On Wed, Nov 9, 2016 at 3:19 PM, Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> wrote: > 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: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> [pci] > Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Tested-by: Tomasz Nowicki <tn@xxxxxxxxxxxx> > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > Cc: Robin Murphy <robin.murphy@xxxxxxx> > Cc: Tomasz Nowicki <tn@xxxxxxxxxxxx> > Cc: Joerg Roedel <joro@xxxxxxxxxx> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> LGTM Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
