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 17:16:32 +0100 |
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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 ?
> + > +static void tmc_update_etf_buffer(struct coresight_device *csdev,
> + * Get a hold of the status register and see if a wrap around > + * has occurred. If so adjust things accordingly. > + */ > + status = readl_relaxed(drvdata->base + TMC_STS); > + if (status & TMC_STS_FULL) { > + local_inc(&buf->lost); > + to_read = drvdata->size; > + } else { > + to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->size); > + } > + > + /* > + * The TMC RAM buffer may be bigger than the space available in the > + * perf ring buffer (handle->size). If so advance the RRP so that we > + * get the latest trace data. > + */ > + if (to_read > handle->size) { > + u32 mask = 0; > + > + /* > + * The value written to RRP must be byte-address aligned to > + * the width of the trace memory databus _and_ to a frame > + * boundary (16 byte), whichever is the biggest. For example, > + * for 32-bit, 64-bit and 128-bit wide trace memory, the four > + * LSBs must be 0s. For 256-bit wide trace memory, the five > + * LSBs must be 0s. > + */ > + switch (drvdata->memwidth) { > + case TMC_MEM_INTF_WIDTH_32BITS: > + case TMC_MEM_INTF_WIDTH_64BITS: > + case TMC_MEM_INTF_WIDTH_128BITS: > + mask = GENMASK(31, 5); > + break; > + case TMC_MEM_INTF_WIDTH_256BITS: > + mask = GENMASK(31, 6); > + break; > + } > + > + /* > + * 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;
> + /* Move the RAM read pointer up */ > + read_ptr = (write_ptr + drvdata->size) - to_read; > + /* Make sure we are still within our limits */ > + read_ptr &= ~(drvdata->size - 1); > + /* Tell the HW */ > + writel_relaxed(read_ptr, drvdata->base + TMC_RRP); > + local_inc(&buf->lost); > + }
Suzuki
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