aboutsummaryrefslogtreecommitdiff
path: root/init/calibrate.c
diff options
context:
space:
mode:
authorAlok Kataria <akataria@vmware.com>2008-06-23 18:21:56 -0700
committerIngo Molnar <mingo@elte.hu>2008-06-24 13:53:46 +0200
commitf3f3149f35b9195ef4b761b1353fc0766b5f53be (patch)
tree96e67c82e8ea6ce57ce5f83a8036f87a8d534867 /init/calibrate.c
parent6ff10de374cc68ff2024247793176dc8a1b317ea (diff)
downloadvexpress-lsk-f3f3149f35b9195ef4b761b1353fc0766b5f53be.tar.gz
x86: use cpu_khz for loops_per_jiffy calculation, cleanup
As suggested by Ingo, remove all references to tsc from init/calibrate.c TSC is x86 specific, and using tsc in variable names in a generic file should be avoided. lpj_tsc is now called lpj_fine, since it is related to fine tuning of lpj value. Also tsc_rate_* is called timer_rate_* Signed-off-by: Alok N Kataria <akataria@vmware.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Daniel Hecht <dhecht@vmware.com> Cc: Tim Mann <mann@vmware.com> Cc: Zach Amsden <zach@vmware.com> Cc: Sahil Rihan <srihan@vmware.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'init/calibrate.c')
-rw-r--r--init/calibrate.c36
1 files changed, 19 insertions, 17 deletions
diff --git a/init/calibrate.c b/init/calibrate.c
index 86286974dad..7963e3fc51d 100644
--- a/init/calibrate.c
+++ b/init/calibrate.c
@@ -10,7 +10,7 @@
#include <linux/timex.h>
#include <linux/smp.h>
-unsigned long lpj_tsc;
+unsigned long lpj_fine;
unsigned long preset_lpj;
static int __init lpj_setup(char *str)
{
@@ -35,9 +35,9 @@ static unsigned long __cpuinit calibrate_delay_direct(void)
unsigned long pre_start, start, post_start;
unsigned long pre_end, end, post_end;
unsigned long start_jiffies;
- unsigned long tsc_rate_min, tsc_rate_max;
- unsigned long good_tsc_sum = 0;
- unsigned long good_tsc_count = 0;
+ unsigned long timer_rate_min, timer_rate_max;
+ unsigned long good_timer_sum = 0;
+ unsigned long good_timer_count = 0;
int i;
if (read_current_timer(&pre_start) < 0 )
@@ -81,22 +81,24 @@ static unsigned long __cpuinit calibrate_delay_direct(void)
}
read_current_timer(&post_end);
- tsc_rate_max = (post_end - pre_start) / DELAY_CALIBRATION_TICKS;
- tsc_rate_min = (pre_end - post_start) / DELAY_CALIBRATION_TICKS;
+ timer_rate_max = (post_end - pre_start) /
+ DELAY_CALIBRATION_TICKS;
+ timer_rate_min = (pre_end - post_start) /
+ DELAY_CALIBRATION_TICKS;
/*
- * If the upper limit and lower limit of the tsc_rate is
+ * If the upper limit and lower limit of the timer_rate is
* >= 12.5% apart, redo calibration.
*/
if (pre_start != 0 && pre_end != 0 &&
- (tsc_rate_max - tsc_rate_min) < (tsc_rate_max >> 3)) {
- good_tsc_count++;
- good_tsc_sum += tsc_rate_max;
+ (timer_rate_max - timer_rate_min) < (timer_rate_max >> 3)) {
+ good_timer_count++;
+ good_timer_sum += timer_rate_max;
}
}
- if (good_tsc_count)
- return (good_tsc_sum/good_tsc_count);
+ if (good_timer_count)
+ return (good_timer_sum/good_timer_count);
printk(KERN_WARNING "calibrate_delay_direct() failed to get a good "
"estimate for loops_per_jiffy.\nProbably due to long platform interrupts. Consider using \"lpj=\" boot option.\n");
@@ -111,8 +113,8 @@ static unsigned long __cpuinit calibrate_delay_direct(void) {return 0;}
* 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
+ * calculated based on the timer frequency.
+ * For the rest of the CPUs we cannot assume that the timer frequency is same as
* the cpu frequency, hence do the calibration for those.
*/
#define LPS_PREC 8
@@ -126,11 +128,11 @@ void __cpuinit calibrate_delay(void)
loops_per_jiffy = preset_lpj;
printk(KERN_INFO
"Calibrating delay loop (skipped) preset value.. ");
- } else if ((smp_processor_id() == 0) && lpj_tsc) {
- loops_per_jiffy = lpj_tsc;
+ } else if ((smp_processor_id() == 0) && lpj_fine) {
+ loops_per_jiffy = lpj_fine;
printk(KERN_INFO
"Calibrating delay loop (skipped), "
- "using tsc calculated value.. ");
+ "value calculated using timer frequency.. ");
} else if ((loops_per_jiffy = calibrate_delay_direct()) != 0) {
printk(KERN_INFO
"Calibrating delay using timer specific routine.. ");