[PATCH] Time: i386 Conversion - part 4: Remove Old timer_opts Code

Remove the old timers/timer_opts infrastructure which has been disabled.  It
is a fairly straightforward set of deletions

Note that this does not provide any i386 clocksources, so you will only have
the jiffies clocksource.  To get full replacements for the code being removed
here, the timeofday-clocks-i386 patch will be needed.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 439 deletions

diff --git a/arch/i386/kernel/timers/timer_tsc.c b/arch/i386/kernel/timers/timer_tsc.c
deleted file mode 100644
index 243ec0484079..000000000000
--- a/arch/i386/kernel/timers/timer_tsc.c
+++ /dev/null
@@ -1,439 +0,0 @@
-/*
- * This code largely moved from arch/i386/kernel/time.c.
- * See comments there for proper credits.
- *
- * 2004-06-25    Jesper Juhl
- *      moved mark_offset_tsc below cpufreq_delayed_get to avoid gcc 3.4
- *      failing to inline.
- */
-
-#include <linux/spinlock.h>
-#include <linux/init.h>
-#include <linux/timex.h>
-#include <linux/errno.h>
-#include <linux/cpufreq.h>
-#include <linux/string.h>
-#include <linux/jiffies.h>
-
-#include <asm/timer.h>
-#include <asm/io.h>
-/* processor.h for distable_tsc flag */
-#include <asm/processor.h>
-
-#include "io_ports.h"
-#include "mach_timer.h"
-
-#include <asm/hpet.h>
-#include <asm/i8253.h>
-
-#ifdef CONFIG_HPET_TIMER
-static unsigned long hpet_usec_quotient;
-static unsigned long hpet_last;
-static struct timer_opts timer_tsc;
-#endif
-
-static int use_tsc;
-/* Number of usecs that the last interrupt was delayed */
-static int delay_at_last_interrupt;
-
-static unsigned long last_tsc_low; /* lsb 32 bits of Time Stamp Counter */
-static unsigned long last_tsc_high; /* msb 32 bits of Time Stamp Counter */
-static unsigned long long monotonic_base;
-static seqlock_t monotonic_lock = SEQLOCK_UNLOCKED;
-
-/* Avoid compensating for lost ticks before TSCs are synched */
-static int detect_lost_ticks;
-static int __init start_lost_tick_compensation(void)
-{
-	detect_lost_ticks = 1;
-	return 0;
-}
-late_initcall(start_lost_tick_compensation);
-
-/* convert from cycles(64bits) => nanoseconds (64bits)
- *  basic equation:
- *		ns = cycles / (freq / ns_per_sec)
- *		ns = cycles * (ns_per_sec / freq)
- *		ns = cycles * (10^9 / (cpu_khz * 10^3))
- *		ns = cycles * (10^6 / cpu_khz)
- *
- *	Then we use scaling math (suggested by george@mvista.com) to get:
- *		ns = cycles * (10^6 * SC / cpu_khz) / SC
- *		ns = cycles * cyc2ns_scale / SC
- *
- *	And since SC is a constant power of two, we can convert the div
- *  into a shift.
- *
- *  We can use khz divisor instead of mhz to keep a better percision, since
- *  cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
- *  (mathieu.desnoyers@polymtl.ca)
- *
- *			-johnstul@us.ibm.com "math is hard, lets go shopping!"
- */
-static unsigned long cyc2ns_scale __read_mostly;
-#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
-
-static inline void set_cyc2ns_scale(unsigned long cpu_khz)
-{
-	cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR)/cpu_khz;
-}
-
-static inline unsigned long long cycles_2_ns(unsigned long long cyc)
-{
-	return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
-}
-
-static int count2; /* counter for mark_offset_tsc() */
-
-/* Cached *multiplier* to convert TSC counts to microseconds.
- * (see the equation below).
- * Equal to 2^32 * (1 / (clocks per usec) ).
- * Initialized in time_init.
