• Daniel Hellstrom's avatar
    sparc32,leon: add GRPCI2 PCI Host driver · 5d07b786
    Daniel Hellstrom authored
    
    
    The DMA region must be accessible in order for PCI peripheral
    drivers to work, the sparc32 has DMA in the normal memory
    zone which requires the GRPCI2 to PCI target BARs so that all
    kernel low mem (192MB) can be mapped 1:1 to PCI address
    space. The GRPCI2 has resizeable target BARs, by default the
    first is made 256MB and all other BARs are disabled.
    
    I/O space are always located on 0x1000-0x10000, but accessed
    through the GRPCI2 PCI I/O Window memory mapped to virtual
    address space.
    
    Configuration space is accessed through the 64KB GRPCI2 PCI
    CFG Window using LDA bypassing the MMU.
    
    The GRPCI2 has a single PCI Window for prefetchable and non-
    prefetchable address space, it is up to the AHB master
    requesting PCI data to determine access type. Memory space
    is mapped 1:1.
    
    The GRPCI2 core can be configured in 4 different IRQ modes,
    where PCI Interrupt, Error Interrupt and DMA Interrupt are
    shared on a single IRQ line or at most 5 IRQs are used. The
    GRPCI2 can mask/unmask PCI interrupts, Err and DMA in the control
    and check status bits which tells us which IRQ really happended.
    The GENIRQ layer is used to unmask/mask each individual IRQ
    source by creating virtual IRQs and implementing a IRQ chip.
    
    The optional DMA functionality of the GRPCI2 is not supported
    by this patch.
    Signed-off-by: default avatarDaniel Hellstrom <daniel@gaisler.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    5d07b786
leon_kernel.c 13.1 KB