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![Tim Schmielau](/assets/img/avatar_default.png)
After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
173 lines
4.7 KiB
C
173 lines
4.7 KiB
C
/* calibrate.c: default delay calibration
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*
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* Excised from init/main.c
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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#include <linux/jiffies.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <asm/timex.h>
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static unsigned long preset_lpj;
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static int __init lpj_setup(char *str)
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{
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preset_lpj = simple_strtoul(str,NULL,0);
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return 1;
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}
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__setup("lpj=", lpj_setup);
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#ifdef ARCH_HAS_READ_CURRENT_TIMER
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/* This routine uses the read_current_timer() routine and gets the
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* loops per jiffy directly, instead of guessing it using delay().
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* Also, this code tries to handle non-maskable asynchronous events
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* (like SMIs)
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*/
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#define DELAY_CALIBRATION_TICKS ((HZ < 100) ? 1 : (HZ/100))
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#define MAX_DIRECT_CALIBRATION_RETRIES 5
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static unsigned long __devinit calibrate_delay_direct(void)
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{
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unsigned long pre_start, start, post_start;
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unsigned long pre_end, end, post_end;
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unsigned long start_jiffies;
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unsigned long tsc_rate_min, tsc_rate_max;
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unsigned long good_tsc_sum = 0;
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unsigned long good_tsc_count = 0;
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int i;
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if (read_current_timer(&pre_start) < 0 )
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return 0;
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/*
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* A simple loop like
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* while ( jiffies < start_jiffies+1)
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* start = read_current_timer();
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* will not do. As we don't really know whether jiffy switch
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* happened first or timer_value was read first. And some asynchronous
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* event can happen between these two events introducing errors in lpj.
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*
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* So, we do
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* 1. pre_start <- When we are sure that jiffy switch hasn't happened
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* 2. check jiffy switch
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* 3. start <- timer value before or after jiffy switch
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* 4. post_start <- When we are sure that jiffy switch has happened
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*
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* Note, we don't know anything about order of 2 and 3.
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* Now, by looking at post_start and pre_start difference, we can
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* check whether any asynchronous event happened or not
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*/
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for (i = 0; i < MAX_DIRECT_CALIBRATION_RETRIES; i++) {
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pre_start = 0;
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read_current_timer(&start);
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start_jiffies = jiffies;
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while (jiffies <= (start_jiffies + 1)) {
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pre_start = start;
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read_current_timer(&start);
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}
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read_current_timer(&post_start);
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pre_end = 0;
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end = post_start;
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while (jiffies <=
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(start_jiffies + 1 + DELAY_CALIBRATION_TICKS)) {
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pre_end = end;
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read_current_timer(&end);
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}
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read_current_timer(&post_end);
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tsc_rate_max = (post_end - pre_start) / DELAY_CALIBRATION_TICKS;
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tsc_rate_min = (pre_end - post_start) / DELAY_CALIBRATION_TICKS;
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/*
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* If the upper limit and lower limit of the tsc_rate is
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* >= 12.5% apart, redo calibration.
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*/
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if (pre_start != 0 && pre_end != 0 &&
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(tsc_rate_max - tsc_rate_min) < (tsc_rate_max >> 3)) {
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good_tsc_count++;
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good_tsc_sum += tsc_rate_max;
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}
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}
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if (good_tsc_count)
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return (good_tsc_sum/good_tsc_count);
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printk(KERN_WARNING "calibrate_delay_direct() failed to get a good "
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"estimate for loops_per_jiffy.\nProbably due to long platform interrupts. Consider using \"lpj=\" boot option.\n");
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return 0;
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}
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#else
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static unsigned long __devinit calibrate_delay_direct(void) {return 0;}
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#endif
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/*
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* This is the number of bits of precision for the loops_per_jiffy. Each
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* bit takes on average 1.5/HZ seconds. This (like the original) is a little
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* better than 1%
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*/
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#define LPS_PREC 8
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void __devinit calibrate_delay(void)
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{
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unsigned long ticks, loopbit;
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int lps_precision = LPS_PREC;
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if (preset_lpj) {
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loops_per_jiffy = preset_lpj;
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printk("Calibrating delay loop (skipped)... "
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"%lu.%02lu BogoMIPS preset\n",
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loops_per_jiffy/(500000/HZ),
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(loops_per_jiffy/(5000/HZ)) % 100);
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} else if ((loops_per_jiffy = calibrate_delay_direct()) != 0) {
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printk("Calibrating delay using timer specific routine.. ");
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printk("%lu.%02lu BogoMIPS (lpj=%lu)\n",
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loops_per_jiffy/(500000/HZ),
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(loops_per_jiffy/(5000/HZ)) % 100,
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loops_per_jiffy);
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} else {
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loops_per_jiffy = (1<<12);
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printk(KERN_DEBUG "Calibrating delay loop... ");
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while ((loops_per_jiffy <<= 1) != 0) {
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/* wait for "start of" clock tick */
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ticks = jiffies;
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while (ticks == jiffies)
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/* nothing */;
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/* Go .. */
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ticks = jiffies;
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__delay(loops_per_jiffy);
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ticks = jiffies - ticks;
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if (ticks)
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break;
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}
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/*
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* Do a binary approximation to get loops_per_jiffy set to
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* equal one clock (up to lps_precision bits)
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*/
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loops_per_jiffy >>= 1;
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loopbit = loops_per_jiffy;
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while (lps_precision-- && (loopbit >>= 1)) {
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loops_per_jiffy |= loopbit;
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ticks = jiffies;
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while (ticks == jiffies)
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/* nothing */;
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ticks = jiffies;
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__delay(loops_per_jiffy);
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if (jiffies != ticks) /* longer than 1 tick */
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loops_per_jiffy &= ~loopbit;
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}
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/* Round the value and print it */
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printk("%lu.%02lu BogoMIPS (lpj=%lu)\n",
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loops_per_jiffy/(500000/HZ),
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(loops_per_jiffy/(5000/HZ)) % 100,
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loops_per_jiffy);
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}
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}
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