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pci-expmem-hack

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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 <adi@broadcom.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Andrew Isaacson 2005-10-19 23:59:46 -07:00 committed by Ralf Baechle
parent 8a1417de9e
commit cb4262481f
1 changed files with 8 additions and 0 deletions
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8
arch/mips/pci/pci-bcm1480.c
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@ -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