* [PATCH] gpio: ljca: reduce struct allocation
@ 2026-03-08 2:12 Rosen Penev
2026-03-08 12:19 ` Sakari Ailus
2026-03-09 9:22 ` Bartosz Golaszewski
0 siblings, 2 replies; 8+ messages in thread
From: Rosen Penev @ 2026-03-08 2:12 UTC (permalink / raw)
To: linux-gpio
Cc: Lixu Zhang, linux-hardening, gustavoars, Sakari Ailus,
Linus Walleij, Bartosz Golaszewski, open list
Convert connect_mode to a flexible array member to avoid calling
kcalloc and to combine the allocations.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
drivers/gpio/gpio-ljca.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/drivers/gpio/gpio-ljca.c b/drivers/gpio/gpio-ljca.c
index f32d1d237795..a531aaa0425f 100644
--- a/drivers/gpio/gpio-ljca.c
+++ b/drivers/gpio/gpio-ljca.c
@@ -63,7 +63,6 @@ struct ljca_gpio_dev {
DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
- u8 *connect_mode;
/* protect irq bus */
struct mutex irq_lock;
struct work_struct work;
@@ -72,6 +71,8 @@ struct ljca_gpio_dev {
u8 obuf[LJCA_GPIO_BUF_SIZE];
u8 ibuf[LJCA_GPIO_BUF_SIZE];
+
+ u8 connect_mode[];
};
static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
@@ -400,22 +401,19 @@ static int ljca_gpio_probe(struct auxiliary_device *auxdev,
const struct auxiliary_device_id *aux_dev_id)
{
struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
+ struct ljca_gpio_info *gpio_info;
struct ljca_gpio_dev *ljca_gpio;
struct gpio_irq_chip *girq;
int ret;
- ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
+ gpio_info = dev_get_platdata(&auxdev->dev);
+ ljca_gpio = devm_kzalloc(&auxdev->dev, struct_size(ljca_gpio, connect_mode, gpio_info->num),
+ GFP_KERNEL);
if (!ljca_gpio)
return -ENOMEM;
ljca_gpio->ljca = ljca;
- ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
- ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
- ljca_gpio->gpio_info->num,
- sizeof(*ljca_gpio->connect_mode),
- GFP_KERNEL);
- if (!ljca_gpio->connect_mode)
- return -ENOMEM;
+ ljca_gpio->gpio_info = gpio_info;
ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
if (ret)
--
2.53.0
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] gpio: ljca: reduce struct allocation
2026-03-08 2:12 [PATCH] gpio: ljca: reduce struct allocation Rosen Penev
@ 2026-03-08 12:19 ` Sakari Ailus
2026-03-08 18:54 ` Rosen Penev
2026-03-09 9:22 ` Bartosz Golaszewski
1 sibling, 1 reply; 8+ messages in thread
From: Sakari Ailus @ 2026-03-08 12:19 UTC (permalink / raw)
To: Rosen Penev
Cc: linux-gpio, Lixu Zhang, linux-hardening, gustavoars,
Linus Walleij, Bartosz Golaszewski, open list
Hi Rosen,
Thanks or the patch.
On Sat, Mar 07, 2026 at 06:12:01PM -0800, Rosen Penev wrote:
> Convert connect_mode to a flexible array member to avoid calling
> kcalloc and to combine the allocations.
>
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
> drivers/gpio/gpio-ljca.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpio/gpio-ljca.c b/drivers/gpio/gpio-ljca.c
> index f32d1d237795..a531aaa0425f 100644
> --- a/drivers/gpio/gpio-ljca.c
> +++ b/drivers/gpio/gpio-ljca.c
> @@ -63,7 +63,6 @@ struct ljca_gpio_dev {
> DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
> DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
> DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
> - u8 *connect_mode;
> /* protect irq bus */
> struct mutex irq_lock;
> struct work_struct work;
> @@ -72,6 +71,8 @@ struct ljca_gpio_dev {
>
> u8 obuf[LJCA_GPIO_BUF_SIZE];
> u8 ibuf[LJCA_GPIO_BUF_SIZE];
> +
> + u8 connect_mode[];
> };
>
> static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
> @@ -400,22 +401,19 @@ static int ljca_gpio_probe(struct auxiliary_device *auxdev,
> const struct auxiliary_device_id *aux_dev_id)
> {
> struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
> + struct ljca_gpio_info *gpio_info;
> struct ljca_gpio_dev *ljca_gpio;
> struct gpio_irq_chip *girq;
> int ret;
>
> - ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
> + gpio_info = dev_get_platdata(&auxdev->dev);
You can do this assignment in variable declaration.
