Commit 0305b709 authored by Alex Elder's avatar Alex Elder Committed by David S. Miller
Browse files

net: ipa: use refcount_t for IPA clock reference count 



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: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ba4ee3c0

drivers/net/ipa/ipa_clock.c

+7 −7
Original line number Diff line number Diff line
@@ -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);