A snapshot session captures trace data only when userspace receives a signal and disables tracing. Before disabling, enable circle mode instead of fill mode to avoid unnecessary interrupt handling.
Signed-off-by: Leo Yan leo.yan@arm.com --- drivers/hwtracing/coresight/coresight-trbe.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 0551ea9b4f8286c156e3c9c7ac94e2ecd3b9dc3f..ee9993d518d2a41f0d709b7d0690b2dfe0bef2d9 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -635,6 +635,12 @@ static void set_trbe_limit_pointer_enabled(struct trbe_buf *buf) trblimitr &= ~TRBLIMITR_EL1_TM_MASK; trblimitr &= ~TRBLIMITR_EL1_LIMIT_MASK;
+ if (buf->snapshot) { + trblimitr |= FIELD_PREP(TRBLIMITR_EL1_FM_MASK, TRBLIMITR_EL1_FM_CBUF) | + FIELD_PREP(TRBLIMITR_EL1_TM_MASK, TRBLIMITR_EL1_TM_IGNR); + goto enable_trace_buf; + } + if (!buf->trbe_count || buf->trbe_write + buf->trbe_count == buf->trbe_limit) { /* @@ -669,6 +675,7 @@ static void set_trbe_limit_pointer_enabled(struct trbe_buf *buf) FIELD_PREP(TRBLIMITR_EL1_TM_MASK, TRBLIMITR_EL1_TM_STOP); }
+enable_trace_buf: trblimitr |= (addr & PAGE_MASK); set_trbe_enabled(buf->cpudata, trblimitr); }