From cb4262481fce1d43ac9a483be4faf36fdd1c7abb Mon Sep 17 00:00:00 2001 From: Andrew Isaacson Date: Wed, 19 Oct 2005 23:59:46 -0700 Subject: pci-expmem-hack CFE 1.2.5 and earlier fails to turn on the ExpMemEn bit in the PCIFeatureControl register, which means that DMA does not work beyond physical address 01_0000_0000, ergo to DRAM beyond 1GB. With ExpMemEn turned on, 01_0000_0000-0f_ffff_ffff is mapped, so DMA works for up to 61 GB of DRAM. Will be fixed in CFE 1.2.6 (yet to be released). Signed-Off-By: Andy Isaacson Signed-off-by: Ralf Baechle --- arch/mips/pci/pci-bcm1480.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch') diff --git a/arch/mips/pci/pci-bcm1480.c b/arch/mips/pci/pci-bcm1480.c index 4905d8593d6..f194b4e4f86 100644 --- a/arch/mips/pci/pci-bcm1480.c +++ b/arch/mips/pci/pci-bcm1480.c @@ -232,6 +232,14 @@ static int __init bcm1480_pcibios_init(void) bcm1480_bus_status |= PCI_BUS_ENABLED; } + /* turn on ExpMemEn */ + cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40)); + printk("PCIFeatureCtrl = %x\n", cmdreg); + WRITECFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40), + cmdreg | 0x10); + cmdreg = READCFG32(CFGOFFSET(0, PCI_DEVFN(PCI_BRIDGE_DEVICE, 0), 0x40)); + printk("PCIFeatureCtrl = %x\n", cmdreg); + /* * Establish mappings in KSEG2 (kernel virtual) to PCI I/O * space. Use "match bytes" policy to make everything look -- cgit v1.2.3-70-g09d2