On Sat, Apr 02, 2022 at 03:51:46PM +0200, Sven Peter wrote: > On Wed, Mar 23, 2022, at 12:19, Krzysztof Kozlowski wrote: > > On 21/03/2022 17:50, Sven Peter wrote: > >> Apple SoCs such as the M1 come with multiple embedded co-processors > >> running proprietary firmware. Communication with those is established > >> over a simple mailbox using the RTKit IPC protocol. > >> > >> Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx> > >> --- > >> drivers/soc/apple/Kconfig | 13 + > >> drivers/soc/apple/Makefile | 3 + > >> drivers/soc/apple/rtkit-crashlog.c | 147 +++++ > >> drivers/soc/apple/rtkit-internal.h | 76 +++ > >> drivers/soc/apple/rtkit.c | 842 +++++++++++++++++++++++++++++ > >> include/linux/soc/apple/rtkit.h | 203 +++++++ > >> 6 files changed, 1284 insertions(+) > > > > Isn't this some implementation of a mailbox? If so, it should be in > > drivers/mailbox. Please don't put all stuff in soc/apple, that's not how > > Linux is organized. To drivers/soc usually we put drivers which do not > > fit regular subsystems. > > > > I put this into soc/apple because I don't think it fits within the mailbox > framework very well. > (It actually uses the mailbox framework for the actual communication > with the hardware with a driver that's already upstream.) > > Essentially, the mailbox subsystem provides a common API to send and > receive messages over indepedent hardware channels and devicetree bindings > to describe the relationship between those channels and other drivers. > > One of the features that doesn't really fit is that we need to be able > to start, shutdown and re-start these co-processors. The NVMe driver remoteproc does that. Did you look at it? Most remoteproc drivers use some combination of mailboxes and shared memory. Rob
