x86: use cpu_khz for loops_per_jiffy calculation

[net-next-2.6.git] / init / calibrate.c

diff --git a/init/calibrate.c b/init/calibrate.c
index d206c7548fe6f80aa14f508d89f7a5f76c4216cd..86286974dada5c3860ab03c97144c8d96afbfffb 100644 (file)
--- a/init/calibrate.c
+++ b/init/calibrate.c
@@ -4,13 +4,14 @@
  *  Copyright (C) 1991, 1992  Linus Torvalds
  */
 
-#include <linux/sched.h>
+#include <linux/jiffies.h>
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/timex.h>
+#include <linux/smp.h>
 
-#include <asm/timex.h>
-
-static unsigned long preset_lpj;
+unsigned long lpj_tsc;
+unsigned long preset_lpj;
 static int __init lpj_setup(char *str)
 {
        preset_lpj = simple_strtoul(str,NULL,0);
@@ -29,7 +30,7 @@ __setup("lpj=", lpj_setup);
 #define DELAY_CALIBRATION_TICKS                        ((HZ < 100) ? 1 : (HZ/100))
 #define MAX_DIRECT_CALIBRATION_RETRIES         5
 
-static unsigned long __devinit calibrate_delay_direct(void)
+static unsigned long __cpuinit calibrate_delay_direct(void)
 {
        unsigned long pre_start, start, post_start;
        unsigned long pre_end, end, post_end;
@@ -102,37 +103,41 @@ static unsigned long __devinit calibrate_delay_direct(void)
        return 0;
 }
 #else
-static unsigned long __devinit calibrate_delay_direct(void) {return 0;}
+static unsigned long __cpuinit calibrate_delay_direct(void) {return 0;}
 #endif
 
 /*
  * This is the number of bits of precision for the loops_per_jiffy.  Each
  * bit takes on average 1.5/HZ seconds.  This (like the original) is a little
  * better than 1%
+ * For the boot cpu we can skip the delay calibration and assign it a value
+ * calculated based on the tsc frequency.
+ * For the rest of the CPUs we cannot assume that the tsc frequency is same as
+ * the cpu frequency, hence do the calibration for those.
  */
 #define LPS_PREC 8
 
-void __devinit calibrate_delay(void)
+void __cpuinit calibrate_delay(void)
 {
        unsigned long ticks, loopbit;
        int lps_precision = LPS_PREC;
 
        if (preset_lpj) {
                loops_per_jiffy = preset_lpj;
-               printk("Calibrating delay loop (skipped)... "
-                       "%lu.%02lu BogoMIPS preset\n",
-                       loops_per_jiffy/(500000/HZ),
-                       (loops_per_jiffy/(5000/HZ)) % 100);
+               printk(KERN_INFO
+                       "Calibrating delay loop (skipped) preset value.. ");
+       } else if ((smp_processor_id() == 0) && lpj_tsc) {
+               loops_per_jiffy = lpj_tsc;
+               printk(KERN_INFO
+                       "Calibrating delay loop (skipped), "
+                       "using tsc calculated value.. ");
        } else if ((loops_per_jiffy = calibrate_delay_direct()) != 0) {
-               printk("Calibrating delay using timer specific routine.. ");
-               printk("%lu.%02lu BogoMIPS (lpj=%lu)\n",
-                       loops_per_jiffy/(500000/HZ),
-                       (loops_per_jiffy/(5000/HZ)) % 100,
-                       loops_per_jiffy);
+               printk(KERN_INFO
+                       "Calibrating delay using timer specific routine.. ");
        } else {
                loops_per_jiffy = (1<<12);
 
-               printk(KERN_DEBUG "Calibrating delay loop... ");
+               printk(KERN_INFO "Calibrating delay loop... ");
                while ((loops_per_jiffy <<= 1) != 0) {
                        /* wait for "start of" clock tick */
                        ticks = jiffies;
@@ -162,12 +167,8 @@ void __devinit calibrate_delay(void)
                        if (jiffies != ticks)   /* longer than 1 tick */
                                loops_per_jiffy &= ~loopbit;
                }
-
-               /* Round the value and print it */
-               printk("%lu.%02lu BogoMIPS (lpj=%lu)\n",
-                       loops_per_jiffy/(500000/HZ),
-                       (loops_per_jiffy/(5000/HZ)) % 100,
-                       loops_per_jiffy);
        }
-
+       printk(KERN_INFO "%lu.%02lu BogoMIPS (lpj=%lu)\n",
+                       loops_per_jiffy/(500000/HZ),
+                       (loops_per_jiffy/(5000/HZ)) % 100, loops_per_jiffy);
 }