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Diffstat (limited to 'arch/s390/kernel/vtime.c')
-rw-r--r--arch/s390/kernel/vtime.c168
1 files changed, 35 insertions, 133 deletions
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index bb48977f546..39ebff50694 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -26,6 +26,7 @@
#include <asm/irq_regs.h>
#include <asm/cputime.h>
#include <asm/irq.h>
+#include "entry.h"
static DEFINE_PER_CPU(struct vtimer_queue, virt_cpu_timer);
@@ -123,153 +124,53 @@ void account_system_vtime(struct task_struct *tsk)
}
EXPORT_SYMBOL_GPL(account_system_vtime);
-void __kprobes vtime_start_cpu(__u64 int_clock, __u64 enter_timer)
+void __kprobes vtime_stop_cpu(void)
{
struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
struct vtimer_queue *vq = &__get_cpu_var(virt_cpu_timer);
- __u64 idle_time, expires;
+ unsigned long long idle_time;
+ unsigned long psw_mask;
- if (idle->idle_enter == 0ULL)
- return;
+ trace_hardirqs_on();
+ /* Don't trace preempt off for idle. */
+ stop_critical_timings();
- /* Account time spent with enabled wait psw loaded as idle time. */
- idle_time = int_clock - idle->idle_enter;
- account_idle_time(idle_time);
- S390_lowcore.steal_timer +=
- idle->idle_enter - S390_lowcore.last_update_clock;
- S390_lowcore.last_update_clock = int_clock;
-
- /* Account system time spent going idle. */
- S390_lowcore.system_timer += S390_lowcore.last_update_timer - vq->idle;
- S390_lowcore.last_update_timer = enter_timer;
-
- /* Restart vtime CPU timer */
- if (vq->do_spt) {
- /* Program old expire value but first save progress. */
- expires = vq->idle - enter_timer;
- expires += get_vtimer();
- set_vtimer(expires);
- } else {
- /* Don't account the CPU timer delta while the cpu was idle. */
- vq->elapsed -= vq->idle - enter_timer;
- }
+ /* Wait for external, I/O or machine check interrupt. */
+ psw_mask = psw_kernel_bits | PSW_MASK_WAIT | PSW_MASK_DAT |
+ PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
+ idle->nohz_delay = 0;
+ /* Call the assembler magic in entry.S */
+ psw_idle(idle, vq, psw_mask, !list_empty(&vq->list));
+
+ /* Reenable preemption tracer. */
+ start_critical_timings();
+
+ /* Account time spent with enabled wait psw loaded as idle time. */
idle->sequence++;
smp_wmb();
+ idle_time = idle->idle_exit - idle->idle_enter;
idle->idle_time += idle_time;
- idle->idle_enter = 0ULL;
+ idle->idle_enter = idle->idle_exit = 0ULL;
idle->idle_count++;
+ account_idle_time(idle_time);
smp_wmb();
idle->sequence++;
}
-void __kprobes vtime_stop_cpu(void)
-{
- struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
- struct vtimer_queue *vq = &__get_cpu_var(virt_cpu_timer);
- psw_t psw;
-
- /* Wait for external, I/O or machine check interrupt. */
- psw.mask = psw_kernel_bits | PSW_MASK_WAIT |
- PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
-
- idle->nohz_delay = 0;
-
- /* Check if the CPU timer needs to be reprogrammed. */
- if (vq->do_spt) {
- __u64 vmax = VTIMER_MAX_SLICE;
- /*
- * The inline assembly is equivalent to
- * vq->idle = get_cpu_timer();
- * set_cpu_timer(VTIMER_MAX_SLICE);
- * idle->idle_enter = get_clock();
- * __load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
- * PSW_MASK_DAT | PSW_MASK_IO |
- * PSW_MASK_EXT | PSW_MASK_MCHECK);
- * The difference is that the inline assembly makes sure that
- * the last three instruction are stpt, stck and lpsw in that
- * order. This is done to increase the precision.
