Fix Pentium CPU rate diagnosis:

	- Don't print out meaningless iCOMP numbers, those are for droids.
	- Use a shorter wait to determine clock rate to avoid deficiencies
	  in DELAY().
	- Use a fixed-point representation with 8 bits of fraction to store
	  the rate and rationalize the variable name.  It would be
	  possible to use even more fraction if it turns out to be
	  worthwhile (I rather doubt it).

The question of source code arrangement remains unaddressed.

5 files changed, 45 insertions, 42 deletions

diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 77cfdb9..e5538b3 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.151 1995/11/14 09:52:25 phk Exp $
+ *	$Id: machdep.c,v 1.152 1995/11/20 12:41:24 phk Exp $
  */
 
 #include "npx.h"
@@ -493,7 +493,6 @@ identifycpu()
 #if defined(I586_CPU)
 	if(cpu_class == CPUCLASS_586) {
 		calibrate_cyclecounter();
-		printf("%d-MHz ", pentium_mhz);
 	}
 #endif
 #if defined(I486_CPU) || defined(I586_CPU)
@@ -513,7 +512,7 @@ identifycpu()
 				strcat(cpu_model, "i486 ");
 #if defined(I586_CPU)
 			} else if ((cpu_id & 0xf00) == 0x500) {
-				strcat(cpu_model, "Pentium ");
+				strcat(cpu_model, "Pentium"); /* nb no space */
 #endif
 			} else {
 				strcat(cpu_model, "unknown ");
@@ -539,22 +538,14 @@ identifycpu()
 				strcat(cpu_model, "DX4"); break;
 #if defined(I586_CPU)
 			case 0x510:
-				if (pentium_mhz == 60) {
-					strcat(cpu_model, "510\\60");
-				} else if (pentium_mhz == 66) {
-					strcat(cpu_model, "567\\66");
-				} else {
-					strcat(cpu_model,"510\\60 or 567\\66");
-				}
-				break;
 			case 0x520:
-				if (pentium_mhz == 90) {
-					strcat(cpu_model, "735\\90");
-				} else if (pentium_mhz == 100) {
-					strcat(cpu_model, "815\\100");
-				} else {
-					strcat(cpu_model,"735\\90 or 815\\100");
-				}
+				/*
+				 * We used to do all sorts of nonsense here
+				 * to print out iCOMP numbers.  Since these
+				 * are meaningless except to Intel
+				 * marketroids, there seems to be little
+				 * sense in doing so.
+				 */
 				break;
 #endif
 			}
@@ -578,7 +569,10 @@ identifycpu()
 #endif
 #if defined(I586_CPU)
 	case CPUCLASS_586:
-		printf("Pentium");
+		printf("%d.%02d-MHz ",
+		       ((100 * i586_ctr_rate) >> I586_CTR_RATE_SHIFT) / 100,
+		       ((100 * i586_ctr_rate) >> I586_CTR_RATE_SHIFT) % 100);
+		printf("586");
 		break;
 #endif
 	default:
diff --git a/sys/i386/i386/microtime.s b/sys/i386/i386/microtime.s
index 7470c16..44b7e97 100644
--- a/sys/i386/i386/microtime.s
+++ b/sys/i386/i386/microtime.s
@@ -1,4 +1,5 @@
-/*-
+/* -*- Fundamental -*- keep Emacs from f***ing up the formatting */
+/*
  * Copyright (c) 1993 The Regents of the University of California.
  * All rights reserved.
  *
@@ -31,10 +32,11 @@
  * SUCH DAMAGE.
  *
  *	from: Steve McCanne's microtime code
- *	$Id: microtime.s,v 1.9 1995/10/13 19:53:25 wollman Exp $
+ *	$Id: microtime.s,v 1.10 1995/10/14 04:53:49 bde Exp $
  */
 
 #include <machine/asmacros.h>
+#include <machine/clock.h>
 
 #include <i386/isa/icu.h>
 #include <i386/isa/isa.h>
@@ -43,7 +45,7 @@
 ENTRY(microtime)
 
 #ifdef I586_CPU
-	movl	_pentium_mhz, %ecx
+	movl	_i586_ctr_rate, %ecx
 	testl	%ecx, %ecx
 	jne	pentium_microtime
 #else
@@ -180,6 +182,8 @@ pentium_microtime:
 	.byte	0x0f, 0x31	# RDTSC
 	subl	_i586_ctr_bias, %eax
 	sbbl	_i586_ctr_bias+4, %edx
+	shldl	$I586_CTR_RATE_SHIFT, %eax, %edx	# magic suggested by
+	shll	$I586_CTR_RATE_SHIFT, %eax		# math_emulate.c
 	divl	%ecx		# get value in usec
 	jmp	common_microtime
 #endif
diff --git a/sys/i386/i386/tsc.c b/sys/i386/i386/tsc.c
index 7259a33..82e0b18 100644
--- a/sys/i386/i386/tsc.c
+++ b/sys/i386/i386/tsc.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
- *	$Id: clock.c,v 1.37 1995/10/12 20:39:49 wollman Exp $
+ *	$Id: clock.c,v 1.38 1995/10/28 15:38:49 phk Exp $
  */
 
