[ARM] 3070/2: Add __ioremap_pfn() API

Patch from Deepak Saxena

In working on adding 36-bit addressed supersection support to ioremap(),
I came to the conclusion that it would be far simpler to do so by just
splitting __ioremap() into a main external interface and adding an
__ioremap_pfn() function that takes a pfn + offset into the page that
__ioremap() can call. This way existing callers of __ioremap() won't have
to change their code and 36-bit systems will just call __ioremap_pfn()
and we will not have to deal with unsigned long long variables.

Note that __ioremap_pfn() should _NOT_ be called directly by drivers
but is reserved for use by arch_ioremap() implementations that map
32-bit resource regions into the real 36-bit address and then call
this new function.

Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/asm-arm/memory.h b/include/asm-arm/memory.h
index 3e572364ee73..3d7f08bd9030 100644
--- a/include/asm-arm/memory.h
+++ b/include/asm-arm/memory.h
@@ -58,6 +58,12 @@
 #endif
 
 /*
+ * Convert a physical address to a Page Frame Number and back
+ */
+#define __phys_to_pfn(paddr)    ((paddr) >> PAGE_SHIFT)
+#define __pfn_to_phys(pfn)      ((pfn) << PAGE_SHIFT)
+
+/*
  * The module space lives between the addresses given by TASK_SIZE
  * and PAGE_OFFSET - it must be within 32MB of the kernel text.
  */