• Stefano Stabellini's avatar
    xen/arm,arm64: enable SWIOTLB_XEN · 83862ccf
    Stefano Stabellini authored
    Xen on arm and arm64 needs SWIOTLB_XEN: when running on Xen we need to
    program the hardware with mfns rather than pfns for dma addresses.
    Remove SWIOTLB_XEN dependency on X86 and PCI and make XEN select
    SWIOTLB_XEN on arm and arm64.
    At the moment always rely on swiotlb-xen, but when Xen starts supporting
    hardware IOMMUs we'll be able to avoid it conditionally on the presence
    of an IOMMU on the platform.
    Implement xen_create_contiguous_region on arm and arm64: for the moment
    we assume that dom0 has been mapped 1:1 (physical addresses == machine
    addresses) therefore we don't need to call XENMEM_exchange. Simply
    return the physical address as dma address.
    Initialize the xen-swiotlb from xen_early_init (before the native
    dma_ops are initialized), set xen_dma_ops to &xen_swiotlb_dma_ops.
    Signed-off-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
    Changes in v8:
    - assume dom0 is mapped 1:1, no need to call XENMEM_exchange.
    Changes in v7:
    - call __set_phys_to_machine_multi from xen_create_contiguous_region and
    xen_destroy_contiguous_region to update the P2M;
    - don't call XENMEM_unpin, it has been removed;
    - call XENMEM_exchange instead of XENMEM_exchange_and_pin;
    - set nr_exchanged to 0 before calling the hypercall.
    Changes in v6:
    - introduce and export xen_dma_ops;
    - call xen_mm_init from as arch_initcall.
    Changes in v4:
    - remove redefinition of DMA_ERROR_CODE;
    - update the code to use XENMEM_exchange_and_pin and XENMEM_unpin;
    - add a note about hardware IOMMU in the commit message.
    Changes in v3:
    - code style changes;
    - warn on XENMEM_put_dma_buf failures.
Kconfig 5.78 KB