From 27a90700a4275c5178b883b65927affdafa5185c Mon Sep 17 00:00:00 2001 From: Kai Jiang Date: Mon, 17 Oct 2011 20:50:20 +0200 Subject: 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 Signed-off-by: Minghuan Lian Signed-off-by: Kumar Gala Signed-off-by: Hans J. Koch Signed-off-by: Greg Kroah-Hartman --- include/linux/uio_driver.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h index 665517c05eaf..fd99ff9298c6 100644 --- a/include/linux/uio_driver.h +++ b/include/linux/uio_driver.h @@ -23,7 +23,10 @@ struct uio_map; /** * 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_map; */ struct uio_mem { const char *name; - unsigned long addr; + phys_addr_t addr; unsigned long size; int memtype; void __iomem *internal_addr; -- cgit v1.2.3