> + ljca_gpio = devm_kzalloc(&auxdev->dev, struct_size(ljca_gpio, connect_mode, gpio_info->num),
This line is a bit long, I'd wrap it.
> + GFP_KERNEL);
> if (!ljca_gpio)
> return -ENOMEM;
>
> ljca_gpio->ljca = ljca;
> - ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
> - ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
> - ljca_gpio->gpio_info->num,
> - sizeof(*ljca_gpio->connect_mode),
> - GFP_KERNEL);
> - if (!ljca_gpio->connect_mode)
> - return -ENOMEM;
> + ljca_gpio->gpio_info = gpio_info;
>
> ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
> if (ret)
--
Kind regards,
Sakari Ailus
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] gpio: ljca: reduce struct allocation
2026-03-08 12:19 ` Sakari Ailus
@ 2026-03-08 18:54 ` Rosen Penev
2026-03-09 7:19 ` Sakari Ailus
0 siblings, 1 reply; 8+ messages in thread
From: Rosen Penev @ 2026-03-08 18:54 UTC (permalink / raw)
To: Sakari Ailus
Cc: linux-gpio, Lixu Zhang, linux-hardening, gustavoars,
Linus Walleij, Bartosz Golaszewski, open list
On Sun, Mar 8, 2026 at 5:19 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Rosen,
>
> Thanks or the patch.
>
> On Sat, Mar 07, 2026 at 06:12:01PM -0800, Rosen Penev wrote:
> > Convert connect_mode to a flexible array member to avoid calling
> > kcalloc and to combine the allocations.
> >
> > Signed-off-by: Rosen Penev <rosenp@gmail.com>
> > ---
> > drivers/gpio/gpio-ljca.c | 16 +++++++---------
> > 1 file changed, 7 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-ljca.c b/drivers/gpio/gpio-ljca.c
> > index f32d1d237795..a531aaa0425f 100644
> > --- a/drivers/gpio/gpio-ljca.c
> > +++ b/drivers/gpio/gpio-ljca.c
> > @@ -63,7 +63,6 @@ struct ljca_gpio_dev {
> > DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
> > DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
> > DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
> > - u8 *connect_mode;
> > /* protect irq bus */
> > struct mutex irq_lock;
> > struct work_struct work;
> > @@ -72,6 +71,8 @@ struct ljca_gpio_dev {
> >
> > u8 obuf[LJCA_GPIO_BUF_SIZE];
> > u8 ibuf[LJCA_GPIO_BUF_SIZE];
> > +
> > + u8 connect_mode[];
> > };
> >
> > static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
> > @@ -400,22 +401,19 @@ static int ljca_gpio_probe(struct auxiliary_device *auxdev,
> > const struct auxiliary_device_id *aux_dev_id)
> > {
> > struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
> > + struct ljca_gpio_info *gpio_info;
> > struct ljca_gpio_dev *ljca_gpio;
> > struct gpio_irq_chip *girq;
> > int ret;
> >
> > - ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
> > + gpio_info = dev_get_platdata(&auxdev->dev);
>
> You can do this assignment in variable declaration.
I avoided doing so to keep reverse christmas tree order. I can still
do so if desired.
>
> > + ljca_gpio = devm_kzalloc(&auxdev->dev, struct_size(ljca_gpio, connect_mode, gpio_info->num),
>
> This line is a bit long, I'd wrap it.
Will fix.
