Re: [PATCH v3 1/5] coresight: etm4x: introduce struct etm4_caps

Yeoreum Yun
2026-04-13T10:03:54Z

Hi Jie,
>
> Hi Yeoreum,
>
> On 4/13/2026 1:55 AM, Yeoreum Yun wrote:
> > introduce struct etm4_caps to describe ETMv4 capabilities
> > and move capabilities information into it.
> >
> > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> > ---
> > .../coresight/coresight-etm4x-core.c | 234 +++++++++---------
> > .../coresight/coresight-etm4x-sysfs.c | 190 ++++++++------
> > drivers/hwtracing/coresight/coresight-etm4x.h | 175 ++++++-------
> > 3 files changed, 327 insertions(+), 272 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > index d565a73f0042..6443f3717b37 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>
> <...>
>
> > +/**
> > + * struct etmv4_caps - specifics ETM capabilities
> > + * @nr_pe: The number of processing entity available for tracing.
> > + * @nr_pe_cmp: The number of processing entity comparator inputs that are
> > + * available for tracing.
> > + * @nr_addr_cmp:Number of pairs of address comparators available
> > + * as found in ETMIDR4 0-3.
> > + * @nr_cntr: Number of counters as found in ETMIDR5 bit 28-30.
> > + * @nr_ext_inp: Number of external input.
> > + * @numcidc: Number of contextID comparators.
>
> @numextinsel:
>
> > + * @numvmidc: Number of VMID comparators.
> > + * @nrseqstate: The number of sequencer states that are implemented.
> > + * @nr_event: Indicates how many events the trace unit support.
> > + * @nr_resource:The number of resource selection pairs available for tracing.
> > + * @nr_ss_cmp: Number of single-shot comparator controls that are available.
> > + * @trcid_size: Indicates the trace ID width.
> > + * @ts_size: Global timestamp size field.
> > + * @ctxid_size: Size of the context ID field to consider.
> > + * @vmid_size: Size of the VM ID comparator to consider.
> > + * @ccsize: Indicates the size of the cycle counter in bits.
> > + * @ccitmin: minimum value that can be programmed in
> > + * @s_ex_level: In secure state, indicates whether instruction tracing is
> > + * supported for the corresponding Exception level.
> > + * @ns_ex_level:In non-secure state, indicates whether instruction tracing is
> > + * supported for the corresponding Exception level.
> > + * @q_support: Q element support characteristics.
> > + * @os_lock_model: OSLock model.
> > + * @instrp0: Tracing of load and store instructions
> > + * as P0 elements is supported.
> > + * @q_filt: Q element filtering support, if Q elements are supported.
> > + * @trcbb: Indicates if the trace unit supports branch broadcast tracing.
> > + * @trccond: If the trace unit supports conditional
> > + * instruction tracing.
> > + * @retstack: Indicates if the implementation supports a return stack.
> > + * @trccci: Indicates if the trace unit supports cycle counting
> > + * for instruction.
> > + * @trc_error: Whether a trace unit can trace a system
> > + * error exception.
> > + * @syncpr: Indicates if an implementation has a fixed
> > + * synchronization period.
> > + * @stallctl: If functionality that prevents trace unit buffer overflows
> > + * is available.
> > + * @sysstall: Does the system support stall control of the PE?
> > + * @nooverflow: Indicate if overflow prevention is supported.
> > + * @atbtrig: If the implementation can support ATB triggers
> > + * @lpoverride: If the implementation can support low-power state over.
> > + * @skip_power_up: Indicates if an implementation can skip powering up
> > + * the trace unit.
> > + */
> > +struct etmv4_caps {
> > + u8 nr_pe;
> > + u8 nr_pe_cmp;
> > + u8 nr_addr_cmp;
> > + u8 nr_cntr;
> > + u8 nr_ext_inp;
> > + u8 numcidc;
> > + u8 numextinsel;
>
> missed kernel_doc.
>
> Thanks,
> Jie

Thanks. I'll add comment for numextinsel.

--
Sincerely,
Yeoreum Yun