Linux Virtualization - Jan 2017 - [PATCH] s390: virtio: constify virtio_config_ops structures

Declare virtio_config_ops structure as const as it is only stored in the
config field of a virtio_device structure. This field is of type const, so
virtio_config_ops structures having this property can be declared const.
Done using Coccinelle:

@r1 disable optional_qualifier@
identifier i;
position p;
@@
static struct virtio_config_ops i at p={...};

@ok1@
identifier r1.i;
position p;
struct virtio_ccw_device x;
@@
x.vdev.config=&i at p

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i at p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct virtio_config_ops i;

File size before and after applying the patch remains the same.
text	data	bss	dec	hex   filename
9235	296	32928	42459	a5db  drivers/s390/virtio/virtio_ccw.o

Signed-off-by: Bhumika Goyal <bhumirks at gmail.com>
---
 drivers/s390/virtio/virtio_ccw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 639ed4e..6508bf4 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -920,7 +920,7 @@ static void virtio_ccw_set_status(struct virtio_device
*vdev, u8 status)
 	kfree(ccw);
 }
 
-static struct virtio_config_ops virtio_ccw_config_ops = {
+static const struct virtio_config_ops virtio_ccw_config_ops = {
 	.get_features = virtio_ccw_get_features,
 	.finalize_features = virtio_ccw_finalize_features,
 	.get = virtio_ccw_get_config,
-- 
1.9.1

On 01/13/2017 07:48 PM, Bhumika Goyal wrote:
> Declare virtio_config_ops structure as const as it is only stored in the
> config field of a virtio_device structure. This field is of type const, so
> virtio_config_ops structures having this property can be declared const.
> Done using Coccinelle:
> 
> @r1 disable optional_qualifier@
> identifier i;
> position p;
> @@
> static struct virtio_config_ops i at p={...};
> 
> @ok1@
> identifier r1.i;
> position p;
> struct virtio_ccw_device x;
> @@
> x.vdev.config=&i at p
> 
> @bad@
> position p!={r1.p,ok1.p};
> identifier r1.i;
> @@
> i at p
> 
> @depends on !bad disable optional_qualifier@
> identifier r1.i;
> @@
> +const
> struct virtio_config_ops i;
> 
> File size before and after applying the patch remains the same.
> text	data	bss	dec	hex   filename
> 9235	296	32928	42459	a5db  drivers/s390/virtio/virtio_ccw.o
> 
> Signed-off-by: Bhumika Goyal <bhumirks at gmail.com>
thanks applied.
> ---
>  drivers/s390/virtio/virtio_ccw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/s390/virtio/virtio_ccw.c
b/drivers/s390/virtio/virtio_ccw.c
> index 639ed4e..6508bf4 100644
> --- a/drivers/s390/virtio/virtio_ccw.c
> +++ b/drivers/s390/virtio/virtio_ccw.c
> @@ -920,7 +920,7 @@ static void virtio_ccw_set_status(struct virtio_device
*vdev, u8 status)
>  	kfree(ccw);
>  }
> 
> -static struct virtio_config_ops virtio_ccw_config_ops = {
> +static const struct virtio_config_ops virtio_ccw_config_ops = {
>  	.get_features = virtio_ccw_get_features,
>  	.finalize_features = virtio_ccw_finalize_features,
>  	.get = virtio_ccw_get_config,
>