>
> > + GFP_KERNEL);
> > if (!ljca_gpio)
> > return -ENOMEM;
> >
> > ljca_gpio->ljca = ljca;
> > - ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
> > - ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
> > - ljca_gpio->gpio_info->num,
> > - sizeof(*ljca_gpio->connect_mode),
> > - GFP_KERNEL);
> > - if (!ljca_gpio->connect_mode)
> > - return -ENOMEM;
> > + ljca_gpio->gpio_info = gpio_info;
> >
> > ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
> > if (ret)
>
> --
> Kind regards,
>
> Sakari Ailus
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] gpio: ljca: reduce struct allocation
2026-03-08 18:54 ` Rosen Penev
@ 2026-03-09 7:19 ` Sakari Ailus
2026-03-09 7:32 ` Rosen Penev
0 siblings, 1 reply; 8+ messages in thread
From: Sakari Ailus @ 2026-03-09 7:19 UTC (permalink / raw)
To: Rosen Penev
Cc: linux-gpio, Lixu Zhang, linux-hardening, gustavoars,
Linus Walleij, Bartosz Golaszewski, open list
Hi Rosen,
On Sun, Mar 08, 2026 at 11:54:07AM -0700, Rosen Penev wrote:
> On Sun, Mar 8, 2026 at 5:19 AM Sakari Ailus
> <sakari.ailus@linux.intel.com> wrote:
> >
> > Hi Rosen,
> >
> > Thanks or the patch.
> >
> > On Sat, Mar 07, 2026 at 06:12:01PM -0800, Rosen Penev wrote:
> > > Convert connect_mode to a flexible array member to avoid calling
> > > kcalloc and to combine the allocations.
> > >
> > > Signed-off-by: Rosen Penev <rosenp@gmail.com>
> > > ---
> > > drivers/gpio/gpio-ljca.c | 16 +++++++---------
> > > 1 file changed, 7 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/drivers/gpio/gpio-ljca.c b/drivers/gpio/gpio-ljca.c
> > > index f32d1d237795..a531aaa0425f 100644
> > > --- a/drivers/gpio/gpio-ljca.c
> > > +++ b/drivers/gpio/gpio-ljca.c
> > > @@ -63,7 +63,6 @@ struct ljca_gpio_dev {
> > > DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
> > > DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
> > > DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
> > > - u8 *connect_mode;
> > > /* protect irq bus */
> > > struct mutex irq_lock;
> > > struct work_struct work;
> > > @@ -72,6 +71,8 @@ struct ljca_gpio_dev {
> > >
> > > u8 obuf[LJCA_GPIO_BUF_SIZE];
> > > u8 ibuf[LJCA_GPIO_BUF_SIZE];
> > > +
> > > + u8 connect_mode[];
> > > };
> > >
> > > static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
> > > @@ -400,22 +401,19 @@ static int ljca_gpio_probe(struct auxiliary_device *auxdev,
> > > const struct auxiliary_device_id *aux_dev_id)
> > > {
> > > struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
> > > + struct ljca_gpio_info *gpio_info;
> > > struct ljca_gpio_dev *ljca_gpio;
> > > struct gpio_irq_chip *girq;
> > > int ret;
> > >
> > > - ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
> > > + gpio_info = dev_get_platdata(&auxdev->dev);
> >
> > You can do this assignment in variable declaration.
> I avoided doing so to keep reverse christmas tree order. I can still
> do so if desired.
How does that affect it? There doesn't seem to be a dependency here -- and
even if there was, the dependency obviously has priority.
> >
> > > + ljca_gpio = devm_kzalloc(&auxdev->dev, struct_size(ljca_gpio, connect_mode, gpio_info->num),
> >
> > This line is a bit long, I'd wrap it.
> Will fix.
