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clk: abstract locking out into helper functions
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Create locking helpers for the global mutex and global spinlock.  The
definitions of these helpers will be expanded upon in the next patch
which introduces reentrancy into the locking scheme.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Cc: David Brown <davidb@codeaurora.org>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
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Mike Turquette committed Apr 2, 2013
1 parent 43c4120 commit eab89f6
Showing 1 changed file with 61 additions and 38 deletions.
99 changes: 61 additions & 38 deletions drivers/clk/clk.c
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Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,29 @@ static HLIST_HEAD(clk_root_list);
static HLIST_HEAD(clk_orphan_list);
static LIST_HEAD(clk_notifier_list);

/*** locking ***/
static void clk_prepare_lock(void)
{
mutex_lock(&prepare_lock);
}

static void clk_prepare_unlock(void)
{
mutex_unlock(&prepare_lock);
}

static unsigned long clk_enable_lock(void)
{
unsigned long flags;
spin_lock_irqsave(&enable_lock, flags);
return flags;
}

static void clk_enable_unlock(unsigned long flags)
{
spin_unlock_irqrestore(&enable_lock, flags);
}

/*** debugfs support ***/

#ifdef CONFIG_COMMON_CLK_DEBUG
Expand Down Expand Up @@ -69,15 +92,15 @@ static int clk_summary_show(struct seq_file *s, void *data)
seq_printf(s, " clock enable_cnt prepare_cnt rate\n");
seq_printf(s, "---------------------------------------------------------------------\n");

mutex_lock(&prepare_lock);
clk_prepare_lock();

hlist_for_each_entry(c, &clk_root_list, child_node)
clk_summary_show_subtree(s, c, 0);

hlist_for_each_entry(c, &clk_orphan_list, child_node)
clk_summary_show_subtree(s, c, 0);

mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return 0;
}
Expand Down Expand Up @@ -130,7 +153,7 @@ static int clk_dump(struct seq_file *s, void *data)

seq_printf(s, "{");

mutex_lock(&prepare_lock);
clk_prepare_lock();

hlist_for_each_entry(c, &clk_root_list, child_node) {
if (!first_node)
Expand All @@ -144,7 +167,7 @@ static int clk_dump(struct seq_file *s, void *data)
clk_dump_subtree(s, c, 0);
}

mutex_unlock(&prepare_lock);
clk_prepare_unlock();

seq_printf(s, "}");
return 0;
Expand Down Expand Up @@ -316,7 +339,7 @@ static int __init clk_debug_init(void)
if (!orphandir)
return -ENOMEM;

mutex_lock(&prepare_lock);
clk_prepare_lock();

hlist_for_each_entry(clk, &clk_root_list, child_node)
clk_debug_create_subtree(clk, rootdir);
Expand All @@ -326,7 +349,7 @@ static int __init clk_debug_init(void)

inited = 1;

mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return 0;
}
Expand Down Expand Up @@ -372,7 +395,7 @@ static void clk_disable_unused_subtree(struct clk *clk)
hlist_for_each_entry(child, &clk->children, child_node)
clk_disable_unused_subtree(child);

spin_lock_irqsave(&enable_lock, flags);
flags = clk_enable_lock();

if (clk->enable_count)
goto unlock_out;
Expand All @@ -393,7 +416,7 @@ static void clk_disable_unused_subtree(struct clk *clk)
}

unlock_out:
spin_unlock_irqrestore(&enable_lock, flags);
clk_enable_unlock(flags);

out:
return;
Expand All @@ -403,7 +426,7 @@ static int clk_disable_unused(void)
{
struct clk *clk;

mutex_lock(&prepare_lock);
clk_prepare_lock();

hlist_for_each_entry(clk, &clk_root_list, child_node)
clk_disable_unused_subtree(clk);
Expand All @@ -417,7 +440,7 @@ static int clk_disable_unused(void)
hlist_for_each_entry(clk, &clk_orphan_list, child_node)
clk_unprepare_unused_subtree(clk);

mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return 0;
}
Expand Down Expand Up @@ -600,9 +623,9 @@ void __clk_unprepare(struct clk *clk)
*/
void clk_unprepare(struct clk *clk)
{
mutex_lock(&prepare_lock);
clk_prepare_lock();
__clk_unprepare(clk);
mutex_unlock(&prepare_lock);
clk_prepare_unlock();
}
EXPORT_SYMBOL_GPL(clk_unprepare);

