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-rw-r--r--arch/powerpc/sysdev/ppc4xx_pci.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/ppc4xx_pci.c b/arch/powerpc/sysdev/ppc4xx_pci.c
index 77fae5f64f2e..5558d932b4d5 100644
--- a/arch/powerpc/sysdev/ppc4xx_pci.c
+++ b/arch/powerpc/sysdev/ppc4xx_pci.c
@@ -204,6 +204,23 @@ static int __init ppc4xx_setup_one_pci_PMM(struct pci_controller *hose,
{
u32 ma, pcila, pciha;
+ /* Hack warning ! The "old" PCI 2.x cell only let us configure the low
+ * 32-bit of incoming PLB addresses. The top 4 bits of the 36-bit
+ * address are actually hard wired to a value that appears to depend
+ * on the specific SoC. For example, it's 0 on 440EP and 1 on 440EPx.
+ *
+ * The trick here is we just crop those top bits and ignore them when
+ * programming the chip. That means the device-tree has to be right
+ * for the specific part used (we don't print a warning if it's wrong
+ * but on the other hand, you'll crash quickly enough), but at least
+ * this code should work whatever the hard coded value is
+ */
+ plb_addr &= 0xffffffffull;
+
+ /* Note: Due to the above hack, the test below doesn't actually test
+ * if you address is above 4G, but it tests that address and
+ * (address + size) are both contained in the same 4G
+ */
if ((plb_addr + size) > 0xffffffffull || !is_power_of_2(size) ||
size < 0x1000 || (plb_addr & (size - 1)) != 0) {
printk(KERN_WARNING "%s: Resource out of range\n",
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