Re: [PATCH v2 7/9] coresight: Refactor out buffer allocation function for ETR

On Fri, 10 Mar 2023 at 16:07, James Clark james.clark@arm.com wrote:

When CATU is moved to the generic enable/disable path system in the next commit, it will need to call into ETR and get it to pre-allocate its buffer so add a function for it.

No functional changes

Signed-off-by: James Clark james.clark@arm.com

.../hwtracing/coresight/coresight-tmc-etr.c | 50 ++++++++++++++++--- drivers/hwtracing/coresight/coresight-tmc.h | 2 + 2 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 223081dc3ad4..cb9621003aef 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1169,7 +1169,7 @@ void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) drvdata->etr_buf = NULL; }

-static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) +static struct etr_buf *tmc_etr_get_sysfs_buffer(struct coresight_device *csdev) { int ret = 0; unsigned long flags; @@ -1192,7 +1192,7 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) /* Allocate memory with the locks released */ free_buf = new_buf = tmc_etr_setup_sysfs_buf(drvdata); if (IS_ERR(new_buf))

•                   return PTR_ERR(new_buf);
  

•                   return new_buf;
  
            /* Let's try again */
            spin_lock_irqsave(&drvdata->spinlock, flags);
  

@@ -1223,17 +1223,33 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) drvdata->sysfs_buf = new_buf; }

•   ret = tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf);
  

•   if (!ret) {
  

•           drvdata->mode = CS_MODE_SYSFS;
  

•           atomic_inc(csdev->refcnt);
  

•   }
  

out: spin_unlock_irqrestore(&drvdata->spinlock, flags);

    /* Free memory outside the spinlock if need be */
    if (free_buf)
            tmc_etr_free_sysfs_buf(free_buf);

•   return ret ? ERR_PTR(ret) : drvdata->sysfs_buf;
  

+}

+static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) +{

•   int ret;
  

•   unsigned long flags;
  

•   struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
  

•   struct etr_buf *sysfs_buf = tmc_etr_get_sysfs_buffer(csdev);
  

•   if (IS_ERR(sysfs_buf))
  

•           return PTR_ERR(sysfs_buf);
  

•   spin_lock_irqsave(&drvdata->spinlock, flags);
  

•   ret = tmc_etr_enable_hw(drvdata, sysfs_buf);
  

•   if (!ret) {
  

•           drvdata->mode = CS_MODE_SYSFS;
  

•           atomic_inc(csdev->refcnt);
  

•   }
  

•   spin_unlock_irqrestore(&drvdata->spinlock, flags);
  
    if (!ret)
            dev_dbg(&csdev->dev, "TMC-ETR enabled\n");
  

@@ -1241,6 +1257,26 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) return ret; }

+struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev,

•                              enum cs_mode mode, void *data)
  

+{

•   struct perf_output_handle *handle = data;
  

•   struct etr_perf_buffer *etr_perf;
  

•   switch (mode) {
  

•   case CS_MODE_SYSFS:
  

•           return tmc_etr_get_sysfs_buffer(csdev);
  

•   case CS_MODE_PERF:
  

•           etr_perf = etm_perf_sink_config(handle);
  

•           if (WARN_ON(!etr_perf || !etr_perf->etr_buf))
  

•                   return ERR_PTR(-EINVAL);
  

•           return etr_perf->etr_buf;
  

•   default:
  

•           return ERR_PTR(-EINVAL);
  

•   }
  

+} +EXPORT_SYMBOL_GPL(tmc_etr_get_buffer);

/*

• alloc_etr_buf: Allocate ETR buffer for use by perf.
• The size of the hardware buffer is dependent on the size configured

diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 01c0382a29c0..b97da39652d2 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -332,5 +332,7 @@ struct coresight_device *tmc_etr_get_catu_device(struct tmc_drvdata *drvdata);

void tmc_etr_set_catu_ops(const struct etr_buf_operations *catu); void tmc_etr_remove_catu_ops(void); +struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev,

•                              enum cs_mode mode, void *data);
  
  

#endif

2.34.1

Reviewed by: Mike Leach mike.leach@linaro.org