On Monday 22 February 2010 06:28:30 am Ralf Baechle wrote:
> It's a while since I last looked into this but here's how things afair
> are working on a MIPS-based Cobalt system.
>
> The system is based on a MIPS processor and a GT-64111 system controller.
> Addresses within a certain CPU address range are passed to the PCI bus as
> I/O cycles without address cycles. Since memory is starting at CPU address
> zero (and has to because of the processors used), that address window has
> to get mapped somewhere else. So a CPU access to some virtual address gets
> translated to physical address 0xf00001f0. The GT-64111 passes this to the
> PCI bus as I/O port address 0xf00001f0. Finally the VT82C586 chip which
> only decodes the low 16 bits drops treats this as an I/O port space address
> 0x1f0.
Yoichi, can you try the patch below? I think this is basically the
approach Ben suggested long ago:
http://marc.info/?l=linux-kernel&m=119733290624544&w=2
Thanks,
Bjorn
diff --git a/arch/mips/pci/fixup-cobalt.c b/arch/mips/pci/fixup-cobalt.c
index 9553b14..7579551 100644
--- a/arch/mips/pci/fixup-cobalt.c
+++ b/arch/mips/pci/fixup-cobalt.c
@@ -51,6 +51,67 @@ static void qube_raq_galileo_early_fixup(struct pci_dev *dev)
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_MARVELL, PCI_DEVICE_ID_MARVELL_GT64111,
qube_raq_galileo_early_fixup);
+static void __devinit cobalt_legacy_ide_resource_fixup(struct pci_dev *dev,
+ struct resource *res)
+{
+ struct pci_controller *hose = (struct pci_controller *)dev->sysdata;
+ unsigned long offset = hose->io_offset;
+ struct resource orig = *res;
+
+ if (!(res->flags & IORESOURCE_IO) ||
+ !(res->flags & IORESOURCE_PCI_FIXED))
+ return;
+
+ res->start -= offset;
+ res->end -= offset;
+ dev_printk(KERN_DEBUG, &dev->dev, "converted legacy %pR to bus %pR\n",
+ &orig, res);
+}
+
+static void __devinit cobalt_legacy_ide_fixup(struct pci_dev *dev)
+{
+ u32 class;
+ u8 progif;
+
+ /*
+ * If the IDE controller is in legacy mode, pci_setup_device() fills in
+ * the resources with the legacy addresses that normally appear on the
+ * PCI bus, just as if we had read them from a BAR.
+ *
+ * However, with the GT-64111, those legacy addresses, e.g., 0x1f0,
+ * will never appear on the PCI bus because it converts memory accesses
+ * in the PCI I/O region (which is never at address zero) into I/O port
+ * accesses with no address translation.
+ *
+ * For example, if GT_DEF_PCI0_IO_BASE is 0x10000000, a load or store
+ * to physical address 0x100001f0 will become a PCI access to I/O port
+ * 0x100001f0. There's no way to generate an access to I/O port 0x1f0,
+ * but the VT82C586 IDE controller does respond at 0x100001f0 because
+ * it only decodes the low 16 bits of the address.
+ *
+ * When this quirk runs, the pci_dev resources should contain bus
+ * addresses, not Linux I/O port numbers, so convert legacy addresses
+ * like 0x1f0 to bus addresses like 0x100001f0. Later, we'll convert
+ * them back with pcibios_fixup_bus() or pcibios_bus_to_resource().
+ */
+ class = dev->class >> 8;
+ if (class != PCI_CLASS_STORAGE_IDE)
+ return;
+
+ pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
+ if ((progif & 1) == 0) {
+ cobalt_legacy_ide_resource_fixup(dev, &dev->resource[0]);
+ cobalt_legacy_ide_resource_fixup(dev, &dev->resource[1]);
+ }
+ if ((progif & 4) == 0) {
+ cobalt_legacy_ide_resource_fixup(dev, &dev->resource[2]);
+ cobalt_legacy_ide_resource_fixup(dev, &dev->resource[3]);
+ }
+}
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_1,
+ cobalt_legacy_ide_fixup);
+
static void qube_raq_via_bmIDE_fixup(struct pci_dev *dev)
{
unsigned short cfgword;
diff --git a/arch/mips/pci/pci.c b/arch/mips/pci/pci.c
index f87f5e1..38bc280 100644
--- a/arch/mips/pci/pci.c
+++ b/arch/mips/pci/pci.c
@@ -251,8 +251,6 @@ static void pcibios_fixup_device_resources(struct pci_dev *dev,
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
if (!dev->resource[i].start)
continue;
- if (dev->resource[i].flags & IORESOURCE_PCI_FIXED)
- continue;
if (dev->resource[i].flags & IORESOURCE_IO)
offset = hose->io_offset;
else if (dev->resource[i].flags & IORESOURCE_MEM)
