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| author | Kai Jiang <Kai.Jiang@freescale.com> | 2011-10-17 22:50:20 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-10-18 22:18:57 +0400 |
| commit | 27a90700a4275c5178b883b65927affdafa5185c (patch) | |
| tree | d140a0c39bc0bf68531a165e0678be58987d2d78 /include/linux | |
| parent | c4253cb0748cd50060d04d838c38b07f1ad0e6e5 (diff) | |
| download | linux-27a90700a4275c5178b883b65927affdafa5185c.tar.xz | |
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>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/uio_driver.h | 7 |
1 files changed, 5 insertions, 2 deletions
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; |