60 lines
1.4 KiB
C
60 lines
1.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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#include <stdio.h>
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#include <errno.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include "cpupower_intern.h"
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#include "acpi_cppc.h"
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/* ACPI CPPC sysfs access ***********************************************/
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static int acpi_cppc_read_file(unsigned int cpu, const char *fname,
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char *buf, size_t buflen)
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{
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char path[SYSFS_PATH_MAX];
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snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/acpi_cppc/%s",
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cpu, fname);
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return cpupower_read_sysfs(path, buf, buflen);
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}
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static const char * const acpi_cppc_value_files[] = {
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[HIGHEST_PERF] = "highest_perf",
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[LOWEST_PERF] = "lowest_perf",
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[NOMINAL_PERF] = "nominal_perf",
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[LOWEST_NONLINEAR_PERF] = "lowest_nonlinear_perf",
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[LOWEST_FREQ] = "lowest_freq",
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[NOMINAL_FREQ] = "nominal_freq",
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[REFERENCE_PERF] = "reference_perf",
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[WRAPAROUND_TIME] = "wraparound_time"
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};
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unsigned long acpi_cppc_get_data(unsigned int cpu, enum acpi_cppc_value which)
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{
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unsigned long long value;
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unsigned int len;
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char linebuf[MAX_LINE_LEN];
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char *endp;
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if (which >= MAX_CPPC_VALUE_FILES)
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return 0;
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len = acpi_cppc_read_file(cpu, acpi_cppc_value_files[which],
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linebuf, sizeof(linebuf));
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if (len == 0)
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return 0;
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value = strtoull(linebuf, &endp, 0);
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if (endp == linebuf || errno == ERANGE)
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return 0;
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return value;
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}
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