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authorPaul Mackerras <paulus@samba.org>2007-05-07 15:16:23 +1000
committerPaul Mackerras <paulus@samba.org>2007-05-08 11:54:19 +1000
commit11fbb00c67e19737757e747ec7dd3ba8d584f5d1 (patch)
tree72490560f34432c23abb3afc9b380f39af2c5047 /arch
parent0bd15c4b503b971024a3962b6a6b34c1af0628bf (diff)
[POWERPC] Cope with PCI host bridge I/O window not starting at 0
Currently our code to set up the data structures for a PCI host bridge and create the mapping for its I/O window assumes that the window starts at I/O port 0 on the PCI side. If this is not true, we can end up with I/O port numbers in the resources for PCI devices which will cause an oops if a driver tries to access them via inb/outb etc., because there is no mapping for the corresponding addresses. Normally the I/O window starts at 0, but there are some situations on partitioned machines with a hypervisor where the window may not start at 0. This fixes the problem by allocating space for the range from 0 to the end of the I/O window. That is, hose->io_base_virt contains the virtual address for I/O port 0 on the PCI bus, and thus the assumption that hose->io_base_virt - pci_io_base is the offset between the "global" I/O port numbers (those in the PCI device resources) and the I/O port numbers on the PCI bus is maintained. For PCI host bridges that are present at boot, we only map the portion of that range that correspond to the bridge's I/O window. For bridges added after boot we ioremap the range from 0 to the end of the I/O window, for now; in fact hot-added bridges should be using reserve_phb_iospace() and __ioremap_explicit (so they get sensible global port numbers), but we don't have the infrastructure yet to do that (basically a free_phb_iospace() routine plus appropriate locking). Interestingly, this makes the two arms of the if statement in get_bus_io_range do almost exactly the same thing; that function could now be simplified in a further patch. Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/pci_64.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
index 60d7d4baa22..706b7f3da5f 100644
--- a/arch/powerpc/kernel/pci_64.c
+++ b/arch/powerpc/kernel/pci_64.c
@@ -1006,8 +1006,9 @@ void __devinit pci_process_bridge_OF_ranges(struct pci_controller *hose,
switch ((pci_space >> 24) & 0x3) {
case 1: /* I/O space */
- hose->io_base_phys = cpu_phys_addr;
- hose->pci_io_size = size;
+ hose->io_base_phys = cpu_phys_addr - pci_addr;
+ /* handle from 0 to top of I/O window */
+ hose->pci_io_size = pci_addr + size;
res = &hose->io_resource;
res->flags = IORESOURCE_IO;
@@ -1117,8 +1118,8 @@ static int get_bus_io_range(struct pci_bus *bus, unsigned long *start_phys,
} else {
/* Root Bus */
res = &hose->io_resource;
- *start_phys = hose->io_base_phys;
- *start_virt = (unsigned long) hose->io_base_virt;
+ *start_phys = hose->io_base_phys + res->start;
+ *start_virt = (unsigned long) hose->io_base_virt + res->start;
if (res->end > res->start)
*size = res->end - res->start + 1;
else {