Re: [PATCH v2 2/4] tty: amiserial: replace get_zeroed_page() with kzalloc()

[Geert Uytterhoeven]

Hi Mike,

On Sun, 31 May 2026 at 09:04, Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx> wrote:
> rs_startup() allocates a transmit ring buffer that is used to buffer reads
> and writes from/to serial data register.
>
> This buffer can be allocated with kmalloc() as there's nothing special
> about it to go directly to the page allocator.
>
> kmalloc() provides a better API that does not require ugly casts and
> kfree() does not need to know the size of the freed object.
>
> Replace use of get_zeroed_page() with kzalloc() and free_page() with
> kfree().
>
> Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@xxxxxxxxxx
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>

Thanks for your patch, which is now commit d26ed502d0c7c05c ("tty:
amiserial: replace get_zeroed_page() with kzalloc()") in tty/tty-next

> --- a/drivers/tty/amiserial.c
> +++ b/drivers/tty/amiserial.c
> @@ -443,23 +443,23 @@ static int rs_startup(struct tty_struct *tty, struct serial_state *info)
>         struct tty_port *port = &info->tport;
>         unsigned long flags;
>         int     retval=0;
> -       unsigned long page;
> +       void *buffer;

"char *", to match the type of info->xmit.buf?

>
> -       page = get_zeroed_page(GFP_KERNEL);
> -       if (!page)
> +       buffer = kzalloc(PAGE_SIZE, GFP_KERNEL);
> +       if (!buffer)
>                 return -ENOMEM;
>
>         local_irq_save(flags);
>
>         if (tty_port_initialized(port)) {
> -               free_page(page);
> +               kfree(buffer);
>                 goto errout;
>         }
>
>         if (info->xmit.buf)
> -               free_page(page);
> +               kfree(buffer);
>         else
> -               info->xmit.buf = (unsigned char *) page;
> +               info->xmit.buf = buffer;
>
>  #ifdef SERIAL_DEBUG_OPEN
>         printk("starting up ttys%d ...", info->line);

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds