• Mark Nutter's avatar
    [PATCH] spufs: enable SPE problem state MMIO access. · 6df10a82
    Mark Nutter authored
    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: default avatarArnd Bergmann <arnd.bergmann@de.ibm.com>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    6df10a82
file.c 28.3 KB