sxitimer(4) is the fourth and final armv7 clock interrupt driver that
needs to switch to clockintr.
- Remove everything related to STATTIMER. We can multiplex TICKTIMER
to handle all clock interrupt events.
- Remove sxitimer-specific clock interrupt scheduling bits and randomized
statclock bits.
- Wire up sxitimer_intrclock.
This is not compile-tested. When we get it to compile, it ought to
survive a release build if that's practical for machines sporting
sxitimer(4).
What sort of machine has one of these?
Index: sys/arch/arm/include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/arm/include/cpu.h,v
retrieving revision 1.61
diff -u -p -r1.61 cpu.h
--- sys/arch/arm/include/cpu.h 6 Jul 2021 09:34:06 -0000 1.61
+++ sys/arch/arm/include/cpu.h 9 Dec 2022 17:27:13 -0000
@@ -149,6 +149,7 @@ void arm32_vector_init(vaddr_t, int);
* Per-CPU information. For now we assume one CPU.
*/
+#include <sys/clockintr.h>
#include <sys/device.h>
#include <sys/sched.h>
#include <sys/srp.h>
@@ -198,7 +199,7 @@ struct cpu_info {
#ifdef GPROF
struct gmonparam *ci_gmon;
#endif
-
+ struct clockintr_queue ci_queue;
char ci_panicbuf[512];
};
Index: sys/arch/arm/include/_types.h
===================================================================
RCS file: /cvs/src/sys/arch/arm/include/_types.h,v
retrieving revision 1.19
diff -u -p -r1.19 _types.h
--- sys/arch/arm/include/_types.h 5 Mar 2018 01:15:25 -0000 1.19
+++ sys/arch/arm/include/_types.h 9 Dec 2022 17:27:13 -0000
@@ -35,6 +35,8 @@
#ifndef _ARM__TYPES_H_
#define _ARM__TYPES_H_
+#define __HAVE_CLOCKINTR
+
#if defined(_KERNEL)
typedef struct label_t {
long val[11];
Index: sys/arch/armv7/sunxi/sxitimer.c
===================================================================
RCS file: /cvs/src/sys/arch/armv7/sunxi/sxitimer.c,v
retrieving revision 1.18
diff -u -p -r1.18 sxitimer.c
--- sys/arch/armv7/sunxi/sxitimer.c 24 Oct 2021 17:52:28 -0000 1.18
+++ sys/arch/armv7/sunxi/sxitimer.c 9 Dec 2022 17:27:14 -0000
@@ -20,7 +20,9 @@
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
+#include <sys/clockintr.h>
#include <sys/device.h>
+#include <sys/stdint.h>
#include <sys/timetc.h>
#include <machine/bus.h>
@@ -94,6 +96,17 @@ static struct timecounter sxitimer_timec
.tc_user = 0,
};
+uint64_t sxitimer_nsec_cycle_ratio;
+uint64_t sxitimer_nsec_max;
+
+void sxitimer_rearm(void *, uint64_t);
+void sxitimer_trigger(void *);
+
+const struct intrclock sxitimer_intrclock = {
+ .ic_rearm = sxitimer_rearm,
+ .ic_trigger = sxitimer_trigger
+};
+
bus_space_tag_t sxitimer_iot;
bus_space_handle_t sxitimer_ioh;
@@ -111,11 +124,6 @@ uint32_t sxitimer_irq[] = {
0
};
-uint32_t sxitimer_stat_tpi, sxitimer_tick_tpi;
-uint32_t sxitimer_statvar, sxitimer_statmin;
-uint32_t sxitimer_tick_nextevt, sxitimer_stat_nextevt;
-uint32_t sxitimer_ticks_err_cnt, sxitimer_ticks_err_sum;
-
struct sxitimer_softc {
struct device sc_dev;
};
@@ -147,7 +155,6 @@ void
sxitimer_attach(struct device *parent, struct device *self, void *aux)
{
struct fdt_attach_args *faa = aux;
- uint32_t freq, ival, now;
KASSERT(faa->fa_nreg > 0);
@@ -163,61 +170,32 @@ sxitimer_attach(struct device *parent, s
& CNT64_CLR_EN)
continue;
- /* timers are down-counters, from interval to 0 */
- now = 0xffffffff; /* known big value */
- freq = sxitimer_freq[TICKTIMER];
-
/* stop timer, and set clk src */
bus_space_write_4(sxitimer_iot, sxitimer_ioh,
TIMER_CTRL(TICKTIMER), TIMER_OSC24M);
- ival = sxitimer_tick_tpi = freq / hz;
- sxitimer_tick_nextevt = now - ival;
-
- sxitimer_ticks_err_cnt = freq % hz;
- sxitimer_ticks_err_sum = 0;
-
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_INTV(TICKTIMER), ival);
-
- /* timers are down-counters, from interval to 0 */
- now = 0xffffffff; /* known big value */
- freq = sxitimer_freq[STATTIMER];
-
- /* stop timer, and set clk src */
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(STATTIMER), TIMER_OSC24M);
+ sxitimer_nsec_cycle_ratio =
+ sxitimer_freq[TICKTIMER] * (1ULL << 32) / 1000000000;
+ sxitimer_nsec_max = UINT64_MAX / sxitimer_nsec_cycle_ratio;
/* 100/1000 or 128/1024 ? */
stathz = 128;
profhz = 1024;
