Re: [PATCH v5 08/13] coresight: Interpret perf config with ATTR_CFG_GET_FLD()

Hi James

On Tue, 18 Nov 2025 at 16:28, James Clark james.clark@linaro.org wrote:

The "config:" string construction in format_attr_contextid_show() can be removed because it either showed the existing context1 or context2 formats which have already been generated, so can be called themselves.

The other conversions are straightforward replacements.

Signed-off-by: James Clark james.clark@linaro.org

drivers/hwtracing/coresight/coresight-etm-perf.c | 26 +++++++++++++++--------- 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index 28f1bfc4579f..1b9ae832a576 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -80,12 +80,19 @@ static ssize_t format_attr_contextid_show(struct device *dev, struct device_attribute *attr, char *page) {

•   int pid_fmt = ETM_OPT_CTXTID;
  

•   /*
  

•    * is_kernel_in_hyp_mode() isn't defined in arm32 so avoid calling it
  

•    * even though is_visible() prevents this function from being called.
  

•    */
  

+#if IS_ENABLED(CONFIG_ARM64)

•   if (is_kernel_in_hyp_mode())
  

•           return contextid2_show(dev, attr, page);
  
  

-#if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X)

•   pid_fmt = is_kernel_in_hyp_mode() ? ETM_OPT_CTXTID2 : ETM_OPT_CTXTID;
  

•   return contextid1_show(dev, attr, page);
  

+#else

•   WARN_ONCE(1, "ETM contextid not supported on arm32\n");
  

•   return 0;
  

Context ID is supported in aarch32 - and traced in etmv3 / ptm and etmv4.

Mike

#endif

•   return sprintf(page, "config:%d\n", pid_fmt);
  

}

static struct device_attribute format_attr_contextid = @@ -337,7 +344,7 @@ static bool sinks_compatible(struct coresight_device *a, static void *etm_setup_aux(struct perf_event *event, void **pages, int nr_pages, bool overwrite) {

•   u32 id, cfg_hash;
  

•   u32 sink_hash, cfg_hash;
    int cpu = event->cpu;
    cpumask_t *mask;
    struct coresight_device *sink = NULL;
  

@@ -350,13 +357,12 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, INIT_WORK(&event_data->work, free_event_data);

    /* First get the selected sink from user space. */

•   if (event->attr.config2 & GENMASK_ULL(31, 0)) {
  

•           id = (u32)event->attr.config2;
  

•           sink = user_sink = coresight_get_sink_by_id(id);
  

•   }
  

•   sink_hash = ATTR_CFG_GET_FLD(&event->attr, sinkid);
  

•   if (sink_hash)
  

•           sink = user_sink = coresight_get_sink_by_id(sink_hash);
  
    /* check if user wants a coresight configuration selected */
  

•   cfg_hash = (u32)((event->attr.config2 & GENMASK_ULL(63, 32)) >> 32);
  

•   cfg_hash = ATTR_CFG_GET_FLD(&event->attr, configid);
    if (cfg_hash) {
            if (cscfg_activate_config(cfg_hash))
                    goto err;
  
  

-- 2.34.1