OMAP: iommu: add initial debugfs support

This enables to peek the following data.

$ /debug/iommu/isp# ls
mem             nr_tlb_entries  regs
mmap            pagetable       tlb
$ /debug/iommu/isp# head pagetable
L:      da:      pa:
-----------------------------------------
2: 00001000 8ae4a002
2: 00002000 8e7bb002
2: 00003000 8ae49002
2: 00004000 8ae65002
.....

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/plat-omap/include/mach/iommu.h b/arch/arm/plat-omap/include/mach/iommu.h
index 769b00b..46d41ac 100644
--- a/arch/arm/plat-omap/include/mach/iommu.h
+++ b/arch/arm/plat-omap/include/mach/iommu.h
@@ -95,7 +95,7 @@
 
 	void (*save_ctx)(struct iommu *obj);
 	void (*restore_ctx)(struct iommu *obj);
-	ssize_t (*dump_ctx)(struct iommu *obj, char *buf);
+	ssize_t (*dump_ctx)(struct iommu *obj, char *buf, ssize_t len);
 };
 
 struct iommu_platform_data {
@@ -162,7 +162,7 @@
 extern int foreach_iommu_device(void *data,
 				int (*fn)(struct device *, void *));
 
-extern ssize_t iommu_dump_ctx(struct iommu *obj, char *buf);
-extern size_t dump_tlb_entries(struct iommu *obj, char *buf);
+extern ssize_t iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t len);
+extern size_t dump_tlb_entries(struct iommu *obj, char *buf, ssize_t len);
 
 #endif /* __MACH_IOMMU_H */