From: kettenis <kettenis@openbsd.org>
Date: Thu, 7 Aug 2008 21:25:47 +0000 (+0000)
Subject: Use %sys_tick to generate clock interrupts on systems that have it.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=ebe3944664f51d4b77a46f56f424f2d60d201ef3;p=openbsd

Use %sys_tick to generate clock interrupts on systems that have it.
---

diff --git a/sys/arch/sparc64/include/cpu.h b/sys/arch/sparc64/include/cpu.h
index 08a9a48c29f..de4057bd262 100644
--- a/sys/arch/sparc64/include/cpu.h
+++ b/sys/arch/sparc64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.64 2008/08/07 18:46:04 kettenis Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.65 2008/08/07 21:25:48 kettenis Exp $	*/
 /*	$NetBSD: cpu.h,v 1.28 2001/06/14 22:56:58 thorpej Exp $ */
 
 /*
@@ -215,6 +215,8 @@ struct clockframe {
 #define	CLKF_PC(framep)		((framep)->t.tf_pc)
 #define	CLKF_INTR(framep)	((framep)->saved_intr_level != 0)
 
+extern void (*cpu_start_clock)(void);
+
 void setsoftnet(void);
 
 #define aston(p)	((p)->p_md.md_astpending = 1)
@@ -249,9 +251,11 @@ caddr_t	reserve_dumppages(caddr_t);
 /* clock.c */
 struct timeval;
 int	tickintr(void *); /* level 10 (tick) interrupt code */
+int	sys_tickintr(void *); /* level 10 (sys_tick) interrupt code */
 int	clockintr(void *);/* level 10 (clock) interrupt code */
 int	statintr(void *);	/* level 14 (statclock) interrupt code */
 void	tick_start(void);
+void	sys_tick_start(void);
 /* locore.s */
 struct fpstate64;
 void	savefpstate(struct fpstate64 *);
diff --git a/sys/arch/sparc64/include/ctlreg.h b/sys/arch/sparc64/include/ctlreg.h
index e033f7ebb2f..68b13fcf01b 100644
--- a/sys/arch/sparc64/include/ctlreg.h
+++ b/sys/arch/sparc64/include/ctlreg.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ctlreg.h,v 1.19 2008/07/12 07:37:25 kettenis Exp $	*/
+/*	$OpenBSD: ctlreg.h,v 1.20 2008/08/07 21:25:48 kettenis Exp $	*/
 /*	$NetBSD: ctlreg.h,v 1.28 2001/08/06 23:55:34 eeh Exp $ */
 
 /*
@@ -584,6 +584,8 @@ sparc_rdpr_ ## name()							\
 
 GEN_RD(asi);
 GEN_RD(asr22);
+GEN_RD(sys_tick);
+GEN_RD(sys_tick_cmpr);
 GEN_RDPR(cwp);
 GEN_RDPR(tick);
 GEN_RDPR(pstate);
@@ -723,10 +725,12 @@ void flush(void *p)
 	    : "memory");
 }
 
-/* read 64-bit %tick register */
+/* Read 64-bit %tick and %sys_tick registers. */
 #define tick() (sparc_rdpr(tick) & TICK_TICKS)
+#define sys_tick() (sparc_rd(sys_tick) & TICK_TICKS)
 
 extern void tickcmpr_set(u_int64_t);
+extern void sys_tickcmpr_set(u_int64_t);
 
 #endif /* _LOCORE */
 #endif /* _SPARC64_CTLREG_ */
diff --git a/sys/arch/sparc64/sparc64/clock.c b/sys/arch/sparc64/sparc64/clock.c
index a4018979f5d..329cf66cc83 100644
--- a/sys/arch/sparc64/sparc64/clock.c
+++ b/sys/arch/sparc64/sparc64/clock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: clock.c,v 1.45 2008/08/07 18:46:04 kettenis Exp $	*/
+/*	$OpenBSD: clock.c,v 1.46 2008/08/07 21:25:47 kettenis Exp $	*/
 /*	$NetBSD: clock.c,v 1.41 2001/07/24 19:29:25 eeh Exp $ */
 
 /*
@@ -612,22 +612,25 @@ cpu_initclocks(void)
 		strlcpy(level0.ih_name, "clock", sizeof(level0.ih_name));
 		intr_establish(10, &level0);
 
+		/* We only have one timer so we have no statclock */
+		stathz = 0;	
+
+		if (sys_tick_rate > 0 && impl != IMPL_HUMMINGBIRD) {
+			tick_increment = sys_tick_rate / hz;
+			level0.ih_fun = sys_tickintr;
+			cpu_start_clock = sys_tick_start;
+		} else {
+			/* set the next interrupt time */
+			tick_increment = cpu_clockrate / hz;
+			level0.ih_fun = tickintr;
+			cpu_start_clock = tick_start;
+		}
+
 		for (ci = cpus; ci != NULL; ci = ci->ci_next)
 			memcpy(&ci->ci_tickintr, &level0, sizeof(level0));
 
-		/* We only have one timer so we have no statclock */
-		stathz = 0;	
+		cpu_start_clock();
 
