40 lines
1003 B
C
40 lines
1003 B
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2020-2022 Martin Whitaker.
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#include <stdint.h>
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#include "cpuinfo.h"
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#include "tsc.h"
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#include "unistd.h"
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//------------------------------------------------------------------------------
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// Public Functions
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//------------------------------------------------------------------------------
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void usleep(unsigned int usec)
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{
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if (clks_per_msec > 0) {
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// If we've measured the CPU speed, we know the TSC is available.
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uint64_t cycles = ((uint64_t)usec * clks_per_msec) / 1000;
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uint64_t t0 = get_tsc();
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do {
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__builtin_ia32_pause();
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} while ((get_tsc() - t0) < cycles);
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} else {
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// This will be highly inaccurate, but should give at least the requested delay.
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volatile uint64_t count = (uint64_t)usec * 1000;
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while (count > 0) {
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count--;
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}
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}
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}
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void sleep(unsigned int sec)
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{
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while (sec > 0) {
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usleep(1000000);
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sec--;
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}
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}
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