Re: [PATCH] zcrypt: handle AP Info notification from CHSC SEI command

[Tony Krowiak]

On 1/30/19 1:32 PM, Sebastian Ott wrote:
> On Wed, 30 Jan 2019, Tony Krowiak wrote:
> > +#if IS_ENABLED(CONFIG_ZCRYPT)
> > +void ap_bus_cfg_chg(void);
> > +#else
> > +#error "no CONFIG_ZCRYPT"
>     ^
> I don't think that's the right thing to do here.

I'd like to leave it. If somebody edits .config
and sets CONFIG_ZCRYPT=n, then the build will
fail. The preprocessor error above tells them
why.

> > +++ b/drivers/s390/cio/chsc.h
> > @@ -9,6 +9,7 @@
> >   #include <asm/chsc.h>
> >   #include <asm/schid.h>
> >   #include <asm/qdio.h>
> > +#include <asm/ap.h>
>
> This should be moved to chsc.c

I can do that, but I'm curious why.

> > +++ b/drivers/s390/crypto/ap_bus.c
> > @@ -35,6 +35,7 @@
> >   #include <linux/mod_devicetable.h>
> >   #include <linux/debugfs.h>
> >   #include <linux/ctype.h>
> > +#include <asm/crw.h>
>
> This is not needed here.

I'll remove it.

> >   /*
> > +* A config change has happened, Force an ap bus rescan.
> > +*/
> > +void ap_bus_cfg_chg(void)
> > +{
> > +	AP_DBF(DBF_INFO, "%s config change, forcing bus rescan\n", __func__);
> > +
> > +	ap_bus_force_rescan();
> > +}
> > +EXPORT_SYMBOL(ap_bus_cfg_chg);
>
> There is no need for the export symbol - you don't call that function
> from module code.
> As an unrelated question, just to be sure: ap_bus.c is compiled as
> built-in even with ZCRYPT=m, right?

No. If you edit .config and set CONFIG_ZCRYPT=m, ap_bus.c will be built
into the zcrypt.ko module. Through some other magic, the zcrypt module
is loaded when linux boots.

> Reviewed-by: Sebastian Ott <sebott@xxxxxxxxxxxxx>
>
> Regards,
> Sebastian