• Lorenzo Pieralisi's avatar
    ACPI: Implement acpi_dma_configure · d760a1ba
    Lorenzo Pieralisi authored
    On DT based systems, the of_dma_configure() API implements DMA
    configuration for a given device. On ACPI systems an API equivalent to
    of_dma_configure() is missing which implies that it is currently not
    possible to set-up DMA operations for devices through the ACPI generic
    kernel layer.
    
    This patch fills the gap by introducing acpi_dma_configure/deconfigure()
    calls that for now are just wrappers around arch_setup_dma_ops() and
    arch_teardown_dma_ops() and also updates ACPI and PCI core code to use
    the newly introduced acpi_dma_configure/acpi_dma_deconfigure functions.
    
    Since acpi_dma_configure() is used to configure DMA operations, the
    function initializes the dma/coherent_dma masks to sane default values
    if the current masks are uninitialized (also to keep the default values
    consistent with DT systems) to make sure the device has a complete
    default DMA set-up.
    
    The DMA range size passed to arch_setup_dma_ops() is sized according
    to the device coherent_dma_mask (starting at address 0x0), mirroring the
    DT probing path behaviour when a dma-ranges property is not provided
    for the device being probed; this changes the current arch_setup_dma_ops()
    call parameters in the ACPI probing case, but since arch_setup_dma_ops()
    is a NOP on all architectures but ARM/ARM64 this patch does not change
    the current kernel behaviour on them.
    Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
    Acked-by: Bjorn Helgaas <bhelgaas@google.com> [pci]
    Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    Reviewed-by: default avatarTomasz Nowicki <tn@semihalf.com>
    Tested-by: default avatarHanjun Guo <hanjun.guo@linaro.org>
    Tested-by: default avatarTomasz Nowicki <tn@semihalf.com>
    Cc: Bjorn Helgaas <bhelgaas@google.com>
    Cc: Robin Murphy <robin.murphy@arm.com>
    Cc: Tomasz Nowicki <tn@semihalf.com>
    Cc: Joerg Roedel <joro@8bytes.org>
    Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    d760a1ba
glue.c 8.61 KB