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-rw-r--r--drivers/hwtracing/coresight/coresight-etb10.c11
-rw-r--r--drivers/hwtracing/coresight/coresight-sysfs.c7
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etf.c20
-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etr.c13
-rw-r--r--drivers/hwtracing/coresight/coresight-tpda.c7
-rw-r--r--drivers/hwtracing/coresight/coresight-tpiu.c14
-rw-r--r--drivers/hwtracing/coresight/ultrasoc-smb.c9
-rw-r--r--include/linux/coresight.h13
8 files changed, 59 insertions, 35 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 145fb815ec1c..306d2af47d63 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -161,7 +161,7 @@ static int etb_enable_sysfs(struct coresight_device *csdev)
local_set(&csdev->mode, CS_MODE_SYSFS);
}
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return ret;
@@ -197,7 +197,7 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data)
* use for this session.
*/
if (drvdata->pid == pid) {
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
goto out;
}
@@ -215,7 +215,7 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data)
/* Associate with monitored process. */
drvdata->pid = pid;
local_set(&drvdata->csdev->mode, CS_MODE_PERF);
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
}
out:
@@ -354,7 +354,8 @@ static int etb_disable(struct coresight_device *csdev)
spin_lock_irqsave(&drvdata->spinlock, flags);
- if (atomic_dec_return(&csdev->refcnt)) {
+ csdev->refcnt--;
+ if (csdev->refcnt) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return -EBUSY;
}
@@ -445,7 +446,7 @@ static unsigned long etb_update_buffer(struct coresight_device *csdev,
spin_lock_irqsave(&drvdata->spinlock, flags);
/* Don't do anything if another tracer is using this sink */
- if (atomic_read(&csdev->refcnt) != 1)
+ if (csdev->refcnt != 1)
goto out;
__etb_disable_hw(drvdata);
diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
index 92cdf8139f23..5992f2c2200a 100644
--- a/drivers/hwtracing/coresight/coresight-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-sysfs.c
@@ -68,7 +68,7 @@ static int coresight_enable_source_sysfs(struct coresight_device *csdev,
return ret;
}
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
return 0;
}
@@ -90,7 +90,8 @@ static bool coresight_disable_source_sysfs(struct coresight_device *csdev,
if (local_read(&csdev->mode) != CS_MODE_SYSFS)
return false;
- if (atomic_dec_return(&csdev->refcnt) == 0) {
+ csdev->refcnt--;
+ if (csdev->refcnt == 0) {
coresight_disable_source(csdev, data);
return true;
}
@@ -190,7 +191,7 @@ int coresight_enable_sysfs(struct coresight_device *csdev)
* source is already enabled.
*/
if (subtype == CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE)
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
goto out;
}
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 2a7e516052a2..f3281c958a57 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -206,7 +206,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev)
* touched.
*/
if (local_read(&csdev->mode) == CS_MODE_SYSFS) {
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
goto out;
}
@@ -229,7 +229,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev)
ret = tmc_etb_enable_hw(drvdata);
if (!ret) {
local_set(&csdev->mode, CS_MODE_SYSFS);
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
} else {
/* Free up the buffer if we failed to enable */
used = false;
@@ -284,7 +284,7 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, void *data)
* use for this session.
*/
if (drvdata->pid == pid) {
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
break;
}
@@ -293,7 +293,7 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, void *data)
/* Associate with monitored process. */
drvdata->pid = pid;
local_set(&csdev->mode, CS_MODE_PERF);
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
}
} while (0);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -338,7 +338,8 @@ static int tmc_disable_etf_sink(struct coresight_device *csdev)
return -EBUSY;
}
- if (atomic_dec_return(&csdev->refcnt)) {
+ csdev->refcnt--;
+ if (csdev->refcnt) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return -EBUSY;
}
@@ -371,7 +372,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
return -EBUSY;
}
- if (atomic_read(&csdev->refcnt) == 0) {
+ if (csdev->refcnt == 0) {
ret = tmc_etf_enable_hw(drvdata);
if (!ret) {
local_set(&csdev->mode, CS_MODE_SYSFS);
@@ -379,7 +380,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
}
}
if (!ret)
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
if (first_enable)
@@ -401,7 +402,8 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
return;
}
- if (atomic_dec_return(&csdev->refcnt) == 0) {
+ csdev->refcnt--;
+ if (csdev->refcnt == 0) {
tmc_etf_disable_hw(drvdata);
local_set(&csdev->mode, CS_MODE_DISABLED);
last_disable = true;
@@ -489,7 +491,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev,
spin_lock_irqsave(&drvdata->spinlock, flags);
/* Don't do anything if another tracer is using this sink */
- if (atomic_read(&csdev->refcnt) != 1)
+ if (csdev->refcnt != 1)
goto out;
CS_UNLOCK(drvdata->base);
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 3dc989d4fcab..88a0fc375b4d 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1231,14 +1231,14 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
* touched, even if the buffer size has changed.
*/
if (local_read(&csdev->mode) == CS_MODE_SYSFS) {
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
goto out;
}
ret = tmc_etr_enable_hw(drvdata, sysfs_buf);
if (!ret) {
local_set(&csdev->mode, CS_MODE_SYSFS);
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
}
out:
@@ -1564,7 +1564,7 @@ tmc_update_etr_buffer(struct coresight_device *csdev,
spin_lock_irqsave(&drvdata->spinlock, flags);
/* Don't do anything if another tracer is using this sink */
- if (atomic_read(&csdev->refcnt) != 1) {
+ if (csdev->refcnt != 1) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
goto out;
}
@@ -1676,7 +1676,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
* use for this session.
