-/* $OpenBSD: clock.c,v 1.32 2021/02/23 04:44:30 cheloha Exp $ */
+/* $OpenBSD: clock.c,v 1.33 2022/12/06 00:40:09 cheloha Exp $ */
/*
* Copyright (c) 1998-2003 Michael Shalayeff
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
+#include <sys/clockintr.h>
+#include <sys/stdint.h>
#include <sys/timetc.h>
#include <dev/clock_subr.h>
#include <machine/cpufunc.h>
#include <machine/autoconf.h>
-u_long cpu_hzticks;
+uint64_t itmr_nsec_cycle_ratio;
+uint64_t itmr_nsec_max;
-int cpu_hardclock(void *);
u_int itmr_get_timecount(struct timecounter *);
+int itmr_intr(void *);
+void itmr_rearm(void *, uint64_t);
+void itmr_trigger(void);
+void itmr_trigger_masked(void);
+void itmr_trigger_wrapper(void *);
struct timecounter itmr_timecounter = {
.tc_get_timecount = itmr_get_timecount,
.tc_user = 0,
};
+const struct intrclock itmr_intrclock = {
+ .ic_rearm = itmr_rearm,
+ .ic_trigger = itmr_trigger_wrapper
+};
+
extern todr_chip_handle_t todr_handle;
struct todr_chip_handle pdc_todr;
void
cpu_initclocks(void)
{
- struct cpu_info *ci = curcpu();
- u_long __itmr;
+ uint64_t itmr_freq = PAGE0->mem_10msec * 100;
pdc_todr.todr_gettime = pdc_gettime;
pdc_todr.todr_settime = pdc_settime;
todr_handle = &pdc_todr;
- cpu_hzticks = (PAGE0->mem_10msec * 100) / hz;
-
- itmr_timecounter.tc_frequency = PAGE0->mem_10msec * 100;
+ itmr_timecounter.tc_frequency = itmr_freq;
tc_init(&itmr_timecounter);
- mfctl(CR_ITMR, __itmr);
- ci->ci_itmr = __itmr;
- __itmr += cpu_hzticks;
- mtctl(__itmr, CR_ITMR);
-}
+ stathz = hz;
+ profhz = stathz * 10;
+ clockintr_init(CL_RNDSTAT);
-int
-cpu_hardclock(void *v)
-{
- struct cpu_info *ci = curcpu();
- u_long __itmr, delta, eta;
- int wrap;
- register_t eiem;
+ itmr_nsec_cycle_ratio = itmr_freq * (1ULL << 32) / 1000000000;
+ itmr_nsec_max = UINT64_MAX / itmr_nsec_cycle_ratio;
- /*
- * Invoke hardclock as many times as there has been cpu_hzticks
- * ticks since the last interrupt.
- */
- for (;;) {
- mfctl(CR_ITMR, __itmr);
- delta = __itmr - ci->ci_itmr;
- if (delta >= cpu_hzticks) {
- hardclock(v);
- ci->ci_itmr += cpu_hzticks;
- } else
- break;
- }
+ cpu_startclock();
+}
- /*
- * Program the next clock interrupt, making sure it will
- * indeed happen in the future. This is done with interrupts
- * disabled to avoid a possible race.
- */
- eta = ci->ci_itmr + cpu_hzticks;
- wrap = eta < ci->ci_itmr; /* watch out for a wraparound */
- __asm volatile("mfctl %%cr15, %0": "=r" (eiem));
- __asm volatile("mtctl %r0, %cr15");
- mtctl(eta, CR_ITMR);
- mfctl(CR_ITMR, __itmr);
- /*
- * If we were close enough to the next tick interrupt
- * value, by the time we have programmed itmr, it might
- * have passed the value, which would cause a complete
- * cycle until the next interrupt occurs. On slow
- * models, this would be a disaster (a complete cycle
- * taking over two minutes on a 715/33).
- *
- * We expect that it will only be necessary to postpone
- * the interrupt once. Thus, there are two cases:
- * - We are expecting a wraparound: eta < cpu_itmr.
- * itmr is in tracks if either >= cpu_itmr or < eta.
- * - We are not wrapping: eta > cpu_itmr.
- * itmr is in tracks if >= cpu_itmr and < eta (we need
- * to keep the >= cpu_itmr test because itmr might wrap
- * before eta does).
