ARMv7 has four interrupt clocks available. I think it'll be easier to
review/test if we do the clockintr switch driver by driver instead of
all at once in a massive single email. When all four driver patches
are confirmed to work, I'll commit them.
Here's a patch to switch agtimer(4/armv7) to clockintr.
- Remove agtimer-specific clock interrupt scheduling bits
and randomized statclock bits.
- Wire up agtimer_intrclock.
I am looking for a tester to help me get it compiling, and then run it
through a kernel-release-upgrade cycle.
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 7 Dec 2022 21:44:08 -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 7 Dec 2022 21:44:08 -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/arm/cortex/agtimer.c
===================================================================
RCS file: /cvs/src/sys/arch/arm/cortex/agtimer.c,v
retrieving revision 1.15
diff -u -p -r1.15 agtimer.c
--- sys/arch/arm/cortex/agtimer.c 12 Mar 2022 14:40:41 -0000 1.15
+++ sys/arch/arm/cortex/agtimer.c 7 Dec 2022 21:44:08 -0000
@@ -17,9 +17,11 @@
*/
#include <sys/param.h>
+#include <sys/clockintr.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
+#include <sys/stdint.h>
#include <sys/timetc.h>
#include <machine/intr.h>
@@ -51,28 +53,12 @@ static struct timecounter agtimer_timeco
.tc_priv = NULL,
};
-struct agtimer_pcpu_softc {
- uint64_t pc_nexttickevent;
- uint64_t pc_nextstatevent;
- u_int32_t pc_ticks_err_sum;
-};
-
struct agtimer_softc {
struct device sc_dev;
int sc_node;
-
- struct agtimer_pcpu_softc sc_pstat[MAXCPUS];
-
- u_int32_t sc_ticks_err_cnt;
u_int32_t sc_ticks_per_second;
- u_int32_t sc_ticks_per_intr;
- u_int32_t sc_statvar;
- u_int32_t sc_statmin;
-
-#ifdef AMPTIMER_DEBUG
- struct evcount sc_clk_count;
- struct evcount sc_stat_count;
-#endif
+ uint64_t sc_nsec_cycle_ratio;
+ uint64_t sc_nsec_max;
};
int agtimer_match(struct device *, void *, void *);
@@ -81,9 +67,11 @@ uint64_t agtimer_readcnt64(void);
int agtimer_intr(void *);
void agtimer_cpu_initclocks(void);
void agtimer_delay(u_int);
+void agtimer_rearm(void *, uint64_t);
void agtimer_setstatclockrate(int stathz);
void agtimer_set_clockrate(int32_t new_frequency);
void agtimer_startclock(void);
+void agtimer_trigger(void *, uint64_t);
const struct cfattach agtimer_ca = {
sizeof (struct agtimer_softc), agtimer_match, agtimer_attach
@@ -93,6 +81,11 @@ struct cfdriver agtimer_cd = {
NULL, "agtimer", DV_DULL
};
+struct intrclock agtimer_intrclock = {
+ .ic_rearm = agtimer_rearm,
+ .ic_trigger = agtimer_trigger
+};
+
uint64_t
agtimer_readcnt64(void)
{
@@ -155,16 +148,13 @@ agtimer_attach(struct device *parent, st
agtimer_frequency =
OF_getpropint(sc->sc_node, "clock-frequency", agtimer_frequency);
sc->sc_ticks_per_second = agtimer_frequency;
-
+ sc->sc_nsec_cycle_ratio =
+ sc->sc_ticks_per_second * (1ULL << 32) / 1000000000;
+ sc->sc_nsec_max = UINT64_MAX / sc->sc_nsec_cycle_ratio;
printf(": %d kHz\n", sc->sc_ticks_per_second / 1000);
/* XXX: disable user access */
-#ifdef AMPTIMER_DEBUG
- evcount_attach(&sc->sc_clk_count, "clock", NULL);
- evcount_attach(&sc->sc_stat_count, "stat", NULL);
-#endif
-
/*
* private timer and interrupts not enabled until
* timer configures
@@ -175,8 +165,9 @@ agtimer_attach(struct device *parent, st
agtimer_timecounter.tc_frequency = sc->sc_ticks_per_second;
agtimer_timecounter.tc_priv = sc;
-
tc_init(&agtimer_timecounter);
+
+ agtimer_intrclock.ic_cookie = sc;
}
u_int
@@ -185,72 +176,30 @@ agtimer_get_timecount(struct timecounter
return agtimer_readcnt64();
}
-int
-agtimer_intr(void *frame)
+void
+agtimer_rearm(void *cookie, uint64_t nsecs)
{
- struct agtimer_softc *sc = agtimer_cd.cd_devs[0];
- struct agtimer_pcpu_softc *pc = &sc->sc_pstat[CPU_INFO_UNIT(curcpu())];
- uint64_t now;
- uint64_t nextevent;
- uint32_t r;
-#if defined(USE_GTIMER_CMP)
- int skip = 1;
-#else
- int64_t delay;
-#endif
- int rc = 0;
-
- /*
- * DSR - I know that the tick timer is 64 bits, but the following
- * code deals with rollover, so there is no point in dealing
- * with the 64 bit math, just let the 32 bit rollover
- * do the right thing
