Re: [PATCH 06/14] mtd: maps: physmap: Remove the MAX_RESOURCES limitation

[Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>]

Hi Boris
On Mon, Oct 8, 2018 at 10:10 PM Boris Brezillon
<boris.brezillon@bootlin.com> wrote:
>
> Remove the MAX_RESOURCES limitation by dynamically allocating the
> ->mtds[] and ->maps[] at probe time based on the number of iomem
> resources attached to the platform device.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> ---
>  drivers/mtd/maps/physmap.c | 44 +++++++++++++++++++++++++++-----------------
>  1 file changed, 27 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/mtd/maps/physmap.c b/drivers/mtd/maps/physmap.c
> index cbc50b53ec9d..86679d149a49 100644
> --- a/drivers/mtd/maps/physmap.c
> +++ b/drivers/mtd/maps/physmap.c
> @@ -22,12 +22,11 @@
>  #include <linux/mtd/concat.h>
>  #include <linux/io.h>
>
> -#define MAX_RESOURCES          4
> -
>  struct physmap_flash_info {
> -       struct mtd_info         *mtds[MAX_RESOURCES];
> +       unsigned int            nmaps;
> +       struct mtd_info         **mtds;
>         struct mtd_info         *cmtd;
> -       struct map_info         maps[MAX_RESOURCES];
> +       struct map_info         *maps;
>         spinlock_t              vpp_lock;
>         int                     vpp_refcnt;
>  };
> @@ -50,7 +49,7 @@ static int physmap_flash_remove(struct platform_device *dev)
>                         mtd_concat_destroy(info->cmtd);
>         }
>
> -       for (i = 0; i < MAX_RESOURCES; i++) {
> +       for (i = 0; i < info->nmaps; i++) {
>                 if (info->mtds[i] != NULL)
>                         map_destroy(info->mtds[i]);
>         }
> @@ -101,7 +100,6 @@ static int physmap_flash_probe(struct platform_device *dev)
>         const char * const *part_types;
>         int err = 0;
>         int i;
> -       int devices_found = 0;
>
>         physmap_data = dev_get_platdata(&dev->dev);
>         if (physmap_data == NULL)
> @@ -114,6 +112,24 @@ static int physmap_flash_probe(struct platform_device *dev)
>                 goto err_out;
>         }
>
> +       while (platform_get_resource(dev, IORESOURCE_MEM, info->nmaps))
> +               info->nmaps++;

Maybe you prefer:
for (info->nmaps = 0; platform_get_resource(dev, IORESOURCE_MEM,
info->nmaps) ; info->nmaps++);

(your choice, they are probably compiled into the same assembly)

> +
> +       if (!info->nmaps)
> +               return -ENODEV;
> +
> +       info->maps = devm_kzalloc(&dev->dev,
> +                                 sizeof(*info->maps) * info->nmaps,
> +                                 GFP_KERNEL);
> +       if (!info->maps)
> +               return -ENOMEM;
> +
> +       info->mtds = devm_kzalloc(&dev->dev,
> +                                 sizeof(*info->mtds) * info->nmaps,
> +                                 GFP_KERNEL);
> +       if (!info->mtds)
> +               return -ENOMEM;
> +
>         if (physmap_data->init) {
>                 err = physmap_data->init(dev);
>                 if (err)
> @@ -122,13 +138,10 @@ static int physmap_flash_probe(struct platform_device *dev)
>
>         platform_set_drvdata(dev, info);
>
> -       for (i = 0; i < MAX_RESOURCES; i++) {
> +       for (i = 0; i < info->nmaps; i++) {
>                 struct resource *res;
>
>                 res = platform_get_resource(dev, IORESOURCE_MEM, i);
> -               if (res)
> -                       break;
> -
>                 info->maps[i].virt = devm_ioremap_resource(&dev->dev, res);
>                 if (IS_ERR(info->maps[i].virt)) {
>                         err = PTR_ERR(info->maps[i].virt);
> @@ -159,21 +172,18 @@ static int physmap_flash_probe(struct platform_device *dev)
>                         dev_err(&dev->dev, "map_probe failed\n");
>                         err = -ENXIO;
>                         goto err_out;
> -               } else {
> -                       devices_found++;
>                 }
>                 info->mtds[i]->dev.parent = &dev->dev;
>         }
>
> -       if (!devices_found) {
> -               err = -ENODEV;
> -       } else if (devices_found == 1) {
> +       if (info->nmaps == 1) {
>                 info->cmtd = info->mtds[0];
>         } else {
>                 /*
>                  * We detected multiple devices. Concatenate them together.
>                  */
> -               info->cmtd = mtd_concat_create(info->mtds, devices_found, dev_name(&dev->dev));
> +               info->cmtd = mtd_concat_create(info->mtds, info->nmaps,
> +                                              dev_name(&dev->dev));
>                 if (info->cmtd == NULL)
>                         err = -ENXIO;
>         }
> @@ -199,7 +209,7 @@ static void physmap_flash_shutdown(struct platform_device *dev)
>         struct physmap_flash_info *info = platform_get_drvdata(dev);
>         int i;
>
> -       for (i = 0; i < MAX_RESOURCES && info->mtds[i]; i++)
> +       for (i = 0; i < info->nmaps && info->mtds[i]; i++)
>                 if (mtd_suspend(info->mtds[i]) == 0)
>                         mtd_resume(info->mtds[i]);
>  }
> --
> 2.14.1
>


-- 
Ricardo Ribalda

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