This patch alters viafb to use the proper Linux in-kernel API to access
PCI configuration space, rather than poking at I/O ports by itself.

It also removes a minor inconsistency with naming of constants for the
PCI device ID of the FUNCTION3 devices.

Signed-off-by: Harald Welte <redacted>
---
 drivers/video/via/hw.c |   64 +++++++++++++++++++++++++++++------------------
 drivers/video/via/hw.h |    4 +-
 2 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/drivers/video/via/hw.c b/drivers/video/via/hw.c
index 6306c88..40b7c0c 100644
--- a/drivers/video/via/hw.c
+++ b/drivers/video/via/hw.c

@@ -2599,24 +2599,37 @@ static void disable_second_display_channel(void)
 	viafb_write_reg_mask(CR6A, VIACR, BIT6, BIT6);
 }
 
+static u_int16_t via_function3[] = {
+	CLE266_FUNCTION3, KM400_FUNCTION3, CN400_FUNCTION3, CN700_FUNCTION3,
+	CX700_FUNCTION3, KM800_FUNCTION3, KM890_FUNCTION3, P4M890_FUNCTION3,
+	P4M900_FUNCTION3, VX800_FUNCTION3, VX855_FUNCTION3,
+};
+
+/* Get the BIOS-configured framebuffer size from PCI configuration space
+ * of function 3 in the respective chipset */
 int viafb_get_fb_size_from_pci(void)
 {
-	unsigned long configid, deviceid, FBSize = 0;
-	int VideoMemSize;
-	int DeviceFound = false;
-
-	for (configid = 0x80000000; configid < 0x80010800; configid += 0x100) {
-		outl(configid, (unsigned long)0xCF8);
-		deviceid = (inl((unsigned long)0xCFC) >> 16) & 0xffff;
-
-		switch (deviceid) {
-		case CLE266:
-		case KM400:
-			outl(configid + 0xE0, (unsigned long)0xCF8);
-			FBSize = inl((unsigned long)0xCFC);
-			DeviceFound = true;	/* Found device id */
-			break;
+	int i;
+	u_int8_t offset = 0;
+	u_int32_t FBSize;
+	u_int32_t VideoMemSize;
+
+	/* search for the "FUNCTION3" device in this chipset */
+	for (i = 0; i < ARRAY_SIZE(via_function3); i++) {
+		struct pci_dev *pdev;
+
+		pdev = pci_get_device(PCI_VENDOR_ID_VIA, via_function3[i],
+				      NULL);