> >
> > > + GFP_KERNEL);
> > > if (!ljca_gpio)
> > > return -ENOMEM;
> > >
> > > ljca_gpio->ljca = ljca;
> > > - ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
> > > - ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
> > > - ljca_gpio->gpio_info->num,
> > > - sizeof(*ljca_gpio->connect_mode),
> > > - GFP_KERNEL);
> > > - if (!ljca_gpio->connect_mode)
> > > - return -ENOMEM;
> > > + ljca_gpio->gpio_info = gpio_info;
> > >
> > > ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
> > > if (ret)
> >
--
Kind regards,
Sakari Ailus
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] gpio: ljca: reduce struct allocation
2026-03-09 7:19 ` Sakari Ailus
@ 2026-03-09 7:32 ` Rosen Penev
0 siblings, 0 replies; 8+ messages in thread
From: Rosen Penev @ 2026-03-09 7:32 UTC (permalink / raw)
To: Sakari Ailus
Cc: linux-gpio, Lixu Zhang, linux-hardening, gustavoars,
Linus Walleij, Bartosz Golaszewski, open list
On Mon, Mar 9, 2026 at 12:20 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Rosen,
>
> On Sun, Mar 08, 2026 at 11:54:07AM -0700, Rosen Penev wrote:
> > On Sun, Mar 8, 2026 at 5:19 AM Sakari Ailus
> > <sakari.ailus@linux.intel.com> wrote:
> > >
> > > Hi Rosen,
> > >
> > > Thanks or the patch.
> > >
> > > On Sat, Mar 07, 2026 at 06:12:01PM -0800, Rosen Penev wrote:
> > > > Convert connect_mode to a flexible array member to avoid calling
> > > > kcalloc and to combine the allocations.
> > > >
> > > > Signed-off-by: Rosen Penev <rosenp@gmail.com>
> > > > ---
> > > > drivers/gpio/gpio-ljca.c | 16 +++++++---------
> > > > 1 file changed, 7 insertions(+), 9 deletions(-)
> > > >
> > > > diff --git a/drivers/gpio/gpio-ljca.c b/drivers/gpio/gpio-ljca.c
> > > > index f32d1d237795..a531aaa0425f 100644
> > > > --- a/drivers/gpio/gpio-ljca.c
> > > > +++ b/drivers/gpio/gpio-ljca.c
> > > > @@ -63,7 +63,6 @@ struct ljca_gpio_dev {
> > > > DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
> > > > DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
> > > > DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
> > > > - u8 *connect_mode;
> > > > /* protect irq bus */
> > > > struct mutex irq_lock;
> > > > struct work_struct work;
> > > > @@ -72,6 +71,8 @@ struct ljca_gpio_dev {
> > > >
> > > > u8 obuf[LJCA_GPIO_BUF_SIZE];
> > > > u8 ibuf[LJCA_GPIO_BUF_SIZE];
> > > > +
> > > > + u8 connect_mode[];
> > > > };
> > > >
> > > > static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
> > > > @@ -400,22 +401,19 @@ static int ljca_gpio_probe(struct auxiliary_device *auxdev,
> > > > const struct auxiliary_device_id *aux_dev_id)
> > > > {
> > > > struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
> > > > + struct ljca_gpio_info *gpio_info;
> > > > struct ljca_gpio_dev *ljca_gpio;
> > > > struct gpio_irq_chip *girq;
> > > > int ret;
> > > >
> > > > - ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
> > > > + gpio_info = dev_get_platdata(&auxdev->dev);
> > >
> > > You can do this assignment in variable declaration.
> > I avoided doing so to keep reverse christmas tree order. I can still
> > do so if desired.
>
> How does that affect it? There doesn't seem to be a dependency here -- and
> even if there was, the dependency obviously has priority.
It's just cosmetic.
>
> > >
> > > > + ljca_gpio = devm_kzalloc(&auxdev->dev, struct_size(ljca_gpio, connect_mode, gpio_info->num),
> > >
> > > This line is a bit long, I'd wrap it.
> > Will fix.
