[PATCH v1 1/2] gpiolib: Provide to_gpio_device() helper

[PATCH v1 1/2] gpiolib: Provide to_gpio_device() helper

[Andy Shevchenko]

Provide to_gpio_device() helper which can be utilized in the existing
and future code.

While at it, make sure it becomes no-op at compilation time.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/gpio/gpiolib.c | 2 +-
 drivers/gpio/gpiolib.h | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 119c9c3a2a50..9b935288db9d 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -547,7 +547,7 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
 
 static void gpiodevice_release(struct device *dev)
 {
-	struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
+	struct gpio_device *gdev = to_gpio_device(dev);
 	unsigned long flags;
 
 	spin_lock_irqsave(&gpio_lock, flags);
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index d900ecdbac46..027674025561 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -20,9 +20,9 @@
 
 /**
  * struct gpio_device - internal state container for GPIO devices
- * @id: numerical ID number for the GPIO chip
  * @dev: the GPIO device struct
  * @chrdev: character device for the GPIO device
+ * @id: numerical ID number for the GPIO chip
  * @mockdev: class device used by the deprecated sysfs interface (may be
  * NULL)
  * @owner: helps prevent removal of modules exporting active GPIOs
@@ -47,9 +47,9 @@
  * userspace.
  */
 struct gpio_device {
-	int			id;
 	struct device		dev;
 	struct cdev		chrdev;
+	int			id;
 	struct device		*mockdev;
 	struct module		*owner;
 	struct gpio_chip	*chip;
@@ -72,6 +72,8 @@ struct gpio_device {
 #endif
 };
 
+#define to_gpio_device(_dev_)	container_of(_dev_, struct gpio_device, dev)
+
 /* gpio suffixes used for ACPI and device tree lookup */
 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
 
-- 
2.35.1

[PATCH v1 2/2] gpiolib: Introduce gpio_device_get() and gpio_device_put()

[Andy Shevchenko]

Introduce gpio_device_get() and gpio_device_put() helpers
and convert existing users.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/gpio/gpiolib-cdev.c | 21 +++++++++------------
 drivers/gpio/gpiolib.c      | 14 ++++++--------
 drivers/gpio/gpiolib.h      | 10 ++++++++++
 3 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index f9288e41e3a7..acfb779767ed 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -265,7 +265,7 @@ static void linehandle_free(struct linehandle_state *lh)
 		if (lh->descs[i])
 			gpiod_free(lh->descs[i]);
 	kfree(lh->label);
-	put_device(&lh->gdev->dev);
+	gpio_device_put(lh->gdev);
 	kfree(lh);
 }
 
@@ -307,8 +307,7 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 	lh = kzalloc(sizeof(*lh), GFP_KERNEL);
 	if (!lh)
 		return -ENOMEM;
-	lh->gdev = gdev;
-	get_device(&gdev->dev);
+	lh->gdev = gpio_device_get(gdev);
 
 	if (handlereq.consumer_label[0] != '\0') {
 		/* label is only initialized if consumer_label is set */
@@ -1480,7 +1479,7 @@ static void linereq_free(struct linereq *lr)
 	}
 	kfifo_free(&lr->events);
 	kfree(lr->label);
-	put_device(&lr->gdev->dev);
+	gpio_device_put(lr->gdev);
 	kfree(lr);
 }
 
@@ -1550,8 +1549,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
 	if (!lr)
 		return -ENOMEM;
 
-	lr->gdev = gdev;
-	get_device(&gdev->dev);
+	lr->gdev = gpio_device_get(gdev);
 
 	for (i = 0; i < ulr.num_lines; i++) {
 		lr->lines[i].req = lr;
@@ -1799,7 +1797,7 @@ static void lineevent_free(struct lineevent_state *le)
 	if (le->desc)
 		gpiod_free(le->desc);
 	kfree(le->label);
-	put_device(&le->gdev->dev);
+	gpio_device_put(le->gdev);
 	kfree(le);
 }
 