- */
- if ((wrap && !(eta > __itmr || __itmr >= ci->ci_itmr)) ||
- (!wrap && !(eta > __itmr && __itmr >= ci->ci_itmr))) {
- eta += cpu_hzticks;
- mtctl(eta, CR_ITMR);
- }
- __asm volatile("mtctl %0, %%cr15":: "r" (eiem));
+void
+cpu_startclock(void)
+{
+ clockintr_cpu_init(&itmr_intrclock);
+ clockintr_trigger();
+}
+int
+itmr_intr(void *v)
+{
+ clockintr_dispatch(v);
return (1);
}
void
setstatclockrate(int newhz)
{
- /* nothing we can do */
+ clockintr_setstatclockrate(newhz);
}
u_int
mfctl(CR_ITMR, __itmr);
return (__itmr);
}
+
+/*
+ * Program the next clock interrupt, making sure it will
+ * indeed happen in the future. This is done with interrupts
+ * disabled to avoid a possible race.
+ */
+void
+itmr_rearm(void *unused, uint64_t nsecs)
+{
+ uint32_t cycles, t0, t1, target;
+ register_t eiem, eirr;
+
+ if (nsecs > itmr_nsec_max)
+ nsecs = itmr_nsec_max;
+ cycles = (nsecs * itmr_nsec_cycle_ratio) >> 32;
+
+ eiem = hppa_intr_disable();
+ mfctl(CR_ITMR, t0);
+ target = t0 + cycles;
+ mtctl(target, CR_ITMR);
+ mfctl(CR_ITMR, t1);
+
+ /*
+ * If the interrupt isn't already pending we need to check if
+ * we missed. In general, we are checking whether ITMR had
+ * already passed the target value when we wrote the register.
+ * There are two cases.
+ *
+ * 1. If (t0 + cycles) did not overflow, we want t1 to be between
+ * t0 and target. If t0 <= t1 < target, we didn't miss.
+ *
+ * 2. If (t0 + cycles) overflowed, either t0 <= t1 or t1 < target
+ * are sufficient to show we didn't miss.
+ *
+ * Only try once. Fall back to itmr_trigger_masked() if we miss.
+ */
+ mfctl(CR_EIRR, eirr);
+ if (!ISSET(eirr, 1U << 31)) {
+ if (t0 <= target) {
+ if (target <= t1 || t1 < t0)
+ itmr_trigger_masked();
+ } else {
+ if (target <= t1 && t1 < t0)
+ itmr_trigger_masked();
+ }
+ }
+ hppa_intr_enable(eiem);
+}
+
+void
+itmr_trigger(void)
+{
+ register_t eiem;
+
+ eiem = hppa_intr_disable();
+ itmr_trigger_masked();
+ hppa_intr_enable(eiem);
+}
+
+/* Trigger our own ITMR interrupt by setting EIR{0}. */
+void
+itmr_trigger_masked(void)
+{
+ struct iomod *cpu = (struct iomod *)curcpu()->ci_hpa;
+
+ cpu->io_eir = 0;
+ __asm volatile ("sync" ::: "memory");
+}
+
+void
+itmr_trigger_wrapper(void *unused)
+{
+ itmr_trigger();
+}
-/* $OpenBSD: cpu.c,v 1.43 2022/03/13 08:04:38 mpi Exp $ */
+/* $OpenBSD: cpu.c,v 1.44 2022/12/06 00:40:09 cheloha Exp $ */
/*
* Copyright (c) 1998-2003 Michael Shalayeff
extern u_int cpu_ticksnum, cpu_ticksdenom;
extern u_int fpu_enable;
/* clock.c */
- extern int cpu_hardclock(void *);
+ extern int itmr_intr(void *);
/* ipi.c */
extern int hppa_ipi_intr(void *);
printf(", %u/%u D/I BTLBs",
pdc_btlb.finfo.num_i, pdc_btlb.finfo.num_d);
- cpu_intr_establish(IPL_CLOCK, 31, cpu_hardclock, NULL, "clock");
+ cpu_intr_establish(IPL_CLOCK, 31, itmr_intr, NULL, "clock");
#ifdef MULTIPROCESSOR
cpu_intr_establish(IPL_IPI, 30, hppa_ipi_intr, NULL, "ipi");
#endif
cpu_hatch(void)
{
struct cpu_info *ci = curcpu();
- extern u_long cpu_hzticks;
- u_long itmr;
int s;
/* Initialise IPIs. */
/* Initialise clock. */
mtctl((1U << 31), CR_EIRR);
- mfctl(CR_ITMR, itmr);
- ci->ci_itmr = itmr;
- itmr += cpu_hzticks;
- mtctl(itmr, CR_ITMR);
ci->ci_mask |= (1U << 31);
+ cpu_startclock();
/* Enable interrupts. */
mtctl(ci->ci_mask, CR_EIEM);
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