> > >
> > > > + GFP_KERNEL);
> > > > if (!ljca_gpio)
> > > > return -ENOMEM;
> > > >
> > > > ljca_gpio->ljca = ljca;
> > > > - ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
> > > > - ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
> > > > - ljca_gpio->gpio_info->num,
> > > > - sizeof(*ljca_gpio->connect_mode),
> > > > - GFP_KERNEL);
> > > > - if (!ljca_gpio->connect_mode)
> > > > - return -ENOMEM;
> > > > + ljca_gpio->gpio_info = gpio_info;
> > > >
> > > > ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
> > > > if (ret)
> > >
>
> --
> Kind regards,
>
> Sakari Ailus
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] gpio: ljca: reduce struct allocation
2026-03-08 2:12 [PATCH] gpio: ljca: reduce struct allocation Rosen Penev
2026-03-08 12:19 ` Sakari Ailus
@ 2026-03-09 9:22 ` Bartosz Golaszewski
2026-03-09 21:48 ` Rosen Penev
1 sibling, 1 reply; 8+ messages in thread
From: Bartosz Golaszewski @ 2026-03-09 9:22 UTC (permalink / raw)
To: Rosen Penev
Cc: linux-gpio, Lixu Zhang, linux-hardening, gustavoars, Sakari Ailus,
Linus Walleij, open list
On Sun, Mar 8, 2026 at 3:12 AM Rosen Penev <rosenp@gmail.com> wrote:
>
> Convert connect_mode to a flexible array member to avoid calling
> kcalloc and to combine the allocations.
>
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
> drivers/gpio/gpio-ljca.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpio/gpio-ljca.c b/drivers/gpio/gpio-ljca.c
> index f32d1d237795..a531aaa0425f 100644
> --- a/drivers/gpio/gpio-ljca.c
> +++ b/drivers/gpio/gpio-ljca.c
> @@ -63,7 +63,6 @@ struct ljca_gpio_dev {
> DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
> DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
> DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
> - u8 *connect_mode;
> /* protect irq bus */
> struct mutex irq_lock;
> struct work_struct work;
> @@ -72,6 +71,8 @@ struct ljca_gpio_dev {
>
> u8 obuf[LJCA_GPIO_BUF_SIZE];
> u8 ibuf[LJCA_GPIO_BUF_SIZE];
> +
> + u8 connect_mode[];
Please use __counted_by().
> };
>
> static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
> @@ -400,22 +401,19 @@ static int ljca_gpio_probe(struct auxiliary_device *auxdev,
> const struct auxiliary_device_id *aux_dev_id)
> {
> struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
> + struct ljca_gpio_info *gpio_info;
> struct ljca_gpio_dev *ljca_gpio;
> struct gpio_irq_chip *girq;
> int ret;
>
> - ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
> + gpio_info = dev_get_platdata(&auxdev->dev);
> + ljca_gpio = devm_kzalloc(&auxdev->dev, struct_size(ljca_gpio, connect_mode, gpio_info->num),
I'm surprised to learn that there's no devm_kzalloc_flex() yet. I
wanted to ask you to use it but it doesn't exist.
Bart
> + GFP_KERNEL);
> if (!ljca_gpio)
> return -ENOMEM;
>
> ljca_gpio->ljca = ljca;
> - ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
> - ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
> - ljca_gpio->gpio_info->num,
> - sizeof(*ljca_gpio->connect_mode),
> - GFP_KERNEL);
> - if (!ljca_gpio->connect_mode)
> - return -ENOMEM;
> + ljca_gpio->gpio_info = gpio_info;
>
> ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
> if (ret)
> --
> 2.53.0
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] gpio: ljca: reduce struct allocation
2026-03-09 9:22 ` Bartosz Golaszewski
@ 2026-03-09 21:48 ` Rosen Penev
2026-03-10 11:52 ` Linus Walleij
0 siblings, 1 reply; 8+ messages in thread
From: Rosen Penev @ 2026-03-09 21:48 UTC (permalink / raw)
To: Bartosz Golaszewski
Cc: linux-gpio, Lixu Zhang, linux-hardening, gustavoars, Sakari Ailus,
Linus Walleij, open list
On Mon, Mar 9, 2026 at 2:22 AM Bartosz Golaszewski <brgl@kernel.org> wrote:
>
> On Sun, Mar 8, 2026 at 3:12 AM Rosen Penev <rosenp@gmail.com> wrote:
> >
> > Convert connect_mode to a flexible array member to avoid calling
> > kcalloc and to combine the allocations.
