On 14/11/2023 13:33, Junhao He wrote:
> Use guards to reduce gotos and simplify control flow.
>
> Signed-off-by: Junhao He <[email protected]>
Nice cleanup!
Reviewed-by: James Clark <[email protected]>
> ---
> drivers/hwtracing/coresight/ultrasoc-smb.c | 70 +++++++---------------
> 1 file changed, 22 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
> index 6e32d31a95fe..cd14b2eded4e 100644
> --- a/drivers/hwtracing/coresight/ultrasoc-smb.c
> +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
> @@ -97,27 +97,19 @@ static int smb_open(struct inode *inode, struct file *file)
> {
> struct smb_drv_data *drvdata = container_of(file->private_data,
> struct smb_drv_data, miscdev);
> - int ret = 0;
>
> - spin_lock(&drvdata->spinlock);
> + guard(spinlock)(&drvdata->spinlock);
>
> - if (drvdata->reading) {
> - ret = -EBUSY;
> - goto out;
> - }
> + if (drvdata->reading)
> + return -EBUSY;
>
> - if (atomic_read(&drvdata->csdev->refcnt)) {
> - ret = -EBUSY;
> - goto out;
> - }
> + if (atomic_read(&drvdata->csdev->refcnt))
> + return -EBUSY;
>
> smb_update_data_size(drvdata);
> -
> drvdata->reading = true;
> -out:
> - spin_unlock(&drvdata->spinlock);
>
> - return ret;
> + return 0;
> }
>
> static ssize_t smb_read(struct file *file, char __user *data, size_t len,
> @@ -160,9 +152,8 @@ static int smb_release(struct inode *inode, struct file *file)
> struct smb_drv_data *drvdata = container_of(file->private_data,
> struct smb_drv_data, miscdev);
>
> - spin_lock(&drvdata->spinlock);
> + guard(spinlock)(&drvdata->spinlock);
> drvdata->reading = false;
> - spin_unlock(&drvdata->spinlock);
>
> return 0;
> }
> @@ -255,19 +246,15 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode,
> struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
> int ret = 0;
>
> - spin_lock(&drvdata->spinlock);
> + guard(spinlock)(&drvdata->spinlock);
>
> /* Do nothing, the trace data is reading by other interface now */
> - if (drvdata->reading) {
> - ret = -EBUSY;
> - goto out;
> - }
> + if (drvdata->reading)
> + return -EBUSY;
>
> /* Do nothing, the SMB is already enabled as other mode */
> - if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode) {
> - ret = -EBUSY;
> - goto out;
> - }
> + if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode)
> + return -EBUSY;
>
> switch (mode) {
> case CS_MODE_SYSFS:
> @@ -281,13 +268,10 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode,
> }
>
> if (ret)
> - goto out;
> + return ret;
>
> atomic_inc(&csdev->refcnt);
> -
> dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n");
> -out:
> - spin_unlock(&drvdata->spinlock);
>
> return ret;
> }
> @@ -295,19 +279,14 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode,
> static int smb_disable(struct coresight_device *csdev)
> {
> struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
> - int ret = 0;
>
> - spin_lock(&drvdata->spinlock);
> + guard(spinlock)(&drvdata->spinlock);
>
> - if (drvdata->reading) {
> - ret = -EBUSY;
> - goto out;
> - }
> + if (drvdata->reading)
> + return -EBUSY;
>
> - if (atomic_dec_return(&csdev->refcnt)) {
> - ret = -EBUSY;
> - goto out;
> - }
> + if (atomic_dec_return(&csdev->refcnt))
> + return -EBUSY;
>
> /* Complain if we (somehow) got out of sync */
> WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
> @@ -317,12 +296,9 @@ static int smb_disable(struct coresight_device *csdev)
> /* Dissociate from the target process. */
> drvdata->pid = -1;
> drvdata->mode = CS_MODE_DISABLED;
> -
> dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n");
> -out:
> - spin_unlock(&drvdata->spinlock);
>
> - return ret;
> + return 0;
> }
>
> static void *smb_alloc_buffer(struct coresight_device *csdev,
> @@ -395,17 +371,17 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev,
> struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
> struct smb_data_buffer *sdb = &drvdata->sdb;
> struct cs_buffers *buf = sink_config;
> - unsigned long data_size = 0;
> + unsigned long data_size;
> bool lost = false;
>
> if (!buf)
> return 0;
>
> - spin_lock(&drvdata->spinlock);
> + guard(spinlock)(&drvdata->spinlock);
>
> /* Don't do anything if another tracer is using this sink. */
> if (atomic_read(&csdev->refcnt) != 1)
> - goto out;
> + return 0;
>
> smb_disable_hw(drvdata);
> smb_update_data_size(drvdata);
> @@ -424,8 +400,6 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev,
> smb_sync_perf_buffer(drvdata, buf, handle->head);
> if (!buf->snapshot && lost)
> perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
> -out:
> - spin_unlock(&drvdata->spinlock);
>
> return data_size;
> }