Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761542Ab3DBJXv (ORCPT ); Tue, 2 Apr 2013 05:23:51 -0400 Received: from mail-ve0-f181.google.com ([209.85.128.181]:49655 "EHLO mail-ve0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760318Ab3DBJXs (ORCPT ); Tue, 2 Apr 2013 05:23:48 -0400 MIME-Version: 1.0 In-Reply-To: <1364504343-12635-2-git-send-email-mturquette@linaro.org> References: <1364445958-2999-1-git-send-email-mturquette@linaro.org> <1364504343-12635-1-git-send-email-mturquette@linaro.org> <1364504343-12635-2-git-send-email-mturquette@linaro.org> Date: Tue, 2 Apr 2013 11:23:47 +0200 Message-ID: Subject: Re: [PATCH 1/2] clk: abstract locking out into helper functions From: Ulf Hansson To: Mike Turquette Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, patches@linaro.org, linaro-kernel@lists.linaro.org, rajagopal.venkat@linaro.org, davidb@codeaurora.org, laurent.pinchart@ideasonboard.com, tglx@linutronix.de Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10985 Lines: 354 On 28 March 2013 21:59, Mike Turquette wrote: > 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 > Cc: Rajagopal Venkat > Cc: David Brown > Cc: Ulf Hansson > Tested-by: Laurent Pinchart > Reviewed-by: Thomas Gleixner > --- > Changes since v5: > * pass flags by value instead of by reference in clk_enable_{un}lock > > drivers/clk/clk.c | 99 +++++++++++++++++++++++++++++++++-------------------- > 1 file changed, 61 insertions(+), 38 deletions(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 5e8ffff..0b5d612 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -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 > @@ -69,7 +92,7 @@ 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); > @@ -77,7 +100,7 @@ static int clk_summary_show(struct seq_file *s, void *data) > 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; > } > @@ -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) > @@ -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; > @@ -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); > @@ -326,7 +349,7 @@ static int __init clk_debug_init(void) > > inited = 1; > > - mutex_unlock(&prepare_lock); > + clk_prepare_unlock(); > > return 0; > } > @@ -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; > @@ -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; > @@ -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); > @@ -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; > } > @@ -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); > > @@ -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; > } > @@ -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); > > @@ -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; > } > @@ -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; > } > @@ -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; > } > @@ -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) > @@ -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; > } > @@ -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; > } > @@ -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); > @@ -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; > @@ -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; > } > @@ -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)) { > @@ -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; > } > @@ -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) > @@ -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; > } > @@ -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) > @@ -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; > } > -- > 1.7.10.4 > Reviewed-by: Ulf Hansson -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/