[PATCH 3/3] ARM: footbridge: restore allocation of CSR I/O resource

[Russell King]

Commit 8ef6e6201b2 ("ARM: footbridge: use fixed PCI i/o mapping") made
two changes: it contains what it says in the summary line, but it also
removes the CSR I/O allocation, which effectively means the DC21285
responds to I/O accesses at address 0..0x7f, which overlap Southbridge
ISA resources on the same PCI bus.

This commit fixes it, but depends on the previous two commits removing
the bus level PCI I/O resource:
  ARM: footbridge: avoid using separate PCI I/O bus resource
  ARM: pci: make bus I/O resources optional

Fixes: 8ef6e6201b2 ("ARM: footbridge: use fixed PCI i/o mapping")
Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
---
 arch/arm/mach-footbridge/dc21285.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-footbridge/dc21285.c b/arch/arm/mach-footbridge/dc21285.c
index f9713dc561cf..d900651a9c8f 100644
--- a/arch/arm/mach-footbridge/dc21285.c
+++ b/arch/arm/mach-footbridge/dc21285.c
@@ -332,6 +332,19 @@ void __init dc21285_preinit(void)
 			    "PCI data parity", NULL);
 
 	if (cfn_mode) {
+		static struct resource csrio;
+
+		csrio.flags  = IORESOURCE_IO;
+		csrio.name   = "Footbridge";
+
+		/*
+		 * Put the Footbridge IO space in the top 256 bytes of IO
+		 * space, which should otherwise remain unused. This avoids
+		 * any conflict with ISA peripherals.
+		 */
+		allocate_resource(&ioport_resource, &csrio, 128,
+				  0xff00, 0xffff, 128, NULL, NULL);
+
 		/*
 		 * Map our SDRAM at a known address in PCI space, just in case
 		 * the firmware had other ideas.  Using a nonzero base is
@@ -339,7 +352,7 @@ void __init dc21285_preinit(void)
 		 * in the range 0x000a0000 to 0x000c0000. (eg, S3 cards).
 		 */
 		*CSR_PCICSRBASE       = 0xf4000000;
-		*CSR_PCICSRIOBASE     = 0;
+		*CSR_PCICSRIOBASE     = csrio.start;
 		*CSR_PCISDRAMBASE     = __virt_to_bus(PAGE_OFFSET);
 		*CSR_PCIROMBASE       = 0;
 		*CSR_PCICMD = PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
-- 
2.20.1