diff options
Diffstat (limited to 'arch/powerpc/platforms/powermac/pci.c')
| -rw-r--r-- | arch/powerpc/platforms/powermac/pci.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powermac/pci.c b/arch/powerpc/platforms/powermac/pci.c index 04cdd32624d..e81403b245b 100644 --- a/arch/powerpc/platforms/powermac/pci.c +++ b/arch/powerpc/platforms/powermac/pci.c @@ -1286,3 +1286,64 @@ static void fixup_k2_sata(struct pci_dev* dev) } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SERVERWORKS, 0x0240, fixup_k2_sata); +/* + * On U4 (aka CPC945) the PCIe root complex "P2P" bridge resource ranges aren't + * configured by the firmware. The bridge itself seems to ignore them but it + * causes problems with Linux which then re-assigns devices below the bridge, + * thus changing addresses of those devices from what was in the device-tree, + * which sucks when those are video cards using offb + * + * We could just mark it transparent but I prefer fixing up the resources to + * properly show what's going on here, as I have some doubts about having them + * badly configured potentially being an issue for DMA. + * + * We leave PIO alone, it seems to be fine + * + * Oh and there's another funny bug. The OF properties advertize the region + * 0xf1000000..0xf1ffffff as being forwarded as memory space. But that's + * actually not true, this region is the memory mapped config space. So we + * also need to filter it out or we'll map things in the wrong place. + */ +static void fixup_u4_pcie(struct pci_dev* dev) +{ + struct pci_controller *host = pci_bus_to_host(dev->bus); + struct resource *region = NULL; + u32 reg; + int i; + + /* Only do that on PowerMac */ + if (!machine_is(powermac)) + return; + + /* Find the largest MMIO region */ + for (i = 0; i < 3; i++) { + struct resource *r = &host->mem_resources[i]; + if (!(r->flags & IORESOURCE_MEM)) + continue; + /* Skip the 0xf0xxxxxx..f2xxxxxx regions, we know they + * are reserved by HW for other things + */ + if (r->start >= 0xf0000000 && r->start < 0xf3000000) + continue; + if (!region || (r->end - r->start) > + (region->end - region->start)) + region = r; + } + /* Nothing found, bail */ + if (region == 0) + return; + + /* Print things out */ + printk(KERN_INFO "PCI: Fixup U4 PCIe bridge range: %pR\n", region); + + /* Fixup bridge config space. We know it's a Mac, resource aren't + * offset so let's just blast them as-is. We also know that they + * fit in 32 bits + */ + reg = ((region->start >> 16) & 0xfff0) | (region->end & 0xfff00000); + pci_write_config_dword(dev, PCI_MEMORY_BASE, reg); + pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0); + pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0); + pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0); +} +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_U4_PCIE, fixup_u4_pcie); |