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authorDavid Woodhouse <dwmw2@infradead.org>2007-01-18 00:34:51 +0100
committerDavid Woodhouse <dwmw2@infradead.org>2007-01-18 00:34:51 +0100
commit9cdf083f981b8d37b3212400a359368661385099 (patch)
treeaa15a6a08ad87e650dea40fb59b3180bef0d345b /drivers/char/ftape/lowlevel/ftape-calibr.c
parent[JFFS2] debug.h: include <linux/sched.h> for current->pid (diff)
parentLinux v2.6.20-rc5 (diff)
downloadlinux-9cdf083f981b8d37b3212400a359368661385099.tar.xz
linux-9cdf083f981b8d37b3212400a359368661385099.zip
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'drivers/char/ftape/lowlevel/ftape-calibr.c')
-rw-r--r--drivers/char/ftape/lowlevel/ftape-calibr.c275
1 files changed, 0 insertions, 275 deletions
diff --git a/drivers/char/ftape/lowlevel/ftape-calibr.c b/drivers/char/ftape/lowlevel/ftape-calibr.c
deleted file mode 100644
index 8e50bfd35a52..000000000000
--- a/drivers/char/ftape/lowlevel/ftape-calibr.c
+++ /dev/null
@@ -1,275 +0,0 @@
-/*
- * Copyright (C) 1993-1996 Bas Laarhoven.
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; see the file COPYING. If not, write to
- the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
-
- *
- * $Source: /homes/cvs/ftape-stacked/ftape/lowlevel/ftape-calibr.c,v $
- * $Revision: 1.2 $
- * $Date: 1997/10/05 19:18:08 $
- *
- * GP calibration routine for processor speed dependent
- * functions.
- */
-
-#include <linux/errno.h>
-#include <linux/jiffies.h>
-#include <asm/system.h>
-#include <asm/io.h>
-#if defined(__alpha__)
-# include <asm/hwrpb.h>
-#elif defined(__x86_64__)
-# include <asm/msr.h>
-# include <asm/timex.h>
-#elif defined(__i386__)
-# include <linux/timex.h>
-#endif
-#include <linux/ftape.h>
-#include "../lowlevel/ftape-tracing.h"
-#include "../lowlevel/ftape-calibr.h"
-#include "../lowlevel/fdc-io.h"
-
-#undef DEBUG
-
-#if !defined(__alpha__) && !defined(__i386__) && !defined(__x86_64__)
-# error Ftape is not implemented for this architecture!
-#endif
-
-#if defined(__alpha__) || defined(__x86_64__)
-static unsigned long ps_per_cycle = 0;
-#endif
-
-static spinlock_t calibr_lock;
-
-/*
- * Note: On Intel PCs, the clock ticks at 100 Hz (HZ==100) which is
- * too slow for certain timeouts (and that clock doesn't even tick
- * when interrupts are disabled). For that reason, the 8254 timer is
- * used directly to implement fine-grained timeouts. However, on
- * Alpha PCs, the 8254 is *not* used to implement the clock tick
- * (which is 1024 Hz, normally) and the 8254 timer runs at some
- * "random" frequency (it seems to run at 18Hz, but it's not safe to
- * rely on this value). Instead, we use the Alpha's "rpcc"
- * instruction to read cycle counts. As this is a 32 bit counter,
- * it will overflow only once per 30 seconds (on a 200MHz machine),
- * which is plenty.
- */
-
-unsigned int ftape_timestamp(void)
-{
-#if defined(__alpha__)
- unsigned long r;
-
- asm volatile ("rpcc %0" : "=r" (r));
- return r;
-#elif defined(__x86_64__)
- unsigned long r;
- rdtscl(r);
- return r;
-#elif defined(__i386__)
-
-/*
- * Note that there is some time between counter underflowing and jiffies
- * increasing, so the code below won't always give correct output.
- * -Vojtech
- */
-
- unsigned long flags;
- __u16 lo;
- __u16 hi;
-
- spin_lock_irqsave(&calibr_lock, flags);
- outb_p(0x00, 0x43); /* latch the count ASAP */
- lo = inb_p(0x40); /* read the latched count */
- lo |= inb(0x40) << 8;
- hi = jiffies;
- spin_unlock_irqrestore(&calibr_lock, flags);
- return ((hi + 1) * (unsigned int) LATCH) - lo; /* downcounter ! */
-#endif
-}
-
-static unsigned int short_ftape_timestamp(void)
-{
-#if defined(__alpha__) || defined(__x86_64__)
- return ftape_timestamp();
-#elif defined(__i386__)
- unsigned int count;
- unsigned long flags;
-
- spin_lock_irqsave(&calibr_lock, flags);
- outb_p(0x00, 0x43); /* latch the count ASAP */
- count = inb_p(0x40); /* read the latched count */
- count |= inb(0x40) << 8;
- spin_unlock_irqrestore(&calibr_lock, flags);
- return (LATCH - count); /* normal: downcounter */
-#endif
-}
-
-static unsigned int diff(unsigned int t0, unsigned int t1)
-{
-#if defined(__alpha__) || defined(__x86_64__)
- return (t1 - t0);
-#elif defined(__i386__)
- /*
- * This is tricky: to work for both short and full ftape_timestamps
- * we'll have to discriminate between these.
