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Subject[PATCH 2/3] perf tools arm64: implement function get_cpuid_str
Date
function get_cpuid_str returns midr_el1 value from first
online cpu available.

Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
---
tools/perf/arch/arm64/util/Build | 1 +
tools/perf/arch/arm64/util/header.c | 51 +++++++++++++++++++++++++++++++++++++
2 files changed, 52 insertions(+)
create mode 100644 tools/perf/arch/arm64/util/header.c

diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build
index cef6fb3..b1ab72d 100644
--- a/tools/perf/arch/arm64/util/Build
+++ b/tools/perf/arch/arm64/util/Build
@@ -1,3 +1,4 @@
+libperf-y += header.o
libperf-$(CONFIG_DWARF) += dwarf-regs.o
libperf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o

diff --git a/tools/perf/arch/arm64/util/header.c b/tools/perf/arch/arm64/util/header.c
new file mode 100644
index 0000000..c0468fe
--- /dev/null
+++ b/tools/perf/arch/arm64/util/header.c
@@ -0,0 +1,51 @@
+#include <fnmatch.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/stringify.h>
+#include "header.h"
+#include "util.h"
+
+#define LINUX_SYS_CPU_DIRECTORY "/sys/devices/system/cpu/"
+#define MIDR "/regs/identification/midr_el1"
+
+char *get_cpuid_str(void)
+{
+ char *buf = malloc(128);
+ FILE *file;
+ char *ret = NULL;
+ int cpu , nr_cpu;
+ char sys_file[256];
+
+ sprintf(sys_file, LINUX_SYS_CPU_DIRECTORY"kernel_max");
+
+ file = fopen(sys_file, "r");
+ if (!file)
+ return ret;
+
+ if (fscanf(file, "%d", &nr_cpu) != 1)
+ return ret;
+
+ /* kernel_max returns nr_cpu -1 */
+ nr_cpu++;
+
+ /*iterate till you read midr of first online cpu */
+ for(cpu = 0; cpu < nr_cpu; cpu++)
+ {
+ sprintf(sys_file, LINUX_SYS_CPU_DIRECTORY"cpu%d"MIDR, cpu);
+ file = fopen(sys_file, "r");
+ if (file) {
+ ret = fgets(buf, 128, file);
+ if (ret) {
+ buf[strlen(buf)-1] ='\0';
+ fclose(file);
+ return buf;
+ }
+ fclose(file);
+ }
+ }
+ free(buf);
+ return ret;
+}
--
1.8.1.4
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