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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2007 by Ralf Baechle
*/
#include <linux/clocksource.h>
#include <linux/init.h>
#include <asm/time.h>
#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-ipd-defs.h>
/*
* Set the current core's cvmcount counter to the value of the
* IPD_CLK_COUNT. We do this on all cores as they are brought
* on-line. This allows for a read from a local cpu register to
* access a synchronized counter.
*
*/
void octeon_init_cvmcount(void)
{
unsigned long flags;
unsigned loops = 2;
/* Clobber loops so GCC will not unroll the following while loop. */
asm("" : "+r" (loops));
local_irq_save(flags);
/*
* Loop several times so we are executing from the cache,
* which should give more deterministic timing.
*/
while (loops--)
write_c0_cvmcount(cvmx_read_csr(CVMX_IPD_CLK_COUNT));
local_irq_restore(flags);
}
static cycle_t octeon_cvmcount_read(struct clocksource *cs)
{
return read_c0_cvmcount();
}
static struct clocksource clocksource_mips = {
.name = "OCTEON_CVMCOUNT",
.read = octeon_cvmcount_read,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
unsigned long long notrace sched_clock(void)
{
return clocksource_cyc2ns(read_c0_cvmcount(),
clocksource_mips.mult,
clocksource_mips.shift);
}
void __init plat_time_init(void)
{
clocksource_mips.rating = 300;
clocksource_set_clock(&clocksource_mips, mips_hpt_frequency);
clocksource_register(&clocksource_mips);
}
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