The CAT non-contiguous selftests have to read the file responsible for
reporting support of non-contiguous CBMs in kernel (resctrl). Then the
test compares if that information matches what is reported by CPUID
output.
Add a generic helper function to read an unsigned number from a file in
/sys/fs/resctrl/info/<RESOURCE>/<FILE>.
Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx>
---
Changelog v4:
- Rewrite function comment.
- Redo ksft_perror() as ksft_print_msg(). (Reinette)
Changelog v3:
- Rewrite patch message.
- Add documentation and rewrote the function. (Reinette)
Changelog v2:
- Add this patch.
tools/testing/selftests/resctrl/resctrl.h | 1 +
tools/testing/selftests/resctrl/resctrlfs.c | 36 +++++++++++++++++++++
2 files changed, 37 insertions(+)
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index a1462029998e..5116ea082d03 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -162,6 +162,7 @@ unsigned int count_contiguous_bits(unsigned long val, unsigned int *start);
int get_full_cbm(const char *cache_type, unsigned long *mask);
int get_mask_no_shareable(const char *cache_type, unsigned long *mask);
int get_cache_size(int cpu_no, const char *cache_type, unsigned long *cache_size);
+int resource_info_unsigned_get(const char *resource, const char *filename, unsigned int *val);
void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
int signal_handler_register(void);
void signal_handler_unregister(void);
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 5750662cce57..e0fbc46a917a 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -249,6 +249,42 @@ static int get_bit_mask(const char *filename, unsigned long *mask)
return 0;
}
+/**
+ * resource_info_unsigned_get - Read an unsigned value from
+ * /sys/fs/resctrl/info/RESOURCE/FILENAME
+ * @resource: Resource name that matches directory name in
+ * /sys/fs/resctrl/info
+ * @filename: File in /sys/fs/resctrl/info/@resource
+ * @val: Contains read value on success.
+ *
+ * Return: = 0 on success, < 0 on failure. On success the read
+ * value is saved into the @val.
+ */
+int resource_info_unsigned_get(const char *resource, const char *filename,
+ unsigned int *val)
+{
+ char file_path[PATH_MAX];
+ FILE *fp;
+
+ snprintf(file_path, sizeof(file_path), "%s/%s/%s", INFO_PATH, resource,
+ filename);
+
+ fp = fopen(file_path, "r");
+ if (!fp) {
+ ksft_print_msg("Error in opening %s\n: %m\n", file_path);
+ return -1;
+ }
+
+ if (fscanf(fp, "%u", val) <= 0) {
+ ksft_print_msg("Could not get contents of %s\n: %m\n", file_path);
+ fclose(fp);
+ return -1;
+ }
+
+ fclose(fp);
+ return 0;
+}
+
/*
* create_bit_mask- Create bit mask from start, len pair
* @start: LSB of the mask
--
2.43.0
