From cb4262481fce1d43ac9a483be4faf36fdd1c7abb Mon Sep 17 00:00:00 2001
From: Andrew Isaacson <adi@broadcom.com>
Date: Wed, 19 Oct 2005 23:59:46 -0700
Subject: [PATCH] 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 <adi@broadcom.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/pci/pci-bcm1480.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/mips/pci/pci-bcm1480.c b/arch/mips/pci/pci-bcm1480.c
index 4905d8593d6d..f194b4e4f86a 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
--
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