uio: Support physical addresses >32 bits on 32-bit systems
To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
extend the width of 'addr' in struct uio_mem. Numerous platforms like
embedded PPC, ARM, and X86 have support for systems with larger physical
address than logical.
Since 'addr' may contain a physical, logical, or virtual address the
easiest solution is to just change the type to 'phys_addr_t' which
should always be greater than or equal to the sizeof(void *) such that
it can properly hold any of the address types.
For physical address we can support up to a 44-bit physical address on a
typical 32-bit system as we utilize remap_pfn_range() for the mapping of
the memory region and pfn's are represnted by shifting the address by
the page size (typically 4k).
Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Hans J. Koch <hjk@hansjkoch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
index 665517c..fd99ff9 100644
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h
@@ -23,7 +23,10 @@
/**
* struct uio_mem - description of a UIO memory region
* @name: name of the memory region for identification
- * @addr: address of the device's memory
+ * @addr: address of the device's memory (phys_addr is used since
+ * addr can be logical, virtual, or physical & phys_addr_t
+ * should always be large enough to handle any of the
+ * address types)
* @size: size of IO
* @memtype: type of memory addr points to
* @internal_addr: ioremap-ped version of addr, for driver internal use
@@ -31,7 +34,7 @@
*/
struct uio_mem {
const char *name;
- unsigned long addr;
+ phys_addr_t addr;
unsigned long size;
int memtype;
void __iomem *internal_addr;
