[PATCH V6 06/12] PCI/VGA: Prefer VGA device owns the firmware framebuffer

[Huacai Chen <chenhuacai@loongson.cn>]

This patch is the fourth step of the rework: On X86 and IA64 platform,
update default VGA device if the new found device owns the firmware
framebuffer because it is the most preferred.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/gpu/vga/vgaarb.c | 45 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index 1daf2a011f83..042e1f1371fc 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -584,6 +584,14 @@ static void vga_arb_update_default_device(struct vga_device *vgadev)
 	struct pci_dev *pdev = vgadev->pdev;
 	struct device *dev = &pdev->dev;
 	struct vga_device *vgadev_default;
+#if defined(CONFIG_X86) || defined(CONFIG_IA64)
+	int i;
+	unsigned long flags;
+	u64 base = screen_info.lfb_base;
+	u64 size = screen_info.lfb_size;
+	u64 limit;
+	resource_size_t start, end;
+#endif
 
 	/*
 	 * If we don't have a default VGA device yet, and this device owns
@@ -610,6 +618,43 @@ static void vga_arb_update_default_device(struct vga_device *vgadev)
 		vgaarb_info(dev, "overriding boot VGA device\n");
 		vga_set_default_device(pdev);
 	}
+
+#if defined(CONFIG_X86) || defined(CONFIG_IA64)
+	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(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 (vgadev->pdev != vga_default_device())
+			vgaarb_info(dev, "overriding boot device\n");
+		vga_set_default_device(vgadev->pdev);
+	}
+#endif
 }
 
 /*
-- 
2.27.0