@@ -1965,8 +1963,7 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 	le = kzalloc(sizeof(*le), GFP_KERNEL);
 	if (!le)
 		return -ENOMEM;
-	le->gdev = gdev;
-	get_device(&gdev->dev);
+	le->gdev = gpio_device_get(gdev);
 
 	if (eventreq.consumer_label[0] != '\0') {
 		/* label is only initialized if consumer_label is set */
@@ -2514,7 +2511,7 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 
 	init_waitqueue_head(&cdev->wait);
 	INIT_KFIFO(cdev->events);
-	cdev->gdev = gdev;
+	cdev->gdev = gpio_device_get(gdev);
 
 	cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify;
 	ret = blocking_notifier_chain_register(&gdev->notifier,
@@ -2522,7 +2519,6 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	if (ret)
 		goto out_free_bitmap;
 
-	get_device(&gdev->dev);
 	file->private_data = cdev;
 
 	ret = nonseekable_open(inode, file);
@@ -2535,6 +2531,7 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	blocking_notifier_chain_unregister(&gdev->notifier,
 					   &cdev->lineinfo_changed_nb);
 out_free_bitmap:
+	gpio_device_put(gdev);
 	bitmap_free(cdev->watched_lines);
 out_free_cdev:
 	kfree(cdev);
@@ -2555,7 +2552,7 @@ static int gpio_chrdev_release(struct inode *inode, struct file *file)
 	bitmap_free(cdev->watched_lines);
 	blocking_notifier_chain_unregister(&gdev->notifier,
 					   &cdev->lineinfo_changed_nb);
-	put_device(&gdev->dev);
+	gpio_device_put(gdev);
 	kfree(cdev);
 
 	return 0;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 9b935288db9d..52a1b03987dc 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -874,7 +874,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 	gpiochip_free_valid_mask(gc);
 	if (gdev->dev.release) {
 		/* release() has been registered by gpiochip_setup_dev() */
-		put_device(&gdev->dev);
+		gpio_device_put(gdev);
 		goto err_print_message;
 	}
 err_remove_from_list:
@@ -961,7 +961,7 @@ void gpiochip_remove(struct gpio_chip *gc)
 	 * gone.
 	 */
 	gcdev_unregister(gdev);
-	put_device(&gdev->dev);
+	gpio_device_put(gdev);
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);
 
@@ -2052,17 +2052,15 @@ static int validate_desc(const struct gpio_desc *desc, const char *func)
 int gpiod_request(struct gpio_desc *desc, const char *label)
 {
 	int ret = -EPROBE_DEFER;
-	struct gpio_device *gdev;
 
 	VALIDATE_DESC(desc);
-	gdev = desc->gdev;
 
-	if (try_module_get(gdev->owner)) {
+	if (try_module_get(desc->gdev->owner)) {
 		ret = gpiod_request_commit(desc, label);
 		if (ret)
-			module_put(gdev->owner);
+			module_put(desc->gdev->owner);
 		else
-			get_device(&gdev->dev);
+			gpio_device_get(desc->gdev);
 	}
 
 	if (ret)
@@ -2123,7 +2121,7 @@ void gpiod_free(struct gpio_desc *desc)
 {
 	if (desc && desc->gdev && gpiod_free_commit(desc)) {
 		module_put(desc->gdev->owner);
-		put_device(&desc->gdev->dev);
+		gpio_device_put(desc->gdev);
 	} else {
 		WARN_ON(extra_checks);
 	}
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 027674025561..13b2c02ec328 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -74,6 +74,16 @@ struct gpio_device {
 
 #define to_gpio_device(_dev_)	container_of(_dev_, struct gpio_device, dev)
 
+static inline struct gpio_device *gpio_device_get(struct gpio_device *gdev)
+{
+	return to_gpio_device(get_device(&gdev->dev));
+}
+
+static inline void gpio_device_put(struct gpio_device *gdev)
+{
+	put_device(&gdev->dev);
+}
+
 /* gpio suffixes used for ACPI and device tree lookup */
 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
 
-- 
2.35.1

Re: [PATCH v1 2/2] gpiolib: Introduce gpio_device_get() and gpio_device_put()

[Linus Walleij]

On Fri, Nov 25, 2022 at 7:11 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:

> Introduce gpio_device_get() and gpio_device_put() helpers
> and convert existing users.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

That's nice coding taste.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

Re: [PATCH v1 2/2] gpiolib: Introduce gpio_device_get() and gpio_device_put()

[Bartosz Golaszewski]

On Fri, Nov 25, 2022 at 7:11 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> Introduce gpio_device_get() and gpio_device_put() helpers
> and convert existing users.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---

This doesn't apply to my for-next branch, can you rebase and resend
(just this one, the other is applied).