> >
> > Signed-off-by: Rosen Penev <rosenp@gmail.com>
> > ---
> > drivers/gpio/gpio-ljca.c | 16 +++++++---------
> > 1 file changed, 7 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-ljca.c b/drivers/gpio/gpio-ljca.c
> > index f32d1d237795..a531aaa0425f 100644
> > --- a/drivers/gpio/gpio-ljca.c
> > +++ b/drivers/gpio/gpio-ljca.c
> > @@ -63,7 +63,6 @@ struct ljca_gpio_dev {
> > DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
> > DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
> > DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
> > - u8 *connect_mode;
> > /* protect irq bus */
> > struct mutex irq_lock;
> > struct work_struct work;
> > @@ -72,6 +71,8 @@ struct ljca_gpio_dev {
> >
> > u8 obuf[LJCA_GPIO_BUF_SIZE];
> > u8 ibuf[LJCA_GPIO_BUF_SIZE];
> > +
> > + u8 connect_mode[];
>
> Please use __counted_by().
Counted by what?
__counted_by(gpio_info->num); does not work.
> > };
> >
> > static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
> > @@ -400,22 +401,19 @@ static int ljca_gpio_probe(struct auxiliary_device *auxdev,
> > const struct auxiliary_device_id *aux_dev_id)
> > {
> > struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
> > + struct ljca_gpio_info *gpio_info;
> > struct ljca_gpio_dev *ljca_gpio;
> > struct gpio_irq_chip *girq;
> > int ret;
> >
> > - ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
> > + gpio_info = dev_get_platdata(&auxdev->dev);
> > + ljca_gpio = devm_kzalloc(&auxdev->dev, struct_size(ljca_gpio, connect_mode, gpio_info->num),
>
> I'm surprised to learn that there's no devm_kzalloc_flex() yet. I
> wanted to ask you to use it but it doesn't exist.
I'm sure a treewide commit will be applied when it gets introduced.
>
> Bart
>
> > + GFP_KERNEL);
> > if (!ljca_gpio)
> > return -ENOMEM;
> >
> > ljca_gpio->ljca = ljca;
> > - ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
> > - ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
> > - ljca_gpio->gpio_info->num,
> > - sizeof(*ljca_gpio->connect_mode),
> > - GFP_KERNEL);
> > - if (!ljca_gpio->connect_mode)
> > - return -ENOMEM;
> > + ljca_gpio->gpio_info = gpio_info;
> >
> > ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
> > if (ret)
> > --
> > 2.53.0
> >
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] gpio: ljca: reduce struct allocation
2026-03-09 21:48 ` Rosen Penev
@ 2026-03-10 11:52 ` Linus Walleij
0 siblings, 0 replies; 8+ messages in thread
From: Linus Walleij @ 2026-03-10 11:52 UTC (permalink / raw)
To: Rosen Penev
Cc: Bartosz Golaszewski, linux-gpio, Lixu Zhang, linux-hardening,
gustavoars, Sakari Ailus, open list
On Mon, Mar 9, 2026 at 10:48 PM Rosen Penev <rosenp@gmail.com> wrote:
> > > + u8 connect_mode[];
> >
> > Please use __counted_by().
> Counted by what?
>
> __counted_by(gpio_info->num); does not work.
As with the other patch (IIRC) just add a new member to the struct
to hold the count.
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2026-03-10 11:52 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-03-08 2:12 [PATCH] gpio: ljca: reduce struct allocation Rosen Penev
2026-03-08 12:19 ` Sakari Ailus
2026-03-08 18:54 ` Rosen Penev
2026-03-09 7:19 ` Sakari Ailus
2026-03-09 7:32 ` Rosen Penev
2026-03-09 9:22 ` Bartosz Golaszewski
2026-03-09 21:48 ` Rosen Penev
2026-03-10 11:52 ` Linus Walleij
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