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

From: James Clark
Date: Fri Mar 10 2023 - 11:36:01 EST


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@xxxxxxx>
---
.../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