Messages in this thread | | | Subject | Re: [PATCH V2 13/15] coresight: tmc: implementing TMC-ETF AUX space API | From | Suzuki K Poulose <> | Date | Tue, 19 Apr 2016 17:50:49 +0100 |
| |
On 19/04/16 17:45, Mathieu Poirier wrote: > On 19 April 2016 at 10:16, Suzuki K Poulose <Suzuki.Poulose@arm.com> wrote: >> On 12/04/16 18:54, Mathieu Poirier wrote: >>> >>> This patch implement the AUX area interfaces required to >>> use the TMC (configured as an ETF) from the Perf sub-system. >>> >>> The heuristic is heavily borrowed from the ETB10 implementation. >>> >>> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> >>> --- >>> drivers/hwtracing/coresight/coresight-tmc-etf.c | 198 >>> ++++++++++++++++++++++++ >>> drivers/hwtracing/coresight/coresight-tmc.h | 21 +++ >>> 2 files changed, 219 insertions(+) >>> >>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c >>> b/drivers/hwtracing/coresight/coresight-tmc-etf.c >>> index a440784e3b27..fff175d4020d 100644 >>> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c >>> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c >>> @@ -15,7 +15,9 @@ >>> * this program. If not, see <http://www.gnu.org/licenses/>. >>> */ >>> >>> +#include <linux/circ_buf.h> >>> #include <linux/coresight.h> >>> +#include <linux/perf_event.h> >>> #include <linux/slab.h> >>> #include "coresight-priv.h" >>> #include "coresight-tmc.h" >>> @@ -295,9 +297,205 @@ static void tmc_disable_etf_link(struct >>> coresight_device *csdev, >>> dev_info(drvdata->dev, "TMC disabled\n"); >>> } >>> >>> +static void *tmc_alloc_etf_buffer(struct coresight_device *csdev, int >>> cpu, >>> + void **pages, int nr_pages, bool >>> overwrite) >> >> >> >> >>> + >>> +static void tmc_free_etf_buffer(void *config) >>> +{ >> >> >>> + >>> +static int tmc_set_etf_buffer(struct coresight_device *csdev, >>> + struct perf_output_handle *handle, >>> + void *sink_config) >> >> >> >>> +static unsigned long tmc_reset_etf_buffer(struct coresight_device *csdev, >>> + struct perf_output_handle >>> *handle, >>> + void *sink_config, bool *lost) >>> +{ >> >> >> >>> /** >>> + * struct cs_buffer - keep track of a recording session' specifics >>> + * @cur: index of the current buffer >>> + * @nr_pages: max number of pages granted to us >>> + * @offset: offset within the current buffer >>> + * @data_size: how much we collected in this run >>> + * @lost: other than zero if we had a HW buffer wrap around >>> + * @snapshot: is this run in snapshot mode >>> + * @data_pages: a handle the ring buffer >>> + */ >>> +struct cs_tmc_buffers { >>> + unsigned int cur; >>> + unsigned int nr_pages; >>> + unsigned long offset; >>> + local_t data_size; >>> + local_t lost; >>> + bool snapshot; >>> + void **data_pages; >>> +}; >> >> >> >> All of the above look exactly the same as what we have in etb10.c (as you >> have mentioned). >> Is there any chance we could reuse them under a generic name ? > > I toyed with the idea many times... > > Today the structures are similar and can be used in both drivers but > it is only a matter for time (probably months) before someone adds new > functionality on one side that isn't compatible with the other side. > When that happens we'll get a bloated struct with fields that aren't > used, depending on where it gets instantiated. Or the struct will be > split again, coming back to what we have today. >
If that happens in future, we know what to do now :)
>>> + * Make sure the new size is aligned in accordance with >>> the >>> + * requirement explained above. >>> + */ >>> + to_read -= handle->size & mask; >> >> >> Shouldn't this be : >> >> to_read = handle->size & mask; > > You are correct.
This applies to the etb10 code as well. So you might want to fix that as well.
Cheers Suzuki
| |