Hi Florian > Subject: Re: [PATCH V8 2/2] mailbox: introduce ARM SMC based mailbox > > Hi Peng, > > On 9/23/2019 6:14 PM, Peng Fan wrote: > > From: Peng Fan <peng.fan@xxxxxxx> > > > > This mailbox driver implements a mailbox which signals transmitted > > data via an ARM smc (secure monitor call) instruction. The mailbox > > receiver is implemented in firmware and can synchronously return data > > when it returns execution to the non-secure world again. > > An asynchronous receive path is not implemented. > > This allows the usage of a mailbox to trigger firmware actions on SoCs > > which either don't have a separate management processor or on which > > such a core is not available. A user of this mailbox could be the SCP > > interface. > > > > Modified from Andre Przywara's v2 patch > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore > > .kernel.org%2Fpatchwork%2Fpatch%2F812999%2F&data=02%7C01%7 > Cpeng.fa > > > n%40nxp.com%7C296c7cd2225e4ca32bb808d74099afb2%7C686ea1d3bc2b4 > c6fa92cd > > > 99c5c301635%7C0%7C0%7C637048901144091126&sdata=JDo%2Be7Tt > hoi4jve0O > > S8qe3%2Fpji4g8CgRxL7ntCQx3Fg%3D&reserved=0 > > > > Cc: Andre Przywara <andre.przywara@xxxxxxx> > > Signed-off-by: Peng Fan <peng.fan@xxxxxxx> > > --- > > [snip] > > > +typedef unsigned long (smc_mbox_fn)(unsigned int, unsigned long, > > + unsigned long, unsigned long, > > + unsigned long, unsigned long, > > + unsigned long); > > +static smc_mbox_fn *invoke_smc_mbox_fn; > > Sorry for spotting this so late, the only thing that concerns me here with this > singleton is if we happen to have both an arm,smc-mbox and arm,hvc-mbox > configured in the system, this would not work. Yes. Thanks for spotting this. I do not believe this could be a > functional use case, but we should probably guard against that or better yet, > move that into the arm_smc_chan_data private structure? Agree. Will Fix in v9. Thanks, Peng. > -- > Florian
