regmap: Fix possible sleep-in-atomic in regmap_bulk_write()

regmap deploys the spinlock for the protection when set up in fast_io
mode.  This may lead to sleep-in-atomic by memory allocation with
GFP_KERNEL in regmap_bulk_write().  This patch fixes it by moving the
allocation out of the lock.

[Fix excessively large locked region -- broonie]

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index e5a5509160fe..35077374f38b 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1520,12 +1520,12 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
         if (reg % map->reg_stride)
                 return -EINVAL;
 
-        map->lock(map->lock_arg);
         /*
          * Some devices don't support bulk write, for
          * them we have a series of single write operations.
          */
         if (!map->bus || map->use_single_rw) {
+                map->lock(map->lock_arg);
                 for (i = 0; i < val_count; i++) {
                         unsigned int ival;
 
@@ -1554,24 +1554,25 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
                         if (ret != 0)
                                 goto out;
                 }
+out:
+                map->unlock(map->lock_arg);
         } else {
                 void *wval;
 
                 wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
                 if (!wval) {
-                        ret = -ENOMEM;
                         dev_err(map->dev, "Error in memory allocation\n");
-                        goto out;
+                        return -ENOMEM;
                 }
                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
                         map->format.parse_inplace(wval + i);
 
+                map->lock(map->lock_arg);
                 ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
+                map->unlock(map->lock_arg);
 
                 kfree(wval);
         }
-out:
-        map->unlock(map->lock_arg);
         return ret;
 }
 EXPORT_SYMBOL_GPL(regmap_bulk_write);