regmap: Allocate buffers with GFP_ATOMIC when fast_io == true

If a regmap is using fast_io, allocate the scratch buffer in
regmap_bulk_write() with GFP_ATOMIC instead of GFP_KERNEL.
Otherwise we may schedule while atomic.

Reported-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index cc557886ab2377a550c1ae529b6ecee23380161f..f3b1445da0a520da4d02e95a66e1ea5b8454b1df 100644 (file)
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -59,6 +59,7 @@ struct regmap {
        regmap_lock lock;
        regmap_unlock unlock;
        void *lock_arg; /* This is passed to lock/unlock functions */
+       gfp_t alloc_flags;
 
        struct device *dev; /* Device we do I/O on */
        void *work_buf;     /* Scratch buffer used to format I/O */

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index afaf56200674a29517678af763bc9a084659224b..0b51190c13df413e6f4e844c35d296942b5bfb0c 100644 (file)
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -561,6 +561,16 @@ struct regmap *__regmap_init(struct device *dev,
                }
                map->lock_arg = map;
        }
+
+       /*
+        * When we write in fast-paths with regmap_bulk_write() don't allocate
+        * scratch buffers with sleeping allocations.
+        */
+       if ((bus && bus->fast_io) || config->fast_io)
+               map->alloc_flags = GFP_ATOMIC;
+       else
+               map->alloc_flags = GFP_KERNEL;
+
        map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
        map->format.pad_bytes = config->pad_bits / 8;
        map->format.val_bytes = DIV_ROUND_UP(config->val_bits, 8);
@@ -1786,7 +1796,7 @@ out:
                if (!val_count)
                        return -EINVAL;
 
-               wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
+               wval = kmemdup(val, val_count * val_bytes, map->alloc_flags);
                if (!wval) {
                        dev_err(map->dev, "Error in memory allocation\n");
                        return -ENOMEM;