From 11fbb00c67e19737757e747ec7dd3ba8d584f5d1 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 7 May 2007 15:16:23 +1000 Subject: [PATCH] [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 --- arch/powerpc/kernel/pci_64.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c index 60d7d4baa227..706b7f3da5ff 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 { -- 2.34.1