-		/* set the next interrupt time */
-		tick_increment = cpu_clockrate / hz;
-#ifdef DEBUG
-		printf("Using %%tick -- intr in %ld cycles...",
-		    tick_increment);
-#endif
-		tick_start();
-#ifdef DEBUG
-		printf("done.\n");
-#endif
 		return;
 	}
 
@@ -772,6 +775,30 @@ tickintr(cap)
 	return (1);
 }
 
+int
+sys_tickintr(cap)
+	void *cap;
+{
+	struct cpu_info *ci = curcpu();
+	u_int64_t s;
+
+	/*
+	 * Do we need to worry about overflow here?
+	 */
+	while (ci->ci_tick < sys_tick()) {
+		ci->ci_tick += tick_increment;
+		hardclock((struct clockframe *)cap);
+		level0.ih_count.ec_count++;
+	}
+
+	/* Reset the interrupt. */
+	s = intr_disable();
+	sys_tickcmpr_set(ci->ci_tick);
+	intr_restore(s);
+
+	return (1);
+}
+
 /*
  * Level 14 (stat clock) interrupt handler.
  */
@@ -930,6 +957,23 @@ tick_start(void)
 	intr_restore(s);
 }
 
+void
+sys_tick_start(void)
+{
+	struct cpu_info *ci = curcpu();
+	u_int64_t s;
+
+	/*
+	 * Try to make the tick interrupts as synchronously as possible on
+	 * all CPUs to avoid inaccuracies for migrating processes.
+	 */
+
+	s = intr_disable();
+	ci->ci_tick = roundup(sys_tick(), tick_increment);
+	sys_tickcmpr_set(ci->ci_tick);
+	intr_restore(s);
+}
+
 u_int
 tick_get_timecount(struct timecounter *tc)
 {
diff --git a/sys/arch/sparc64/sparc64/cpu.c b/sys/arch/sparc64/sparc64/cpu.c
index 193cebcdca4..2d0dd141742 100644
--- a/sys/arch/sparc64/sparc64/cpu.c
+++ b/sys/arch/sparc64/sparc64/cpu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.c,v 1.45 2008/07/21 13:30:05 art Exp $	*/
+/*	$OpenBSD: cpu.c,v 1.46 2008/08/07 21:25:47 kettenis Exp $	*/
 /*	$NetBSD: cpu.c,v 1.13 2001/05/26 21:27:15 chs Exp $ */
 
 /*
@@ -76,6 +76,8 @@ struct cacheinfo cacheinfo = {
 	us_dcache_flush_page
 };
 
+void (*cpu_start_clock)(void);
+
 /* Linked list of all CPUs in system. */
 struct cpu_info *cpus = NULL;
 
@@ -502,7 +504,7 @@ cpu_hatch(void)
 	microuptime(&ci->ci_schedstate.spc_runtime);
 	splx(s);
 
-	tick_start();
+	cpu_start_clock();
 
 	SCHED_LOCK(s);
 	cpu_switchto(NULL, sched_chooseproc());
diff --git a/sys/arch/sparc64/sparc64/locore.s b/sys/arch/sparc64/sparc64/locore.s
index bb5d4dff754..f996fa7d13f 100644
--- a/sys/arch/sparc64/sparc64/locore.s
+++ b/sys/arch/sparc64/sparc64/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.150 2008/08/07 18:46:04 kettenis Exp $	*/
+/*	$OpenBSD: locore.s,v 1.151 2008/08/07 21:25:47 kettenis Exp $	*/
 /*	$NetBSD: locore.s,v 1.137 2001/08/13 06:10:10 jdolecek Exp $	*/
 
 /*
@@ -4282,10 +4282,11 @@ _C_LABEL(sparc_interrupt):
 	 * If this is a %tick softint, clear it then call interrupt_vector.
 	 */
 	rd	SOFTINT, %g1
-	btst	TICK_INT, %g1
+	set	(TICK_INT|STICK_INT), %g2
+	andcc	%g2, %g1, %g2
 	bz,pt	%icc, 0f
 	 GET_CPUINFO_VA(%g7)
-	wr	%g0, TICK_INT, CLEAR_SOFTINT
+	wr	%g2, 0, CLEAR_SOFTINT
 	ba,pt	%icc, setup_sparcintr
 	 add	%g7, CI_TICKINTR, %g5
 0:
@@ -8918,6 +8919,26 @@ ENTRY(tickcmpr_set)
 	retl
 	 nop
 
+ENTRY(sys_tickcmpr_set)
+	ba	1f
+	 mov	8, %o2			! Initial step size
+	.align	64
+1:	wr	%o0, 0, %sys_tick_cmpr
+	rd	%sys_tick_cmpr, %g0
+
+	rd	%sys_tick, %o1		! Read current %sys_tick
+	sllx	%o1, 1, %o1
+	srlx	%o1, 1, %o1
+
+	cmp	%o0, %o1		! Make sure the value we wrote to
+	bg,pt	%xcc, 2f		!   %sys_tick_cmpr was in the future.
+	 add	%o0, %o2, %o0		! If not, add the step size, double
+	ba,pt	%xcc, 1b		!   the step size and try again.
+	 sllx	%o2, 1, %o2
+2:
+	retl
+	 nop
+
 #define MICROPERSEC	(1000000)
 	.data
 	.align	16