From: Ivan K. <in...@ju...> - 2005-06-28 11:52:24
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[This refers to "gregkh-pci-pci-collect-host-bridge-resources-02.patch" which went into 2.6.12-mm1 and -mm2] On Thu, Jun 02, 2005 at 03:41:49PM -0700, raj...@in... wrote: > This patch reads and stores host bridge resources reported by > ACPI BIOS for i386 and x86_64 systems. This is needed since > ACPI hotplug code now uses the PCI core for resource management. That patch introduces two major problems. 1. The new root bus resources aren't properly inserted into global resource tree (missing request_resource calls). This leads to completely messed up PCI setup, especially with pci_assign_unassigned_resources() call, as seen in -mm1 (mm2 is also unsafe, though). 2. Transparent bridge handling is broken, no matter is it old code in Linus' tree or the new one in -mm. At the point then pcibios_setup_root_windows() is called, the "transparent" resource pointers have been already set up in pci_read_bridge_bases() (typically to ioport_resource and iomem_resource), so after changing the root bus windows these pointers are wrong. The appended patch fixes that. Just compare /proc/ioports and /proc/iomem with and without it. ;-) Ivan. --- 2.6.12-mm2/arch/i386/pci/acpi.c 2005-06-28 13:30:24.000000000 +0400 +++ linux/arch/i386/pci/acpi.c 2005-06-28 14:13:51.000000000 +0400 @@ -107,10 +107,22 @@ verify_root_windows(struct pci_bus *bus) continue; switch (bus->resource[i]->flags & type_mask) { case IORESOURCE_IO: - num_io++; + if (!request_resource(&ioport_resource, + bus->resource[i])) + num_io++; + else { + kfree(bus->resource[i]); + bus->resource[i] = NULL; + } break; case IORESOURCE_MEM: - num_mem++; + if (!request_resource(&iomem_resource, + bus->resource[i])) + num_mem++; + else { + kfree(bus->resource[i]); + bus->resource[i] = NULL; + } break; default: break; @@ -126,6 +138,21 @@ verify_root_windows(struct pci_bus *bus) } static void __devinit +fixup_transparent_bridges(struct list_head *bus_list) +{ + int i; + struct pci_bus *b; + + list_for_each_entry(b, bus_list, node) { + if (b->self && b->self->transparent) { + for (i = 3; i < PCI_BUS_NUM_RESOURCES; i++) + b->resource[i] = b->parent->resource[i - 3]; + } + fixup_transparent_bridges(&b->children); + } +} + +static void __devinit pcibios_setup_root_windows(struct pci_bus *bus, acpi_handle handle) { int i; @@ -147,6 +174,21 @@ pcibios_setup_root_windows(struct pci_bu kfree(bus->resource[i]); bus->resource[i] = bres[i]; } + } else { + /* Squeeze out unused resource pointers. */ + int idx = 0; + + for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) { + if (bus->resource[i]) + bus->resource[idx++] = bus->resource[i]; + } + for (; idx < PCI_BUS_NUM_RESOURCES; idx++) + bus->resource[idx] = NULL; + + /* The root bus resources have been changed. Fix up the + resource pointers of buses behind "transparent" bridges + as well. */ + fixup_transparent_bridges(&bus->children); } } |