- */
- asm volatile(
-#ifndef CONFIG_64BIT
- " basr 1,0\n"
- "0: ahi 1,1f-0b\n"
- " st 1,4(%2)\n"
-#else /* CONFIG_64BIT */
- " larl 1,1f\n"
- " stg 1,8(%2)\n"
-#endif /* CONFIG_64BIT */
- " stpt 0(%4)\n"
- " spt 0(%5)\n"
- " stck 0(%3)\n"
-#ifndef CONFIG_64BIT
- " lpsw 0(%2)\n"
-#else /* CONFIG_64BIT */
- " lpswe 0(%2)\n"
-#endif /* CONFIG_64BIT */
- "1:"
- : "=m" (idle->idle_enter), "=m" (vq->idle)
- : "a" (&psw), "a" (&idle->idle_enter),
- "a" (&vq->idle), "a" (&vmax), "m" (vmax), "m" (psw)
- : "memory", "cc", "1");
- } else {
- /*
- * The inline assembly is equivalent to
- * vq->idle = get_cpu_timer();
- * idle->idle_enter = get_clock();
- * __load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
- * PSW_MASK_DAT | PSW_MASK_IO |
- * PSW_MASK_EXT | PSW_MASK_MCHECK);
- * The difference is that the inline assembly makes sure that
- * the last three instruction are stpt, stck and lpsw in that
- * order. This is done to increase the precision.
- */
- asm volatile(
-#ifndef CONFIG_64BIT
- " basr 1,0\n"
- "0: ahi 1,1f-0b\n"
- " st 1,4(%2)\n"
-#else /* CONFIG_64BIT */
- " larl 1,1f\n"
- " stg 1,8(%2)\n"
-#endif /* CONFIG_64BIT */
- " stpt 0(%4)\n"
- " stck 0(%3)\n"
-#ifndef CONFIG_64BIT
- " lpsw 0(%2)\n"
-#else /* CONFIG_64BIT */
- " lpswe 0(%2)\n"
-#endif /* CONFIG_64BIT */
- "1:"
- : "=m" (idle->idle_enter), "=m" (vq->idle)
- : "a" (&psw), "a" (&idle->idle_enter),
- "a" (&vq->idle), "m" (psw)
- : "memory", "cc", "1");
- }
-}
-
cputime64_t s390_get_idle_time(int cpu)
{
- struct s390_idle_data *idle;
- unsigned long long now, idle_time, idle_enter;
+ struct s390_idle_data *idle = &per_cpu(s390_idle, cpu);
+ unsigned long long now, idle_enter, idle_exit;
unsigned int sequence;
- idle = &per_cpu(s390_idle, cpu);
-
- now = get_clock();
-repeat:
- sequence = idle->sequence;
- smp_rmb();
- if (sequence & 1)
- goto repeat;
- idle_time = 0;
- idle_enter = idle->idle_enter;
- if (idle_enter != 0ULL && idle_enter < now)
- idle_time = now - idle_enter;
- smp_rmb();
- if (idle->sequence != sequence)
- goto repeat;
- return idle_time;
+ do {
+ now = get_clock();
+ sequence = ACCESS_ONCE(idle->sequence);
+ idle_enter = ACCESS_ONCE(idle->idle_enter);
+ idle_exit = ACCESS_ONCE(idle->idle_exit);
+ } while ((sequence & 1) || (idle->sequence != sequence));
+ return idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
}
/*
@@ -319,7 +220,7 @@ static void do_callbacks(struct list_head *cb_list)
/*
* Handler for the virtual CPU timer.
*/
-static void do_cpu_timer_interrupt(unsigned int ext_int_code,
+static void do_cpu_timer_interrupt(struct ext_code ext_code,
unsigned int param32, unsigned long param64)
{
struct vtimer_queue *vq;
@@ -346,7 +247,6 @@ static void do_cpu_timer_interrupt(unsigned int ext_int_code,
}
spin_unlock(&vq->lock);
- vq->do_spt = list_empty(&cb_list);
do_callbacks(&cb_list);
/* next event is first in list */
@@ -355,8 +255,7 @@ static void do_cpu_timer_interrupt(unsigned int ext_int_code,
if (!list_empty(&vq->list)) {
event = list_first_entry(&vq->list, struct vtimer_list, entry);
next = event->expires;
- } else
- vq->do_spt = 0;
+ }
spin_unlock(&vq->lock);
/*
* To improve precision add the time spent by the
@@ -570,6 +469,9 @@ void init_cpu_vtimer(void)
/* enable cpu timer interrupts */
__ctl_set_bit(0,10);
+
+ /* set initial cpu timer */
+ set_vtimer(0x7fffffffffffffffULL);
}
static int __cpuinit s390_nohz_notify(struct notifier_block *self,
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-12 02:10:26 +0000