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From:   Arnd Bergmann <arnd@kernel.org>
Date:   Mon, 16 Nov 2020 16:47:11 +0100
Message-ID: <CAK8P3a0UZHmM2xfKegZ4mo_7N15614YPhx_FoY_h6WWF9M58Uw@mail.gmail.com>
Subject: Re: [PATCH v3 4/7] crypto: sun4i-ss: handle BigEndian for cipher
To:     Corentin Labbe <clabbe@baylibre.com>
Cc:     Arnd Bergmann <arnd@arndb.de>, David Miller <davem@davemloft.net>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Jernej Skrabec <jernej.skrabec@siol.net>,
        Maxime Ripard <mripard@kernel.org>,
        Chen-Yu Tsai <wens@csie.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" 
        <linux-crypto@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        linux-sunxi <linux-sunxi@googlegroups.com>,
        "# 3.4.x" <stable@vger.kernel.org>
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On Mon, Nov 16, 2020 at 2:53 PM Corentin Labbe <clabbe@baylibre.com> wrote:
>
> Ciphers produce invalid results on BE.
> Key and IV need to be written in LE.
>
> Fixes: 6298e948215f2 ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
> ---
>  drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
> index 53478c3feca6..8f4621826330 100644
> --- a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
> +++ b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
> @@ -52,13 +52,13 @@ static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
>
>         spin_lock_irqsave(&ss->slock, flags);
>
> -       for (i = 0; i < op->keylen; i += 4)
> -               writel(*(op->key + i / 4), ss->base + SS_KEY0 + i);
> +       for (i = 0; i < op->keylen / 4; i++)
> +               writesl(ss->base + SS_KEY0 + i * 4, &op->key[i], 1);
>

This looks correct, but I wonder if we should just introduce
memcpy_toio32() and memcpy_fromio32() as a generic interface,
as this seems to come up occasionally, and the method here
(a loop around an inline function with another loop) is a bit clumsy.

      Arnd