acfc3c5257
Add a tickless timer driver for x86. The driver defaults to using TSC_DEADLINE mode, but falls back to the apic if that feature is not available.
48 lines
1.2 KiB
C
48 lines
1.2 KiB
C
/*
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* Copyright 2019, Data61
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* Commonwealth Scientific and Industrial Research Organisation (CSIRO)
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* ABN 41 687 119 230.
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*
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* This software may be distributed and modified according to the terms of
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* the GNU General Public License version 2. Note that NO WARRANTY is provided.
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* See "LICENSE_GPLv2.txt" for details.
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*
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* @TAG(DATA61_GPL)
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*/
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#ifndef __MODE_UTIL_H
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#define __MODE_UTIL_H
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#include <config.h>
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#include <types.h>
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#include <arch/model/statedata.h>
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static inline CONST uint64_t div64(uint64_t numerator, uint32_t denominator)
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{
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uint64_t quotient = 0llu;
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uint64_t long_denom = (uint64_t) denominator;
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if (unlikely(denominator > numerator)) {
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return 0;
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}
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assert(numerator > 0);
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assert(denominator > 0);
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/* align denominator to numerator */
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uint64_t c = ((uint64_t) 32u + clzl(denominator)) - clzll(numerator);
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long_denom = long_denom << c;
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/* perform binary long division */
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while (c < UINT64_MAX) {
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if (numerator >= long_denom) {
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numerator -= long_denom;
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quotient |= (1llu << c);
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}
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c--;
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long_denom = long_denom >> 1llu;
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}
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return quotient;
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}
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#endif /* __MODE_UTIL_H */
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