diff options
| author | Lars-Peter Clausen <lars@metafoo.de> | 2013-05-24 10:29:22 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2013-05-25 11:16:02 -0400 |
| commit | 92ab1aab59c61b3e05200b9aa0e05ab770059142 (patch) | |
| tree | 53c798ac04a0ffabcdca31f33e69420fe864f1e7 | |
| parent | 81485f5220770c381ac076573642ac44f13723af (diff) | |
| download | op-kernel-dev-92ab1aab59c61b3e05200b9aa0e05ab770059142.zip op-kernel-dev-92ab1aab59c61b3e05200b9aa0e05ab770059142.tar.gz | |
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 <lars@metafoo.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
| -rw-r--r-- | drivers/base/regmap/internal.h | 1 | ||||
| -rw-r--r-- | drivers/base/regmap/regmap.c | 7 |
2 files changed, 6 insertions, 2 deletions
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index b33a4ff..ae23d83 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 307f5a1..1a01553 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) |
