Release 4.10 arch/x86/kernel/pvclock.c
/* paravirtual clock -- common code used by kvm/xen
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/kernel.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
#include <linux/sched.h>
#include <linux/gfp.h>
#include <linux/bootmem.h>
#include <asm/fixmap.h>
#include <asm/pvclock.h>
static u8 valid_flags __read_mostly = 0;
void pvclock_set_flags(u8 flags)
{
valid_flags = flags;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| glauber costa | glauber costa | 12 | 100.00% | 1 | 100.00% |
| Total | 12 | 100.00% | 1 | 100.00% |
unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src)
{
u64 pv_tsc_khz = 1000000ULL << 32;
do_div(pv_tsc_khz, src->tsc_to_system_mul);
if (src->tsc_shift < 0)
pv_tsc_khz <<= -src->tsc_shift;
else
pv_tsc_khz >>= src->tsc_shift;
return pv_tsc_khz;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| glauber de oliveira costa | glauber de oliveira costa | 47 | 90.38% | 1 | 50.00% |
| harvey harrison | harvey harrison | 5 | 9.62% | 1 | 50.00% |
| Total | 52 | 100.00% | 2 | 100.00% |
void pvclock_touch_watchdogs(void)
{
touch_softlockup_watchdog_sync();
clocksource_touch_watchdog();
rcu_cpu_stall_reset();
reset_hung_task_detector();
}
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| Person | Tokens | Prop | Commits | CommitProp |
| marcelo tosatti | marcelo tosatti | 19 | 100.00% | 2 | 100.00% |
| Total | 19 | 100.00% | 2 | 100.00% |
static atomic64_t last_value = ATOMIC64_INIT(0);
void pvclock_resume(void)
{
atomic64_set(&last_value, 0);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| jeremy fitzhardinge | jeremy fitzhardinge | 15 | 100.00% | 1 | 100.00% |
| Total | 15 | 100.00% | 1 | 100.00% |
u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src)
{
unsigned version;
u8 flags;
do {
version = pvclock_read_begin(src);
flags = src->flags;
} while (pvclock_read_retry(src, version));
return flags & valid_flags;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| marcelo tosatti | marcelo tosatti | 35 | 74.47% | 1 | 33.33% |
| paolo bonzini | paolo bonzini | 7 | 14.89% | 1 | 33.33% |
| minfei huang | minfei huang | 5 | 10.64% | 1 | 33.33% |
| Total | 47 | 100.00% | 3 | 100.00% |
u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
{
unsigned version;
u64 ret;
u64 last;
u8 flags;
do {
version = pvclock_read_begin(src);
ret = __pvclock_read_cycles(src, rdtsc_ordered());
flags = src->flags;
} while (pvclock_read_retry(src, version));
if (unlikely((flags & PVCLOCK_GUEST_STOPPED) != 0)) {
src->flags &= ~PVCLOCK_GUEST_STOPPED;
pvclock_touch_watchdogs();
}
if ((valid_flags & PVCLOCK_TSC_STABLE_BIT) &&
(flags & PVCLOCK_TSC_STABLE_BIT))
return ret;
/*
* Assumption here is that last_value, a global accumulator, always goes
* forward. If we are less than that, we should not be much smaller.
* We assume there is an error marging we're inside, and then the correction
* does not sacrifice accuracy.
*
* For reads: global may have changed between test and return,
* but this means someone else updated poked the clock at a later time.
* We just need to make sure we are not seeing a backwards event.
*
* For updates: last_value = ret is not enough, since two vcpus could be
* updating at the same time, and one of them could be slightly behind,
* making the assumption that last_value always go forward fail to hold.
*/
last = atomic64_read(&last_value);
do {
if (ret < last)
return last;
last = atomic64_cmpxchg(&last_value, last, ret);
} while (unlikely(last != ret));
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| glauber costa | glauber costa | 63 | 43.15% | 2 | 20.00% |
| gerd hoffmann | gerd hoffmann | 31 | 21.23% | 1 | 10.00% |
| marcelo tosatti | marcelo tosatti | 30 | 20.55% | 3 | 30.00% |
| paolo bonzini | paolo bonzini | 19 | 13.01% | 2 | 20.00% |
| thomas gleixner | thomas gleixner | 2 | 1.37% | 1 | 10.00% |
| minfei huang | minfei huang | 1 | 0.68% | 1 | 10.00% |
| Total | 146 | 100.00% | 10 | 100.00% |
void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
struct pvclock_vcpu_time_info *vcpu_time,
struct timespec *ts)
{
u32 version;
u64 delta;
struct timespec now;
/* get wallclock at system boot */
do {
version = wall_clock->version;
rmb(); /* fetch version before time */
now.tv_sec = wall_clock->sec;
now.tv_nsec = wall_clock->nsec;
rmb(); /* fetch time before checking version */
} while ((wall_clock->version & 1) || (version != wall_clock->version));
delta = pvclock_clocksource_read(vcpu_time); /* time since system boot */
delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec;
now.tv_nsec = do_div(delta, NSEC_PER_SEC);
now.tv_sec = delta;
set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| gerd hoffmann | gerd hoffmann | 136 | 100.00% | 1 | 100.00% |
| Total | 136 | 100.00% | 1 | 100.00% |
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| gerd hoffmann | gerd hoffmann | 177 | 37.82% | 1 | 5.56% |
| marcelo tosatti | marcelo tosatti | 99 | 21.15% | 6 | 33.33% |
| glauber costa | glauber costa | 91 | 19.44% | 3 | 16.67% |
| glauber de oliveira costa | glauber de oliveira costa | 47 | 10.04% | 1 | 5.56% |
| paolo bonzini | paolo bonzini | 26 | 5.56% | 2 | 11.11% |
| jeremy fitzhardinge | jeremy fitzhardinge | 15 | 3.21% | 1 | 5.56% |
| minfei huang | minfei huang | 6 | 1.28% | 2 | 11.11% |
| harvey harrison | harvey harrison | 5 | 1.07% | 1 | 5.56% |
| thomas gleixner | thomas gleixner | 2 | 0.43% | 1 | 5.56% |
| Total | 468 | 100.00% | 18 | 100.00% |
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