• Benjamin Herrenschmidt's avatar
    powerpc/powernv: PCI support for p7IOC under OPAL v2 · 184cd4a3
    Benjamin Herrenschmidt authored
    This adds support for p7IOC (and possibly other IODA v1 IO Hubs)
    using OPAL v2 interfaces.
    
    We completely take over resource assignment and assign them using an
    algorithm that hands out device BARs in a way that makes them fit in
    individual segments of the M32 window of the bridge, which enables us
    to assign individual PEs to devices and functions.
    
    The current implementation gives out a PE per functions on PCIe, and a
    PE for the entire bridge for PCIe to PCI-X bridges.
    
    This can be adjusted / fine tuned later.
    
    We also setup DMA resources (32-bit only for now) and MSIs (both 32-bit
    and 64-bit MSI are supported).
    
    The DMA allocation tries to divide the available 256M segments of the
    32-bit DMA address space "fairly" among PEs. This is done using a
    "weight" heuristic which assigns less value to things like OHCI USB
    controllers than, for example SCSI RAID controllers. This algorithm
    will probably want some fine tuning for specific devices or device
    types.
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
    184cd4a3
pci_dn.c 4.84 KB