- */
-static unsigned long fast_gettimeoffset_quotient;
-
-static unsigned long get_offset_tsc(void)
-{
-	register unsigned long eax, edx;
-
-	/* Read the Time Stamp Counter */
-
-	rdtsc(eax,edx);
-
-	/* .. relative to previous jiffy (32 bits is enough) */
-	eax -= last_tsc_low;	/* tsc_low delta */
-
-	/*
-         * Time offset = (tsc_low delta) * fast_gettimeoffset_quotient
-         *             = (tsc_low delta) * (usecs_per_clock)
-         *             = (tsc_low delta) * (usecs_per_jiffy / clocks_per_jiffy)
-	 *
-	 * Using a mull instead of a divl saves up to 31 clock cycles
-	 * in the critical path.
-         */
-
-	__asm__("mull %2"
-		:"=a" (eax), "=d" (edx)
-		:"rm" (fast_gettimeoffset_quotient),
-		 "0" (eax));
-
-	/* our adjusted time offset in microseconds */
-	return delay_at_last_interrupt + edx;
-}
-
-static unsigned long long monotonic_clock_tsc(void)
-{
-	unsigned long long last_offset, this_offset, base;
-	unsigned seq;
-	
-	/* atomically read monotonic base & last_offset */
-	do {
-		seq = read_seqbegin(&monotonic_lock);
-		last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
-		base = monotonic_base;
-	} while (read_seqretry(&monotonic_lock, seq));
-
-	/* Read the Time Stamp Counter */
-	rdtscll(this_offset);
-
-	/* return the value in ns */
-	return base + cycles_2_ns(this_offset - last_offset);
-}
-
-static void delay_tsc(unsigned long loops)
-{
-	unsigned long bclock, now;
-	
-	rdtscl(bclock);
-	do
-	{
-		rep_nop();
-		rdtscl(now);
-	} while ((now-bclock) < loops);
-}
-
-#ifdef CONFIG_HPET_TIMER
-static void mark_offset_tsc_hpet(void)
-{
-	unsigned long long this_offset, last_offset;
- 	unsigned long offset, temp, hpet_current;
-
-	write_seqlock(&monotonic_lock);
-	last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
-	/*
-	 * It is important that these two operations happen almost at
-	 * the same time. We do the RDTSC stuff first, since it's
-	 * faster. To avoid any inconsistencies, we need interrupts
-	 * disabled locally.
-	 */
-	/*
-	 * Interrupts are just disabled locally since the timer irq
-	 * has the SA_INTERRUPT flag set. -arca
-	 */
-	/* read Pentium cycle counter */
-
-	hpet_current = hpet_readl(HPET_COUNTER);
-	rdtsc(last_tsc_low, last_tsc_high);
-
-	/* lost tick compensation */
-	offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
-	if (unlikely(((offset - hpet_last) > hpet_tick) && (hpet_last != 0))
-					&& detect_lost_ticks) {
-		int lost_ticks = (offset - hpet_last) / hpet_tick;
-		jiffies_64 += lost_ticks;
-	}
-	hpet_last = hpet_current;
-
-	/* update the monotonic base value */
-	this_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
-	monotonic_base += cycles_2_ns(this_offset - last_offset);
-	write_sequnlock(&monotonic_lock);
-
-	/* calculate delay_at_last_interrupt */
-	/*
-	 * Time offset = (hpet delta) * ( usecs per HPET clock )
-	 *             = (hpet delta) * ( usecs per tick / HPET clocks per tick)
-	 *             = (hpet delta) * ( hpet_usec_quotient ) / (2^32)
-	 * Where,
-	 * hpet_usec_quotient = (2^32 * usecs per tick)/HPET clocks per tick
-	 */
-	delay_at_last_interrupt = hpet_current - offset;
-	ASM_MUL64_REG(temp, delay_at_last_interrupt,
-			hpet_usec_quotient, delay_at_last_interrupt);
-}
-#endif
-
-static void mark_offset_tsc(void)
-{
-	unsigned long lost,delay;
-	unsigned long delta = last_tsc_low;
-	int count;
-	int countmp;
-	static int count1 = 0;
-	unsigned long long this_offset, last_offset;
-	static int lost_count = 0;
-
-	write_seqlock(&monotonic_lock);
-	last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
-	/*
-	 * It is important that these two operations happen almost at
-	 * the same time. We do the RDTSC stuff first, since it's
-	 * faster. To avoid any inconsistencies, we need interrupts
-	 * disabled locally.
