My bad, the earlier email went out to soon.
> Op 09-03-2026 07:01 CET schreef Greg KH <[email protected]>:
> >
> > arch/powerpc/platforms/book3s/vas-api.c | 34 +++++++++++++++++++------
> > 1 file changed, 26 insertions(+), 8 deletions(-)
> >
> > diff --git a/arch/powerpc/platforms/book3s/vas-api.c
> > b/arch/powerpc/platforms/book3s/vas-api.c
> > index ea4ffa63f043..e377981fd533 100644
> > --- a/arch/powerpc/platforms/book3s/vas-api.c
> > +++ b/arch/powerpc/platforms/book3s/vas-api.c
> > @@ -45,7 +45,7 @@ static struct coproc_dev {
> > struct device *device;
> > char *name;
> > dev_t devt;
> > - struct class *class;
> > + const struct class *class;
> > enum vas_cop_type cop_type;
> > const struct vas_user_win_ops *vops;
> > } coproc_device;
> > @@ -599,6 +599,21 @@ static struct file_operations coproc_fops = {
> > .unlocked_ioctl = coproc_ioctl,
> > };
> >
> > +static const struct class nx_gzip_class = {
> > + .name = "nx-gzip",
> > + .devnode = coproc_devnode
> > +};
> > +
> > +static const struct class* cop_to_class(enum vas_cop_type cop)
> > +{
> > + switch (cop) {
> > + case VAS_COP_TYPE_GZIP: return &nx_gzip_class;
> > + default:
> > + pr_err("No device class defined for cop type %d\n", cop);
> > + return NULL;
> > + }
> > +}
> > +
> > /*
> > * Supporting only nx-gzip coprocessor type now, but this API code
> > * extended to other coprocessor types later.
> > @@ -609,6 +624,10 @@ int vas_register_coproc_api(struct module *mod, enum
> > vas_cop_type cop_type,
> > {
> > int rc = -EINVAL;
> > dev_t devno;
> > + const struct class* class = cop_to_class(cop_type);
> > +
> > + if (!class)
> > + return rc;
>
> How can this happen?
>
> This feels odd, are different types of devices being registered here? I
> don't see where VAS_COP_TYPE_GZIP was being tested in the original code,
> why add this additional logic?
>
My line of thought is this:
There is a function vas_register_coproc_api() that does some kind of registering
for different coprocessor types. It has the following comment above:
/*
* Supporting only nx-gzip coprocessor type now, but this API code
* extended to other coprocessor types later.
*/
If you look at where this function is eventually triggered it is indeed only
ever
passed VAS_COP_TYPE_GZIP. For instance, line 1238 of
drivers/crypto/nx/nx-common-series.c
has the call
ret = vas_register_api_pseries(THIS_MODULE, VAS_COP_TYPE_GZIP,
"nx-gzip");
(which immediately calls vas_register_coproc_api())
It also passes a hard-coded name for the device ("nx-gzip"), and this name is
also
used as the device class name. Now, this is a problem if we want to get rid of
class_create(). Somehow "nx-gzip" needs to get linked to the appropriate const
struct
class. I figured it is better to use the cop_type, and a cop_to_class()
function to
set this link. However, since the other co-processor types are not implemented
(yet)
it would seem silly to already assign struct classes for these, hence the NULL
return.
It is meant to signal: not implemented. Then again, if ever a new co-processor
was added
you must update the cop_to_class()... but at least this is my line of thought.
There is also a function static char *cop_to_str(int cop) that strangely takes
an int instead of an enum vas_cop_type, and also misses an option I think.
> thanks,
>
> greg k-h
Thanks,
Jori
