• David S. Miller's avatar
    sparc64: Get rid of indirect p1275 PROM call buffer. · 25edd694
    David S. Miller authored
    This is based upon a report by Meelis Roos showing that it's possible
    that we'll try to fetch a property that is 32K in size with some
    devices.  With the current fixed 3K buffer we use for moving data in
    and out of the firmware during PROM calls, that simply won't work.
    
    In fact, it will scramble random kernel data during bootup.
    
    The reasoning behind the temporary buffer is entirely historical.  It
    used to be the case that we had problems referencing dynamic kernel
    memory (including the stack) early in the boot process before we
    explicitly told the firwmare to switch us over to the kernel trap
    table.
    
    So what we did was always give the firmware buffers that were locked
    into the main kernel image.
    
    But we no longer have problems like that, so get rid of all of this
    indirect bounce buffering.
    
    Besides fixing Meelis's bug, this also makes the kernel data about 3K
    smaller.
    
    It was also discovered during these conversions that the
    implementation of prom_retain() was completely wrong, so that was
    fixed here as well.  Currently that interface is not in use.
    Reported-by: default avatarMeelis Roos <mroos@linux.ee>
    Tested-by: default avatarMeelis Roos <mroos@linux.ee>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    25edd694
devops_64.c 1.33 KB