adding DRM device search and intel pci device map

src/intel/FlintInstance.zig

@@ -1,6 +1,8 @@
 const std = @import("std");
 const vk = @import("vulkan");
 const base = @import("base");
+const lib = @import("lib.zig");
+
 const FlintPhysicalDevice = @import("FlintPhysicalDevice.zig");
 
 const Dispatchable = base.Dispatchable;
@@ -59,17 +61,59 @@ fn destroy(interface: *Interface, allocator: std.mem.Allocator) VkError!void {
     allocator.destroy(self);
 }
 
-fn requestPhysicalDevices(interface: *Interface, allocator: std.mem.Allocator) VkError!void {
-    _ = interface;
-    _ = allocator;
+fn requestPhysicalDevices(interface: *Interface, allocator: std.mem.Allocator, devices: []base.drm.Card) VkError!void {
+    if (interface.physical_devices.items.len != 0) {
+        return;
+    }
+
+    const io_var = interface.io();
+
+    for (devices[0..]) |device| {
+        const drm_device = device.getDevice(io_var, allocator, .{}) catch continue;
+
+        if (drm_device.node_type != .render or
+            std.meta.activeTag(drm_device.device_info) != .pci or
+            drm_device.device_info.pci.vendor_id != lib.INTEL_PCI_VENDOR_ID)
+            continue;
+
+        const physical_device = try FlintPhysicalDevice.create(allocator, interface, &drm_device);
+        errdefer physical_device.interface.release(allocator) catch {};
+
+        const dispatchable = try Dispatchable(base.PhysicalDevice).wrap(allocator, &physical_device.interface);
+        errdefer dispatchable.destroy(allocator);
+
+        interface.physical_devices.append(allocator, dispatchable) catch return VkError.OutOfHostMemory;
+    }
 }
 
 fn releasePhysicalDevices(interface: *Interface, allocator: std.mem.Allocator) VkError!void {
-    _ = interface;
-    _ = allocator;
+    var result: ?VkError = null;
+
+    for (interface.physical_devices.items) |physical_device| {
+        physical_device.object.release(allocator) catch |err| {
+            if (result == null) {
+                result = err;
+            }
+        };
+        physical_device.destroy(allocator);
+    }
+
+    interface.physical_devices.deinit(allocator);
+    interface.physical_devices = .empty;
+
+    if (result) |err| {
+        return err;
+    }
 }
 
 fn io(interface: *Interface) std.Io {
     const self: *Self = @alignCast(@fieldParentPtr("interface", interface));
     return self.io_impl;
 }
+
+fn mapDeviceEnumerationError(err: anyerror) VkError {
+    return switch (err) {
+        error.OutOfMemory => VkError.OutOfHostMemory,
+        else => VkError.InitializationFailed,
+    };
+}