freq(struct pvclock_vcpu_time_info *ti); 135 uint64_t pvclock_get_timecount(struct pvclock_vcpu_time_info *ti); 136 void pvclock_get_wallclock(struct pvclock_wall_clock *wc, 137 struct timespec *ts); 138 139 void pvclock_init(struct pvclock *pvc, device_t dev, 140 const char *tc_name, int tc_quality, u_int tc_flags); 141 void pvclock_gettime(struct pvclock *pvc, struct timespec *ts); 142 int pvclock_destroy(struct pvclock *pvc); 143 144 #endif /* _KERNEL */ 145 146 #endif 147