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Message-ID: <20231114133346.30489-5-hejunhao3@huawei.com>
Date: Tue, 14 Nov 2023 21:33:46 +0800
From: Junhao He <hejunhao3@...wei.com>
To: <suzuki.poulose@....com>, <james.clark@....com>
CC: <coresight@...ts.linaro.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-kernel@...r.kernel.org>, <linuxarm@...wei.com>,
<jonathan.cameron@...wei.com>, <yangyicong@...wei.com>,
<prime.zeng@...ilicon.com>, <hejunhao3@...wei.com>,
<u.kleine-koenig@...gutronix.de>
Subject: [PATCH v3 4/4] coresight: ultrasoc-smb: Use guards to cleanup
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Junhao He <hejunhao3@...wei.com>
---
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;
}
--
2.33.0
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