coresight: Refactor out buffer allocation function for ETR

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

Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230425143542.2305069-12-james.clark@arm.com

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 23fa70c..7993398 100644 (file)
--- 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 @@ out:
        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 01c0382..b97da39 100644 (file)
--- 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