-	 */
-
-	/*
-	 * Interrupts are just disabled locally since the timer irq
-	 * has the SA_INTERRUPT flag set. -arca
-	 */
-
-	/* read Pentium cycle counter */
-
-	rdtsc(last_tsc_low, last_tsc_high);
-
-	spin_lock(&i8253_lock);
-	outb_p(0x00, PIT_MODE);     /* latch the count ASAP */
-
-	count = inb_p(PIT_CH0);    /* read the latched count */
-	count |= inb(PIT_CH0) << 8;
-
-	/*
-	 * VIA686a test code... reset the latch if count > max + 1
-	 * from timer_pit.c - cjb
-	 */
-	if (count > LATCH) {
-		outb_p(0x34, PIT_MODE);
-		outb_p(LATCH & 0xff, PIT_CH0);
-		outb(LATCH >> 8, PIT_CH0);
-		count = LATCH - 1;
-	}
-
-	spin_unlock(&i8253_lock);
-
-	if (pit_latch_buggy) {
-		/* get center value of last 3 time lutch */
-		if ((count2 >= count && count >= count1)
-		    || (count1 >= count && count >= count2)) {
-			count2 = count1; count1 = count;
-		} else if ((count1 >= count2 && count2 >= count)
-			   || (count >= count2 && count2 >= count1)) {
-			countmp = count;count = count2;
-			count2 = count1;count1 = countmp;
-		} else {
-			count2 = count1; count1 = count; count = count1;
-		}
-	}
-
-	/* lost tick compensation */
-	delta = last_tsc_low - delta;
-	{
-		register unsigned long eax, edx;
-		eax = delta;
-		__asm__("mull %2"
-		:"=a" (eax), "=d" (edx)
-		:"rm" (fast_gettimeoffset_quotient),
-		 "0" (eax));
-		delta = edx;
-	}
-	delta += delay_at_last_interrupt;
-	lost = delta/(1000000/HZ);
-	delay = delta%(1000000/HZ);
-	if (lost >= 2 && detect_lost_ticks) {
-		jiffies_64 += lost-1;
-
-		/* sanity check to ensure we're not always losing ticks */
-		if (lost_count++ > 100) {
-			printk(KERN_WARNING "Losing too many ticks!\n");
-			printk(KERN_WARNING "TSC cannot be used as a timesource.  \n");
-			printk(KERN_WARNING "Possible reasons for this are:\n");
-			printk(KERN_WARNING "  You're running with Speedstep,\n");
-			printk(KERN_WARNING "  You don't have DMA enabled for your hard disk (see hdparm),\n");
-			printk(KERN_WARNING "  Incorrect TSC synchronization on an SMP system (see dmesg).\n");
-			printk(KERN_WARNING "Falling back to a sane timesource now.\n");
-
-			clock_fallback();
-		}
-	} else
-		lost_count = 0;
-	/* update the monotonic base value */
-	this_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
-	monotonic_base += cycles_2_ns(this_offset - last_offset);
-	write_sequnlock(&monotonic_lock);
-
-	/* calculate delay_at_last_interrupt */
-	count = ((LATCH-1) - count) * TICK_SIZE;
-	delay_at_last_interrupt = (count + LATCH/2) / LATCH;
-
-	/* catch corner case where tick rollover occured
-	 * between tsc and pit reads (as noted when
-	 * usec delta is > 90% # of usecs/tick)
-	 */
-	if (lost && abs(delay - delay_at_last_interrupt) > (900000/HZ))
-		jiffies_64++;
-}
-
-static int __init init_tsc(char* override)
-{
-
-	/* check clock override */
-	if (override[0] && strncmp(override,"tsc",3)) {
-#ifdef CONFIG_HPET_TIMER
-		if (is_hpet_enabled()) {
-			printk(KERN_ERR "Warning: clock= override failed. Defaulting to tsc\n");
-		} else
-#endif
-		{
-			return -ENODEV;
-		}
-	}
-
-	/*
-	 * If we have APM enabled or the CPU clock speed is variable
-	 * (CPU stops clock on HLT or slows clock to save power)
-	 * then the TSC timestamps may diverge by up to 1 jiffy from
-	 * 'real time' but nothing will break.