- */
+ struct agtimer_softc *sc = cookie;
+ uint32_t cycles;
- now = agtimer_readcnt64();
-
- while (pc->pc_nexttickevent <= now) {
- pc->pc_nexttickevent += sc->sc_ticks_per_intr;
- pc->pc_ticks_err_sum += sc->sc_ticks_err_cnt;
-
- /* looping a few times is faster than divide */
- while (pc->pc_ticks_err_sum > hz) {
- pc->pc_nexttickevent += 1;
- pc->pc_ticks_err_sum -= hz;
- }
-
-#ifdef AMPTIMER_DEBUG
- sc->sc_clk_count.ec_count++;
-#endif
- rc = 1;
- hardclock(frame);
- }
- while (pc->pc_nextstatevent <= now) {
- do {
- r = random() & (sc->sc_statvar -1);
- } while (r == 0); /* random == 0 not allowed */
- pc->pc_nextstatevent += sc->sc_statmin + r;
-
- /* XXX - correct nextstatevent? */
-#ifdef AMPTIMER_DEBUG
- sc->sc_stat_count.ec_count++;
-#endif
- rc = 1;
- statclock(frame);
- }
-
- if (pc->pc_nexttickevent < pc->pc_nextstatevent)
- nextevent = pc->pc_nexttickevent;
- else
- nextevent = pc->pc_nextstatevent;
-
- delay = nextevent - now;
- if (delay < 0)
- delay = 1;
+ if (nsecs > sc->sc_nsec_max)
+ nsecs = sc->sc_nsec_max;
+ cycles = (nsecs * sc->sc_nsec_cycle_ratio) >> 32;
+ if (cycles > INT32_MAX)
+ cycles = INT32_MAX;
+ agtimer_set_tval(cycles);
+}
- agtimer_set_tval(delay);
+void
+agtimer_trigger(void *unused)
+{
+ agtimer_set_tval(0);
+}
- return (rc);
+int
+agtimer_intr(void *frame)
+{
+ return clockintr_dispatch(frame);
}
void
@@ -264,7 +213,12 @@ agtimer_set_clockrate(int32_t new_freque
return;
sc->sc_ticks_per_second = agtimer_frequency;
+ sc->sc_nsec_cycle_ratio =
+ sc->sc_ticks_per_second * (1ULL << 32) / 1000000000;
+ sc->sc_nsec_max = UINT64_MAX / sc->sc_nsec_cycle_ratio;
+
agtimer_timecounter.tc_frequency = sc->sc_ticks_per_second;
+
printf("agtimer0: adjusting clock: new rate %d kHz\n",
sc->sc_ticks_per_second / 1000);
}
@@ -273,22 +227,17 @@ void
agtimer_cpu_initclocks(void)
{
struct agtimer_softc *sc = agtimer_cd.cd_devs[0];
- struct agtimer_pcpu_softc *pc = &sc->sc_pstat[CPU_INFO_UNIT(curcpu())];
uint32_t reg;
- uint64_t next;
stathz = hz;
- profhz = hz * 10;
+ profhz = stathz * 10;
+ clockintr_init(CL_RNDSTAT);
if (sc->sc_ticks_per_second != agtimer_frequency) {
agtimer_set_clockrate(agtimer_frequency);
}
- agtimer_setstatclockrate(stathz);
-
- sc->sc_ticks_per_intr = sc->sc_ticks_per_second / hz;
- sc->sc_ticks_err_cnt = sc->sc_ticks_per_second % hz;
- pc->pc_ticks_err_sum = 0;
+ clockintr_cpu_init(&agtimer_intrclock);
/* Setup secure and non-secure timer IRQs. */
arm_intr_establish_fdt_idx(sc->sc_node, 0, IPL_CLOCK,
@@ -296,14 +245,13 @@ agtimer_cpu_initclocks(void)
arm_intr_establish_fdt_idx(sc->sc_node, 1, IPL_CLOCK,
agtimer_intr, NULL, "tick");
- next = agtimer_readcnt64() + sc->sc_ticks_per_intr;
- pc->pc_nexttickevent = pc->pc_nextstatevent = next;
-
reg = agtimer_get_ctrl();
reg &= ~GTIMER_CNTP_CTL_IMASK;
reg |= GTIMER_CNTP_CTL_ENABLE;
- agtimer_set_tval(sc->sc_ticks_per_second);
+ agtimer_set_tval(INT32_MAX);
agtimer_set_ctrl(reg);
+
+ clockintr_trigger();
}
void
@@ -340,45 +288,23 @@ agtimer_delay(u_int usecs)
void
agtimer_setstatclockrate(int newhz)
{
- struct agtimer_softc *sc = agtimer_cd.cd_devs[0];
- int minint, statint;
- int s;
-
- s = splclock();
-
- statint = sc->sc_ticks_per_second / newhz;
- /* calculate largest 2^n which is smaller that just over half statint */
- sc->sc_statvar = 0x40000000; /* really big power of two */
- minint = statint / 2 + 100;
- while (sc->sc_statvar > minint)
- sc->sc_statvar >>= 1;
-
- sc->sc_statmin = statint - (sc->sc_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);
}
void
agtimer_startclock(void)
{
- struct agtimer_softc *sc = agtimer_cd.cd_devs[0];
- struct agtimer_pcpu_softc *pc = &sc->sc_pstat[CPU_INFO_UNIT(curcpu())];
- uint64_t nextevent;
uint32_t reg;
- nextevent = agtimer_readcnt64() + sc->sc_ticks_per_intr;
- pc->pc_nexttickevent = pc->pc_nextstatevent = nextevent;
+ clockintr_cpu_init(&agtimer_intrclock);
reg = agtimer_get_ctrl();
reg &= ~GTIMER_CNTP_CTL_IMASK;
reg |= GTIMER_CNTP_CTL_ENABLE;
- agtimer_set_tval(sc->sc_ticks_per_second);
+ agtimer_set_tval(INT32_MAX);
agtimer_set_ctrl(reg);
+
+ clockintr_trigger();
}
void
