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Diffstat (limited to 'arch/x86_64/kernel/time.c')
-rw-r--r--arch/x86_64/kernel/time.c87
1 files changed, 41 insertions, 46 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 7392570f975d..ebbee6f59ff5 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -8,7 +8,7 @@
  *  Copyright (c) 1995  Markus Kuhn
  *  Copyright (c) 1996  Ingo Molnar
  *  Copyright (c) 1998  Andrea Arcangeli
- *  Copyright (c) 2002  Vojtech Pavlik
+ *  Copyright (c) 2002,2006  Vojtech Pavlik
  *  Copyright (c) 2003  Andi Kleen
  *  RTC support code taken from arch/i386/kernel/timers/time_hpet.c
  */
@@ -51,14 +51,21 @@ extern int using_apic_timer;
 static char *time_init_gtod(void);
 
 DEFINE_SPINLOCK(rtc_lock);
+EXPORT_SYMBOL(rtc_lock);
 DEFINE_SPINLOCK(i8253_lock);
 
 int nohpet __initdata = 0;
 static int notsc __initdata = 0;
 
-#undef HPET_HACK_ENABLE_DANGEROUS
+#define USEC_PER_TICK (USEC_PER_SEC / HZ)
+#define NSEC_PER_TICK (NSEC_PER_SEC / HZ)
+#define FSEC_PER_TICK (FSEC_PER_SEC / HZ)
+
+#define NS_SCALE	10 /* 2^10, carefully chosen */
+#define US_SCALE	32 /* 2^32, arbitralrily chosen */
 
 unsigned int cpu_khz;					/* TSC clocks / usec, not used here */
+EXPORT_SYMBOL(cpu_khz);
 static unsigned long hpet_period;			/* fsecs / HPET clock */
 unsigned long hpet_tick;				/* HPET clocks / interrupt */
 int hpet_use_timer;				/* Use counter of hpet for time keeping, otherwise PIT */
@@ -90,7 +97,7 @@ static inline unsigned int do_gettimeoffset_tsc(void)
 	t = get_cycles_sync();
 	if (t < vxtime.last_tsc) 
 		t = vxtime.last_tsc; /* hack */
-	x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> 32;
+	x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> US_SCALE;
 	return x;
 }
 
@@ -98,7 +105,7 @@ static inline unsigned int do_gettimeoffset_hpet(void)
 {
 	/* cap counter read to one tick to avoid inconsistencies */
 	unsigned long counter = hpet_readl(HPET_COUNTER) - vxtime.last;
-	return (min(counter,hpet_tick) * vxtime.quot) >> 32;
+	return (min(counter,hpet_tick) * vxtime.quot) >> US_SCALE;
 }
 
 unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc;
@@ -118,7 +125,7 @@ void do_gettimeofday(struct timeval *tv)
 		seq = read_seqbegin(&xtime_lock);
 
 		sec = xtime.tv_sec;
-		usec = xtime.tv_nsec / 1000;
+		usec = xtime.tv_nsec / NSEC_PER_USEC;
 
 		/* i386 does some correction here to keep the clock 
 		   monotonous even when ntpd is fixing drift.
@@ -129,14 +136,14 @@ void do_gettimeofday(struct timeval *tv)
 		   in arch/x86_64/kernel/vsyscall.c and export all needed
 		   variables in vmlinux.lds. -AK */ 
 
-		t = (jiffies - wall_jiffies) * (1000000L / HZ) +
+		t = (jiffies - wall_jiffies) * USEC_PER_TICK +
 			do_gettimeoffset();
 		usec += t;
 
 	} while (read_seqretry(&xtime_lock, seq));
 
-	tv->tv_sec = sec + usec / 1000000;
-	tv->tv_usec = usec % 1000000;
+	tv->tv_sec = sec + usec / USEC_PER_SEC;
+	tv->tv_usec = usec % USEC_PER_SEC;
 }
 
 EXPORT_SYMBOL(do_gettimeofday);
@@ -157,8 +164,8 @@ int do_settimeofday(struct timespec *tv)
 
 	write_seqlock_irq(&xtime_lock);
 
-	nsec -= do_gettimeoffset() * 1000 +
-		(jiffies - wall_jiffies) * (NSEC_PER_SEC/HZ);
+	nsec -= do_gettimeoffset() * NSEC_PER_USEC +
+		(jiffies - wall_jiffies) * NSEC_PER_TICK;
 
 	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
@@ -288,7 +295,7 @@ unsigned long long monotonic_clock(void)
 			this_offset = hpet_readl(HPET_COUNTER);
 		} while (read_seqretry(&xtime_lock, seq));
 		offset = (this_offset - last_offset);
-		offset *= (NSEC_PER_SEC/HZ) / hpet_tick;
+		offset *= NSEC_PER_TICK / hpet_tick;
 	} else {
 		do {
 			seq = read_seqbegin(&xtime_lock);
@@ -297,7 +304,8 @@ unsigned long long monotonic_clock(void)
 			base = monotonic_base;
 		} while (read_seqretry(&xtime_lock, seq));
 		this_offset = get_cycles_sync();
-		offset = (this_offset - last_offset)*1000 / cpu_khz; 
+		/* FIXME: 1000 or 1000000? */
+		offset = (this_offset - last_offset)*1000 / cpu_khz;
 	}
 	return base + offset;
 }
@@ -382,7 +390,7 @@ void main_timer_handler(struct pt_regs *regs)
 		}
 
 		monotonic_base += 
-			(offset - vxtime.last)*(NSEC_PER_SEC/HZ) / hpet_tick;
+			(offset - vxtime.last) * NSEC_PER_TICK / hpet_tick;
 
 		vxtime.last = offset;
 #ifdef CONFIG_X86_PM_TIMER
@@ -391,24 +399,25 @@ void main_timer_handler(struct pt_regs *regs)
 #endif
 	} else {
 		offset = (((tsc - vxtime.last_tsc) *
-			   vxtime.tsc_quot) >> 32) - (USEC_PER_SEC / HZ);
+			   vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK;
 
 		if (offset < 0)
 			offset = 0;
 