-	 * The most frequent case is that the CPU is "woken" from a halt
-	 * state by the timer interrupt itself, so we get 0 error. In the
-	 * rare cases where a driver would "wake" the CPU and request a
-	 * timestamp, the maximum error is < 1 jiffy. But timestamps are
-	 * still perfectly ordered.
-	 * Note that the TSC counter will be reset if APM suspends
-	 * to disk; this won't break the kernel, though, 'cuz we're
-	 * smart.  See arch/i386/kernel/apm.c.
-	 */
- 	/*
- 	 *	Firstly we have to do a CPU check for chips with
- 	 * 	a potentially buggy TSC. At this point we haven't run
- 	 *	the ident/bugs checks so we must run this hook as it
- 	 *	may turn off the TSC flag.
- 	 *
- 	 *	NOTE: this doesn't yet handle SMP 486 machines where only
- 	 *	some CPU's have a TSC. Thats never worked and nobody has
- 	 *	moaned if you have the only one in the world - you fix it!
- 	 */
-
-	count2 = LATCH; /* initialize counter for mark_offset_tsc() */
-
-	if (cpu_has_tsc) {
-		unsigned long tsc_quotient;
-#ifdef CONFIG_HPET_TIMER
-		if (is_hpet_enabled() && hpet_use_timer) {
-			unsigned long result, remain;
-			printk("Using TSC for gettimeofday\n");
-			tsc_quotient = calibrate_tsc_hpet(NULL);
-			timer_tsc.mark_offset = &mark_offset_tsc_hpet;
-			/*
-			 * Math to calculate hpet to usec multiplier
-			 * Look for the comments at get_offset_tsc_hpet()
-			 */
-			ASM_DIV64_REG(result, remain, hpet_tick,
-					0, KERNEL_TICK_USEC);
-			if (remain > (hpet_tick >> 1))
-				result++; /* rounding the result */
-
-			hpet_usec_quotient = result;
-		} else
-#endif
-		{
-			tsc_quotient = calibrate_tsc();
-		}
-
-		if (tsc_quotient) {
-			fast_gettimeoffset_quotient = tsc_quotient;
-			use_tsc = 1;
-			/*
-			 *	We could be more selective here I suspect
-			 *	and just enable this for the next intel chips ?
-			 */
-			/* report CPU clock rate in Hz.
-			 * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
-			 * clock/second. Our precision is about 100 ppm.
-			 */
-			{	unsigned long eax=0, edx=1000;
-				__asm__("divl %2"
-		       		:"=a" (cpu_khz), "=d" (edx)
-        	       		:"r" (tsc_quotient),
-	                	"0" (eax), "1" (edx));
-				printk("Detected %u.%03u MHz processor.\n",
-					cpu_khz / 1000, cpu_khz % 1000);
-			}
-			set_cyc2ns_scale(cpu_khz);
-			return 0;
-		}
-	}
-	return -ENODEV;
-}
-
-static int tsc_resume(void)
-{
-	write_seqlock(&monotonic_lock);
-	/* Assume this is the last mark offset time */
-	rdtsc(last_tsc_low, last_tsc_high);
-#ifdef CONFIG_HPET_TIMER
-	if (is_hpet_enabled() && hpet_use_timer)
-		hpet_last = hpet_readl(HPET_COUNTER);
-#endif
-	write_sequnlock(&monotonic_lock);
-	return 0;
-}
-
-
-
-
-/************************************************************/
-
-/* tsc timer_opts struct */
-static struct timer_opts timer_tsc = {
-	.name = "tsc",
-	.mark_offset = mark_offset_tsc, 
-	.get_offset = get_offset_tsc,
-	.monotonic_clock = monotonic_clock_tsc,
-	.delay = delay_tsc,
-	.read_timer = read_timer_tsc,
-	.resume	= tsc_resume,
-};
-
-struct init_timer_opts __initdata timer_tsc_init = {
-	.init = init_tsc,
-	.opts = &timer_tsc,
-};