*/
if (drvdata->pid == pid) {
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
goto unlock_out;
}
@@ -1686,7 +1686,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
drvdata->pid = pid;
local_set(&csdev->mode, CS_MODE_PERF);
drvdata->perf_buf = etr_perf->etr_buf;
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
}
unlock_out:
@@ -1719,7 +1719,8 @@ static int tmc_disable_etr_sink(struct coresight_device *csdev)
return -EBUSY;
}
- if (atomic_dec_return(&csdev->refcnt)) {
+ csdev->refcnt--;
+ if (csdev->refcnt) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return -EBUSY;
}
diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
index c813ec427b8d..f8f6413cc711 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.c
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -152,7 +152,8 @@ static int __tpda_enable(struct tpda_drvdata *drvdata, int port)
* Only do pre-port enable for first port that calls enable when the
* device's main refcount is still 0
*/
- if (!atomic_read(&drvdata->csdev->refcnt))
+ lockdep_assert_held(&drvdata->spinlock);
+ if (!drvdata->csdev->refcnt)
tpda_enable_pre_port(drvdata);
ret = tpda_enable_port(drvdata, port);
@@ -173,7 +174,7 @@ static int tpda_enable(struct coresight_device *csdev,
ret = __tpda_enable(drvdata, in->dest_port);
if (!ret) {
atomic_inc(&in->dest_refcnt);
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", in->dest_port);
}
}
@@ -204,7 +205,7 @@ static void tpda_disable(struct coresight_device *csdev,
spin_lock(&drvdata->spinlock);
if (atomic_dec_return(&in->dest_refcnt) == 0) {
__tpda_disable(drvdata, in->dest_port);
- atomic_dec(&csdev->refcnt);
+ csdev->refcnt--;
}
spin_unlock(&drvdata->spinlock);
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index 7e69048ac944..29024f880fda 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -58,6 +58,7 @@ struct tpiu_drvdata {
void __iomem *base;
struct clk *atclk;
struct coresight_device *csdev;
+ spinlock_t spinlock;
};
static void tpiu_enable_hw(struct csdev_access *csa)
@@ -72,8 +73,11 @@ static void tpiu_enable_hw(struct csdev_access *csa)
static int tpiu_enable(struct coresight_device *csdev, enum cs_mode mode,
void *__unused)
{
+ struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ guard(spinlock)(&drvdata->spinlock);
tpiu_enable_hw(&csdev->access);
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
dev_dbg(&csdev->dev, "TPIU enabled\n");
return 0;
}
@@ -96,7 +100,11 @@ static void tpiu_disable_hw(struct csdev_access *csa)
static int tpiu_disable(struct coresight_device *csdev)
{
- if (atomic_dec_return(&csdev->refcnt))
+ struct tpiu_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+ guard(spinlock)(&drvdata->spinlock);
+ csdev->refcnt--;
+ if (csdev->refcnt)
return -EBUSY;
tpiu_disable_hw(&csdev->access);
@@ -132,6 +140,8 @@ static int tpiu_probe(struct amba_device *adev, const struct amba_id *id)
if (!drvdata)
return -ENOMEM;
+ spin_lock_init(&drvdata->spinlock);
+
drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
if (!IS_ERR(drvdata->atclk)) {
ret = clk_prepare_enable(drvdata->atclk);
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
index bef633960173..a92c5b750f81 100644
--- a/drivers/hwtracing/coresight/ultrasoc-smb.c
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -103,7 +103,7 @@ static int smb_open(struct inode *inode, struct file *file)
if (drvdata->reading)
return -EBUSY;
- if (atomic_read(&drvdata->csdev->refcnt))
+ if (drvdata->csdev->refcnt)
return -EBUSY;
smb_update_data_size(drvdata);
@@ -271,7 +271,7 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode,
if (ret)
return ret;
- atomic_inc(&csdev->refcnt);
+ csdev->refcnt++;
dev_dbg(&csdev->dev, "Ultrasoc SMB enabled\n");
return ret;
@@ -286,7 +286,8 @@ static int smb_disable(struct coresight_device *csdev)
if (drvdata->reading)
return -EBUSY;
- if (atomic_dec_return(&csdev->refcnt))
+ csdev->refcnt--;
+ if (csdev->refcnt)
return -EBUSY;
/* Complain if we (somehow) got out of sync */
@@ -381,7 +382,7 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev,
guard(spinlock)(&drvdata->spinlock);
/* Don't do anything if another tracer is using this sink. */
- if (atomic_read(&csdev->refcnt) != 1)
+ if (csdev->refcnt != 1)
return 0;
smb_disable_hw(drvdata);
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 365b28022c5b..74bcec526aa9 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -230,8 +230,15 @@ struct coresight_sysfs_link {
* actually an 'enum cs_mode', but is stored in an atomic type.
* This is always accessed through local_read() and local_set(),
* but wherever it's done from within the Coresight device's lock,
- * a non-atomic read would also work.
- * @refcnt: keep track of what is in use.
+ * a non-atomic read would also work. This is the main point of
+ * synchronisation between code happening inside the sysfs mode's
+ * coresight_mutex and outside when running in Perf mode. A compare
+ * and exchange swap is done to atomically claim one mode or the
+ * other.
+ * @refcnt: keep track of what is in use. Only access this outside of the
+ * device's spinlock when the coresight_mutex held and mode ==
+ * CS_MODE_SYSFS. Otherwise it must be accessed from inside the
+ * spinlock.
* @orphan: true if the component has connections that haven't been linked.
* @sysfs_sink_activated: 'true' when a sink has been selected for use via sysfs
* by writing a 1 to the 'enable_sink' file. A sink can be
@@ -257,7 +264,7 @@ struct coresight_device {
struct csdev_access access;
struct device dev;
local_t mode;
- atomic_t refcnt;
+ int refcnt;
bool orphan;
/* sink specific fields */
bool sysfs_sink_activated;
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