eabdd0252a
The value from raw_read_cntfrq_el0() could be large enough to cause overflow when multiplied by USECS_PER_SEC. To prevent this, both USECS_PER_SEC and hz can be reduced by dividing them by their GCD. This patch also modifies the return type of `timer_hz()` from `uint64_t` to `uint32_t`, assuming that in practice the timestamp counter should never be that fast. BUG=b:307790895 TEST=boot to kernel and check the timestamps from `cbmem` Change-Id: Ia55532490651fcf47128b83a8554751f050bcc89 Signed-off-by: Yidi Lin <yidilin@chromium.org> Reviewed-on: https://review.coreboot.org/c/coreboot/+/78888 Reviewed-by: Julius Werner <jwerner@chromium.org> Reviewed-by: Yu-Ping Wu <yupingso@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
48 lines
1.8 KiB
C
48 lines
1.8 KiB
C
/*
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*
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* Copyright (C) 2008 Advanced Micro Devices, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/**
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* @file x86/timer.c
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* x86 specific timer routines
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*/
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#include <libpayload.h>
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#include <arch/rdtsc.h>
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#include <assert.h>
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uint32_t timer_hz(void)
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{
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assert(UINT32_MAX / 1000 >= lib_sysinfo.cpu_khz);
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return lib_sysinfo.cpu_khz * 1000;
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}
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uint64_t timer_raw_value(void)
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{
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return rdtsc();
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}
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