[PATCH net-next v2 1/7] net: ipa: use refcount_t for IPA clock reference count

Alex Elder
2020-09-12T00:46:43Z

Take advantage of the checking provided by refcount_t, rather than
using a plain atomic to represent the IPA clock reference count.

Note that we need to *set* the value to 1 in ipa_clock_get() rather
than incrementing it from 0 (because doing that is considered an
error for a refcount_t).

Signed-off-by: Alex Elder <elder@linaro.org>
---
v2: This patch is new in version 2 of the series.

drivers/net/ipa/ipa_clock.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ipa/ipa_clock.c b/drivers/net/ipa/ipa_clock.c
index 398f2e47043d8..b703866f2e20b 100644
--- a/drivers/net/ipa/ipa_clock.c
+++ b/drivers/net/ipa/ipa_clock.c
@@ -4,7 +4,7 @@
* Copyright (C) 2018-2020 Linaro Ltd.
*/

-#include <linux/atomic.h>
+#include <linux/refcount.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <linux/device.h>
@@ -51,7 +51,7 @@
* @config_path: Configuration space interconnect
*/
struct ipa_clock {
- atomic_t count;
+ refcount_t count;
struct mutex mutex; /* protects clock enable/disable */
struct clk *core;
struct icc_path *memory_path;
@@ -195,7 +195,7 @@ static void ipa_clock_disable(struct ipa *ipa)
*/
bool ipa_clock_get_additional(struct ipa *ipa)
{
- return !!atomic_inc_not_zero(&ipa->clock->count);
+ return refcount_inc_not_zero(&ipa->clock->count);
}

/* Get an IPA clock reference. If the reference count is non-zero, it is
@@ -231,7 +231,7 @@ void ipa_clock_get(struct ipa *ipa)

ipa_endpoint_resume(ipa);

- atomic_inc(&clock->count);
+ refcount_set(&clock->count, 1);

out_mutex_unlock:
mutex_unlock(&clock->mutex);
@@ -246,7 +246,7 @@ void ipa_clock_put(struct ipa *ipa)
struct ipa_clock *clock = ipa->clock;

/* If this is not the last reference there's nothing more to do */
- if (!atomic_dec_and_mutex_lock(&clock->count, &clock->mutex))
+ if (!refcount_dec_and_mutex_lock(&clock->count, &clock->mutex))
return;

ipa_endpoint_suspend(ipa);
@@ -294,7 +294,7 @@ struct ipa_clock *ipa_clock_init(struct device *dev)
goto err_kfree;

mutex_init(&clock->mutex);
- atomic_set(&clock->count, 0);
+ refcount_set(&clock->count, 0);

return clock;

@@ -311,7 +311,7 @@ void ipa_clock_exit(struct ipa_clock *clock)
{
struct clk *clk = clock->core;

- WARN_ON(atomic_read(&clock->count) != 0);
+ WARN_ON(refcount_read(&clock->count) != 0);
mutex_destroy(&clock->mutex);
ipa_interconnect_exit(clock);
kfree(clock);
--
2.20.1