kernel-ark/arch/x86/lib/delay_64.c
Mike Travis 92cb7612ae x86: convert cpuinfo_x86 array to a per_cpu array
cpu_data is currently an array defined using NR_CPUS.  This means that
we overallocate since we will rarely really use maximum configured cpus.
When NR_CPU count is raised to 4096 the size of cpu_data becomes
3,145,728 bytes.

These changes were adopted from the sparc64 (and ia64) code.  An
additional field was added to cpuinfo_x86 to be a non-ambiguous cpu
index.  This corresponds to the index into a cpumask_t as well as the
per_cpu index.  It's used in various places like show_cpuinfo().

cpu_data is defined to be the boot_cpu_data structure for the NON-SMP
case.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-19 20:35:04 +02:00

59 lines
1.1 KiB
C

/*
* Precise Delay Loops for x86-64
*
* Copyright (C) 1993 Linus Torvalds
* Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
*
* The __delay function must _NOT_ be inlined as its execution time
* depends wildly on alignment on many x86 processors.
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <asm/delay.h>
#include <asm/msr.h>
#ifdef CONFIG_SMP
#include <asm/smp.h>
#endif
int read_current_timer(unsigned long *timer_value)
{
rdtscll(*timer_value);
return 0;
}
void __delay(unsigned long loops)
{
unsigned bclock, now;
rdtscl(bclock);
do
{
rep_nop();
rdtscl(now);
}
while((now-bclock) < loops);
}
EXPORT_SYMBOL(__delay);
inline void __const_udelay(unsigned long xloops)
{
__delay(((xloops * HZ *
cpu_data(raw_smp_processor_id()).loops_per_jiffy) >> 32) + 1);
}
EXPORT_SYMBOL(__const_udelay);
void __udelay(unsigned long usecs)
{
__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
}
EXPORT_SYMBOL(__udelay);
void __ndelay(unsigned long nsecs)
{
__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
}
EXPORT_SYMBOL(__ndelay);