tree e8615f4c00a44f4e4a609d59c51e958f0300526b
parent a33a7d7309d79656bc19a0e96fc4547a1633283e
author Mark Nutter <mnutter@us.ibm.com> 1143068412 +0100
committer Paul Mackerras <paulus@samba.org> 1143431308 +1100

[PATCH] spufs: enable SPE problem state MMIO access.

This patch is layered on top of CONFIG_SPARSEMEM
and is patterned after direct mapping of LS.

This patch allows mmap() of the following regions:
"mfc", which represents the area from [0x3000 - 0x3fff];
"cntl", which represents the area from [0x4000 - 0x4fff];
"signal1" which begins at offset 0x14000; "signal2" which
begins at offset 0x1c000.

The signal1 & signal2 files may be mmap()'d by regular user
processes.  The cntl and mfc file, on the other hand, may
only be accessed if the owning process has CAP_SYS_RAWIO,
because they have the potential to confuse the kernel
with regard to parallel access to the same files with
regular file operations: the kernel always holds a spinlock
when accessing registers in these areas to serialize them,
which can not be guaranteed with user mmaps,

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>