ARM: Add fixed PCI i/o mapping

This adds a fixed virtual mapping for PCI i/o addresses. The mapping is
located at the last 2MB of vmalloc region (0xfee00000-0xff000000). 2MB
is used to align with PMD size, but IO_SPACE_LIMIT is 1MB. The space
is reserved after .map_io and can be mapped at any time later with
pci_ioremap_io. Platforms which need early i/o mapping (e.g. for vga
console) can call pci_map_io_early in their .map_io function.

This has changed completely from the 1st implementation which only
supported creating the static mapping at .map_io.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>

3 files changed, 26 insertions, 0 deletions

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 815c669fec0a..8f4db67533e5 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -113,11 +113,19 @@ static inline void __iomem *__typesafe_io(unsigned long addr)
 #define __iowmb()		do { } while (0)
 #endif
 
+/* PCI fixed i/o mapping */
+#define PCI_IO_VIRT_BASE	0xfee00000
+
+extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr);
+
 /*
  * Now, pick up the machine-defined IO definitions
  */
 #ifdef CONFIG_NEED_MACH_IO_H
 #include <mach/io.h>
+#elif defined(CONFIG_PCI)
+#define IO_SPACE_LIMIT	((resource_size_t)0xfffff)
+#define __io(a)		__typesafe_io(PCI_IO_VIRT_BASE + ((a) & IO_SPACE_LIMIT))
 #else
 #define __io(a)		__typesafe_io((a) & IO_SPACE_LIMIT)
 #endif
diff --git a/arch/arm/include/asm/mach/map.h b/arch/arm/include/asm/mach/map.h
index a6efcdd6fd25..195ac2f9d3d3 100644
--- a/arch/arm/include/asm/mach/map.h
+++ b/arch/arm/include/asm/mach/map.h
@@ -9,6 +9,9 @@
  *
  *  Page table mapping constructs and function prototypes
  */
+#ifndef __ASM_MACH_MAP_H
+#define __ASM_MACH_MAP_H
+
 #include <asm/io.h>
 
 struct map_desc {
@@ -34,6 +37,8 @@ struct map_desc {
 
 #ifdef CONFIG_MMU
 extern void iotable_init(struct map_desc *, int);
+extern void vm_reserve_area_early(unsigned long addr, unsigned long size,
+				  void *caller);
 
 struct mem_type;
 extern const struct mem_type *get_mem_type(unsigned int type);
@@ -44,4 +49,7 @@ extern int ioremap_page(unsigned long virt, unsigned long phys,
 			const struct mem_type *mtype);
 #else
 #define iotable_init(map,num)	do { } while (0)
+#define vm_reserve_area_early(a,s,c)	do { } while (0)
+#endif
+
 #endif
diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
index 26c511fddf8f..df818876fa31 100644
--- a/arch/arm/include/asm/mach/pci.h
+++ b/arch/arm/include/asm/mach/pci.h
@@ -11,6 +11,7 @@
 #ifndef __ASM_MACH_PCI_H
 #define __ASM_MACH_PCI_H
 
+
 struct pci_sys_data;
 struct pci_ops;
 struct pci_bus;
@@ -55,6 +56,15 @@ struct pci_sys_data {
 void pci_common_init(struct hw_pci *);
 
 /*
+ * Setup early fixed I/O mapping.
+ */
+#if defined(CONFIG_PCI)
+extern void pci_map_io_early(unsigned long pfn);
+#else
+static inline void pci_map_io_early(unsigned long pfn) {}
+#endif
+
+/*
  * PCI controllers
  */
 extern struct pci_ops iop3xx_ops;