pci root complex: support for tile architecture

This change enables PCI root complex support for TILEPro.  Unlike
TILE-Gx, TILEPro has no support for memory-mapped I/O, so the PCI
support consists of hypervisor upcalls for PIO, DMA, etc.  However,
the performance is fine for the devices we have tested with so far
(1Gb Ethernet, SATA, etc.).

The <asm/io.h> header was tweaked to be a little bit more aggressive
about disabling attempts to map/unmap IO port space.  The hacky
<asm/pci-bridge.h> header was rolled into the <asm/pci.h> header
and the result was simplified.  Both of the latter two headers were
preliminary versions not meant for release before now - oh well.

There is one quirk for our TILEmpower platform, which accidentally
negotiates up to 5GT and needs to be kicked down to 2.5GT.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/include/asm/io.h b/arch/tile/include/asm/io.h
index ee43328..d3cbb9b 100644
--- a/arch/tile/include/asm/io.h
+++ b/arch/tile/include/asm/io.h
@@ -55,9 +55,6 @@
 #define ioremap_writethrough(physaddr, size)	ioremap(physaddr, size)
 #define ioremap_fullcache(physaddr, size)	ioremap(physaddr, size)
 
-void __iomem *ioport_map(unsigned long port, unsigned int len);
-extern inline void ioport_unmap(void __iomem *addr) {}
-
 #define mmiowb()
 
 /* Conversion between virtual and physical mappings.  */
@@ -189,12 +186,22 @@
  * we never run, uses them unconditionally.
  */
 
-static inline int ioport_panic(void)
+static inline long ioport_panic(void)
 {
 	panic("inb/outb and friends do not exist on tile");
 	return 0;
 }
 
+static inline void __iomem *ioport_map(unsigned long port, unsigned int len)
+{
+	return (void __iomem *) ioport_panic();
+}
+
+static inline void ioport_unmap(void __iomem *addr)
+{
+	ioport_panic();
+}
+
 static inline u8 inb(unsigned long addr)
 {
 	return ioport_panic();