On Tue, Nov 17, 2020 at 03:00:32PM +0100, Arnaud POULIQUEN wrote: > The dma_declare_coherent_memory allows to associate vdev0buffer memory region > to the remoteproc virtio device (vdev parent). This region is used to > allocated > the rpmsg buffers. > The memory for the rpmsg buffer is allocated by the rpmsg_virtio device in > rpmsg_virtio_bus[1]. The size depends on the total size needed for the rpmsg > buffers. > > The vrings are allocated directly by the remoteproc device.
Weird. I thought virtio was pretty strict in not allowing diret DMA API usage in drivers to support the legacy no-mapping case. Either way, the point stands: if you want these magic buffers handed out to specific rpmsg instances I think not having to detour through the DMA API is going to make everyones life easier.