 /*
@@ -94,7 +94,7 @@ int	adjkerntz = 0;		/* offset from CMOS clock */
 int	disable_rtc_set	= 0;	/* disable resettodr() if != 0 */
 u_int	idelayed;
 #ifdef I586_CPU
-int	pentium_mhz;
+unsigned	i586_ctr_rate;
 long long	i586_ctr_bias;
 long long	i586_last_tick;
 #endif
@@ -295,13 +295,13 @@ calibrate_cyclecounter(void)
 	 */
 	unsigned long long count;
 
+#define howlong ((unsigned)4*tick)
 	__asm __volatile(".byte 0x0f, 0x30" : : "A"(0LL), "c" (0x10));
-	DELAY(1000000);
+	DELAY(howlong);
 	__asm __volatile(".byte 0xf,0x31" : "=A" (count));
-	/*
-	 * XX lose if the clock rate is not nearly a multiple of 1000000.
-	 */
-	pentium_mhz = (count + 500000) / 1000000;
+
+	i586_ctr_rate = (count << I586_CTR_RATE_SHIFT) / howlong;
+#undef howlong
 }
 #endif
 
@@ -573,7 +573,7 @@ cpu_initclocks()
 	/*
 	 * Finish setting up anti-jitter measures.
 	 */
-	if (pentium_mhz) {
+	if (i586_ctr_rate) {
 		I586_CYCLECTR(i586_last_tick);
 		i586_ctr_bias = i586_last_tick;
 	}
diff --git a/sys/i386/include/clock.h b/sys/i386/include/clock.h
index 96476a7..c231f5e 100644
--- a/sys/i386/include/clock.h
+++ b/sys/i386/include/clock.h
@@ -2,6 +2,8 @@
  * Kernel interface to machine-dependent clock driver.
  * Garrett Wollman, September 1994.
  * This file is in the public domain.
+ *
+ *	$Id$
  */
 
 #ifndef _MACHINE_CLOCK_H_
@@ -22,7 +24,7 @@
  */
 #define CPU_CLOCKUPDATE(otime, ntime) \
 	do { \
-	if(pentium_mhz) { \
+	if(i586_ctr_rate) { \
 		disable_intr(); \
 		i586_ctr_bias = i586_last_tick; \
 		*(otime) = *(ntime); \
@@ -39,6 +41,8 @@
 #define CPU_THISTICKLEN(dflt) dflt
 #endif
 
+#define		I586_CTR_RATE_SHIFT	8
+
 #if defined(KERNEL) && !defined(LOCORE)
 #include <sys/cdefs.h>
 #include <machine/frame.h>
@@ -51,7 +55,7 @@
 extern int	adjkerntz;
 extern int	disable_rtc_set;
 #ifdef I586_CPU
-extern int	pentium_mhz;
+extern unsigned	i586_ctr_rate;	/* fixed point */
 extern long long i586_last_tick;
 extern long long i586_ctr_bias;
 #endif
@@ -72,10 +76,11 @@ cpu_thisticklen(u_long dflt)
 	long long old;
 	long rv;
 	
-	if (pentium_mhz) {
+	if (i586_ctr_rate) {
 		old = i586_last_tick;
 		I586_CYCLECTR(i586_last_tick);
-		rv = (i586_last_tick - old) / pentium_mhz;
+		rv = ((i586_last_tick - old) << I586_CTR_RATE_SHIFT)
+			/ i586_ctr_rate;
 	} else {
 		rv = dflt;
 	}
diff --git a/sys/i386/isa/clock.c b/sys/i386/isa/clock.c
index 7259a33..82e0b18 100644
--- a/sys/i386/isa/clock.c
+++ b/sys/i386/isa/clock.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)clock.c	7.2 (Berkeley) 5/12/91
- *	$Id: clock.c,v 1.37 1995/10/12 20:39:49 wollman Exp $
+ *	$Id: clock.c,v 1.38 1995/10/28 15:38:49 phk Exp $
  */
 
 /*
@@ -94,7 +94,7 @@ int	adjkerntz = 0;		/* offset from CMOS clock */
 int	disable_rtc_set	= 0;	/* disable resettodr() if != 0 */
 u_int	idelayed;
 #ifdef I586_CPU
-int	pentium_mhz;
+unsigned	i586_ctr_rate;
 long long	i586_ctr_bias;
 long long	i586_last_tick;
 #endif
@@ -295,13 +295,13 @@ calibrate_cyclecounter(void)
 	 */
 	unsigned long long count;
 
+#define howlong ((unsigned)4*tick)
 	__asm __volatile(".byte 0x0f, 0x30" : : "A"(0LL), "c" (0x10));
-	DELAY(1000000);
+	DELAY(howlong);
 	__asm __volatile(".byte 0xf,0x31" : "=A" (count));
-	/*
-	 * XX lose if the clock rate is not nearly a multiple of 1000000.
-	 */
-	pentium_mhz = (count + 500000) / 1000000;
+
+	i586_ctr_rate = (count << I586_CTR_RATE_SHIFT) / howlong;
+#undef howlong
 }
 #endif
 
@@ -573,7 +573,7 @@ cpu_initclocks()
 	/*
 	 * Finish setting up anti-jitter measures.
 	 */
-	if (pentium_mhz) {
+	if (i586_ctr_rate) {
 		I586_CYCLECTR(i586_last_tick);
 		i586_ctr_bias = i586_last_tick;
 	}