- Wrap exchanging td_intr_frame and calling the event timer callback in

a critical section as apparently required by both. I don't think either
  belongs in the event timer front-ends but the callback should handle
  this as necessary instead just like for example intr_event_handle()
  does but this is how the other architectures currently handle it, either
  explicitly or implicitly.
- Further rename and reword references to hardclock as this front-end no
  longer has a notion of actually calling it.
This commit is contained in:
Marius Strobl 2010-10-19 19:44:05 +00:00
parent 96a911f614
commit 10c2bb0a10
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=214071
3 changed files with 19 additions and 17 deletions

View file

@ -29,7 +29,7 @@
#ifndef _MACHINE_TICK_H_
#define _MACHINE_TICK_H_
extern u_int hardclock_use_stick;
extern u_int tick_et_use_stick;
void tick_clear(u_int cpu_impl);
void tick_stop(u_int cpu_impl);

View file

@ -318,7 +318,7 @@ ap_start(phandle_t node, u_int mid, u_int cpu_impl)
if (OF_getprop(node, "clock-frequency", &clock, sizeof(clock)) <= 0)
panic("%s: couldn't determine CPU frequency", __func__);
if (clock != PCPU_GET(clock))
hardclock_use_stick = 1;
tick_et_use_stick = 1;
csa = &cpu_start_args;
csa->csa_state = 0;

View file

@ -74,9 +74,9 @@ static int adjust_ticks = 0;
SYSCTL_INT(_machdep_tick, OID_AUTO, adjust_ticks, CTLFLAG_RD, &adjust_ticks,
0, "total number of tick interrupts with adjustment");
u_int hardclock_use_stick = 0;
SYSCTL_INT(_machdep_tick, OID_AUTO, hardclock_use_stick, CTLFLAG_RD,
&hardclock_use_stick, 0, "hardclock uses STICK instead of TICK timer");
u_int tick_et_use_stick = 0;
SYSCTL_INT(_machdep_tick, OID_AUTO, tick_et_use_stick, CTLFLAG_RD,
&tick_et_use_stick, 0, "tick event timer uses STICK instead of TICK");
static struct timecounter stick_tc;
static struct timecounter tick_tc;
@ -96,9 +96,9 @@ static int tick_et_start(struct eventtimer *et,
static int tick_et_stop(struct eventtimer *et);
static void tick_intr(struct trapframe *tf);
static void tick_intr_bbwar(struct trapframe *tf);
static inline void tick_hardclock_periodic(struct trapframe *tf, u_long tick,
u_long tick_increment, u_long adj);
static inline void tick_process(struct trapframe *tf);
static inline void tick_process_periodic(struct trapframe *tf, u_long tick,
u_long tick_increment, u_long adj);
static void stick_intr(struct trapframe *tf);
static uint64_t
@ -127,7 +127,7 @@ cpu_initclocks(void)
* Given that the STICK timers typically are driven at rather low
* frequencies they shouldn't be used except when really necessary.
*/
if (hardclock_use_stick != 0) {
if (tick_et_use_stick != 0) {
intr_setup(PIL_TICK, stick_intr, -1, NULL, NULL);
/*
* We don't provide a CPU ticker as long as the frequency
@ -180,11 +180,11 @@ cpu_initclocks(void)
#endif
tc_init(&stick_tc);
}
tick_et.et_name = hardclock_use_stick ? "stick" : "tick";
tick_et.et_name = tick_et_use_stick ? "stick" : "tick";
tick_et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT |
ET_FLAGS_PERCPU;
tick_et.et_quality = 1000;
tick_et.et_frequency = hardclock_use_stick ? sclock : clock;
tick_et.et_frequency = tick_et_use_stick ? sclock : clock;
tick_et.et_min_period.sec = 0;
tick_et.et_min_period.frac = 0x00010000LLU << 32; /* To be safe. */
tick_et.et_max_period.sec = 3600 * 24; /* No practical limit. */
@ -203,6 +203,7 @@ tick_process(struct trapframe *tf)
struct trapframe *oldframe;
struct thread *td;
critical_enter();
if (tick_et.et_active) {
td = curthread;
oldframe = td->td_intr_frame;
@ -210,13 +211,14 @@ tick_process(struct trapframe *tf)
tick_et.et_event_cb(&tick_et, tick_et.et_arg);
td->td_intr_frame = oldframe;
}
critical_exit();
}
/*
* NB: the sequence of reading the (S)TICK register, calculating the value
* of the next tick and writing it to the (S)TICK_COMPARE register must not
* be interrupted, not even by an IPI, otherwise a value that is in the past
* could be written in the worst case, causing hardclock to stop.
* could be written in the worst case, causing the periodic timer to stop.
*/
static void
@ -232,7 +234,7 @@ tick_intr(struct trapframe *tf)
tick = rd(tick);
wr(tick_cmpr, tick + tick_increment - adj, 0);
intr_restore(s);
tick_hardclock_periodic(tf, tick, tick_increment, adj);
tick_process_periodic(tf, tick, tick_increment, adj);
} else {
intr_restore(s);
tick_process(tf);
@ -252,7 +254,7 @@ tick_intr_bbwar(struct trapframe *tf)
tick = rd(tick);
wrtickcmpr(tick + tick_increment - adj, 0);
intr_restore(s);
tick_hardclock_periodic(tf, tick, tick_increment, adj);
tick_process_periodic(tf, tick, tick_increment, adj);
} else {
intr_restore(s);
tick_process(tf);
@ -272,7 +274,7 @@ stick_intr(struct trapframe *tf)
stick = rdstick();
wrstickcmpr(stick + tick_increment - adj, 0);
intr_restore(s);
tick_hardclock_periodic(tf, stick, tick_increment, adj);
tick_process_periodic(tf, stick, tick_increment, adj);
} else {
intr_restore(s);
tick_process(tf);
@ -280,7 +282,7 @@ stick_intr(struct trapframe *tf)
}
static inline void
tick_hardclock_periodic(struct trapframe *tf, u_long tick,
tick_process_periodic(struct trapframe *tf, u_long tick,
u_long tick_increment, u_long adj)
{
u_long ref;
@ -385,7 +387,7 @@ tick_et_start(struct eventtimer *et, struct bintime *first,
* out one tick to make sure that it is not missed.
*/
s = intr_disable();
if (hardclock_use_stick != 0)
if (tick_et_use_stick != 0)
base = rdstick();
else
base = rd(tick);
@ -394,7 +396,7 @@ tick_et_start(struct eventtimer *et, struct bintime *first,
base = roundup(base, div);
}
PCPU_SET(tickref, base);
if (hardclock_use_stick != 0)
if (tick_et_use_stick != 0)
wrstickcmpr(base + fdiv, 0);
else
wrtickcmpr(base + fdiv, 0);