From: George Beshers <gbeshers@redhat.com>
Date: Mon, 27 Aug 2007 14:44:27 -0400
Subject: [ia64] proc/iomem wiped out on non ACPI kernel
Message-id: 46D31B8B.8050305@redhat.com
O-Subject: [Rhel 5.1 BZ257001] proc/iomem wiped out on non ACPI kernels, kdump uses /proc/iomem
Bugzilla: 257001

[Sorry if you see this twice]
[BZ#257001 and IT#117278]

Exception Request.

The following patch should have been part of ACPI I/O support
and its lack was detected during testing.

The ACPI patches that were included enables proper ACPI support
on systems with the newer prom revisions.  This patch is required for
the Altix systems in the field with older proms (shame on me for
keeping the machines at RedHat up to date :-/).

>From the IT 117278:
  On a non ACPI enabled kernel the pci windows won't be created at the
  time this pci-to-system address space conversion is done.  Because of
  that we must later go thru and manually overwrite these pci addresses
  with the PIO addresses.  This happens in sn_io_slot_fixup().  As a
  result of manually overwriting these addresses, the iomem tree will
  no longer be a  ``sorted tree''... And because of it no longer being
  sorted, /proc/iomem sometimes appears truncated.

  So why is this an issue?  Well kdump uses this table to located the
  "Crash kernel" entry within the /proc/iomem tree... if the iomem tree
  is corrupted, /etc/init.d/kdump will fail to load the kdump kernel.

diff --git a/arch/ia64/sn/kernel/io_init.c b/arch/ia64/sn/kernel/io_init.c
index 113ad40..d62e0ca 100644
--- a/arch/ia64/sn/kernel/io_init.c
+++ b/arch/ia64/sn/kernel/io_init.c
@@ -247,10 +247,19 @@ sn_io_slot_fixup(struct pci_dev *dev)
 		addr = ((addr << 4) >> 4) | __IA64_UNCACHED_OFFSET;
 		dev->resource[idx].start = addr;
 		dev->resource[idx].end = addr + size;
+
+		/*
+		 * if it's already in the device structure, remove it before
+		 * inserting
+		 */
+		if (dev->resource[idx].parent && dev->resource[idx].parent->child)
+			release_resource(&dev->resource[idx]);
+ 
 		if (dev->resource[idx].flags & IORESOURCE_IO)
-			dev->resource[idx].parent = &ioport_resource;
+			insert_resource(&ioport_resource, &dev->resource[idx]);
 		else
-			dev->resource[idx].parent = &iomem_resource;
+			insert_resource(&iomem_resource, &dev->resource[idx]);
+
 		/* If ROM, mark as shadowed in PROM */
 		if (idx == PCI_ROM_RESOURCE)
 			dev->resource[idx].flags |= IORESOURCE_ROM_BIOS_COPY;