Re: [PATCH] pata_falcon: Add missing __iomem annotations

[Geert Uytterhoeven]

Hi Finn,

On Wed, Nov 24, 2021 at 8:36 AM Finn Thain <fthain@xxxxxxxxxxxxxx> wrote:
> The zero day bot reported some sparse complaints in pata_falcon.c. E.g.
>
> drivers/ata/pata_falcon.c:58:41: warning: cast removes address space '__iomem' of expression
> drivers/ata/pata_falcon.c:58:41: warning: incorrect type in argument 1 (different address spaces)
> drivers/ata/pata_falcon.c:58:41:    expected unsigned short volatile [noderef] [usertype] __iomem *port
> drivers/ata/pata_falcon.c:58:41:    got unsigned short [usertype] *
>
> The same thing shows up in 8 places, all told. Avoid this by use of
> __iomem type casts.
>
> Cc: Michael Schmitz <schmitzmic@xxxxxxxxx>
> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
> Cc: Jens Axboe <axboe@xxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxx>

Thanks for your patch!

> --- a/drivers/ata/pata_falcon.c
> +++ b/drivers/ata/pata_falcon.c
> @@ -55,14 +55,14 @@ static unsigned int pata_falcon_data_xfer(struct ata_queued_cmd *qc,
>         /* Transfer multiple of 2 bytes */
>         if (rw == READ) {
>                 if (swap)
> -                       raw_insw_swapw((u16 *)data_addr, (u16 *)buf, words);
> +                       raw_insw_swapw((u16 __iomem *)data_addr, (u16 *)buf, words);
>                 else
> -                       raw_insw((u16 *)data_addr, (u16 *)buf, words);
> +                       raw_insw((u16 __iomem *)data_addr, (u16 *)buf, words);
>         } else {
>                 if (swap)
> -                       raw_outsw_swapw((u16 *)data_addr, (u16 *)buf, words);
> +                       raw_outsw_swapw((u16 __iomem *)data_addr, (u16 *)buf, words);
>                 else
> -                       raw_outsw((u16 *)data_addr, (u16 *)buf, words);
> +                       raw_outsw((u16 __iomem *)data_addr, (u16 *)buf, words);

Can't you just drop the casts? data_addr is an __iomem void *.

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