- * If it _looks_ like short stamps with wrapping around we'll
- * asume it are. This will generate a small error if it really
- * was a (very large) delta from full ftape_timestamps.
- */
- return (t1 <= t0 && t0 <= LATCH) ? t1 + LATCH - t0 : t1 - t0;
-#endif
-}
-
-static unsigned int usecs(unsigned int count)
-{
-#if defined(__alpha__) || defined(__x86_64__)
- return (ps_per_cycle * count) / 1000000UL;
-#elif defined(__i386__)
- return (10000 * count) / ((CLOCK_TICK_RATE + 50) / 100);
-#endif
-}
-
-unsigned int ftape_timediff(unsigned int t0, unsigned int t1)
-{
- /*
- * Calculate difference in usec for ftape_timestamp results t0 & t1.
- * Note that on the i386 platform with short time-stamps, the
- * maximum allowed timespan is 1/HZ or we'll lose ticks!
- */
- return usecs(diff(t0, t1));
-}
-
-/* To get an indication of the I/O performance,
- * measure the duration of the inb() function.
- */
-static void time_inb(void)
-{
- int i;
- int t0, t1;
- unsigned long flags;
- int status;
- TRACE_FUN(ft_t_any);
-
- spin_lock_irqsave(&calibr_lock, flags);
- t0 = short_ftape_timestamp();
- for (i = 0; i < 1000; ++i) {
- status = inb(fdc.msr);
- }
- t1 = short_ftape_timestamp();
- spin_unlock_irqrestore(&calibr_lock, flags);
- TRACE(ft_t_info, "inb() duration: %d nsec", ftape_timediff(t0, t1));
- TRACE_EXIT;
-}
-
-static void init_clock(void)
-{
- TRACE_FUN(ft_t_any);
-
-#if defined(__x86_64__)
- ps_per_cycle = 1000000000UL / cpu_khz;
-#elif defined(__alpha__)
- extern struct hwrpb_struct *hwrpb;
- ps_per_cycle = (1000*1000*1000*1000UL) / hwrpb->cycle_freq;
-#endif
- TRACE_EXIT;
-}
-
-/*
- * Input: function taking int count as parameter.
- * pointers to calculated calibration variables.
- */
-void ftape_calibrate(char *name,
- void (*fun) (unsigned int),
- unsigned int *calibr_count,
- unsigned int *calibr_time)
-{
- static int first_time = 1;
- int i;
- unsigned int tc = 0;
- unsigned int count;
- unsigned int time;
-#if defined(__i386__)
- unsigned int old_tc = 0;
- unsigned int old_count = 1;
- unsigned int old_time = 1;
-#endif
- TRACE_FUN(ft_t_flow);
-
- if (first_time) { /* get idea of I/O performance */
- init_clock();
- time_inb();
- first_time = 0;
- }
- /* value of timeout must be set so that on very slow systems
- * it will give a time less than one jiffy, and on
- * very fast systems it'll give reasonable precision.
- */
-
- count = 40;
- for (i = 0; i < 15; ++i) {
- unsigned int t0;
- unsigned int t1;
- unsigned int once;
- unsigned int multiple;
- unsigned long flags;
-
- *calibr_count =
- *calibr_time = count; /* set TC to 1 */
- spin_lock_irqsave(&calibr_lock, flags);
- fun(0); /* dummy, get code into cache */
- t0 = short_ftape_timestamp();
- fun(0); /* overhead + one test */
- t1 = short_ftape_timestamp();
- once = diff(t0, t1);
- t0 = short_ftape_timestamp();
- fun(count); /* overhead + count tests */
- t1 = short_ftape_timestamp();
- multiple = diff(t0, t1);
- spin_unlock_irqrestore(&calibr_lock, flags);
- time = ftape_timediff(0, multiple - once);
- tc = (1000 * time) / (count - 1);
- TRACE(ft_t_any, "once:%3d us,%6d times:%6d us, TC:%5d ns",
- usecs(once), count - 1, usecs(multiple), tc);
-#if defined(__alpha__) || defined(__x86_64__)
- /*
- * Increase the calibration count exponentially until the
- * calibration time exceeds 100 ms.
- */
- if (time >= 100*1000) {
- break;
- }
-#elif defined(__i386__)
- /*
- * increase the count until the resulting time nears 2/HZ,
- * then the tc will drop sharply because we lose LATCH counts.
- */
- if (tc <= old_tc / 2) {
- time = old_time;
- count = old_count;
- break;
- }
- old_tc = tc;
- old_count = count;
- old_time = time;
-#endif
- count *= 2;
- }
- *calibr_count = count - 1;
- *calibr_time = time;
- TRACE(ft_t_info, "TC for `%s()' = %d nsec (at %d counts)",
- name, (1000 * *calibr_time) / *calibr_count, *calibr_count);
- TRACE_EXIT;
-}