[PATCH <i-g-t> v4 1/4] lib/igt_device_scan: Enable finding all IGT devices for a specific driver

[Soham Purkait <soham.purkait@intel.com>]

    Add function to find all the available GPU
cards by driver name and card type.
Add driver field to igt_device_card structure 
for storing driver names.

v2 : fix for refactoring GPUTOP into a
     vendor-agnostic tool (Lucas)

v3 : Separate commit for lib (Kamil)

v4 : Refactor to use composition strategy
     for driver and device type filtering
     Refactor code to improve memory
     allocation and error handling (Lucas)

Signed-off-by: Soham Purkait <soham.purkait@intel.com>
---
 lib/igt_device_scan.c | 58 +++++++++++++++++++++++++++++++++++++++++++
 lib/igt_device_scan.h |  3 +++
 2 files changed, 61 insertions(+)

diff --git a/lib/igt_device_scan.c b/lib/igt_device_scan.c
index 711bedc5c..4d243126e 100644
--- a/lib/igt_device_scan.c
+++ b/lib/igt_device_scan.c
@@ -774,6 +774,10 @@ __copy_dev_to_card(struct igt_device *dev, struct igt_device_card *card)
 		safe_strncpy(card->render, dev->drm_render,
 			     sizeof(card->render));
 
+	if (dev->driver != NULL)
+		safe_strncpy(card->driver, dev->driver,
+			     sizeof(card->driver));
+
 	if (dev->pci_slot_name != NULL)
 		safe_strncpy(card->pci_slot_name, dev->pci_slot_name,
 			     sizeof(card->pci_slot_name));
@@ -820,6 +824,60 @@ static bool __find_first_intel_card_by_driver_name(struct igt_device_card *card,
 	return false;
 }
 
+/**
+ * Iterate over all igt_devices array and find all discrete/integrated cards.
+ * @card: double pointer to igt_device_card structure, containing
+ * an array of igt_device_card structures upon successful return.
+ * @card_type: flag to indicate whether to find discrete, integrated, or
+ * both types of cards. Use 0 for integrated, 1 for discrete, and 2 for both.
+ * @drv_name: name of the driver to match.
+ *
+ * Returns the number of cards found, or -1 on error.
+ */
+int find_all_intel_card_by_driver_name(struct igt_device_card **card,
+				       uint8_t card_type, const char *drv_name)
+{
+	int count = 0;
+	struct igt_device *dev;
+	int is_integrated;
+	struct igt_device_card *tmp;
+	struct igt_device_card *crd = NULL;
+
+	igt_assert(drv_name);
+	*card = NULL;
+
+	igt_list_for_each_entry(dev, &igt_devs.all, link) {
+		if (!is_pci_subsystem(dev) || strcmp(dev->driver, drv_name))
+			continue;
+
+		is_integrated = !strncmp(dev->pci_slot_name, INTEGRATED_I915_GPU_PCI_ID,
+						PCI_SLOT_NAME_SIZE);
+
+		if ((card_type == 1 && !is_integrated) ||
+		    (card_type == 0 && is_integrated) ||
+		    card_type == 2) {
+			tmp = realloc(crd, sizeof(struct igt_device_card) * (count + 1));
+			if (!tmp) {
+				free(crd);
+				return -1;
+			}
+
+			crd = tmp;
+			__copy_dev_to_card(dev, &crd[count]);
+			count++;
+		}
+	}
+
+	if (!count) {
+		if (!crd)
+			free(crd);
+		return 0;
+	}
+
+	*card = crd;
+	return count;
+}
+
 bool igt_device_find_first_i915_discrete_card(struct igt_device_card *card)
 {
 	igt_assert(card);
diff --git a/lib/igt_device_scan.h b/lib/igt_device_scan.h
index 92741fe3c..4fbb11193 100644
--- a/lib/igt_device_scan.h
+++ b/lib/igt_device_scan.h
@@ -59,6 +59,7 @@ struct igt_device_card {
 	char subsystem[NAME_MAX];
 	char card[NAME_MAX];
 	char render[NAME_MAX];
+	char driver[NAME_MAX];
 	char pci_slot_name[PCI_SLOT_NAME_SIZE+1];
 	uint16_t pci_vendor, pci_device;
 };
@@ -92,6 +93,8 @@ bool igt_device_find_first_i915_discrete_card(struct igt_device_card *card);
 bool igt_device_find_integrated_card(struct igt_device_card *card);
 bool igt_device_find_first_xe_discrete_card(struct igt_device_card *card);
 bool igt_device_find_xe_integrated_card(struct igt_device_card *card);
+int find_all_intel_card_by_driver_name(struct igt_device_card **card,
+				       uint8_t want_discrete, const char *drv_name);
 char *igt_device_get_pretty_name(struct igt_device_card *card, bool numeric);
 int igt_open_card(struct igt_device_card *card);
 int igt_open_render(struct igt_device_card *card);
-- 
2.34.1