Expand Down Expand Up @@ -648,9 +671,9 @@ int clk_prepare(struct clk *clk)
{
int ret;

mutex_lock(&prepare_lock);
clk_prepare_lock();
ret = __clk_prepare(clk);
mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return ret;
}
Expand Down Expand Up @@ -692,9 +715,9 @@ void clk_disable(struct clk *clk)
{
unsigned long flags;

spin_lock_irqsave(&enable_lock, flags);
flags = clk_enable_lock();
__clk_disable(clk);
spin_unlock_irqrestore(&enable_lock, flags);
clk_enable_unlock(flags);
}
EXPORT_SYMBOL_GPL(clk_disable);

Expand Down Expand Up @@ -745,9 +768,9 @@ int clk_enable(struct clk *clk)
unsigned long flags;
int ret;

spin_lock_irqsave(&enable_lock, flags);
flags = clk_enable_lock();
ret = __clk_enable(clk);
spin_unlock_irqrestore(&enable_lock, flags);
clk_enable_unlock(flags);

return ret;
}
Expand Down Expand Up @@ -792,9 +815,9 @@ long clk_round_rate(struct clk *clk, unsigned long rate)
{
unsigned long ret;

mutex_lock(&prepare_lock);
clk_prepare_lock();
ret = __clk_round_rate(clk, rate);
mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return ret;
}
Expand Down Expand Up @@ -889,13 +912,13 @@ unsigned long clk_get_rate(struct clk *clk)
{
unsigned long rate;

mutex_lock(&prepare_lock);
clk_prepare_lock();

if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
__clk_recalc_rates(clk, 0);

rate = __clk_get_rate(clk);
mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return rate;
}
Expand Down Expand Up @@ -1100,7 +1123,7 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
int ret = 0;

/* prevent racing with updates to the clock topology */
mutex_lock(&prepare_lock);
clk_prepare_lock();

/* bail early if nothing to do */
if (rate == clk->rate)
Expand Down Expand Up @@ -1132,7 +1155,7 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
clk_change_rate(top);

out:
mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return ret;
}
Expand All @@ -1148,9 +1171,9 @@ struct clk *clk_get_parent(struct clk *clk)
{
struct clk *parent;

mutex_lock(&prepare_lock);
clk_prepare_lock();
parent = __clk_get_parent(clk);
mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return parent;
}
Expand Down Expand Up @@ -1294,19 +1317,19 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent)
__clk_prepare(parent);

/* FIXME replace with clk_is_enabled(clk) someday */
spin_lock_irqsave(&enable_lock, flags);
flags = clk_enable_lock();
if (clk->enable_count)
__clk_enable(parent);
spin_unlock_irqrestore(&enable_lock, flags);
clk_enable_unlock(flags);

/* change clock input source */
ret = clk->ops->set_parent(clk->hw, i);

/* clean up old prepare and enable */
spin_lock_irqsave(&enable_lock, flags);
flags = clk_enable_lock();
if (clk->enable_count)
__clk_disable(old_parent);
spin_unlock_irqrestore(&enable_lock, flags);
clk_enable_unlock(flags);

if (clk->prepare_count)
__clk_unprepare(old_parent);
Expand Down Expand Up @@ -1338,7 +1361,7 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
return -ENOSYS;

/* prevent racing with updates to the clock topology */
mutex_lock(&prepare_lock);
clk_prepare_lock();

if (clk->parent == parent)
goto out;
Expand Down Expand Up @@ -1367,7 +1390,7 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
__clk_reparent(clk, parent);

out:
mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return ret;
}
Expand All @@ -1390,7 +1413,7 @@ int __clk_init(struct device *dev, struct clk *clk)
if (!clk)
return -EINVAL;

mutex_lock(&prepare_lock);
clk_prepare_lock();

/* check to see if a clock with this name is already registered */
if (__clk_lookup(clk->name)) {
Expand Down Expand Up @@ -1514,7 +1537,7 @@ int __clk_init(struct device *dev, struct clk *clk)
clk_debug_register(clk);

out:
mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return ret;
}
Expand Down Expand Up @@ -1748,7 +1771,7 @@ int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
if (!clk || !nb)
return -EINVAL;

mutex_lock(&prepare_lock);
clk_prepare_lock();

/* search the list of notifiers for this clk */
list_for_each_entry(cn, &clk_notifier_list, node)
Expand All @@ -1772,7 +1795,7 @@ int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
clk->notifier_count++;

out:
mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return ret;
}
Expand All @@ -1797,7 +1820,7 @@ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
if (!clk || !nb)
return -EINVAL;

mutex_lock(&prepare_lock);
clk_prepare_lock();

list_for_each_entry(cn, &clk_notifier_list, node)
if (cn->clk == clk)
Expand All @@ -1818,7 +1841,7 @@ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
ret = -ENOENT;
}

mutex_unlock(&prepare_lock);
clk_prepare_unlock();

return ret;
}
Expand Down

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