/*-
* Copyright (c) 2014, Bryan Venteicher <bryanv@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef X86_PVCLOCK
#define X86_PVCLOCK
#include <sys/types.h>
#ifdef _KERNEL
#include <sys/timetc.h>
#endif /* _KERNEL */
#define PVCLOCK_CDEVNAME "pvclock"
struct pvclock_vcpu_time_info {
uint32_t version;
uint32_t pad0;
uint64_t tsc_timestamp;
uint64_t system_time;
uint32_t tsc_to_system_mul;
int8_t tsc_shift;
uint8_t flags;
uint8_t pad[2];
};
#define PVCLOCK_FLAG_TSC_STABLE 0x01
#define PVCLOCK_FLAG_GUEST_PASUED 0x02
/*
* Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
* yielding a 64-bit result.
*/
static inline uint64_t
pvclock_scale_delta(uint64_t delta, uint32_t mul_frac, int shift)
{
uint64_t product;
if (shift < 0)
delta >>= -shift;
else
delta <<= shift;
#if defined(__i386__)
{
uint32_t tmp1, tmp2;
/**
* For i386, the formula looks like:
*
* lower = (mul_frac * (delta & UINT_MAX)) >> 32
* upper = mul_frac * (delta >> 32)
* product = lower + upper
*/
__asm__ (
"mul %5 ; "
"mov %4,%%eax ; "
"mov %%edx,%4 ; "
"mul %5 ; "
"xor %5,%5 ; "
"add %4,%%eax ; "
"adc %5,%%edx ; "
: "=A" (product), "=r" (tmp1), "=r" (tmp2)
: "a" ((uint32_t)delta), "1" ((uint32_t)(delta >> 32)),
"2" (mul_frac) );
}
#elif defined(__amd64__)
{
unsigned long tmp;
__asm__ (
"mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
: [lo]"=a" (product), [hi]"=d" (tmp)
: "0" (delta), [mul_frac]"rm"((uint64_t)mul_frac));
}
#else
#error "pvclock: unsupported x86 architecture?"
#endif
return (product);
}
#ifdef _KERNEL
typedef struct pvclock_wall_clock *pvclock_get_wallclock_t(void *arg);
struct pvclock_wall_clock {
uint32_t version;
uint32_t sec;
uint32_t nsec;
};
struct pvclock {
/* Public; initialized by the caller of 'pvclock_init()': */
pvclock_get_wallclock_t *get_wallclock;
void *get_wallclock_arg;
struct pvclock_vcpu_time_info *timeinfos;
bool stable_flag_supported;
/* Private; initialized by the 'pvclock' API: */
bool vdso_force_unstable;
bool vdso_enable_without_rdtscp;
struct timecounter tc;
struct cdev *cdev;
};
/*
* NOTE: 'pvclock_get_timecount()' and 'pvclock_get_wallclock()' are purely
* transitional; they should be removed after 'dev/xen/timer/timer.c' has been
* migrated to the 'struct pvclock' API.
*/
void pvclock_resume(void);
uint64_t pvclock_tsc_freq(struct pvclock_vcpu_time_info *ti);
uint64_t pvclock_get_timecount(struct pvclock_vcpu_time_info *ti);
void pvclock_get_wallclock(struct pvclock_wall_clock *wc,
struct timespec *ts);
void pvclock_init(struct pvclock *pvc, device_t dev,
const char *tc_name, int tc_quality, u_int tc_flags);
void pvclock_gettime(struct pvclock *pvc, struct timespec *ts);
int pvclock_destroy(struct pvclock *pvc);
#endif /* _KERNEL */
#endif
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