-		if (offset > (USEC_PER_SEC / HZ)) {
-			lost = offset / (USEC_PER_SEC / HZ);
-			offset %= (USEC_PER_SEC / HZ);
+		if (offset > USEC_PER_TICK) {
+			lost = offset / USEC_PER_TICK;
+			offset %= USEC_PER_TICK;
 		}
 
-		monotonic_base += (tsc - vxtime.last_tsc)*1000000/cpu_khz ;
+		/* FIXME: 1000 or 1000000? */
+		monotonic_base += (tsc - vxtime.last_tsc) * 1000000 / cpu_khz;
 
 		vxtime.last_tsc = tsc - vxtime.quot * delay / vxtime.tsc_quot;
 
 		if ((((tsc - vxtime.last_tsc) *
-		      vxtime.tsc_quot) >> 32) < offset)
+		      vxtime.tsc_quot) >> US_SCALE) < offset)
 			vxtime.last_tsc = tsc -
-				(((long) offset << 32) / vxtime.tsc_quot) - 1;
+				(((long) offset << US_SCALE) / vxtime.tsc_quot) - 1;
 	}
 
 	if (lost > 0) {
@@ -468,16 +477,15 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 }
 
 static unsigned int cyc2ns_scale __read_mostly;
-#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
 
 static inline void set_cyc2ns_scale(unsigned long cpu_khz)
 {
-	cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR)/cpu_khz;
+	cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / cpu_khz;
 }
 
 static inline unsigned long long cycles_2_ns(unsigned long long cyc)
 {
-	return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
+	return (cyc * cyc2ns_scale) >> NS_SCALE;
 }
 
 unsigned long long sched_clock(void)
@@ -490,7 +498,7 @@ unsigned long long sched_clock(void)
            Disadvantage is a small drift between CPUs in some configurations,
 	   but that should be tolerable. */
 	if (__vxtime.mode == VXTIME_HPET)
-		return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> 32;
+		return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> US_SCALE;
 #endif
 
 	/* Could do CPU core sync here. Opteron can execute rdtsc speculatively,
@@ -633,7 +641,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
 
 		cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
 		if (!(freq->flags & CPUFREQ_CONST_LOOPS))
-			vxtime.tsc_quot = (1000L << 32) / cpu_khz;
+			vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
 	}
 	
 	set_cyc2ns_scale(cpu_khz_ref);
@@ -789,8 +797,8 @@ static int hpet_timer_stop_set_go(unsigned long tick)
 	if (hpet_use_timer) {
 		hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
 		    HPET_TN_32BIT, HPET_T0_CFG);
-		hpet_writel(hpet_tick, HPET_T0_CMP);
-		hpet_writel(hpet_tick, HPET_T0_CMP); /* AK: why twice? */
+		hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */
+		hpet_writel(hpet_tick, HPET_T0_CMP); /* period */
 		cfg |= HPET_CFG_LEGACY;
 	}
 /*
@@ -825,8 +833,7 @@ static int hpet_init(void)
 	if (hpet_period < 100000 || hpet_period > 100000000)
 		return -1;
 
-	hpet_tick = (1000000000L * (USEC_PER_SEC / HZ) + hpet_period / 2) /
-		hpet_period;
+	hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period;
 
 	hpet_use_timer = (id & HPET_ID_LEGSUP);
 
@@ -890,18 +897,6 @@ void __init time_init(void)
 	char *timename;
 	char *gtod;
 
-#ifdef HPET_HACK_ENABLE_DANGEROUS
-        if (!vxtime.hpet_address) {
-		printk(KERN_WARNING "time.c: WARNING: Enabling HPET base "
-		       "manually!\n");
-                outl(0x800038a0, 0xcf8);
-                outl(0xff000001, 0xcfc);
-                outl(0x800038a0, 0xcf8);
-                vxtime.hpet_address = inl(0xcfc) & 0xfffffffe;
-		printk(KERN_WARNING "time.c: WARNING: Enabled HPET "
-		       "at %#lx.\n", vxtime.hpet_address);
-        }
-#endif
 	if (nohpet)
 		vxtime.hpet_address = 0;
 
@@ -912,7 +907,7 @@ void __init time_init(void)
 	                        -xtime.tv_sec, -xtime.tv_nsec);
 
 	if (!hpet_init())
-                vxtime_hz = (1000000000000000L + hpet_period / 2) / hpet_period;
+                vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period;
 	else
 		vxtime.hpet_address = 0;
 
@@ -941,8 +936,8 @@ void __init time_init(void)
 	       vxtime_hz / 1000000, vxtime_hz % 1000000, timename, gtod);
 	printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
 		cpu_khz / 1000, cpu_khz % 1000);
-	vxtime.quot = (1000000L << 32) / vxtime_hz;
-	vxtime.tsc_quot = (1000L << 32) / cpu_khz;
+	vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz;
+	vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
 	vxtime.last_tsc = get_cycles_sync();
 	setup_irq(0, &irq0);
 
@@ -956,10 +951,10 @@ void __init time_init(void)
 __cpuinit int unsynchronized_tsc(void)
 {
 #ifdef CONFIG_SMP
-	if (oem_force_hpet_timer())
+	if (apic_is_clustered_box())
 		return 1;
  	/* Intel systems are normally all synchronized. Exceptions
- 	   are handled in the OEM check above. */
+ 	   are handled in the check above. */
  	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
  		return 0;
 #endif
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-10-04 06:21:12 +0000