[PATCH v2 03/11] coresight: trbe: Track trigger count support per CPU

[Leo Yan]

Some TRBE errata are not compatible with using trigger count mode. In
particular, CPUs affected by the overwrite-in-fill-mode or out-of-range
workarounds must continue to use the existing fill-mode handling.

Record whether trigger count mode is supported in each CPU's probe.
This prepares the enable path to avoid programming TRBTRG_EL1 on
affected CPUs.

Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 09ed9bcf4a70479169094697dcc3d445629cfaae..92cd9c28cb4f6d9da7d41aa9eeedf4295a810006 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -140,6 +140,7 @@ struct trbe_save_state {
  * @trbe_align		- Software alignment used for the TRBPTR_EL1.
  * @cpu			- CPU this TRBE belongs to.
  * @mode		- Mode of current operation. (perf/disabled)
+ * @trig_is_supported	- Trigger count support flag.
  * @buf			- Buffer configuration retained for the enabled session.
  * @handle		- Perf output handle from successful enable until disable.
  * @drvdata		- TRBE specific drvdata
@@ -151,6 +152,7 @@ struct trbe_cpudata {
 	u64 trbe_align;
 	int cpu;
 	enum cs_mode mode;
+	bool trig_is_supported;
 	struct trbe_buf *buf;
 	struct perf_output_handle *handle;
 	struct trbe_drvdata *drvdata;
@@ -222,6 +224,15 @@ static bool trbe_is_broken(struct trbe_cpudata *cpudata)
 	return trbe_has_erratum(cpudata, TRBE_IS_BROKEN);
 }
 
+static bool trbe_trigger_count_supported(struct trbe_cpudata *cpudata)
+{
+	if (trbe_may_overwrite_in_fill_mode(cpudata) ||
+	    trbe_may_write_out_of_range(cpudata))
+		return false;
+
+	return true;
+}
+
 static int trbe_alloc_node(struct perf_event *event)
 {
 	if (event->cpu == -1)
@@ -1609,6 +1620,7 @@ static void arm_trbe_probe_cpu(void *info)
 	else
 		cpudata->trbe_align = cpudata->trbe_hw_align;
 
+	cpudata->trig_is_supported = trbe_trigger_count_supported(cpudata);
 	cpudata->trbe_flag = get_trbe_flag_update(trbidr);
 	cpudata->cpu = cpu;
 	cpudata->drvdata = drvdata;

-- 
2.34.1