Messages in this thread |  | | Date | Fri, 11 Dec 2020 14:31:41 -0700 | From | Mathieu Poirier <> | Subject | Re: [RFC 10/11] coresgith: etm-perf: Connect TRBE sink with ETE source |
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On Tue, Nov 10, 2020 at 06:15:08PM +0530, Anshuman Khandual wrote: > Unlike traditional sink devices, individual TRBE instances are not detected > via DT or ACPI nodes. Instead TRBE instances are detected during CPU online > process. Hence a path connecting ETE and TRBE on a given CPU would not have > been established until then. This adds two coresight helpers that will help > modify outward connections from a source device to establish and terminate > path to a given sink device. But this method might not be optimal and would > be reworked later. > > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > --- > drivers/hwtracing/coresight/coresight-etm-perf.c | 30 ++++++++++++++++++++++++ > drivers/hwtracing/coresight/coresight-etm-perf.h | 4 ++++ > drivers/hwtracing/coresight/coresight-platform.c | 3 ++- > drivers/hwtracing/coresight/coresight-trbe.c | 2 ++ > include/linux/coresight.h | 2 ++ > 5 files changed, 40 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c > index 1a37991..b4ab1d4 100644 > --- a/drivers/hwtracing/coresight/coresight-etm-perf.c > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c > @@ -664,3 +664,33 @@ void __exit etm_perf_exit(void) > { > perf_pmu_unregister(&etm_pmu); > } > + > +#ifdef CONFIG_CORESIGHT_TRBE > +void coresight_trbe_connect_ete(struct coresight_device *csdev_trbe, int cpu) > +{ > + struct coresight_device *csdev_ete = per_cpu(csdev_src, cpu);
As Suzuki pointed out that won't work if the TRBE gets probed before the ETMv4-ETE. I also agree with Suzuki this situation should be better handled with a per csdev_trbe that should be declared in the coresight-core.c file. That way both sysfs and perf have access to it.
> + > + if (!csdev_ete) { > + pr_err("Corresponding ETE device not present on cpu %d\n", cpu); > + return; > + } > + csdev_ete->def_sink = csdev_trbe;
That should be done in function coresight_find_default_sink(). If per_cpu(csdev_trbe, cpu) exists then that's the what we pick. If not then move along with coresight_find_sink().
> + csdev_ete->pdata->nr_outport++; > + if (!csdev_ete->pdata->conns) > + coresight_alloc_conns(&csdev_ete->dev, csdev_ete->pdata); > + csdev_ete->pdata->conns[csdev_ete->pdata->nr_outport - 1].child_dev = csdev_trbe;
I don't think we have to go through all that dance since the TRBE is directly connected to the ETE. With the above about coresight_find_default_sink() in mind, all we need to do is fix coresight_build_path() to check if the sink parameter is the same as csdev->def_sink. If so then just add the sink to the patch, no need to follow ports as we do for other classic components.
Thanks, Mathieu
> +} > + > +void coresight_trbe_remove_ete(struct coresight_device *csdev_trbe, int cpu) > +{ > + struct coresight_device *csdev_ete = per_cpu(csdev_src, cpu); > + > + if (!csdev_ete) { > + pr_err("Corresponding ETE device not present on cpu %d\n", cpu); > + return; > + } > + csdev_ete->pdata->conns[csdev_ete->pdata->nr_outport - 1].child_dev = NULL; > + csdev_ete->def_sink = NULL; > + csdev_ete->pdata->nr_outport--; > +} > +#endif > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h > index 3e4f2ad..20386cf 100644 > --- a/drivers/hwtracing/coresight/coresight-etm-perf.h > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.h > @@ -85,4 +85,8 @@ static inline void *etm_perf_sink_config(struct perf_output_handle *handle) > int __init etm_perf_init(void); > void __exit etm_perf_exit(void); > > +#ifdef CONFIG_CORESIGHT_TRBE > +void coresight_trbe_connect_ete(struct coresight_device *csdev, int cpu); > +void coresight_trbe_remove_ete(struct coresight_device *csdev, int cpu); > +#endif > #endif > diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c > index c594f45..8fa7406 100644 > --- a/drivers/hwtracing/coresight/coresight-platform.c > +++ b/drivers/hwtracing/coresight/coresight-platform.c > @@ -23,7 +23,7 @@ > * coresight_alloc_conns: Allocate connections record for each output > * port from the device. > */ > -static int coresight_alloc_conns(struct device *dev, > +int coresight_alloc_conns(struct device *dev, > struct coresight_platform_data *pdata) > { > if (pdata->nr_outport) { > @@ -35,6 +35,7 @@ static int coresight_alloc_conns(struct device *dev, > > return 0; > } > +EXPORT_SYMBOL_GPL(coresight_alloc_conns); > > static struct device * > coresight_find_device_by_fwnode(struct fwnode_handle *fwnode) > diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c > index 48a8ec3..afd1a1c 100644 > --- a/drivers/hwtracing/coresight/coresight-trbe.c > +++ b/drivers/hwtracing/coresight/coresight-trbe.c > @@ -507,6 +507,7 @@ static void arm_trbe_probe_coresight_cpu(void *info) > if (IS_ERR(cpudata->csdev)) > goto cpu_clear; > > + coresight_trbe_connect_ete(cpudata->csdev, cpudata->cpu); > dev_set_drvdata(&cpudata->csdev->dev, cpudata); > cpudata->trbe_dbm = get_trbe_flag_update(); > cpudata->trbe_align = 1ULL << get_trbe_address_align(); > @@ -586,6 +587,7 @@ static int arm_trbe_cpu_teardown(unsigned int cpu, struct hlist_node *node) > > if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) { > cpudata = per_cpu_ptr(drvdata->cpudata, cpu); > + coresight_trbe_remove_ete(cpudata->csdev, cpu); > if (cpudata->csdev) { > coresight_unregister(cpudata->csdev); > cpudata->drvdata = NULL; > diff --git a/include/linux/coresight.h b/include/linux/coresight.h > index c2d0a2a..c657813 100644 > --- a/include/linux/coresight.h > +++ b/include/linux/coresight.h > @@ -496,6 +496,8 @@ void coresight_relaxed_write64(struct coresight_device *csdev, > u64 val, u32 offset); > void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset); > > +int coresight_alloc_conns(struct device *dev, > + struct coresight_platform_data *pdata); > > #else > static inline struct coresight_device * > -- > 2.7.4 >
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