dm: Introduce DMA constraints into the core device model
Calculating the DMA offset between a bus address space and CPU's every time we call phys_to_bus() and bus_to_phys() isn't ideal performance wise, as it implies traversing the device tree from the device's node up to the root. Since this information is static and available before the device's initialization, parse it before the probe call an provide the DMA offset in 'struct udevice' for the address translation code to use it. Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: NSimon Glass <sjg@chromium.org> Tested-by: NPeter Robinson <pbrobinson@gmail.com> Signed-off-by: NMatthias Brugger <mbrugger@suse.com>
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