| Message ID | 20210921134121.2423546-13-suzuki.poulose@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Self-hosted trace related errata workarounds | expand |
On 9/21/21 7:11 PM, Suzuki K Poulose wrote: > Add a helper to get the CPU specific data for TRBE instance, from > a given perf handle. This also adds extra checks to make sure that > the event associated with the handle is "bound" to the CPU and is > active on the TRBE. > > Cc: Anshuman Khandual <anshuman.khandual@arm.com> > Cc: Mike Leach <mike.leach@linaro.org> > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Leo Yan <leo.yan@linaro.org> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c > index 983dd5039e52..797d978f9fa7 100644 > --- a/drivers/hwtracing/coresight/coresight-trbe.c > +++ b/drivers/hwtracing/coresight/coresight-trbe.c > @@ -268,6 +268,15 @@ static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle) > return buf->nr_pages * PAGE_SIZE; > } > > +static inline struct trbe_cpudata * > +trbe_handle_to_cpudata(struct perf_output_handle *handle) This is actually a perf handle not a TRBE handle. Hence should be renamed as 'perf_handle_to_cpudata' instead. > +{ > + struct trbe_buf *buf = etm_perf_sink_config(handle); > + > + BUG_ON(!buf || !buf->cpudata); > + return buf->cpudata; > +} > + > /* > * TRBE Limit Calculation > * > @@ -533,8 +542,7 @@ static enum trbe_fault_action trbe_get_fault_act(struct perf_output_handle *hand > { > int ec = get_trbe_ec(trbsr); > int bsc = get_trbe_bsc(trbsr); > - struct trbe_buf *buf = etm_perf_sink_config(handle); > - struct trbe_cpudata *cpudata = buf->cpudata; > + struct trbe_cpudata *cpudata = trbe_handle_to_cpudata(handle); > > WARN_ON(is_trbe_running(trbsr)); > if (is_trbe_trg(trbsr) || is_trbe_abort(trbsr)) >
On Tue, Sep 21, 2021 at 02:41:16PM +0100, Suzuki K Poulose wrote: > Add a helper to get the CPU specific data for TRBE instance, from > a given perf handle. This also adds extra checks to make sure that > the event associated with the handle is "bound" to the CPU and is > active on the TRBE. > > Cc: Anshuman Khandual <anshuman.khandual@arm.com> > Cc: Mike Leach <mike.leach@linaro.org> > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Leo Yan <leo.yan@linaro.org> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c > index 983dd5039e52..797d978f9fa7 100644 > --- a/drivers/hwtracing/coresight/coresight-trbe.c > +++ b/drivers/hwtracing/coresight/coresight-trbe.c > @@ -268,6 +268,15 @@ static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle) > return buf->nr_pages * PAGE_SIZE; > } > > +static inline struct trbe_cpudata * > +trbe_handle_to_cpudata(struct perf_output_handle *handle) > +{ > + struct trbe_buf *buf = etm_perf_sink_config(handle); > + > + BUG_ON(!buf || !buf->cpudata); > + return buf->cpudata; > +} > + > /* > * TRBE Limit Calculation > * > @@ -533,8 +542,7 @@ static enum trbe_fault_action trbe_get_fault_act(struct perf_output_handle *hand > { > int ec = get_trbe_ec(trbsr); > int bsc = get_trbe_bsc(trbsr); > - struct trbe_buf *buf = etm_perf_sink_config(handle); > - struct trbe_cpudata *cpudata = buf->cpudata; > + struct trbe_cpudata *cpudata = trbe_handle_to_cpudata(handle); There is two other places where this pattern is present: is_perf_trbe() and __trbe_normal_offset(). I have to stop here for today. More comments tomorrow. Thanks, Mathieu > > WARN_ON(is_trbe_running(trbsr)); > if (is_trbe_trg(trbsr) || is_trbe_abort(trbsr)) > -- > 2.24.1 >
Hi Mathieu On 04/10/2021 18:42, Mathieu Poirier wrote: > On Tue, Sep 21, 2021 at 02:41:16PM +0100, Suzuki K Poulose wrote: >> Add a helper to get the CPU specific data for TRBE instance, from >> a given perf handle. This also adds extra checks to make sure that >> the event associated with the handle is "bound" to the CPU and is >> active on the TRBE. >> >> Cc: Anshuman Khandual <anshuman.khandual@arm.com> >> Cc: Mike Leach <mike.leach@linaro.org> >> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> >> Cc: Leo Yan <leo.yan@linaro.org> >> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> >> --- >> drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++++++-- >> 1 file changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c >> index 983dd5039e52..797d978f9fa7 100644 >> --- a/drivers/hwtracing/coresight/coresight-trbe.c >> +++ b/drivers/hwtracing/coresight/coresight-trbe.c >> @@ -268,6 +268,15 @@ static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle) >> return buf->nr_pages * PAGE_SIZE; >> } >> >> +static inline struct trbe_cpudata * >> +trbe_handle_to_cpudata(struct perf_output_handle *handle) >> +{ >> + struct trbe_buf *buf = etm_perf_sink_config(handle); >> + >> + BUG_ON(!buf || !buf->cpudata); >> + return buf->cpudata; >> +} >> + >> /* >> * TRBE Limit Calculation >> * >> @@ -533,8 +542,7 @@ static enum trbe_fault_action trbe_get_fault_act(struct perf_output_handle *hand >> { >> int ec = get_trbe_ec(trbsr); >> int bsc = get_trbe_bsc(trbsr); >> - struct trbe_buf *buf = etm_perf_sink_config(handle); >> - struct trbe_cpudata *cpudata = buf->cpudata; >> + struct trbe_cpudata *cpudata = trbe_handle_to_cpudata(handle); > > There is two other places where this pattern is present: is_perf_trbe() and > __trbe_normal_offset(). I skipped them, as they have to get access to the "trbe_buf" anyways. So the step by step, made sense. But I could replace them too to make it transparent. What do you think ? Suzuki
On Tue, Oct 05, 2021 at 11:35:13PM +0100, Suzuki K Poulose wrote: > Hi Mathieu > > On 04/10/2021 18:42, Mathieu Poirier wrote: > > On Tue, Sep 21, 2021 at 02:41:16PM +0100, Suzuki K Poulose wrote: > > > Add a helper to get the CPU specific data for TRBE instance, from > > > a given perf handle. This also adds extra checks to make sure that > > > the event associated with the handle is "bound" to the CPU and is > > > active on the TRBE. > > > > > > Cc: Anshuman Khandual <anshuman.khandual@arm.com> > > > Cc: Mike Leach <mike.leach@linaro.org> > > > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > > > Cc: Leo Yan <leo.yan@linaro.org> > > > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > > > --- > > > drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++++++-- > > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c > > > index 983dd5039e52..797d978f9fa7 100644 > > > --- a/drivers/hwtracing/coresight/coresight-trbe.c > > > +++ b/drivers/hwtracing/coresight/coresight-trbe.c > > > @@ -268,6 +268,15 @@ static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle) > > > return buf->nr_pages * PAGE_SIZE; > > > } > > > +static inline struct trbe_cpudata * > > > +trbe_handle_to_cpudata(struct perf_output_handle *handle) > > > +{ > > > + struct trbe_buf *buf = etm_perf_sink_config(handle); > > > + > > > + BUG_ON(!buf || !buf->cpudata); > > > + return buf->cpudata; > > > +} > > > + > > > /* > > > * TRBE Limit Calculation > > > * > > > @@ -533,8 +542,7 @@ static enum trbe_fault_action trbe_get_fault_act(struct perf_output_handle *hand > > > { > > > int ec = get_trbe_ec(trbsr); > > > int bsc = get_trbe_bsc(trbsr); > > > - struct trbe_buf *buf = etm_perf_sink_config(handle); > > > - struct trbe_cpudata *cpudata = buf->cpudata; > > > + struct trbe_cpudata *cpudata = trbe_handle_to_cpudata(handle); > > > > There is two other places where this pattern is present: is_perf_trbe() and > > __trbe_normal_offset(). > > I skipped them, as they have to get access to the "trbe_buf" anyways. > So the step by step, made sense. But I could replace them too to make it > transparent. > > What do you think ? Humm... I don't think there is a right way or a wrong way here. If we move forward with this patchset we have two ways of getting to buf->cpudata. One using trbe_handle_to_cpudata() and another one as laid out in is_perf_trbe() and __trbe_normal_offset(), each with an equal number of occurences (2 for each). I am usually not fond of small functions like trbe_handle_to_cpudata() and to me keeping the current heuristic in trbe_get_fault_act() would have been just fine. I agree with the argument that trbe_handle_to_cpudata() provides more checks but is it really worth it if they aren't done everywhere? In short I would get rid of trbe_handle_to_cpudata() entirely and live without the extra checks... But I'm not strongly opinionated on this either. > > Suzuki > >
