Hi Suzuki,
On Wed, 15 Jan 2020 at 11:14, Suzuki Kuruppassery Poulose
<suzuki.poulose@xxxxxxx> wrote:
>
> On 13/01/2020 21:31, Mike Leach wrote:
> > The CoreSight subsystem enables a path of devices from source to sink.
> > Any CTI devices associated with the path devices must be enabled at the
> > same time.
> >
> > This patch adds an associated coresight_device element to the main
> > coresight device structure, and uses this to create associations between
> > the CTI and other devices based on the device tree data. The associated
> > device element is used to enable CTI in conjunction with the path elements.
> >
> > CTI devices are reference counted so where a single CTI is associated with
> > multiple elements on the path, it will be enabled on the first associated
> > device enable, and disabled with the last associated device disable.
> >
> > Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
> > Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > ---
> > drivers/hwtracing/coresight/coresight-cti.c | 129 ++++++++++++++++++
> > drivers/hwtracing/coresight/coresight-cti.h | 1 +
> > .../hwtracing/coresight/coresight-platform.c | 1 +
> > drivers/hwtracing/coresight/coresight-priv.h | 12 ++
> > drivers/hwtracing/coresight/coresight.c | 71 +++++++++-
> > include/linux/coresight.h | 4 +
> > 6 files changed, 213 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
> > index 77c2af247917..2be1b310e854 100644
> > --- a/drivers/hwtracing/coresight/coresight-cti.c
> > +++ b/drivers/hwtracing/coresight/coresight-cti.c
> > @@ -4,6 +4,7 @@
> > * Author: Mike Leach <mike.leach@xxxxxxxxxx>
> > */
> >
> > +#include <linux/property.h>
> > #include "coresight-cti.h"
> >
> > /**
> > @@ -440,6 +441,131 @@ int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
> > return err;
> > }
> >
> > +/*
> > + * Look for a matching connection device name in the list of connections.
> > + * If found then swap in the csdev name, set trig con association pointer
> > + * and return found.
> > + */
> > +static bool
> > +cti_match_fixup_csdev(struct cti_device *ctidev, const char *node_name,
> > + struct coresight_device *csdev)
> > +{
> > + struct cti_trig_con *trig_con;
>
> super minor nit: Please use "struct cti_trig_con *tc;" consistent with
> the naming everywhere else. Helps a lot in reading the code, especially
> which has a lot of different structures.
>
> > + const char *csdev_name;
> > +
> > + list_for_each_entry(trig_con, &ctidev->trig_cons, node) {
> > + if (trig_con->con_dev_name) {
>
> This was allocated via devm_* and ...
>
> > + if (!strcmp(node_name, trig_con->con_dev_name)) {
> > + /* match: so swap in csdev name & dev */
> > + kfree(trig_con->con_dev_name);
>
> ... we free it here using kfree() without devm_ being aware. This could
> cause double-free when the device is removed. This should either be
> devm_kfree() or simply overwritten with the new string and leave
> the device cleanup to free it.
>
Agreed - fixed up in v9.
> > + csdev_name = dev_name(&csdev->dev);
> > + trig_con->con_dev_name =
> > + kstrdup(csdev_name, GFP_KERNEL);
>
> Please use devm_kstrdup() here on the CTI device to have a consistent
> allocation.
>
>
> > + trig_con->con_dev = csdev;
> > + return true;
> > + }
> > + }
> > + }
> > + return false;
> > +}
> >
>
>
> > +/*
> > + * Removing the associated devices is easier.
> > + * A CTI will not have a value for csdev->ect_dev.
> > + */
> > +void cti_remove_assoc_from_csdev(struct coresight_device *csdev)
> > +{
> > + struct cti_drvdata *ctidrv;
> > + struct cti_trig_con *tc;
> > + struct cti_device *ctidev;
> > +
> > + mutex_lock(&ect_mutex);
> > + if (csdev->ect_dev) {
> > + ctidrv = csdev_to_cti_drvdata(csdev->ect_dev);
> > + ctidev = &ctidrv->ctidev;
> > + list_for_each_entry(tc, &ctidev->trig_cons, node) {
> > + if (tc->con_dev == csdev->ect_dev) {
> > + tc->con_dev = NULL;
>
> Should we clear/free the name too ?
>
Not now devm_ allocation is being used.
> > + break;
> > + }
> > + }
> > + csdev->ect_dev = NULL;
> > + }
> > + mutex_unlock(&ect_mutex);
> > +}
> > +EXPORT_SYMBOL_GPL(cti_remove_assoc_from_csdev);
> > +
>
> ...
>
> > diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h
> > index 469a06a1bb78..578d7e9ac67e 100644
> > --- a/drivers/hwtracing/coresight/coresight-cti.h
> > +++ b/drivers/hwtracing/coresight/coresight-cti.h
> > @@ -216,6 +216,7 @@ int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
> > u32 channel_idx);
> > struct coresight_platform_data *
> > coresight_cti_get_platform_data(struct device *dev);
> > +const char *cti_plat_get_node_name(struct fwnode_handle *fwnode);
> >
> > /* cti powered and enabled */
> > static inline bool cti_active(struct cti_config *cfg)
> > diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> > index 43418a2126ff..421d4fc95f41 100644
> > --- a/drivers/hwtracing/coresight/coresight-platform.c
> > +++ b/drivers/hwtracing/coresight/coresight-platform.c
> > @@ -313,6 +313,7 @@ static int of_get_coresight_platform_data(struct device *dev,
> >
> > return 0;
> > }
> > +
>
> nit : spurious hunk ?
>
> > #else
> > static inline int
> > of_get_coresight_platform_data(struct device *dev,
>
> Otherwise looks good to me
>
> Suzuki
Thanks.
Mike
--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
