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author | Kai Jiang <Kai.Jiang@freescale.com> | 2011-10-17 20:50:20 +0200 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-10-18 11:18:57 -0700 |
commit | 27a90700a4275c5178b883b65927affdafa5185c (patch) | |
tree | d140a0c39bc0bf68531a165e0678be58987d2d78 /Documentation/blackfin | |
parent | c4253cb0748cd50060d04d838c38b07f1ad0e6e5 (diff) |
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 'Documentation/blackfin')
0 files changed, 0 insertions, 0 deletions