Messages in this thread | | | Date | Fri, 26 Nov 2021 14:28:54 +0000 | From | Sudeep Holla <> | Subject | Re: [PATCH] firmware: arm_scmi: optee: Drop the support for the OPTEE shared dynamic buffer |
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On Fri, Nov 26, 2021 at 08:59:45AM +0100, Etienne Carriere wrote: > Hello Sudeep, > > On Thu, 25 Nov 2021 at 19:25, Cristian Marussi <cristian.marussi@arm.com> wrote: > > > > On Thu, Nov 25, 2021 at 03:07:30PM +0000, Sudeep Holla wrote: > > > The shared memory buffer allocated by the optee driver is normal cached > > > memory and can't be used with IOMEM APIs used in shmem_*. > > > > > > We currently support only IO memory for shared memory and supporting > > > normal cached memory needs more changes and needs to be thought through > > > properly. So for now, let us drop the support for this OPTEE shared buffer. > > > > > > Cc: Cristian Marussi <cristian.marussi@arm.com> > > > Cc: Etienne Carriere <etienne.carriere@linaro.org> > > > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> > > > --- > > > > Hi, > > > > > > > drivers/firmware/arm_scmi/optee.c | 19 +------------------ > > > 1 file changed, 1 insertion(+), 18 deletions(-) > > > > > > diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c > > > index 901737c9f5f8..175b39bcd470 100644 > > > --- a/drivers/firmware/arm_scmi/optee.c > > > +++ b/drivers/firmware/arm_scmi/optee.c > > > @@ -282,23 +282,6 @@ static void scmi_optee_clear_channel(struct scmi_chan_info *cinfo) > > > shmem_clear_channel(channel->shmem); > > > } > > > > > > -static int setup_dynamic_shmem(struct device *dev, struct scmi_optee_channel *channel) > > > -{ > > > - const size_t msg_size = SCMI_OPTEE_MAX_MSG_SIZE; > > > - > > > - channel->tee_shm = tee_shm_alloc_kernel_buf(scmi_optee_private->tee_ctx, msg_size); > > > - if (IS_ERR(channel->tee_shm)) { > > > - dev_err(channel->cinfo->dev, "shmem allocation failed\n"); > > > - return -ENOMEM; > > > - } > > > - > > > - channel->shmem = (void *)tee_shm_get_va(channel->tee_shm, 0); > > > - memset(channel->shmem, 0, msg_size); > > > - shmem_clear_channel(channel->shmem); > > > - > > > - return 0; > > > -} > > > - > > > static int setup_static_shmem(struct device *dev, struct scmi_chan_info *cinfo, > > > struct scmi_optee_channel *channel) > > > { > > > @@ -342,7 +325,7 @@ static int setup_shmem(struct device *dev, struct scmi_chan_info *cinfo, > > > if (of_find_property(cinfo->dev->of_node, "shmem", NULL)) > > > return setup_static_shmem(dev, cinfo, channel); > > > else > > > - return setup_dynamic_shmem(dev, channel); > > > + return -ENOMEM; > > > } > > > > > I would rather find an alternate way to support tee shared memory.
Sure
> I think OP-TEE could use msg.c format when handling tee memory.
Okay
> Linux and OP-TEE Scmi transport discovery negotiate the channel type and > support for msg format could allow OP-TEE to use its shm management.
I am fine with that, just that what we have in for-next/scmi is broken and I want to remove the support just because it is buggy and not because I disagree with the requirement.
> I will prepare an implementation but if you prefer the current remove > support and later introduce back tee shm support, I'm fine. >
Sure, we may need to support this in a generic way. I mean in a way, other transport can also use them if they need it. I remember someone else had asked this in the past.
So yes, I am happy to merge the support for tee shm when that is ready. What we have now is buggy and needs to be dropped. Sorry for not identifying it early.
-- Regards, Sudeep
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