e7a3481c02
If the guest domain has been suspend/resumed or migrated, then the system clock backing the pvclock clocksource may revert to a smaller value (ie, can be non-monotonic across the migration/save-restore). Make sure we zero last_value in that case so that the domain continues to see clock updates. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
#ifndef _ASM_X86_PVCLOCK_H
|
|
#define _ASM_X86_PVCLOCK_H
|
|
|
|
#include <linux/clocksource.h>
|
|
#include <asm/pvclock-abi.h>
|
|
|
|
/* some helper functions for xen and kvm pv clock sources */
|
|
cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
|
|
void pvclock_set_flags(u8 flags);
|
|
unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
|
|
void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
|
|
struct pvclock_vcpu_time_info *vcpu,
|
|
struct timespec *ts);
|
|
void pvclock_resume(void);
|
|
|
|
/*
|
|
* Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
|
|
* yielding a 64-bit result.
|
|
*/
|
|
static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
|
|
{
|
|
u64 product;
|
|
#ifdef __i386__
|
|
u32 tmp1, tmp2;
|
|
#endif
|
|
|
|
if (shift < 0)
|
|
delta >>= -shift;
|
|
else
|
|
delta <<= shift;
|
|
|
|
#ifdef __i386__
|
|
__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" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
|
|
#elif defined(__x86_64__)
|
|
__asm__ (
|
|
"mul %%rdx ; shrd $32,%%rdx,%%rax"
|
|
: "=a" (product) : "0" (delta), "d" ((u64)mul_frac) );
|
|
#else
|
|
#error implement me!
|
|
#endif
|
|
|
|
return product;
|
|
}
|
|
|
|
#endif /* _ASM_X86_PVCLOCK_H */
|