[PATCH i-g-t 1/2] lib/igt_sriov_device: Add intel_is_vf_device helper

[Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>]

Introduce intel_is_vf_device helper to determine whether a given device
is a Virtual Function (VF). The function reads the VF_CAPABILITY_REGISTER
and checks if the least significant bit is set to identify VF device.

Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Cc: Adam Miszczak <adam.miszczak@linux.intel.com>
Cc: Jakub Kolakowski <jakub1.kolakowski@intel.com>
Cc: Lukasz Laguna <lukasz.laguna@intel.com>
Cc: Michał Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Cc: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
---
 lib/igt_sriov_device.c | 26 ++++++++++++++++++++++++++
 lib/igt_sriov_device.h |  1 +
 2 files changed, 27 insertions(+)

diff --git a/lib/igt_sriov_device.c b/lib/igt_sriov_device.c
index 2b83cd43c..ffa996d6b 100644
--- a/lib/igt_sriov_device.c
+++ b/lib/igt_sriov_device.c
@@ -14,6 +14,7 @@
 #include "igt_device.h"
 #include "igt_sriov_device.h"
 #include "igt_sysfs.h"
+#include "intel_io.h"
 #include "xe/xe_query.h"
 
 /**
@@ -464,3 +465,28 @@ bool igt_sriov_device_reset(int pf, unsigned int vf_num)
 
 	return ret;
 }
+
+/**
+ * intel_is_vf_device - Check if device is VF
+ * @device: device file descriptor
+ *
+ * Determines if a device is a Virtual Function (VF)
+ * by reading VF_CAPABILITY_REGISTER. If the least
+ * significant bit is set the device is VF.
+ *
+ * Return:
+ * True if device is VF, false otherwise.
+ */
+bool intel_is_vf_device(int fd)
+{
+#define VF_CAP_REG		0x1901f8
+	struct intel_mmio_data mmio_data;
+	uint32_t value;
+
+	intel_register_access_init(&mmio_data, igt_device_get_pci_device(fd), false);
+	value = intel_register_read(&mmio_data, VF_CAP_REG);
+	intel_register_access_fini(&mmio_data);
+	igt_require((value & ~1) == 0);
+
+	return (value & 1) != 0;
+}
diff --git a/lib/igt_sriov_device.h b/lib/igt_sriov_device.h
index 2b6acb6d7..912449086 100644
--- a/lib/igt_sriov_device.h
+++ b/lib/igt_sriov_device.h
@@ -33,6 +33,7 @@ void igt_sriov_unbind_vf_drm_driver(int pf, unsigned int vf_num);
 int igt_sriov_device_sysfs_open(int pf, unsigned int vf_num);
 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);
 
 /**
  * __is_valid_range - Helper to check VF range is valid
-- 
2.31.1