[PATCH v2 1/3] lib/igt_sriov_device: Add helper to get SR-IOV function name

[Lukasz Laguna <lukasz.laguna@intel.com>]

Introduce a helper to format SR-IOV function names. It returns "PF" for
physical function and "VF%u" for virtual functions.

Signed-off-by: Lukasz Laguna <lukasz.laguna@intel.com>
---
 lib/igt_sriov_device.c | 23 +++++++++++++++++++++++
 lib/igt_sriov_device.h |  1 +
 2 files changed, 24 insertions(+)

diff --git a/lib/igt_sriov_device.c b/lib/igt_sriov_device.c
index 6c9fbdf70..392c80346 100644
--- a/lib/igt_sriov_device.c
+++ b/lib/igt_sriov_device.c
@@ -61,6 +61,29 @@ const char *igt_sriov_func_str(unsigned int vf_num)
 	return buf;
 }
 
+/**
+ * igt_sriov_function_name - Get SR-IOV function name
+ * @vf_num: VF number (1-based to identify single VF) or 0 for PF
+ * @buf: buffer
+ * @size: size of the buffer
+ *
+ * It formats the function name as "PF" when @vf_num is 0, or as "VF%u"
+ * when @vf_num is greater than 0.
+ *
+ * Return: formatted function name.
+ */
+const char *igt_sriov_function_name(unsigned int vf_num, char *buf, size_t size)
+{
+	int n;
+
+	n = vf_num ? snprintf(buf, size, "VF%u", vf_num) :
+		     snprintf(buf, size, "PF");
+
+	igt_assert(n >= 0 && (size_t)n < size);
+
+	return buf;
+}
+
 static bool __pf_attr_get_u32(int pf, const char *attr, uint32_t *value)
 {
 	int sysfs;
diff --git a/lib/igt_sriov_device.h b/lib/igt_sriov_device.h
index 4e4ba230a..a969d4172 100644
--- a/lib/igt_sriov_device.h
+++ b/lib/igt_sriov_device.h
@@ -36,6 +36,7 @@ bool igt_sriov_device_reset_exists(int pf, unsigned int vf_num);
 bool igt_sriov_device_reset(int pf, unsigned int vf_num);
 bool intel_is_vf_device(int device);
 const char *igt_sriov_func_str(unsigned int vf_num);
+const char *igt_sriov_function_name(unsigned int vf_num, char *buf, size_t size);
 typedef void (*igt_sriov_exit_cleanup_fn)(int pf, int sig, void *user_data);
 void igt_sriov_install_exit_handler(int pf,
 				    igt_sriov_exit_cleanup_fn cleanup_fn,
-- 
2.43.0