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