PCI legacy resource fix
Since commit 368c73d4f689dae0807d0a2aa74c61fd2b9b075f the kernel will try
to update the non-writeable BAR registers 0..3 of PIIX4 IDE adapters if
pci_assign_unassigned_resources() is used to do full resource assignment of
the bus. This fails because in the PIIX4 these BAR registers have
implicitly assumed values and read back as zero; it used to work because
the kernel used to just write zero to that register the read back value did
match what was written.
The fix is a new resource flag IORESOURCE_PCI_FIXED used to mark a resource
as non-movable. This will also be useful to keep other import system
resources from being moved around - for example system consoles on PCI
busses.
[akpm@osdl.org: cleanup]
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index cf8696d..15228d7 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -91,6 +91,9 @@
#define IORESOURCE_ROM_COPY (1<<2) /* ROM is alloc'd copy, resource field overlaid */
#define IORESOURCE_ROM_BIOS_COPY (1<<3) /* ROM is BIOS copy, resource field overlaid */
+/* PCI control bits. Shares IORESOURCE_BITS with above PCI ROM. */
+#define IORESOURCE_PCI_FIXED (1<<4) /* Do not move resource */
+
/* PC/ISA/whatever - the normal PC address spaces: IO and memory */
extern struct resource ioport_resource;
extern struct resource iomem_resource;