x86: use cpu_khz for loops_per_jiffy calculation, cleanup
Alok Kataria [Tue, 24 Jun 2008 01:21:56 +0000 (18:21 -0700)]
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>

arch/x86/kernel/time_64.c
arch/x86/kernel/tsc_32.c
include/linux/delay.h
init/calibrate.c

index 12b4a71..39ae851 100644 (file)
@@ -123,7 +123,7 @@ void __init time_init(void)
                (boot_cpu_data.x86_vendor == X86_VENDOR_AMD))
                cpu_khz = calculate_cpu_khz();
 
-       lpj_tsc = ((unsigned long)tsc_khz * 1000)/HZ;
+       lpj_fine = ((unsigned long)tsc_khz * 1000)/HZ;
 
        if (unsynchronized_tsc())
                mark_tsc_unstable("TSCs unsynchronized");
index 0af49fb..048baab 100644 (file)
@@ -425,7 +425,7 @@ void __init tsc_init(void)
 
        lpj = ((u64)tsc_khz * 1000);
        do_div(lpj, HZ);
-       lpj_tsc = lpj;
+       lpj_fine = lpj;
 
        printk("Detected %lu.%03lu MHz processor.\n",
                                (unsigned long)cpu_khz / 1000,
index 01aec60..fd832c6 100644 (file)
@@ -41,7 +41,7 @@ static inline void ndelay(unsigned long x)
 #define ndelay(x) ndelay(x)
 #endif
 
-extern unsigned long lpj_tsc;
+extern unsigned long lpj_fine;
 void calibrate_delay(void);
 void msleep(unsigned int msecs);
 unsigned long msleep_interruptible(unsigned int msecs);
index 8628697..7963e3f 100644 (file)
@@ -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.. ");