Re: [PATCH 02/13] coresight: cti: Add sysfs coresight mgmt register access

[Mathieu Poirier]

On Thu, 19 Mar 2020 at 01:54, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Mar 18, 2020 at 01:28:05PM -0600, Mathieu Poirier wrote:
> > On Wed, 18 Mar 2020 at 12:22, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > On Wed, Mar 18, 2020 at 12:16:04PM -0600, Mathieu Poirier wrote:
> > > > On Wed, Mar 18, 2020 at 02:18:21PM +0100, Greg KH wrote:
> > > > > On Mon, Mar 09, 2020 at 10:17:37AM -0600, Mathieu Poirier wrote:
> > > > > > From: Mike Leach <mike.leach@xxxxxxxxxx>
> > > > > >
> > > > > > Adds sysfs access to the coresight management registers.
> > > > > >
> > > > > > Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
> > > > > > Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > > > > > Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > > > > > [Fixed abbreviation in title]
> > > > > > Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > > > > > ---
> > > > > >  .../hwtracing/coresight/coresight-cti-sysfs.c | 53 +++++++++++++++++++
> > > > > >  drivers/hwtracing/coresight/coresight-priv.h  |  1 +
> > > > > >  2 files changed, 54 insertions(+)
> > > > > >
> > > > > > diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> > > > > > index a832b8c6b866..507f8eb487fe 100644
> > > > > > --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> > > > > > +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> > > > > > @@ -62,11 +62,64 @@ static struct attribute *coresight_cti_attrs[] = {
> > > > > >   NULL,
> > > > > >  };
> > > > > >
> > > > > > +/* register based attributes */
> > > > > > +
> > > > > > +/* macro to access RO registers with power check only (no enable check). */
> > > > > > +#define coresight_cti_reg(name, offset)                  \
> > > > > > +static ssize_t name##_show(struct device *dev,                           \
> > > > > > +                    struct device_attribute *attr, char *buf)    \
> > > > > > +{                                                                        \
> > > > > > + struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);     \
> > > > > > + u32 val = 0;                                                    \
> > > > > > + pm_runtime_get_sync(dev->parent);                               \
> > > > > > + spin_lock(&drvdata->spinlock);                                  \
> > > > > > + if (drvdata->config.hw_powered)                                 \
> > > > > > +         val = readl_relaxed(drvdata->base + offset);            \
> > > > > > + spin_unlock(&drvdata->spinlock);                                \
> > > > > > + pm_runtime_put_sync(dev->parent);                               \
> > > > > > + return scnprintf(buf, PAGE_SIZE, "0x%x\n", val);                \
> > > > > > +}                                                                        \
> > > > > > +static DEVICE_ATTR_RO(name)
> > > > > > +
> > > > > > +/* coresight management registers */
> > > > > > +coresight_cti_reg(devaff0, CTIDEVAFF0);
> > > > > > +coresight_cti_reg(devaff1, CTIDEVAFF1);
> > > > > > +coresight_cti_reg(authstatus, CORESIGHT_AUTHSTATUS);
> > > > > > +coresight_cti_reg(devarch, CORESIGHT_DEVARCH);
> > > > > > +coresight_cti_reg(devid, CORESIGHT_DEVID);
> > > > > > +coresight_cti_reg(devtype, CORESIGHT_DEVTYPE);
> > > > > > +coresight_cti_reg(pidr0, CORESIGHT_PERIPHIDR0);
> > > > > > +coresight_cti_reg(pidr1, CORESIGHT_PERIPHIDR1);
> > > > > > +coresight_cti_reg(pidr2, CORESIGHT_PERIPHIDR2);
> > > > > > +coresight_cti_reg(pidr3, CORESIGHT_PERIPHIDR3);
> > > > > > +coresight_cti_reg(pidr4, CORESIGHT_PERIPHIDR4);
> > > > > > +
> > > > > > +static struct attribute *coresight_cti_mgmt_attrs[] = {
> > > > > > + &dev_attr_devaff0.attr,
> > > > > > + &dev_attr_devaff1.attr,
> > > > > > + &dev_attr_authstatus.attr,
> > > > > > + &dev_attr_devarch.attr,
> > > > > > + &dev_attr_devid.attr,
> > > > > > + &dev_attr_devtype.attr,
> > > > > > + &dev_attr_pidr0.attr,
> > > > > > + &dev_attr_pidr1.attr,
> > > > > > + &dev_attr_pidr2.attr,
> > > > > > + &dev_attr_pidr3.attr,
> > > > > > + &dev_attr_pidr4.attr,
> > > > > > + NULL,
> > > > > > +};
> > > > > > +
> > > > > >  static const struct attribute_group coresight_cti_group = {
> > > > > >   .attrs = coresight_cti_attrs,
> > > > > >  };
> > > > > >
> > > > > > +static const struct attribute_group coresight_cti_mgmt_group = {
> > > > > > + .attrs = coresight_cti_mgmt_attrs,
> > > > > > + .name = "mgmt",
> > > > > > +};
> > > > > > +
> > > > > >  const struct attribute_group *coresight_cti_groups[] = {
> > > > > >   &coresight_cti_group,
> > > > > > + &coresight_cti_mgmt_group,
> > > > > >   NULL,
> > > > > >  };
> > > > > > diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> > > > > > index 82e563cdc879..aba6b789c969 100644
> > > > > > --- a/drivers/hwtracing/coresight/coresight-priv.h
> > > > > > +++ b/drivers/hwtracing/coresight/coresight-priv.h
> > > > > > @@ -22,6 +22,7 @@
> > > > > >  #define CORESIGHT_CLAIMCLR       0xfa4
> > > > > >  #define CORESIGHT_LAR            0xfb0
> > > > > >  #define CORESIGHT_LSR            0xfb4
> > > > > > +#define CORESIGHT_DEVARCH        0xfbc
> > > > > >  #define CORESIGHT_AUTHSTATUS     0xfb8
> > > > > >  #define CORESIGHT_DEVID          0xfc8
> > > > > >  #define CORESIGHT_DEVTYPE        0xfcc
> > > > > > --
> > > > > > 2.20.1
> > > > > >
> > > > >
> > > > > I do not see any Documentation/ABI/ entries for these new sysfs files,
> > > > > did I miss it somehow?  I can't take new sysfs code without
> > > > > documentation.
> > > >
> > > > All the ABI is documented in this patch, which is part of this set.
> > > >
> > > > [1]. https://lkml.org/lkml/2020/3/9/642
> > >
> > > That is not in the required Documentation/ABI/ form that all sysfs files
> > > should have.  If they don't, it's a bug.
> >
> > Now I'm very confused...  As far as I can tell Mike has followed the
> > (very loose) guidelines set out in the ABI documentation [1].  I have
> > also taken a look at the patches that were merged in the v5.5 cycle -
> > nothing is very different than what Mike has put together.  It is also
> > based on the work I did a while back [2] that you merged.
>
> {sigh}
>
> I churned through 1200+ patches yesterday to get caught up and I think I
> totally missed this, sorry.  Yes, that is the correct format, I was
> looking at the .rst files you added to this series and missed this API
> file instead.

That's understandable - I review patches for only 2 subsystems and I
get overwhelmed.

>
> Ugh, my fault.
>
> Can you just resend this whole series and I'll go through it again?

I'll address the issues we agree on over in the other thread and will respin.

Thanks,
Mathieu

>
> thanks,
>
> greg k-h