On 30/09/2021 18:54, Mathieu Poirier wrote:
Hi Suzuki,
On Tue, Sep 21, 2021 at 02:41:07PM +0100, Suzuki K Poulose wrote:
We collect the trace from the TRBE on FILL event from IRQ context and when via update_buffer(), when the event is stopped. Let us
s/"and when via"/"and via"
consolidate how we calculate the trace generated into a helper.
Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Mike Leach mike.leach@linaro.org Cc: Leo Yan leo.yan@linaro.org Reviewed-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com
drivers/hwtracing/coresight/coresight-trbe.c | 48 ++++++++++++-------- 1 file changed, 30 insertions(+), 18 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 63f7edd5fd1f..063c4505a203 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -527,6 +527,30 @@ static enum trbe_fault_action trbe_get_fault_act(u64 trbsr) return TRBE_FAULT_ACT_SPURIOUS; } +static unsigned long trbe_get_trace_size(struct perf_output_handle *handle,
struct trbe_buf *buf,bool wrap)Stacking
Ack
+{
- u64 write;
- u64 start_off, end_off;
- /*
* If the TRBE has wrapped around the write pointer has* wrapped and should be treated as limit.*/- if (wrap)
write = get_trbe_limit_pointer();- else
write = get_trbe_write_pointer();- end_off = write - buf->trbe_base;
In both arm_trbe_alloc_buffer() and trbe_handle_overflow() the base address is acquired using get_trbe_base_pointer() but here it is referenced directly - any reason for that? It certainly makes reviewing this simple patch quite difficult because I keep wondering if I am missing something subtle...
Very good observation. So far, we always prgrammed the TRBBASER with the the VA(ring_buffer[0]). And thus reading the BASER and using the buf->trbe_base is all fine.
But going forward, we are going to use different values for the TRBBASER to work around erratum. Thus to make the computation of the "offsets" within the ring buffer, it is always correct to use this field. I could move this to the patch where the work around is introduced, and put in a comment there.
Thanks for the review
Suzuki