Hi, Upstream commit, commit bb1860efc817c18fce4112f25f51043e44346d1b Author: Linu Cherian <lcherian@xxxxxxxxxxx> Date: Wed Sep 16 13:17:34 2020 -0600 coresight: etm: perf: Sink selection using sysfs is deprecated need to go along with this, else there will be build breakage. This applies for 5.4, 5.8 and 5.9 Mathieu, could you please ACK ? Please let me know if i need to send the patch to stable@xxxxxxxxxxxxxxx separately. Thanks. On Tue, Oct 27, 2020 at 5:20 AM Sasha Levin <sashal@xxxxxxxxxx> wrote: > > From: Linu Cherian <lcherian@xxxxxxxxxxx> > > [ Upstream commit 6d578258b955fc8888e1bbd9a8fefe7b10065a84 ] > > Coresight driver assumes sink is common across all the ETMs, > and tries to build a path between ETM and the first enabled > sink found using bus based search. This breaks sysFS usage > on implementations that has multiple per core sinks in > enabled state. > > To fix this, coresight_get_enabled_sink API is updated to > do a connection based search starting from the given source, > instead of bus based search. > With sink selection using sysfs depecrated for perf interface, > provision for reset is removed as well in this API. > > Signed-off-by: Linu Cherian <lcherian@xxxxxxxxxxx> > [Fixed indentation problem and removed obsolete comment] > Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> > Link: https://lore.kernel.org/r/20200916191737.4001561-15-mathieu.poirier@xxxxxxxxxx > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > drivers/hwtracing/coresight/coresight-priv.h | 3 +- > drivers/hwtracing/coresight/coresight.c | 62 +++++++++----------- > 2 files changed, 29 insertions(+), 36 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h > index f2dc625ea5856..5fe773c4d6cc5 100644 > --- a/drivers/hwtracing/coresight/coresight-priv.h > +++ b/drivers/hwtracing/coresight/coresight-priv.h > @@ -148,7 +148,8 @@ static inline void coresight_write_reg_pair(void __iomem *addr, u64 val, > void coresight_disable_path(struct list_head *path); > int coresight_enable_path(struct list_head *path, u32 mode, void *sink_data); > struct coresight_device *coresight_get_sink(struct list_head *path); > -struct coresight_device *coresight_get_enabled_sink(bool reset); > +struct coresight_device * > +coresight_get_enabled_sink(struct coresight_device *source); > struct coresight_device *coresight_get_sink_by_id(u32 id); > struct coresight_device * > coresight_find_default_sink(struct coresight_device *csdev); > diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c > index e9c90f2de34ac..bb4f9e0a5438d 100644 > --- a/drivers/hwtracing/coresight/coresight.c > +++ b/drivers/hwtracing/coresight/coresight.c > @@ -540,50 +540,46 @@ struct coresight_device *coresight_get_sink(struct list_head *path) > return csdev; > } > > -static int coresight_enabled_sink(struct device *dev, const void *data) > +static struct coresight_device * > +coresight_find_enabled_sink(struct coresight_device *csdev) > { > - const bool *reset = data; > - struct coresight_device *csdev = to_coresight_device(dev); > + int i; > + struct coresight_device *sink; > > if ((csdev->type == CORESIGHT_DEV_TYPE_SINK || > csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) && > - csdev->activated) { > - /* > - * Now that we have a handle on the sink for this session, > - * disable the sysFS "enable_sink" flag so that possible > - * concurrent perf session that wish to use another sink don't > - * trip on it. Doing so has no ramification for the current > - * session. > - */ > - if (*reset) > - csdev->activated = false; > + csdev->activated) > + return csdev; > > - return 1; > + /* > + * Recursively explore each port found on this element. > + */ > + for (i = 0; i < csdev->pdata->nr_outport; i++) { > + struct coresight_device *child_dev; > + > + child_dev = csdev->pdata->conns[i].child_dev; > + if (child_dev) > + sink = coresight_find_enabled_sink(child_dev); > + if (sink) > + return sink; > } > > - return 0; > + return NULL; > } > > /** > - * coresight_get_enabled_sink - returns the first enabled sink found on the bus > - * @deactivate: Whether the 'enable_sink' flag should be reset > - * > - * When operated from perf the deactivate parameter should be set to 'true'. > - * That way the "enabled_sink" flag of the sink that was selected can be reset, > - * allowing for other concurrent perf sessions to choose a different sink. > + * coresight_get_enabled_sink - returns the first enabled sink using > + * connection based search starting from the source reference > * > - * When operated from sysFS users have full control and as such the deactivate > - * parameter should be set to 'false', hence mandating users to explicitly > - * clear the flag. > + * @source: Coresight source device reference > */ > -struct coresight_device *coresight_get_enabled_sink(bool deactivate) > +struct coresight_device * > +coresight_get_enabled_sink(struct coresight_device *source) > { > - struct device *dev = NULL; > - > - dev = bus_find_device(&coresight_bustype, NULL, &deactivate, > - coresight_enabled_sink); > + if (!source) > + return NULL; > > - return dev ? to_coresight_device(dev) : NULL; > + return coresight_find_enabled_sink(source); > } > > static int coresight_sink_by_id(struct device *dev, const void *data) > @@ -988,11 +984,7 @@ int coresight_enable(struct coresight_device *csdev) > goto out; > } > > - /* > - * Search for a valid sink for this session but don't reset the > - * "enable_sink" flag in sysFS. Users get to do that explicitly. > - */ > - sink = coresight_get_enabled_sink(false); > + sink = coresight_get_enabled_sink(csdev); > if (!sink) { > ret = -EINVAL; > goto out; > -- > 2.25.1 > > _______________________________________________ > CoreSight mailing list > CoreSight@xxxxxxxxxxxxxxxx > https://lists.linaro.org/mailman/listinfo/coresight
