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Message-ID: <Y0BOrU9jzM+5Lb3G@e120937-lin>
Date: Fri, 7 Oct 2022 17:07:09 +0100
From: Cristian Marussi <cristian.marussi@....com>
To: Vincent Guittot <vincent.guittot@...aro.org>
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
sudeep.holla@....com, james.quinlan@...adcom.com,
Jonathan.Cameron@...wei.com, f.fainelli@...il.com,
etienne.carriere@...aro.org, souvik.chakravarty@....com,
wleavitt@...vell.com, peter.hilber@...nsynergy.com,
nicola.mazzucato@....com, tarek.el-sherbiny@....com
Subject: Re: [PATCH v3 0/9] Introduce a unified API for SCMI Server testing
On Fri, Oct 07, 2022 at 05:58:59PM +0200, Vincent Guittot wrote:
> On Fri, 7 Oct 2022 at 17:37, Cristian Marussi <cristian.marussi@....com> wrote:
> >
> > On Fri, Oct 07, 2022 at 04:23:33PM +0200, Vincent Guittot wrote:
> > > Hi Cristian,
> > >
> >
> > Hi Vincent
> >
> > thanks for give it a try !
> >
> > > On Sat, 3 Sept 2022 at 20:31, Cristian Marussi <cristian.marussi@....com> wrote:
> > > >
> > > > Hi all,
> > > >
> > > > This series aims to introduce a new SCMI unified userspace interface meant
> > > > to ease testing an SCMI Server implementation for compliance, fuzzing etc.,
> > > > from the perspective of the OSPM agent (non-secure world only ...)
> > > >
> > > > It is proposed as a testing/development facility, it is NOT meant to be a
> > > > feature to use in production, but only enabled in Kconfig for test
> > > > deployments.
> > > >
> > > > Currently an SCMI Compliance Suite like the one at [1] can only work by
> > > > injecting SCMI messages at the SCMI transport layer using the mailbox test
> > > > driver (CONFIG_MAILBOX_TEST) via its few debugfs entries and looking at
> > > > the related replies from the SCMI backend Server.
> > > >
> > >
> > > ...
> > >
> > > >
> > > > In V2 the runtime enable/disable switching capability has been removed
> > > > (for now) since still not deemed to be stable/reliable enough: as a
> > > > consequence when SCMI Raw support is compiled in, the regular SCMI stack
> > > > drivers are now inhibited permanently for that Kernel.
> > > >
> > > > A quick and trivial example from the shell...reading from a sensor
> > > > injecting a properly crafted packet in raw mode:
> > > >
> > > > # INJECT THE SENSOR_READING MESSAGE FOR SENSOR ID=1 (binary little endian)
> > > > root@...-buster-arm64:~# echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00 > /sys/kernel/debug/scmi_raw/message
> > >
> > > I have tried your patchset with an SCMI server using an optee-os
> > > transport channel but I have a timed out error when trying your
> > > example above to read sensor1
> > >
> > > # echo -e -n \\x06\\x54\\x00\\x00\\x01\\x00\\x00\\x00\\x00\\x00\\x00\\x00
> > > > /sys/kernel/debug/scmi_raw/message
> > > # [ 93.306690] arm-scmi firmware:scmi0: timed out in RAW response -
> > > HDR:00005406
> > >
> > > and there no response available when trying to read it with
> > > # cat /sys/kernel/debug/scmi_raw/message
> > >
> >
> > is there anything cat'ting /sys/kernel/debug/scmi_raw/errors ?
>
> It was empty
>
> >
> > >
> > > The sensor 1 can be successfully read in normal mode:
> > > # cat /sys/class/hwmon/hwmon0/temp1_input
> > > 25000
> > > #
> > >
> > > In both case, the SCMI server received the requests and replied successfully
> > >
> > > Could it be that you process the answer differently in case of raw mode ?
> > >
> >
> > Well, absolutely, when in raw mode the reply is picked up directly into
> > the RX path and copied in a message queue to be read from asyncrhnously
> > later via debugfs.
