From: Lars-Peter Clausen Date: Fri, 24 May 2013 08:29:22 +0000 (+0200) Subject: regmap: Make regmap-mmio usable from atomic contexts X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=92ab1aab59c61b3e05200b9aa0e05ab770059142;p=linux-beck.git regmap: Make regmap-mmio usable from atomic contexts regmap-mmio uses a spinlock with spin_lock() and spin_unlock() for locking. To be able to use the regmap API from different contexts (atomic vs non-atomic), without the risk of race conditions, we need to use spin_lock_irqsave() and spin_lock_irqrestore() instead. A new field, the spinlock_flags field, is added to regmap struct to store the flags between regmap_{,un}lock_spinlock(). The spinlock_flags field itself is also protected by the spinlock. Thanks to Stephen Warren for the suggestion of this particular solution. Signed-off-by: Lars-Peter Clausen Reviewed-by: Stephen Warren Signed-off-by: Mark Brown --- diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index b33a4ff67adf..ae23d8391aa0 100644 --- a/drivers/base/regmap/internal.h +++ b/drivers/base/regmap/internal.h @@ -52,6 +52,7 @@ struct regmap_async { struct regmap { struct mutex mutex; spinlock_t spinlock; + unsigned long spinlock_flags; regmap_lock lock; regmap_unlock unlock; void *lock_arg; /* This is passed to lock/unlock functions */ diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 307f5a1c1fe8..1a01553189b3 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -302,13 +302,16 @@ static void regmap_unlock_mutex(void *__map) static void regmap_lock_spinlock(void *__map) { struct regmap *map = __map; - spin_lock(&map->spinlock); + unsigned long flags; + + spin_lock_irqsave(&map->spinlock, flags); + map->spinlock_flags = flags; } static void regmap_unlock_spinlock(void *__map) { struct regmap *map = __map; - spin_unlock(&map->spinlock); + spin_unlock_irqrestore(&map->spinlock, map->spinlock_flags); } static void dev_get_regmap_release(struct device *dev, void *res)