linux-kernel - Re: [PATCH 15/23] gpio: mockup: use dynamic device IDs

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Message-ID: <20200904164917.GC1891694@smile.fi.intel.com>
Date:   Fri, 4 Sep 2020 19:49:17 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Bartosz Golaszewski <brgl@...ev.pl>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Jonathan Corbet <corbet@....net>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Kent Gibson <warthog618@...il.com>, linux-gpio@...r.kernel.org,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-acpi@...r.kernel.org,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: Re: [PATCH 15/23] gpio: mockup: use dynamic device IDs

On Fri, Sep 04, 2020 at 05:45:39PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@...libre.com>
> 
> We're currently creating chips at module init time only so using a
> static index for dummy devices is fine. We want to support dynamically
> created chips however so we need to switch to dynamic device IDs.

It misses ida_destroy().

What about XArray API?

> Signed-off-by: Bartosz Golaszewski <bgolaszewski@...libre.com>
> ---
>  drivers/gpio/gpio-mockup.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
> index 96976ba66598..995e37fef9c5 100644
> --- a/drivers/gpio/gpio-mockup.c
> +++ b/drivers/gpio/gpio-mockup.c
> @@ -9,6 +9,7 @@
>  
>  #include <linux/debugfs.h>
>  #include <linux/gpio/driver.h>
> +#include <linux/idr.h>
>  #include <linux/interrupt.h>
>  #include <linux/irq.h>
>  #include <linux/irq_sim.h>
> @@ -70,6 +71,8 @@ module_param_named(gpio_mockup_named_lines,
>  
>  static struct dentry *gpio_mockup_dbg_dir;
>  
> +static DEFINE_IDA(gpio_mockup_ida);
> +
>  static int gpio_mockup_range_base(unsigned int index)
>  {
>  	return gpio_mockup_ranges[index * 2];
> @@ -480,8 +483,12 @@ static LIST_HEAD(gpio_mockup_devices);
>  
>  static void gpio_mockup_unregister_one_device(struct gpio_mockup_device *dev)
>  {
> +	int id;
> +
>  	list_del(&dev->list);
> +	id = dev->pdev->id;
>  	platform_device_unregister(dev->pdev);
> +	ida_free(&gpio_mockup_ida, id);
>  	kfree(dev);
>  }
>  
> @@ -587,12 +594,19 @@ static int __init gpio_mockup_init(void)
>  		}
>  
>  		pdevinfo.name = "gpio-mockup";
> -		pdevinfo.id = i;
>  		pdevinfo.properties = properties;
>  
> +		pdevinfo.id = ida_alloc(&gpio_mockup_ida, GFP_KERNEL);
> +		if (pdevinfo.id < 0) {
> +			kfree_strarray(line_names, ngpio);
> +			err = pdevinfo.id;
> +			goto err_out;
> +		}
> +
>  		mockup_dev = kzalloc(sizeof(*mockup_dev), GFP_KERNEL);
>  		if (!mockup_dev) {
>  			kfree_strarray(line_names, ngpio);
> +			ida_free(&gpio_mockup_ida, pdevinfo.id);
>  			err = -ENOMEM;
>  			goto err_out;
>  		}
> @@ -601,6 +615,7 @@ static int __init gpio_mockup_init(void)
>  		kfree_strarray(line_names, ngpio);
>  		if (IS_ERR(mockup_dev->pdev)) {
>  			pr_err("error registering device");
> +			ida_free(&gpio_mockup_ida, pdevinfo.id);
>  			kfree(mockup_dev);
>  			err = PTR_ERR(mockup_dev->pdev);
>  			goto err_out;
> -- 
> 2.26.1
> 

-- 
With Best Regards,
Andy Shevchenko