[RFC][PATCH] linux-2.5.59_cyclone-fixes_A0

[john stultz]

All,
	This patch "fixes" the timer_cyclone code by having it initialize
fast_gettimeoffset_quotient and cpu_khz in the same manner as timer_tsc.

Ideally fast_gettimeoffset_quotient would not be used outside timer_tsc
and cpu_khz would be initialized generically outside the timer
subsystem. I have patches to do this, but they touch quite a bit of
generic code, and I'd rather not make the timer_cyclone enablement
(patch to follow) depend on these larger changes. 

Comments, flames and suggestions welcome.

thanks
-john

diff -Nru a/arch/i386/kernel/timers/timer_cyclone.c b/arch/i386/kernel/timers/timer_cyclone.c
--- a/arch/i386/kernel/timers/timer_cyclone.c	Mon Feb  3 11:23:11 2003
+++ b/arch/i386/kernel/timers/timer_cyclone.c	Mon Feb  3 11:23:11 2003
@@ -17,7 +17,7 @@
 #include <asm/fixmap.h>
 
 extern spinlock_t i8253_lock;
-
+extern unsigned long fast_gettimeoffset_quotient;
 /* Number of usecs that the last interrupt was delayed */
 static int delay_at_last_interrupt;
 
@@ -142,6 +142,28 @@
 			printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n");
 			cyclone_timer = 0;
 			return -ENODEV;
+		}
+	}
+
+	/* init fast_gettimeoffset_quotent and cpu_khz.
+	 * XXX - This should really be done elsewhere, 
+	 * 		and in a more generic fashion. [e-mail]
+	 */
+	if (cpu_has_tsc) {
+		unsigned long tsc_quotient = calibrate_tsc();
+		if (tsc_quotient) {
+			fast_gettimeoffset_quotient = tsc_quotient;
+			/* report CPU clock rate in Hz.
+			 * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
+			 * clock/second. Our precision is about 100 ppm.
+			 */
+			{	unsigned long eax=0, edx=1000;
+				__asm__("divl %2"
+		       		:"=a" (cpu_khz), "=d" (edx)
+        	       		:"r" (tsc_quotient),
+	                	"0" (eax), "1" (edx));
+				printk("Detected %lu.%03lu MHz processor.\n", cpu_khz / 1000, cpu_khz % 1000);
+			}
 		}
 	}
 
diff -Nru a/arch/i386/kernel/timers/timer_tsc.c b/arch/i386/kernel/timers/timer_tsc.c
--- a/arch/i386/kernel/timers/timer_tsc.c	Mon Feb  3 11:23:11 2003
+++ b/arch/i386/kernel/timers/timer_tsc.c	Mon Feb  3 11:23:11 2003
@@ -130,7 +130,7 @@
 #define CALIBRATE_LATCH	(5 * LATCH)
 #define CALIBRATE_TIME	(5 * 1000020/HZ)
 
-static unsigned long __init calibrate_tsc(void)
+unsigned long __init calibrate_tsc(void)
 {
        /* Set the Gate high, disable speaker */
 	outb((inb(0x61) & ~0x02) | 0x01, 0x61);