• Geert Uytterhoeven's avatar
    swiotlb: Add swiotlb=noforce debug option · fff5d992
    Geert Uytterhoeven authored
    On architectures like arm64, swiotlb is tied intimately to the core
    architecture DMA support. In addition, ZONE_DMA cannot be disabled.
    To aid debugging and catch devices not supporting DMA to memory outside
    the 32-bit address space, add a kernel command line option
    "swiotlb=noforce", which disables the use of bounce buffers.
    If specified, trying to map memory that cannot be used with DMA will
    fail, and a rate-limited warning will be printed.
    Note that io_tlb_nslabs is set to 1, which is the minimal supported
    Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
    Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
kernel-parameters.txt 153 KB