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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2007-12-20 14:55:04 +1100
committerPaul Mackerras <paulus@samba.org>2007-12-20 16:18:15 +1100
commitbe8cbcd8896670a01ead7a29e33ffe29604ed734 (patch)
treec4253a4191279a74d7896099dab13fb57b1a9d27
parentd0264ce796e4e3d77fdadf72d6625f8e6c1c96bd (diff)
[POWERPC] Fixup skipping of PowerMac PCI<->PCI bridge "closed" resources
Apple firmware has a strange way to "close" bridge resources by setting them to some bogus values that overlap RAM (strangely, I haven't seen it conflicting with DMA so far...). This explicitely closes them to avoid problems. Previously, they would be closed as a consequence of failing to be allocated, but this makes it more explicit, and thus the log message is more explicit too. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
-rw-r--r--arch/powerpc/kernel/pci-common.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index b6d4767e4e2..1037b3a093e 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -776,6 +776,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pcibios_fixup_resources);
static void __devinit __pcibios_fixup_bus(struct pci_bus *bus)
{
+ struct pci_controller *hose = pci_bus_to_host(bus);
struct pci_dev *dev = bus->self;
pr_debug("PCI: Fixup bus %d (%s)\n", bus->number, dev ? pci_name(dev) : "PHB");
@@ -793,6 +794,27 @@ static void __devinit __pcibios_fixup_bus(struct pci_bus *bus)
if (!res->flags || bus->self->transparent)
continue;
+ /* On PowerMac, Apple leaves bridge windows open over
+ * an inaccessible region of memory space (0...fffff)
+ * which is somewhat bogus, but that's what they think
+ * means disabled...
+ *
+ * We clear those to force them to be reallocated later
+ *
+ * We detect such regions by the fact that the base is
+ * equal to the pci_mem_offset of the host bridge and
+ * their size is smaller than 1M.
+ */
+ if (res->start == hose->pci_mem_offset &&
+ res->end < 0x100000) {
+ printk(KERN_INFO
+ "PCI: Closing bogus Apple Firmware"
+ " region %d on bus 0x%02x\n",
+ i, bus->number);
+ res->flags = 0;
+ continue;
+ }
+
pr_debug("PCI:%s Bus rsrc %d %016llx-%016llx [%x] fixup...\n",
pci_name(dev), i,
(unsigned long long)res->start,\