[PATCH i-g-t v6 2/5] lib/igt_device_scan: Enable finding all matched IGT devices

[Soham Purkait]

Add filter functions to find all the
available GPUs or few among them
by driver name and card type or card number.
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)

v5 : Introduce device card match function
     to return collection of matching 
     devices using device filter.

v6 : Separate commit for device card match
     function.                     (Zbigniew)
     Function description modification for device
     card match function.          (Zbigniew)

Signed-off-by: Soham Purkait <soham.purkait at intel.com>
---
 lib/igt_device_scan.c | 62 +++++++++++++++++++++++++++++++++++++++++++
 lib/igt_device_scan.h |  2 ++
 2 files changed, 64 insertions(+)

diff --git a/lib/igt_device_scan.c b/lib/igt_device_scan.c
index ea14d8e23..89215c3e0 100644
--- a/lib/igt_device_scan.c
+++ b/lib/igt_device_scan.c
@@ -2121,6 +2121,68 @@ bool igt_device_card_match_pci(const char *filter,
        return __igt_device_card_match(filter, card, true);
 }
 
+/**
+ * igt_device_card_match_all
+ * @filter: filter string.
+ * @card: double pointer to igt_device_card structure, containing
+ * an array of igt_device_card structures upon successful return.
+ * @request_pci_ss: a boolean parameter determines whether to
+ * consider PCI subsystem information during this process.
+ * @drivers: this holds the list of supported driver string by
+ * the caller.
+ * Function applies filter to match device from device array.
+ *
+ * Returns: the number of cards found.
+ * 
+ * Note: The caller is responsible for freeing the memory which is
+ * dynamically allocated for the array of igt_device_card structures
+ * upon successful return.
+ */
+int igt_device_card_match_all(const char *filter, struct igt_device_card **card,
+			      bool request_pci_ss, const char * const drivers[])
+{
+	struct igt_device *dev = NULL;
+	struct igt_device_card *crd = NULL;
+	struct igt_device_card *tmp;
+	int count = 0;
+
+	igt_devices_scan();
+
+	if (igt_device_filter_apply(filter) == false)
+		return 0;
+
+	if (igt_list_empty(&igt_devs.filtered))
+		return 0;
+
+	igt_list_for_each_entry(dev, &igt_devs.filtered, link) {
+		for (int i = 0;
+		     drivers && drivers[i] && !strcmp(drivers[i],
+		     dev->driver); i++) {
+			tmp = realloc(crd, sizeof(struct igt_device_card) * (count + 1));
+			if (!tmp && crd) {
+				free(crd);
+				return 0;
+			}
+
+			crd = tmp;
+
+			if (request_pci_ss && !is_pci_subsystem(dev) &&
+			    dev->parent && is_pci_subsystem(dev->parent))
+				__copy_dev_to_card(dev->parent, crd);
+			else
+				__copy_dev_to_card(dev, crd);
+			count++;
+			break;
+		}
+	}
+
+	if (!count)
+		return 0;
+
+	*card = crd;
+	return count;
+}
+
 /**
  * igt_device_get_pretty_name
  * @card: pointer to igt_device_card struct
diff --git a/lib/igt_device_scan.h b/lib/igt_device_scan.h
index f1cd3b1e9..ca51eeeba 100644
--- a/lib/igt_device_scan.h
+++ b/lib/igt_device_scan.h
@@ -89,6 +89,8 @@ int igt_device_filter_pci(void);
 bool igt_device_card_match(const char *filter, struct igt_device_card *card);
 bool igt_device_card_match_pci(const char *filter,
 	struct igt_device_card *card);
+int igt_device_card_match_all(const char *filter, struct igt_device_card **card,
+	bool request_pci_ss, const char * const drivers[]);
 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);
-- 
2.34.1