> >
> > ... mmm I think I found the problem...the reply is picked up on the RX *IRQ*
> > path as of now...but in optee/SMC there is no interrupt (sometime there is in
> > SMC) and the reply is instead read back straight away (transport is marked as
> > sync_cmds_completed_on_ret=true in fact).... so this is the issue probably ...
> > I have NOT tested on anything but mailbox and virtio till now...and I
> > missed this possibility that this NO-irq reply was a thing even when NOT
> > in polling mode (which I do not support)...my bad :<
> >
> > Ok, next week I'll rework the series to fix this big_BUG and some other minor
> > things...in the meantime if you want to try this snippet down below...
> >
> > ... this won't definitely be the final patch but it could let you experiment
> > more (only build tested though )
>
> Thanks.
> The patch below fixes my problem with optee transport layer
>
Good, thanks for the patience.
Thanks,
Cristian
> >
> > Thanks for testing !
> > Cristian
> >
> > --->8-------
> >
> > diff --git a/drivers/firmware/arm_scmi/raw_mode.c b/drivers/firmware/arm_scmi/raw_mode.c
> > index 13eeebe4b7a8..b9fcb66a1b6a 100644
> > --- a/drivers/firmware/arm_scmi/raw_mode.c
> > +++ b/drivers/firmware/arm_scmi/raw_mode.c
> > @@ -197,6 +197,8 @@ struct scmi_dbg_raw_data {
> > size_t rx_size;
> > };
> >
> > +void scmi_raw_message_report(void *r, struct scmi_xfer *xfer, unsigned int idx);
> > +
> > static inline
> > struct scmi_raw_buffer *scmi_raw_buffer_get(struct scmi_raw_mode_info *raw,
> > unsigned int idx)
> > @@ -389,22 +391,34 @@ static void scmi_xfer_raw_worker(struct work_struct *work)
> >
> > xfer = rw->xfer;
> >
> > - /*
> > - * Waiters are queued by wait-deadline at the end, so some of
> > - * them could have been already expired when processed, BUT we
> > - * have to check the completion status anyway just in case a
> > - * virtually expired (aged) transaction was indeed completed
> > - * fine and we'll have to wait for the asynchronous part (if
> > - * any).
> > - */
> > - aging = jiffies - rw->start_jiffies;
> > - tmo = max_tmo > aging ? max_tmo - aging : 0;
> > -
> > - if ((tmo && !wait_for_completion_timeout(&xfer->done, tmo)) ||
> > - (!tmo && !try_wait_for_completion(&xfer->done))) {
> > - dev_err(dev, "timed out in RAW response - HDR:%08X\n",
> > - pack_scmi_header(&xfer->hdr));
> > - ret = -ETIMEDOUT;
> > + if (!raw->desc->sync_cmds_completed_on_ret) {
> > + /*
> > + * Waiters are queued by wait-deadline at the end, so some of
> > + * them could have been already expired when processed, BUT we
> > + * have to check the completion status anyway just in case a
> > + * virtually expired (aged) transaction was indeed completed
> > + * fine and we'll have to wait for the asynchronous part (if
> > + * any).
> > + */
> > + aging = jiffies - rw->start_jiffies;
> > + tmo = max_tmo > aging ? max_tmo - aging : 0;
> > +
> > + if ((tmo &&
> > + !wait_for_completion_timeout(&xfer->done, tmo)) ||
> > + (!tmo && !try_wait_for_completion(&xfer->done))) {
> > + dev_err(dev,
> > + "timed out in RAW response - HDR:%08X\n",
> > + pack_scmi_header(&xfer->hdr));
> > + ret = -ETIMEDOUT;
> > + }
> > + } else {
> > + raw->desc->ops->fetch_response(rw->cinfo, xfer);
> > + /* Trace polled replies. */
> > + trace_scmi_msg_dump(xfer->hdr.protocol_id, xfer->hdr.id,
> > + "RESP",
> > + xfer->hdr.seq, xfer->hdr.status,
> > + xfer->rx.buf, xfer->rx.len);
> > + scmi_raw_message_report(raw, xfer, SCMI_RAW_REPLY_QUEUE);
> > }
> >
> > /* Avoid unneeded async waits */
> >
> >
> > ---8<-------
> >
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