On Sunday, 17 June 2018 11:22:11 AM AEST Benjamin Herrenschmidt wrote:
> On Sun, 2018-06-17 at 11:17 +1000, Benjamin Herrenschmidt wrote:
> >
> > We have everything that cronus needs and more than pdbg needs afaik :-)
Yep, has what we need and more (such as put scom under mask and indirect scom).
Only other useful thing would be repeated getsom/putscom operations (eg. read
the same scom address n times) as they would help with ADU access which can do
autoincrement or scanscom (although we should just use the scan engine directly
for that so not a big issue).
> + for (retries = 0; retries < SCOM_MAX_RETRIES; retries++) {
> + rc = raw_get_scom(scom, value, addr, &status);
> + if (rc) {
> + /* Try resetting the bridge if FSI fails */
> + if (rc != -ENODEV && retries == 0) {
> + fsi_device_write(scom->fsi_dev,
> SCOM_FSI2PIB_RESET_REG,
> + &dummy, sizeof(uint32_t));
> + rc = -EBUSY;
> + } else
> + return rc;
> + } else
> + rc = handle_fsi2pib_status(scom, status);
> + if (rc && rc != -EBUSY)
> + break;
> + if (rc == 0) {
> + rc = handle_pib_status(scom,
> + (status &
> SCOM_STATUS_PIB_RESP_MASK)
> + >> SCOM_STATUS_PIB_RESP_SHIFT);
> + if (rc && rc != -EBUSY)
> + break;
> + }
> + if (rc == 0)
> + break;
> + msleep(1);
> + }
The rc handling above took me a little while to grok but I didn't come up with a
cleaner alternative and I think it's correct.
- Alistair
> >
> > That said, cronus does a bunch of other stupid things that I'm still
> > trying to figure out how to fix.
> >
> > We might need to create a /dev/cfam rather than going through that
> > magic sysfs "raw" file, and I wouldn't mind using a single IDA so that
> > all the devices below a given FSI slace (cfam itself, sbefifo, occ,
> > ...) have the same "number".
>
> Also while we're at reworking how all this is exposed to our broken
> userspace, I wouldn't mind putting all these dev entries under a
> directory, if I can figure out how to do that (I haven't really looked
> yet).
>
> /dev/fsi/{cfamN,sbefifoN,occN, ...} and possibly similar by-id and by-
> path that other subsystems use, so we have something more deterministic
> than the "random number" crap we do now.
>
> We can always keep hacks to do symlinks in our kernel tree until we
> have converted all our userspace users.
>
> We currently control the only userspace users of this, so now is a good
> time to cleanup how we expose things. This won't always be the case.
>
> Cheers,
> Ben.
>
>
