omap iommu: simple virtual address space management

This patch provides a device drivers, which has a omap iommu, with
address mapping APIs between device virtual address(iommu), physical
address and MPU virtual address.

There are 4 possible patterns for iommu virtual address(iova/da) mapping.

    |iova/			  mapping		iommu_		page
    | da	pa	va	(d)-(p)-(v)		function	type
  ---------------------------------------------------------------------------
  1 | c		c	c	 1 - 1 - 1	  _kmap() / _kunmap()	s
  2 | c		c,a	c	 1 - 1 - 1	_kmalloc()/ _kfree()	s
  3 | c		d	c	 1 - n - 1	  _vmap() / _vunmap()	s
  4 | c		d,a	c	 1 - n - 1	_vmalloc()/ _vfree()	n*

    'iova':	device iommu virtual address
    'da':	alias of 'iova'
    'pa':	physical address
    'va':	mpu virtual address

    'c':	contiguous memory area
    'd':	dicontiguous memory area
    'a':	anonymous memory allocation
    '()':	optional feature

    'n':	a normal page(4KB) size is used.
    's':	multiple iommu superpage(16MB, 1MB, 64KB, 4KB) size is used.

    '*':	not yet, but feasible.

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 9f88dd3be601..0ab75c60f7cf 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -110,6 +110,12 @@ static int remap_area_pages(unsigned long start, unsigned long pfn,
         return err;
 }
 
+int ioremap_page(unsigned long virt, unsigned long phys,
+                 const struct mem_type *mtype)
+{
+        return remap_area_pages(virt, __phys_to_pfn(phys), PAGE_SIZE, mtype);
+}
+EXPORT_SYMBOL(ioremap_page);
 
 void __check_kvm_seq(struct mm_struct *mm)
 {