[v2,09/15] spi: Use struct_size() helper
Commit Message
Prefer struct_size() over open-coded versions.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
include/linux/spi/spi.h | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
Comments
On 10.07.2023 18:49:26, Andy Shevchenko wrote:
> Prefer struct_size() over open-coded versions.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> include/linux/spi/spi.h | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index c9479badf38c..9fb8efb068c6 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -17,6 +17,7 @@
> #include <linux/minmax.h>
> #include <linux/mod_devicetable.h>
> #include <linux/mutex.h>
> +#include <linux/overflow.h>
> #include <linux/scatterlist.h>
> #include <linux/slab.h>
> #include <linux/smp.h>
> @@ -1095,6 +1096,8 @@ struct spi_transfer {
> * @state: for use by whichever driver currently owns the message
> * @resources: for resource management when the spi message is processed
> * @prepared: spi_prepare_message was called for the this message
> + * @t: for use with spi_message_alloc() when message and transfers have
> + * been allocated together
> *
> * A @spi_message is used to execute an atomic sequence of data transfers,
> * each represented by a struct spi_transfer. The sequence is "atomic"
> @@ -1147,6 +1150,9 @@ struct spi_message {
>
> /* List of spi_res reources when the spi message is processed */
> struct list_head resources;
> +
> + /* For embedding transfers into the memory of the message */
> + struct spi_transfer t[];
You might want to use the DECLARE_FLEX_ARRAY helper here.
Marc
On Mon, Jul 10, 2023 at 05:59:55PM +0200, Marc Kleine-Budde wrote:
> On 10.07.2023 18:49:26, Andy Shevchenko wrote:
...
> > + struct spi_transfer t[];
>
> You might want to use the DECLARE_FLEX_ARRAY helper here.
Technically, yes, semantically documentation [1] disagrees with
you, so I leave it as is.
[1]: Documentation/process/deprecated.rst:269
On Mon, Jul 10, 2023 at 07:10:43PM +0300, Andy Shevchenko wrote:
> On Mon, Jul 10, 2023 at 05:59:55PM +0200, Marc Kleine-Budde wrote:
> > On 10.07.2023 18:49:26, Andy Shevchenko wrote:
...
> > > + struct spi_transfer t[];
> >
> > You might want to use the DECLARE_FLEX_ARRAY helper here.
>
> Technically, yes, semantically documentation [1] disagrees with
"and [2]"
> you, so I leave it as is.
>
> [1]: Documentation/process/deprecated.rst:269
[2]: Documentation/process/deprecated.rst:350
@@ -17,6 +17,7 @@
#include <linux/minmax.h>
#include <linux/mod_devicetable.h>
#include <linux/mutex.h>
+#include <linux/overflow.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/smp.h>
@@ -1095,6 +1096,8 @@ struct spi_transfer {
* @state: for use by whichever driver currently owns the message
* @resources: for resource management when the spi message is processed
* @prepared: spi_prepare_message was called for the this message
+ * @t: for use with spi_message_alloc() when message and transfers have
+ * been allocated together
*
* A @spi_message is used to execute an atomic sequence of data transfers,
* each represented by a struct spi_transfer. The sequence is "atomic"
@@ -1147,6 +1150,9 @@ struct spi_message {
/* List of spi_res reources when the spi message is processed */
struct list_head resources;
+
+ /* For embedding transfers into the memory of the message */
+ struct spi_transfer t[];
};
static inline void spi_message_init_no_memset(struct spi_message *m)
@@ -1207,16 +1213,13 @@ static inline struct spi_message *spi_message_alloc(unsigned ntrans, gfp_t flags
{
struct spi_message *m;
- m = kzalloc(sizeof(struct spi_message)
- + ntrans * sizeof(struct spi_transfer),
- flags);
+ m = kzalloc(struct_size(m, t, ntrans), flags);
if (m) {
unsigned i;
- struct spi_transfer *t = (struct spi_transfer *)(m + 1);
spi_message_init_no_memset(m);
- for (i = 0; i < ntrans; i++, t++)
- spi_message_add_tail(t, m);
+ for (i = 0; i < ntrans; i++)
+ spi_message_add_tail(&m->t[i], m);
}
return m;
}