Constify two structs that are never modified.
The first patch constifies a static v4l2_m2m_ops struct which contains
function pointers.
The second constifies mxc_jpeg_fmt, which contains read-only data. In
order to do that, a number of function arguments, return values and
pointers was made const as well.
Rikard Falkeborn (2):
media: imx-jpeg: Constify static struct v4l2_m2m_ops
media: imx-jpeg: Constify static struct mxc_jpeg_fmt
drivers/media/platform/imx-jpeg/mxc-jpeg.c | 18 +++++++++---------
drivers/media/platform/imx-jpeg/mxc-jpeg.h | 18 +++++++++---------
2 files changed, 18 insertions(+), 18 deletions(-)
--
2.32.0
It is only read-from, so make it const. In order to be able to do this,
constify all places where mxc_jpeg_fmt is used, in function arguments,
return values and pointers. On top of that, make the name a pointer to
const char.
On aarch64, this shrinks object code size with 550 bytes with gcc 11.1.0,
and almost 2kB with clang 12.0.0.
Signed-off-by: Rikard Falkeborn <[email protected]>
---
drivers/media/platform/imx-jpeg/mxc-jpeg.c | 16 ++++++++--------
drivers/media/platform/imx-jpeg/mxc-jpeg.h | 18 +++++++++---------
2 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/drivers/media/platform/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
index 3a49007e1264..755138063ee6 100644
--- a/drivers/media/platform/imx-jpeg/mxc-jpeg.c
+++ b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
@@ -62,7 +62,7 @@
#include "mxc-jpeg-hw.h"
#include "mxc-jpeg.h"
-static struct mxc_jpeg_fmt mxc_formats[] = {
+static const struct mxc_jpeg_fmt mxc_formats[] = {
{
.name = "JPEG",
.fourcc = V4L2_PIX_FMT_JPEG,
@@ -341,7 +341,7 @@ static inline struct mxc_jpeg_ctx *mxc_jpeg_fh_to_ctx(struct v4l2_fh *fh)
return container_of(fh, struct mxc_jpeg_ctx, fh);
}
-static int enum_fmt(struct mxc_jpeg_fmt *mxc_formats, int n,
+static int enum_fmt(const struct mxc_jpeg_fmt *mxc_formats, int n,
struct v4l2_fmtdesc *f, u32 type)
{
int i, num = 0;
@@ -368,13 +368,13 @@ static int enum_fmt(struct mxc_jpeg_fmt *mxc_formats, int n,
return 0;
}
-static struct mxc_jpeg_fmt *mxc_jpeg_find_format(struct mxc_jpeg_ctx *ctx,
- u32 pixelformat)
+static const struct mxc_jpeg_fmt *mxc_jpeg_find_format(struct mxc_jpeg_ctx *ctx,
+ u32 pixelformat)
{
unsigned int k;
for (k = 0; k < MXC_JPEG_NUM_FORMATS; k++) {
- struct mxc_jpeg_fmt *fmt = &mxc_formats[k];
+ const struct mxc_jpeg_fmt *fmt = &mxc_formats[k];
if (fmt->fourcc == pixelformat)
return fmt;
@@ -1536,7 +1536,7 @@ static int mxc_jpeg_enum_fmt_vid_out(struct file *file, void *priv,
MXC_JPEG_FMT_TYPE_RAW);
}
-static int mxc_jpeg_try_fmt(struct v4l2_format *f, struct mxc_jpeg_fmt *fmt,
+static int mxc_jpeg_try_fmt(struct v4l2_format *f, const struct mxc_jpeg_fmt *fmt,
struct mxc_jpeg_ctx *ctx, int q_type)
{
struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
@@ -1612,7 +1612,7 @@ static int mxc_jpeg_try_fmt_vid_cap(struct file *file, void *priv,
struct mxc_jpeg_ctx *ctx = mxc_jpeg_fh_to_ctx(priv);
struct mxc_jpeg_dev *jpeg = ctx->mxc_jpeg;
struct device *dev = jpeg->dev;
- struct mxc_jpeg_fmt *fmt;
+ const struct mxc_jpeg_fmt *fmt;
u32 fourcc = f->fmt.pix_mp.pixelformat;
int q_type = (jpeg->mode == MXC_JPEG_DECODE) ?
@@ -1643,7 +1643,7 @@ static int mxc_jpeg_try_fmt_vid_out(struct file *file, void *priv,
struct mxc_jpeg_ctx *ctx = mxc_jpeg_fh_to_ctx(priv);
struct mxc_jpeg_dev *jpeg = ctx->mxc_jpeg;
struct device *dev = jpeg->dev;
- struct mxc_jpeg_fmt *fmt;
+ const struct mxc_jpeg_fmt *fmt;
u32 fourcc = f->fmt.pix_mp.pixelformat;
int q_type = (jpeg->mode == MXC_JPEG_ENCODE) ?
diff --git a/drivers/media/platform/imx-jpeg/mxc-jpeg.h b/drivers/media/platform/imx-jpeg/mxc-jpeg.h
index 7697de490d2e..4c210852e876 100644
--- a/drivers/media/platform/imx-jpeg/mxc-jpeg.h
+++ b/drivers/media/platform/imx-jpeg/mxc-jpeg.h
@@ -51,7 +51,7 @@ enum mxc_jpeg_mode {
* @flags: flags describing format applicability
*/
struct mxc_jpeg_fmt {
- char *name;
+ const char *name;
u32 fourcc;
enum v4l2_jpeg_chroma_subsampling subsampling;
int nc;
@@ -74,14 +74,14 @@ struct mxc_jpeg_desc {
} __packed;
struct mxc_jpeg_q_data {
- struct mxc_jpeg_fmt *fmt;
- u32 sizeimage[MXC_JPEG_MAX_PLANES];
- u32 bytesperline[MXC_JPEG_MAX_PLANES];
- int w;
- int w_adjusted;
- int h;
- int h_adjusted;
- unsigned int sequence;
+ const struct mxc_jpeg_fmt *fmt;
+ u32 sizeimage[MXC_JPEG_MAX_PLANES];
+ u32 bytesperline[MXC_JPEG_MAX_PLANES];
+ int w;
+ int w_adjusted;
+ int h;
+ int h_adjusted;
+ unsigned int sequence;
};
struct mxc_jpeg_ctx {
--
2.32.0
The only usage of mxc_jpeg_m2m_ops is to pass its address to
v4l2_m2m_init() which takes a pointer to const struct v4l2_m2m_ops. Make
it const to allow the compiler to put it in read-only memory.
Signed-off-by: Rikard Falkeborn <[email protected]>
---
drivers/media/platform/imx-jpeg/mxc-jpeg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/media/platform/imx-jpeg/mxc-jpeg.c b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
index 03b9264af068..3a49007e1264 100644
--- a/drivers/media/platform/imx-jpeg/mxc-jpeg.c
+++ b/drivers/media/platform/imx-jpeg/mxc-jpeg.c
@@ -1890,7 +1890,7 @@ static const struct v4l2_file_operations mxc_jpeg_fops = {
.mmap = v4l2_m2m_fop_mmap,
};
-static struct v4l2_m2m_ops mxc_jpeg_m2m_ops = {
+static const struct v4l2_m2m_ops mxc_jpeg_m2m_ops = {
.device_run = mxc_jpeg_device_run,
};
--
2.32.0