Bartosz

Re: [PATCH v1 2/2] gpiolib: Introduce gpio_device_get() and gpio_device_put()

[Andy Shevchenko]

On Tue, Nov 29, 2022 at 02:54:10PM +0100, Bartosz Golaszewski wrote:
> On Fri, Nov 25, 2022 at 7:11 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> >
> > Introduce gpio_device_get() and gpio_device_put() helpers
> > and convert existing users.

> This doesn't apply to my for-next branch, can you rebase and resend
> (just this one, the other is applied).

The problem is that you don't merge or cherry-pick fixes into your
for-next branch and they are getting diverged.

In PDx86 subsystem we decided to cherry-pick the fixes into for-next.
Some other subsystems are doing back-merges (but I remember that Linus
T. complained about back merges, although I dunno if it's still
the case). Some subsystems merges their fixes into for-next, dunno
if it's the best practice either.

That said, this can be submitted after v6.2-rc1 is out.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 2/2] gpiolib: Introduce gpio_device_get() and gpio_device_put()

[Bartosz Golaszewski]

On Tue, Nov 29, 2022 at 3:47 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Tue, Nov 29, 2022 at 02:54:10PM +0100, Bartosz Golaszewski wrote:
> > On Fri, Nov 25, 2022 at 7:11 PM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > >
> > > Introduce gpio_device_get() and gpio_device_put() helpers
> > > and convert existing users.
>
> > This doesn't apply to my for-next branch, can you rebase and resend
> > (just this one, the other is applied).
>
> The problem is that you don't merge or cherry-pick fixes into your
> for-next branch and they are getting diverged.
>
> In PDx86 subsystem we decided to cherry-pick the fixes into for-next.
> Some other subsystems are doing back-merges (but I remember that Linus
> T. complained about back merges, although I dunno if it's still
> the case). Some subsystems merges their fixes into for-next, dunno
> if it's the best practice either.
>
> That said, this can be submitted after v6.2-rc1 is out.
>

I do merge tags if I need to. Normally you'd mention any requirements
for the series in the cover letter.

I have not sent any fixes so far in this release cycle BTW.

Bart

Re: [PATCH v1 2/2] gpiolib: Introduce gpio_device_get() and gpio_device_put()

[Andy Shevchenko]

On Tue, Nov 29, 2022 at 04:49:34PM +0100, Bartosz Golaszewski wrote:
> On Tue, Nov 29, 2022 at 3:47 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:
> > On Tue, Nov 29, 2022 at 02:54:10PM +0100, Bartosz Golaszewski wrote:
> > > On Fri, Nov 25, 2022 at 7:11 PM Andy Shevchenko
> > > <andriy.shevchenko@linux.intel.com> wrote:
> > > >
> > > > Introduce gpio_device_get() and gpio_device_put() helpers
> > > > and convert existing users.
> >
> > > This doesn't apply to my for-next branch, can you rebase and resend
> > > (just this one, the other is applied).
> >
> > The problem is that you don't merge or cherry-pick fixes into your
> > for-next branch and they are getting diverged.
> >
> > In PDx86 subsystem we decided to cherry-pick the fixes into for-next.
> > Some other subsystems are doing back-merges (but I remember that Linus
> > T. complained about back merges, although I dunno if it's still
> > the case). Some subsystems merges their fixes into for-next, dunno
> > if it's the best practice either.
> >
> > That said, this can be submitted after v6.2-rc1 is out.
> 
> I do merge tags if I need to. Normally you'd mention any requirements
> for the series in the cover letter.

It's my fault. But thanks for clarifying the process.

> I have not sent any fixes so far in this release cycle BTW.

Yes, that's now obvious...