On 06/10/2021 18:15, Mathieu Poirier wrote: > On Tue, Oct 05, 2021 at 11:35:13PM +0100, Suzuki K Poulose wrote: >> Hi Mathieu >> >> On 04/10/2021 18:42, Mathieu Poirier wrote: >>> On Tue, Sep 21, 2021 at 02:41:16PM +0100, Suzuki K Poulose wrote: >>>> Add a helper to get the CPU specific data for TRBE instance, from >>>> a given perf handle. This also adds extra checks to make sure that >>>> the event associated with the handle is "bound" to the CPU and is >>>> active on the TRBE. >>>> >>>> Cc: Anshuman Khandual <anshuman.khandual@arm.com> >>>> Cc: Mike Leach <mike.leach@linaro.org> >>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> >>>> Cc: Leo Yan <leo.yan@linaro.org> >>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> >>>> --- >>>> drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++++++-- >>>> 1 file changed, 10 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c >>>> index 983dd5039e52..797d978f9fa7 100644 >>>> --- a/drivers/hwtracing/coresight/coresight-trbe.c >>>> +++ b/drivers/hwtracing/coresight/coresight-trbe.c >>>> @@ -268,6 +268,15 @@ static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle) >>>> return buf->nr_pages * PAGE_SIZE; >>>> } >>>> +static inline struct trbe_cpudata * >>>> +trbe_handle_to_cpudata(struct perf_output_handle *handle) >>>> +{ >>>> + struct trbe_buf *buf = etm_perf_sink_config(handle); >>>> + >>>> + BUG_ON(!buf || !buf->cpudata); >>>> + return buf->cpudata; >>>> +} >>>> + >>>> /* >>>> * TRBE Limit Calculation >>>> * >>>> @@ -533,8 +542,7 @@ static enum trbe_fault_action trbe_get_fault_act(struct perf_output_handle *hand >>>> { >>>> int ec = get_trbe_ec(trbsr); >>>> int bsc = get_trbe_bsc(trbsr); >>>> - struct trbe_buf *buf = etm_perf_sink_config(handle); >>>> - struct trbe_cpudata *cpudata = buf->cpudata; >>>> + struct trbe_cpudata *cpudata = trbe_handle_to_cpudata(handle); >>> >>> There is two other places where this pattern is present: is_perf_trbe() and >>> __trbe_normal_offset(). >> >> I skipped them, as they have to get access to the "trbe_buf" anyways. >> So the step by step, made sense. But I could replace them too to make it >> transparent. >> >> What do you think ? > > Humm... I don't think there is a right way or a wrong way here. If we move > forward with this patchset we have two ways of getting to buf->cpudata. One > using trbe_handle_to_cpudata() and another one as laid out in is_perf_trbe() and > __trbe_normal_offset(), each with an equal number of occurences (2 for each). > > I am usually not fond of small functions like trbe_handle_to_cpudata() and to me > keeping the current heuristic in trbe_get_fault_act() would have been just fine. There is another user introduced in the work around patch. But, yes, I agree, we could open code it, rather than having it inconsistent across the driver. > I agree with the argument that trbe_handle_to_cpudata() provides more checks but > is it really worth it if they aren't done everywhere? > > In short I would get rid of trbe_handle_to_cpudata() entirely and live without > the extra checks... But I'm not strongly opinionated on this either. Ok, I will remove this then. Thanks for the feedback. Suzuki
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 983dd5039e52..797d978f9fa7 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -268,6 +268,15 @@ static unsigned long trbe_snapshot_offset(struct perf_output_handle *handle) return buf->nr_pages * PAGE_SIZE; } +static inline struct trbe_cpudata * +trbe_handle_to_cpudata(struct perf_output_handle *handle) +{ + struct trbe_buf *buf = etm_perf_sink_config(handle); + + BUG_ON(!buf || !buf->cpudata); + return buf->cpudata; +} + /* * TRBE Limit Calculation * @@ -533,8 +542,7 @@ static enum trbe_fault_action trbe_get_fault_act(struct perf_output_handle *hand { int ec = get_trbe_ec(trbsr); int bsc = get_trbe_bsc(trbsr); - struct trbe_buf *buf = etm_perf_sink_config(handle); - struct trbe_cpudata *cpudata = buf->cpudata; + struct trbe_cpudata *cpudata = trbe_handle_to_cpudata(handle); WARN_ON(is_trbe_running(trbsr)); if (is_trbe_trg(trbsr) || is_trbe_abort(trbsr))
Add a helper to get the CPU specific data for TRBE instance, from a given perf handle. This also adds extra checks to make sure that the event associated with the handle is "bound" to the CPU and is active on the TRBE. Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Mike Leach <mike.leach@linaro.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Leo Yan <leo.yan@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> --- drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)