PCI/VGA: Factor out vga_select_framebuffer_device()

On x86 and ia64, if a VGA device BARs include a framebuffer reported by
platform firmware, we select the device as the default VGA device.  Factor
this code to a separate function.  No functional change intended.

Link: https://lore.kernel.org/r/20220224224753.297579-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Bruno Prémont <bonbons@linux-vserver.org>

Author: bjorn-helgaas

drivers/pci/vgaarb.c

@@ -565,6 +565,58 @@ void vga_put(struct pci_dev *pdev, unsigned int rsrc)
 }
 EXPORT_SYMBOL(vga_put);
 
+static void __init vga_select_framebuffer_device(struct pci_dev *pdev)
+{
+#if defined(CONFIG_X86) || defined(CONFIG_IA64)
+	struct device *dev = &pdev->dev;
+	u64 base = screen_info.lfb_base;
+	u64 size = screen_info.lfb_size;
+	u64 limit;
+	resource_size_t start, end;
+	unsigned long flags;
+	int i;
+
+	/* Select the device owning the boot framebuffer if there is one */
+
+	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
+		base |= (u64)screen_info.ext_lfb_base << 32;
+
+	limit = base + size;
+
+	/*
+	 * Override vga_arbiter_add_pci_device()'s I/O based detection
+	 * as it may take the wrong device (e.g. on Apple system under
+	 * EFI).
+	 *
+	 * Select the device owning the boot framebuffer if there is
+	 * one.
+	 */
+
+	/* Does firmware framebuffer belong to us? */
+	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
+		flags = pci_resource_flags(pdev, i);
+
+		if ((flags & IORESOURCE_MEM) == 0)
+			continue;
+
+		start = pci_resource_start(pdev, i);
+		end  = pci_resource_end(pdev, i);
+
+		if (!start || !end)
+			continue;
+
+		if (base < start || limit >= end)
+			continue;
+
+		if (!vga_default_device())
+			vgaarb_info(dev, "setting as boot device\n");
+		else if (pdev != vga_default_device())
+			vgaarb_info(dev, "overriding boot device\n");
+		vga_set_default_device(pdev);
+	}
+#endif
+}
+
 static bool vga_arb_integrated_gpu(struct device *dev)
 {
 #if defined(CONFIG_ACPI)
@@ -1446,54 +1498,9 @@ static void __init vga_arb_select_default_device(void)
 	struct pci_dev *pdev, *found = NULL;
 	struct vga_device *vgadev;
 
-#if defined(CONFIG_X86) || defined(CONFIG_IA64)
-	u64 base = screen_info.lfb_base;
-	u64 size = screen_info.lfb_size;
-	u64 limit;
-	resource_size_t start, end;
-	unsigned long flags;
-	int i;
-
-	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
-		base |= (u64)screen_info.ext_lfb_base << 32;
-
-	limit = base + size;
-
 	list_for_each_entry(vgadev, &vga_list, list) {
-		struct device *dev = &vgadev->pdev->dev;
-		/*
-		 * Override vga_arbiter_add_pci_device()'s I/O based detection
-		 * as it may take the wrong device (e.g. on Apple system under
-		 * EFI).
-		 *
-		 * Select the device owning the boot framebuffer if there is
-		 * one.
-		 */
-
-		/* Does firmware framebuffer belong to us? */
-		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
-			flags = pci_resource_flags(vgadev->pdev, i);
-
-			if ((flags & IORESOURCE_MEM) == 0)
-				continue;
-
-			start = pci_resource_start(vgadev->pdev, i);
-			end  = pci_resource_end(vgadev->pdev, i);
-
-			if (!start || !end)
-				continue;
-
-			if (base < start || limit >= end)
-				continue;
-
-			if (!vga_default_device())
-				vgaarb_info(dev, "setting as boot device\n");
-			else if (vgadev->pdev != vga_default_device())
-				vgaarb_info(dev, "overriding boot device\n");
-			vga_set_default_device(vgadev->pdev);
-		}
+		vga_select_framebuffer_device(vgadev->pdev);
 	}
-#endif
 
 	if (!vga_default_device()) {
 		list_for_each_entry_reverse(vgadev, &vga_list, list) {