On Tue, Dec 07, 2021 at 04:48:39PM +0100, Clément Léger wrote: > Ethernet frames can be extracted or injected autonomously to or from > the device’s DDR3/DDR3L memory and/or PCIe memory space. Linked list > data structures in memory are used for injecting or extracting Ethernet > frames. The FDMA generates interrupts when frame extraction or > injection is done and when the linked lists need updating. > > The FDMA is shared between all the ethernet ports of the switch and > uses a linked list of descriptors (DCB) to inject and extract packets. > Before adding descriptors, the FDMA channels must be stopped. It would > be inefficient to do that each time a descriptor would be added so the > channels are restarted only once they stopped. > > Both channels uses ring-like structure to feed the DCBs to the FDMA. > head and tail are never touched by hardware and are completely handled > by the driver. On top of that, page recycling has been added and is > mostly taken from gianfar driver. > > Co-developed-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> > Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> > Signed-off-by: Clément Léger <clement.leger@xxxxxxxxxxx> > --- Looks good to me, thanks! Reviewed-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
