• Michael Schmitz's avatar
    m68k/atari: Reserve some ST-RAM early on for device buffer use · 217bbd81
    Michael Schmitz authored
    Based on an original patch from Michael Schmitz:
    
    Because mem_init() is now called before device init, devices that rely on
    ST-RAM may find all ST-RAM already allocated to other users by the time
    device init happens. In particular, a large initrd RAM disk may use up
    enough of ST-RAM to cause atari_stram_alloc() to resort to
    __get_dma_pages() allocation.
    
    In the current state of Atari memory management, all of RAM is marked
    DMA capable, so __get_dma_pages() may well return RAM that is not in actual
    fact DMA capable. Using this for frame buffer or SCSI DMA buffer causes
    subtle failure.
    
    The ST-RAM allocator has been changed to allocate memory from a pool of
    reserved ST-RAM of configurable size, set aside on ST-RAM init (i.e.
    before mem_init()). As long as this pool is not exhausted, allocation of
    real ST-RAM can be guaranteed.
    
    Other changes:
      - Replace the custom allocator in the ST-RAM pool by the existing allocator
        in the resource subsystem,
      - Remove mem_init_done and its hook, as memory init is now done before
        device init,
      - Remove /proc/stram, as ST-RAM usage now shows up under /proc/iomem, e.g.
    
    	005f2000-006f1fff : ST-RAM Pool
    	  005f2000-0063dfff : atafb
    	  0063e000-00641fff : ataflop
    	  00642000-00642fff : SCSI
    Signed-off-by: default avatarMichael Schmitz <schmitz@debian.org>
    [Andreas Schwab <schwab@linux-m68k.org>: Use memparse()]
    [Geert: Use the resource subsystem instead of a custom allocator]
    Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
    217bbd81
Kconfig.mmu 13.7 KB