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-rw-r--r--tools/power/cpupower/lib/cpupower.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/tools/power/cpupower/lib/cpupower.c b/tools/power/cpupower/lib/cpupower.c
new file mode 100644
index 000000000..3f7d0c0c5
--- /dev/null
+++ b/tools/power/cpupower/lib/cpupower.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * (C) 2004-2009 Dominik Brodowski <linux@dominikbrodowski.de>
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+
+#include "cpupower.h"
+#include "cpupower_intern.h"
+
+unsigned int cpupower_read_sysfs(const char *path, char *buf, size_t buflen)
+{
+ ssize_t numread;
+ int fd;
+
+ fd = open(path, O_RDONLY);
+ if (fd == -1)
+ return 0;
+
+ numread = read(fd, buf, buflen - 1);
+ if (numread < 1) {
+ close(fd);
+ return 0;
+ }
+
+ buf[numread] = '\0';
+ close(fd);
+
+ return (unsigned int) numread;
+}
+
+unsigned int cpupower_write_sysfs(const char *path, char *buf, size_t buflen)
+{
+ ssize_t numwritten;
+ int fd;
+
+ fd = open(path, O_WRONLY);
+ if (fd == -1)
+ return 0;
+
+ numwritten = write(fd, buf, buflen - 1);
+ if (numwritten < 1) {
+ perror(path);
+ close(fd);
+ return -1;
+ }
+
+ close(fd);
+
+ return (unsigned int) numwritten;
+}
+
+/*
+ * Detect whether a CPU is online
+ *
+ * Returns:
+ * 1 -> if CPU is online
+ * 0 -> if CPU is offline
+ * negative errno values in error case
+ */
+int cpupower_is_cpu_online(unsigned int cpu)
+{
+ char path[SYSFS_PATH_MAX];
+ int fd;
+ ssize_t numread;
+ unsigned long long value;
+ char linebuf[MAX_LINE_LEN];
+ char *endp;
+ struct stat statbuf;
+
+ snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u", cpu);
+
+ if (stat(path, &statbuf) != 0)
+ return 0;
+
+ /*
+ * kernel without CONFIG_HOTPLUG_CPU
+ * -> cpuX directory exists, but not cpuX/online file
+ */
+ snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/online", cpu);
+ if (stat(path, &statbuf) != 0)
+ return 1;
+
+ fd = open(path, O_RDONLY);
+ if (fd == -1)
+ return -errno;
+
+ numread = read(fd, linebuf, MAX_LINE_LEN - 1);
+ if (numread < 1) {
+ close(fd);
+ return -EIO;
+ }
+ linebuf[numread] = '\0';
+ close(fd);
+
+ value = strtoull(linebuf, &endp, 0);
+ if (value > 1)
+ return -EINVAL;
+
+ return value;
+}
+
+/* returns -1 on failure, 0 on success */
+static int sysfs_topology_read_file(unsigned int cpu, const char *fname, int *result)
+{
+ char linebuf[MAX_LINE_LEN];
+ char *endp;
+ char path[SYSFS_PATH_MAX];
+
+ snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/topology/%s",
+ cpu, fname);
+ if (cpupower_read_sysfs(path, linebuf, MAX_LINE_LEN) == 0)
+ return -1;
+ *result = strtol(linebuf, &endp, 0);
+ if (endp == linebuf || errno == ERANGE)
+ return -1;
+ return 0;
+}
+
+static int __compare(const void *t1, const void *t2)
+{
+ struct cpuid_core_info *top1 = (struct cpuid_core_info *)t1;
+ struct cpuid_core_info *top2 = (struct cpuid_core_info *)t2;
+ if (top1->pkg < top2->pkg)
+ return -1;
+ else if (top1->pkg > top2->pkg)
+ return 1;
+ else if (top1->core < top2->core)
+ return -1;
+ else if (top1->core > top2->core)
+ return 1;
+ else if (top1->cpu < top2->cpu)
+ return -1;
+ else if (top1->cpu > top2->cpu)
+ return 1;
+ else
+ return 0;
+}
+
+/*
+ * Returns amount of cpus, negative on error, cpu_top must be
+ * passed to cpu_topology_release to free resources
+ *
+ * Array is sorted after ->pkg, ->core, then ->cpu
+ */
+int get_cpu_topology(struct cpupower_topology *cpu_top)
+{
+ int cpu, last_pkg, cpus = sysconf(_SC_NPROCESSORS_CONF);
+
+ cpu_top->core_info = malloc(sizeof(struct cpuid_core_info) * cpus);
+ if (cpu_top->core_info == NULL)
+ return -ENOMEM;
+ cpu_top->pkgs = cpu_top->cores = 0;
+ for (cpu = 0; cpu < cpus; cpu++) {
+ cpu_top->core_info[cpu].cpu = cpu;
+ cpu_top->core_info[cpu].is_online = cpupower_is_cpu_online(cpu);
+ if(sysfs_topology_read_file(
+ cpu,
+ "physical_package_id",
+ &(cpu_top->core_info[cpu].pkg)) < 0) {
+ cpu_top->core_info[cpu].pkg = -1;
+ cpu_top->core_info[cpu].core = -1;
+ continue;
+ }
+ if(sysfs_topology_read_file(
+ cpu,
+ "core_id",
+ &(cpu_top->core_info[cpu].core)) < 0) {
+ cpu_top->core_info[cpu].pkg = -1;
+ cpu_top->core_info[cpu].core = -1;
+ continue;
+ }
+ }
+
+ qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info),
+ __compare);
+
+ /* Count the number of distinct pkgs values. This works
+ because the primary sort of the core_info struct was just
+ done by pkg value. */
+ last_pkg = cpu_top->core_info[0].pkg;
+ for(cpu = 1; cpu < cpus; cpu++) {
+ if (cpu_top->core_info[cpu].pkg != last_pkg &&
+ cpu_top->core_info[cpu].pkg != -1) {
+
+ last_pkg = cpu_top->core_info[cpu].pkg;
+ cpu_top->pkgs++;
+ }
+ }
+ if (!(cpu_top->core_info[0].pkg == -1))
+ cpu_top->pkgs++;
+
+ /* Intel's cores count is not consecutively numbered, there may
+ * be a core_id of 3, but none of 2. Assume there always is 0
+ * Get amount of cores by counting duplicates in a package
+ for (cpu = 0; cpu_top->core_info[cpu].pkg = 0 && cpu < cpus; cpu++) {
+ if (cpu_top->core_info[cpu].core == 0)
+ cpu_top->cores++;
+ */
+ return cpus;
+}
+
+void cpu_topology_release(struct cpupower_topology cpu_top)
+{
+ free(cpu_top.core_info);
+}