- sxitimer_setstatclockrate(stathz);
-
- ival = sxitimer_stat_tpi = freq / stathz;
- sxitimer_stat_nextevt = now - ival;
-
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_INTV(STATTIMER), ival);
-
- /* timers are down-counters, from interval to 0 */
- now = 0xffffffff; /* known big value */
- freq = sxitimer_freq[CNTRTIMER];
+ clockintr_init(CL_RNDSTAT);
/* stop timer, and set clk src */
bus_space_write_4(sxitimer_iot, sxitimer_ioh,
TIMER_CTRL(CNTRTIMER), TIMER_OSC24M);
+ bus_space_write_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_INTV(CNTRTIMER), UINT32_MAX);
- ival = now;
-
- sxitimer_timecounter.tc_frequency = freq;
+ sxitimer_timecounter.tc_frequency = sxitimer_freq[CNTRTIMER];
tc_init(&sxitimer_timecounter);
+
arm_clock_register(sxitimer_cpu_initclocks, sxitimer_delay,
sxitimer_setstatclockrate, NULL);
- printf(": %d kHz", freq / 1000);
-
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_INTV(CNTRTIMER), ival);
+ printf(": %d kHz", sxitimer_freq[CNTRTIMER] / 1000);
printf("\n");
}
@@ -233,20 +211,18 @@ sxitimer_cpu_initclocks(void)
{
uint32_t isr, ier, ctrl;
- /* establish interrupts */
+ /* establish interrupt */
arm_intr_establish(sxitimer_irq[TICKTIMER], IPL_CLOCK,
sxitimer_tickintr, NULL, "tick");
- arm_intr_establish(sxitimer_irq[STATTIMER], IPL_STATCLOCK,
- sxitimer_statintr, NULL, "stattick");
/* clear timer interrupt pending bits */
isr = bus_space_read_4(sxitimer_iot, sxitimer_ioh, TIMER_ISR);
- isr |= TIMER_IRQ(STATTIMER) | TIMER_IRQ(TICKTIMER);
+ isr |= TIMER_IRQ(TICKTIMER);
bus_space_write_4(sxitimer_iot, sxitimer_ioh, TIMER_ISR, isr);
- /* enable timer IRQs */
+ /* enable timer IRQ */
ier = bus_space_read_4(sxitimer_iot, sxitimer_ioh, TIMER_IER);
- ier |= TIMER_IRQ(STATTIMER) | TIMER_IRQ(TICKTIMER);
+ ier |= TIMER_IRQ(TICKTIMER);
bus_space_write_4(sxitimer_iot, sxitimer_ioh, TIMER_IER, ier);
/* enable timers */
@@ -256,153 +232,21 @@ sxitimer_cpu_initclocks(void)
TIMER_CTRL(CNTRTIMER),
ctrl | TIMER_ENABLE | TIMER_RELOAD | TIMER_CONTINOUS);
- ctrl = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(STATTIMER));
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(STATTIMER),
- ctrl | TIMER_ENABLE | TIMER_RELOAD | TIMER_SINGLESHOT);
-
- ctrl = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(TICKTIMER));
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(TICKTIMER),
- ctrl | TIMER_ENABLE | TIMER_RELOAD | TIMER_SINGLESHOT);
+ /* start clock interrupt cycle */
+ clockintr_cpu_init(&sxitimer_intrclock);
+ clockintr_trigger();
}
-/*
- * See comment in arm/xscale/i80321_clock.c
- *
- * Counter is count up, but with autoreload timers it is not possible
- * to detect how many interrupts passed while interrupts were blocked.
- * Also it is not possible to atomically add to the register.
- *
- * To work around this two timers are used, one is used as a reference
- * clock without reload, however we just disable the interrupt it
- * could generate.
- *
- * Internally this keeps track of when the next timer should fire
- * and based on that time and the current value of the reference
- * clock a number is written into the timer count register to schedule
- * the next event.
- */
-/* XXX update above comment */
int
sxitimer_tickintr(void *frame)
{
- uint32_t now, nextevent;
- uint32_t val;
- int rc = 0;
-
splassert(IPL_CLOCK);
/* clear timer pending interrupt bit */
bus_space_write_4(sxitimer_iot, sxitimer_ioh,
TIMER_ISR, TIMER_IRQ(TICKTIMER));
- now = sxitimer_readcnt32();
-
- while ((int32_t)(now - sxitimer_tick_nextevt) < 0) {
- sxitimer_tick_nextevt -= sxitimer_tick_tpi;
- sxitimer_ticks_err_sum += sxitimer_ticks_err_cnt;
-
- while (sxitimer_ticks_err_sum > hz) {
- sxitimer_tick_nextevt += 1;
- sxitimer_ticks_err_sum -= hz;
- }
-
- rc = 1;
- hardclock(frame);
- }
- nextevent = now - sxitimer_tick_nextevt;
- if (nextevent < 10 /* XXX */)
- nextevent = 10;
-
- if (nextevent > sxitimer_tick_tpi) {
- /*
- * If interrupts are blocked too long, like during
- * the root prompt or ddb, the timer can roll over,
- * this will allow the system to continue to run
- * even if time is lost.
