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coresight: Drop atomics in connection refcounts

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These belong to the device being enabled or disabled and are only ever
used inside the device's spinlock. Remove the atomics to not imply that
there are any other concurrent accesses.

If atomics were necessary I don't think they would have been enough
anyway. There would be nothing to prevent an enable or disable running
concurrently if not for the spinlock.

Signed-off-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20241128121414.2425119-1-james.clark@linaro.org
This commit is contained in:
James Clark
2024-11-28 12:14:14 +00:00
committed by Suzuki K Poulose
parent c8ea5f41b4
commit 5aec7c065f
4 changed files with 11 additions and 11 deletions
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6
drivers/hwtracing/coresight/coresight-funnel.c
View File

@@ -86,14 +86,14 @@ static int funnel_enable(struct coresight_device *csdev,
bool first_enable = false;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (atomic_read(&in->dest_refcnt) == 0) {
if (in->dest_refcnt == 0) {
if (drvdata->base)
rc = dynamic_funnel_enable_hw(drvdata, in->dest_port);
if (!rc)
first_enable = true;
}
if (!rc)
atomic_inc(&in->dest_refcnt);
in->dest_refcnt++;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
if (first_enable)
@@ -130,7 +130,7 @@ static void funnel_disable(struct coresight_device *csdev,
bool last_disable = false;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (atomic_dec_return(&in->dest_refcnt) == 0) {
if (--in->dest_refcnt == 0) {
if (drvdata->base)
dynamic_funnel_disable_hw(drvdata, in->dest_port);
last_disable = true;

6
drivers/hwtracing/coresight/coresight-replicator.c
View File

@@ -126,7 +126,7 @@ static int replicator_enable(struct coresight_device *csdev,
bool first_enable = false;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (atomic_read(&out->src_refcnt) == 0) {
if (out->src_refcnt == 0) {
if (drvdata->base)
rc = dynamic_replicator_enable(drvdata, in->dest_port,
out->src_port);
@@ -134,7 +134,7 @@ static int replicator_enable(struct coresight_device *csdev,
first_enable = true;
}
if (!rc)
atomic_inc(&out->src_refcnt);
out->src_refcnt++;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
if (first_enable)
@@ -180,7 +180,7 @@ static void replicator_disable(struct coresight_device *csdev,
bool last_disable = false;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (atomic_dec_return(&out->src_refcnt) == 0) {
if (--out->src_refcnt == 0) {
if (drvdata->base)
dynamic_replicator_disable(drvdata, in->dest_port,
out->src_port);

6
drivers/hwtracing/coresight/coresight-tpda.c
View File

@@ -190,10 +190,10 @@ static int tpda_enable(struct coresight_device *csdev,
int ret = 0;
spin_lock(&drvdata->spinlock);
if (atomic_read(&in->dest_refcnt) == 0) {
if (in->dest_refcnt == 0) {
ret = __tpda_enable(drvdata, in->dest_port);
if (!ret) {
atomic_inc(&in->dest_refcnt);
in->dest_refcnt++;
csdev->refcnt++;
dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", in->dest_port);
}
@@ -223,7 +223,7 @@ static void tpda_disable(struct coresight_device *csdev,
struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
spin_lock(&drvdata->spinlock);
if (atomic_dec_return(&in->dest_refcnt) == 0) {
if (--in->dest_refcnt == 0) {
__tpda_disable(drvdata, in->dest_port);
csdev->refcnt--;
}

4
include/linux/coresight.h
View File

@@ -200,8 +200,8 @@ struct coresight_connection {
struct coresight_device *dest_dev;
struct coresight_sysfs_link *link;
struct coresight_device *src_dev;
atomic_t src_refcnt;
atomic_t dest_refcnt;
int src_refcnt;
int dest_refcnt;
};
/**