CS5536: apply pci quirk for BIOS SMBUS bug

The new cs5535-* drivers use PCI header config info rather than MSRs to
determine the memory region to use for things like GPIOs and MFGPTs. As
anticipated, we've run into a buggy BIOS:

[ 0.081818] pci 0000:00:14.0: reg 10: [io 0x6000-0x7fff]
[ 0.081906] pci 0000:00:14.0: reg 14: [io 0x6100-0x61ff]
[ 0.082015] pci 0000:00:14.0: reg 18: [io 0x6200-0x63ff]
[ 0.082917] pci 0000:00:14.2: reg 20: [io 0xe000-0xe00f]
[ 0.083551] pci 0000:00:15.0: reg 10: [mem 0xa0010000-0xa0010fff]
[ 0.084436] pci 0000:00:15.1: reg 10: [mem 0xa0011000-0xa0011fff]
[ 0.088816] PCI: pci_cache_line_size set to 32 bytes
[ 0.088938] pci 0000:00:14.0: address space collision: [io 0x6100-0x61ff] already in use
[ 0.089052] pci 0000:00:14.0: can't reserve [io 0x6100-0x61ff]

This is a Soekris board, and its BIOS sets the size of the PCI ISA bridge
device's BAR0 to 8k. In reality, it should be 8 bytes (BAR0 is used for
SMBus stuff). This quirk checks for an incorrect size, and resets it
accordingly.

Signed-off-by: Andres Salomon <[e-mail]>
Tested-by: Leigh Porter <[e-mail]>
Tested-by: Jens Rottmann <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/pci/quirks.c

···
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_S3,	PCI_DEVICE_ID_S3_868,		quirk_s3_64M);
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_S3,	PCI_DEVICE_ID_S3_968,		quirk_s3_64M);
 
+/*
+ * Some CS5536 BIOSes (for example, the Soekris NET5501 board w/ comBIOS
+ * ver. 1.33  20070103) don't set the correct ISA PCI region header info.
+ * BAR0 should be 8 bytes; instead, it may be set to something like 8k
+ * (which conflicts w/ BAR1's memory range).
+ */
+static void __devinit quirk_cs5536_vsa(struct pci_dev *dev)
+{
+	if (pci_resource_len(dev, 0) != 8) {
+		struct resource *res = &dev->resource[0];
+		res->end = res->start + 8 - 1;
+		dev_info(&dev->dev, "CS5536 ISA bridge bug detected "
+				"(incorrect header); workaround applied.\n");
+	}
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA, quirk_cs5536_vsa);
+
 static void __devinit quirk_io_region(struct pci_dev *dev, unsigned region,
 	unsigned size, int nr, const char *name)
 {