[PATCH v3 05/10] coresight: trbe: Drop duplicate TRUNCATE flags

[Anshuman Khandual]

On 9/14/21 3:56 PM, Suzuki K Poulose wrote:
> We mark the buffer as TRUNCATED when there is no space left
> in the buffer. But we do it at different points.
>     __trbe_normal_offset()
> and also, at all the callers of the above function via
> compute_trbe_buffer_limit(), when the limit == base (i.e
> offset = 0 as returned by the __trbe_normal_offset()).
> 
> So, given that the callers already mark the buffer as TRUNCATED
> drop the caller inside the __trbe_normal_offset().
> 
> This is in preparation to moving the handling of TRUNCATED
> into a central place.
> 
> Cc: Anshuman Khandual <anshuman.khandual at arm.com>
> Cc: Mathieu Poirier <mathieu.poirier at linaro.org>
> Cc: Mike Leach <mike.leach at linaro.org>
> Cc: Leo Yan <leo.yan at linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>

Reviewed-by: Anshuman Khandual <anshuman.khandual at arm.com>

A small nit though.

> ---
> Change since v2:
>   - Added the flag for trbe_handle_spurious() -  Anshuman
> ---
>  drivers/hwtracing/coresight/coresight-trbe.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
> index 81bf183a73a1..5297b11f26b7 100644
> --- a/drivers/hwtracing/coresight/coresight-trbe.c
> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
> @@ -252,13 +252,9 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle)
>  	 * trbe_base				trbe_base + nr_pages
>  	 *
>  	 * Perf aux buffer does not have any space for the driver to write into.
> -	 * Just communicate trace truncation event to the user space by marking
> -	 * it with PERF_AUX_FLAG_TRUNCATED.

Should not this comment be moved, where PERF_AUX_FLAG_TRUNCATED
gets marked after this change ?

>  	 */
> -	if (!handle->size) {
> -		perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
> +	if (!handle->size)
>  		return 0;
> -	}
>  
>  	/* Compute the tail and wakeup indices now that we've aligned head */
>  	tail = PERF_IDX2OFF(handle->head + handle->size, buf);
> @@ -360,7 +356,6 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle)
>  		return limit;
>  
>  	trbe_pad_buf(handle, handle->size);
> -	perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
>  	return 0;
>  }
>  
> @@ -688,6 +683,7 @@ static void trbe_handle_spurious(struct perf_output_handle *handle)
>  	buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf);
>  	if (buf->trbe_limit == buf->trbe_base) {
>  		trbe_drain_and_disable_local();
> +		perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
>  		return;
>  	}
>  	trbe_enable_hw(buf);
>