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 2/2] gpiolib: Introduce gpio_device_get() and gpio_device_put()

[Andy Shevchenko]

On Tue, Nov 29, 2022 at 06:21:28PM +0200, Andy Shevchenko wrote:
> On Tue, Nov 29, 2022 at 04:49:34PM +0100, Bartosz Golaszewski wrote:
> > On Tue, Nov 29, 2022 at 3:47 PM Andy Shevchenko
> > <andriy.shevchenko@linux.intel.com> wrote:
> > > On Tue, Nov 29, 2022 at 02:54:10PM +0100, Bartosz Golaszewski wrote:

...

> > > That said, this can be submitted after v6.2-rc1 is out.

Btw, since you are trying to fix a user space race, I would like to
postpone this since it will conflict with that one anyway.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 2/2] gpiolib: Introduce gpio_device_get() and gpio_device_put()

[Linus Walleij]

On Tue, Nov 29, 2022 at 3:47 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:

> In PDx86 subsystem we decided to cherry-pick the fixes into for-next.
> Some other subsystems are doing back-merges (but I remember that Linus
> T. complained about back merges, although I dunno if it's still
> the case). Some subsystems merges their fixes into for-next, dunno
> if it's the best practice either.

I usually (A) let it conflict (Torvalds will solve) if it is small and
Rothwell fixed it up in next (B) back-merge some -rcN if is is big
and annoying or as last resort (C) apply the patch to for-next
(git will cope, but not elegant).

Yours,
Linus Walleij

Re: [PATCH v1 1/2] gpiolib: Provide to_gpio_device() helper

[Bartosz Golaszewski]

On Fri, Nov 25, 2022 at 7:11 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> Provide to_gpio_device() helper which can be utilized in the existing
> and future code.
>
> While at it, make sure it becomes no-op at compilation time.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/gpio/gpiolib.c | 2 +-
>  drivers/gpio/gpiolib.h | 6 ++++--
>  2 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 119c9c3a2a50..9b935288db9d 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -547,7 +547,7 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
>
>  static void gpiodevice_release(struct device *dev)
>  {
> -       struct gpio_device *gdev = container_of(dev, struct gpio_device, dev);
> +       struct gpio_device *gdev = to_gpio_device(dev);
>         unsigned long flags;
>
>         spin_lock_irqsave(&gpio_lock, flags);
> diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
> index d900ecdbac46..027674025561 100644
> --- a/drivers/gpio/gpiolib.h
> +++ b/drivers/gpio/gpiolib.h
> @@ -20,9 +20,9 @@
>
>  /**
>   * struct gpio_device - internal state container for GPIO devices
> - * @id: numerical ID number for the GPIO chip
>   * @dev: the GPIO device struct
>   * @chrdev: character device for the GPIO device
> + * @id: numerical ID number for the GPIO chip
>   * @mockdev: class device used by the deprecated sysfs interface (may be
>   * NULL)
>   * @owner: helps prevent removal of modules exporting active GPIOs
> @@ -47,9 +47,9 @@
>   * userspace.
>   */
>  struct gpio_device {
> -       int                     id;
>         struct device           dev;
>         struct cdev             chrdev;
> +       int                     id;
>         struct device           *mockdev;
>         struct module           *owner;
>         struct gpio_chip        *chip;
> @@ -72,6 +72,8 @@ struct gpio_device {
>  #endif
>  };
>
> +#define to_gpio_device(_dev_)  container_of(_dev_, struct gpio_device, dev)
> +

Just make it a static inline, please.

Bartosz

>  /* gpio suffixes used for ACPI and device tree lookup */
>  static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };
>
> --
> 2.35.1
>

Re: [PATCH v1 1/2] gpiolib: Provide to_gpio_device() helper

[Andy Shevchenko]

On Mon, Nov 28, 2022 at 07:04:28PM +0100, Bartosz Golaszewski wrote:
> On Fri, Nov 25, 2022 at 7:11 PM Andy Shevchenko
> <andriy.shevchenko@linux.intel.com> wrote:

...

> > +#define to_gpio_device(_dev_)  container_of(_dev_, struct gpio_device, dev)
> > +
> 
> Just make it a static inline, please.

Made in v2. Thanks for review!

-- 
With Best Regards,
Andy Shevchenko