- */
- nextevent = sxitimer_tick_tpi;
- sxitimer_tick_nextevt = now;
- }
-
- val = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(TICKTIMER));
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(TICKTIMER), val & ~TIMER_ENABLE);
-
- sxitimer_sync();
-
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_INTV(TICKTIMER), nextevent);
-
- val = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(TICKTIMER));
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(TICKTIMER),
- val | TIMER_ENABLE | TIMER_RELOAD | TIMER_SINGLESHOT);
-
- return rc;
-}
-
-int
-sxitimer_statintr(void *frame)
-{
- uint32_t now, nextevent, r;
- uint32_t val;
- int rc = 0;
-
- splassert(IPL_STATCLOCK);
-
- /* clear timer pending interrupt bit */
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_ISR, TIMER_IRQ(STATTIMER));
-
- now = sxitimer_readcnt32();
- while ((int32_t)(now - sxitimer_stat_nextevt) < 0) {
- do {
- r = random() & (sxitimer_statvar -1);
- } while (r == 0); /* random == 0 not allowed */
- sxitimer_stat_nextevt -= sxitimer_statmin + r;
- rc = 1;
- statclock(frame);
- }
-
- nextevent = now - sxitimer_stat_nextevt;
-
- if (nextevent < 10 /* XXX */)
- nextevent = 10;
-
- if (nextevent > sxitimer_stat_tpi) {
- /*
- * If interrupts are blocked too long, like during
- * the root prompt or ddb, the timer can roll over,
- * this will allow the system to continue to run
- * even if time is lost.
- */
- nextevent = sxitimer_stat_tpi;
- sxitimer_stat_nextevt = now;
- }
-
- val = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(STATTIMER));
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(STATTIMER), val & ~TIMER_ENABLE);
-
- sxitimer_sync();
-
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_INTV(STATTIMER), nextevent);
-
- val = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(STATTIMER));
- bus_space_write_4(sxitimer_iot, sxitimer_ioh,
- TIMER_CTRL(STATTIMER),
- val | TIMER_ENABLE | TIMER_RELOAD | TIMER_SINGLESHOT);
-
- return rc;
+ return clockintr_dispatch(frame);
}
uint64_t
@@ -457,29 +301,62 @@ sxitimer_delay(u_int usecs)
void
sxitimer_setstatclockrate(int newhz)
{
- int minint, statint, s;
-
- s = splstatclock();
-
- statint = sxitimer_freq[STATTIMER] / newhz;
- /* calculate largest 2^n which is smaller than just over half statint */
- sxitimer_statvar = 0x40000000; /* really big power of two */
- minint = statint / 2 + 100;
- while (sxitimer_statvar > minint)
- sxitimer_statvar >>= 1;
-
- sxitimer_statmin = statint - (sxitimer_statvar >> 1);
-
- splx(s);
-
- /*
- * XXX this allows the next stat timer to occur then it switches
- * to the new frequency. Rather than switching instantly.
- */
+ clockintr_setstatclockrate(newhz);
}
u_int
sxitimer_get_timecount(struct timecounter *tc)
{
return (u_int)UINT_MAX - sxitimer_readcnt32();
+}
+
+void
+sxitimer_rearm(void *unused, uint64_t nsecs)
+{
+ uint32_t ctrl, cycles;
+
+ if (nsecs > sxitimer_nsec_max)
+ nsecs = sxitimer_nsec_max;
+ cycles = (nsecs * sxitimer_nsec_cycle_ratio) >> 32;
+ if (cycles < 10)
+ cycles = 10; /* XXX Why do we need to round up to 10? */
+
+ ctrl = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_CTRL(TICKTIMER));
+ bus_space_write_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_CTRL(TICKTIMER), ctrl & ~TIMER_ENABLE);
+
+ sxitimer_sync();
+
+ bus_space_write_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_INTV(TICKTIMER), cycles);
+
+ ctrl = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_CTRL(TICKTIMER));
+ bus_space_write_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_CTRL(TICKTIMER),
+ ctrl | TIMER_ENABLE | TIMER_RELOAD | TIMER_SINGLESHOT);
+}
+
+void
+sxitimer_trigger(void *unused)
+{
+ uint32_t ctrl;
+
+ ctrl = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_CTRL(TICKTIMER));
+ bus_space_write_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_CTRL(TICKTIMER), ctrl & ~TIMER_ENABLE);
+
+ sxitimer_sync();
+
+ /* XXX Why do we need to round up to 10? */
+ bus_space_write_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_INTV(TICKTIMER), 10);
+
+ ctrl = bus_space_read_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_CTRL(TICKTIMER));
+ bus_space_write_4(sxitimer_iot, sxitimer_ioh,
+ TIMER_CTRL(TICKTIMER),
+ ctrl | TIMER_ENABLE | TIMER_RELOAD | TIMER_SINGLESHOT);
}
