hwrng: n2-drv - Introduce the use of the managed version of kzalloc

This patch moves data allocated using kzalloc to managed data allocated
using devm_kzalloc and cleans now unnecessary kfrees in probe and remove
functions. The NULL assignment to np->units is removed as there is no
interaction between this field and sun4v_hvapi_unregister. Also, the
labels out_free_units and out_free are removed as they are no longer
required.

The following Coccinelle semantic patch was used for making the change:

@platform@
identifier p, probefn, removefn;
@@
struct platform_driver p = {
  .probe = probefn,
  .remove = removefn,
};

@prb@
identifier platform.probefn, pdev;
expression e, e1, e2;
@@
probefn(struct platform_device *pdev, ...) {
  <+...
- e = kzalloc(e1, e2)
+ e = devm_kzalloc(&pdev->dev, e1, e2)
  ...
?-kfree(e);
  ...+>
}

@rem depends on prb@
identifier platform.removefn;
expression e;
@@
removefn(...) {
  <...
- kfree(e);
  ...>
}

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/char/hw_random/n2-drv.c b/drivers/char/hw_random/n2-drv.c
index 432232e..292a588 100644 (file)
--- a/drivers/char/hw_random/n2-drv.c
+++ b/drivers/char/hw_random/n2-drv.c
@@ -632,7 +632,7 @@ static int n2rng_probe(struct platform_device *op)
        multi_capable = (match->data != NULL);
 
        n2rng_driver_version();
-       np = kzalloc(sizeof(*np), GFP_KERNEL);
+       np = devm_kzalloc(&op->dev, sizeof(*np), GFP_KERNEL);
        if (!np)
                goto out;
        np->op = op;
@@ -653,7 +653,7 @@ static int n2rng_probe(struct platform_device *op)
                                         &np->hvapi_minor)) {
                        dev_err(&op->dev, "Cannot register suitable "
                                "HVAPI version.\n");
-                       goto out_free;
+                       goto out;
                }
        }
 
@@ -676,15 +676,16 @@ static int n2rng_probe(struct platform_device *op)
        dev_info(&op->dev, "Registered RNG HVAPI major %lu minor %lu\n",
                 np->hvapi_major, np->hvapi_minor);
 
-       np->units = kzalloc(sizeof(struct n2rng_unit) * np->num_units,
-                           GFP_KERNEL);
+       np->units = devm_kzalloc(&op->dev,
+                                sizeof(struct n2rng_unit) * np->num_units,
+                                GFP_KERNEL);
        err = -ENOMEM;
        if (!np->units)
                goto out_hvapi_unregister;
 
        err = n2rng_init_control(np);
        if (err)
-               goto out_free_units;
+               goto out_hvapi_unregister;
 
        dev_info(&op->dev, "Found %s RNG, units: %d\n",
                 ((np->flags & N2RNG_FLAG_MULTI) ?
@@ -697,7 +698,7 @@ static int n2rng_probe(struct platform_device *op)
 
        err = hwrng_register(&np->hwrng);
        if (err)
-               goto out_free_units;
+               goto out_hvapi_unregister;
 
        platform_set_drvdata(op, np);
 
@@ -705,15 +706,9 @@ static int n2rng_probe(struct platform_device *op)
 
        return 0;
 
-out_free_units:
-       kfree(np->units);
-       np->units = NULL;
-
 out_hvapi_unregister:
        sun4v_hvapi_unregister(HV_GRP_RNG);
 
-out_free:
-       kfree(np);
 out:
        return err;
 }
@@ -730,11 +725,6 @@ static int n2rng_remove(struct platform_device *op)
 
        sun4v_hvapi_unregister(HV_GRP_RNG);
 
-       kfree(np->units);
-       np->units = NULL;
-
-       kfree(np);
-
        return 0;
 }