diff mbox series

[v2,4/7] crypto: sun4i-ss: handle BigEndian for cipher

Message ID 1600627038-40000-5-git-send-email-clabbe@baylibre.com (mailing list archive)
State Changes Requested
Delegated to: Herbert Xu
Headers show
Series crypto: sun4i-ss: prevent always fallback for ciphers | expand

Commit Message

Corentin Labbe Sept. 20, 2020, 6:37 p.m. UTC
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(-)

Comments

Arnd Bergmann Sept. 23, 2020, 2 p.m. UTC | #1
On Sun, Sep 20, 2020 at 8:37 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 c6c25204780d..a05889745097 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++)
> +               writel(cpu_to_le32(op->key[i]), ss->base + SS_KEY0 + i * 4);

I suspect what you actually want here is writesl() in place of the
loop. This skips the byteswap on big-endian, rather than swapping
each word twice.

The point is that this register seems to act as a FIFO for a byte-stream
rather than a 32-bit fixed-endian register.

     Arnd
Corentin Labbe Sept. 23, 2020, 6:06 p.m. UTC | #2
On Wed, Sep 23, 2020 at 04:00:32PM +0200, Arnd Bergmann wrote:
> On Sun, Sep 20, 2020 at 8:37 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 c6c25204780d..a05889745097 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++)
> > +               writel(cpu_to_le32(op->key[i]), ss->base + SS_KEY0 + i * 4);
> 
> I suspect what you actually want here is writesl() in place of the
> loop. This skips the byteswap on big-endian, rather than swapping
> each word twice.
> 
> The point is that this register seems to act as a FIFO for a byte-stream
> rather than a 32-bit fixed-endian register.
> 
>      Arnd

Thanks, using writesl() fixes the warning, but I need to keep the loop since the register is different each time.
Or does it is better to use directly __raw_writel() ?
Arnd Bergmann Sept. 23, 2020, 6:59 p.m. UTC | #3
On Wed, Sep 23, 2020 at 8:08 PM LABBE Corentin <clabbe@baylibre.com> wrote:
> On Wed, Sep 23, 2020 at 04:00:32PM +0200, Arnd Bergmann wrote:
> > On Sun, Sep 20, 2020 at 8:37 PM Corentin Labbe <clabbe@baylibre.com> wrote:
> > > diff --git a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
> > > index c6c25204780d..a05889745097 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++)
> > > +               writel(cpu_to_le32(op->key[i]), ss->base + SS_KEY0 + i * 4);
> >
> > I suspect what you actually want here is writesl() in place of the
> > loop. This skips the byteswap on big-endian, rather than swapping
> > each word twice.
> >
> > The point is that this register seems to act as a FIFO for a byte-stream
> > rather than a 32-bit fixed-endian register.
>
> Thanks, using writesl() fixes the warning, but I need to keep the loop
> since the register is different each time.

Ah, I see. I thought we had an interface for that as well, but I can't
find it now. I see memcpy_toio32() in one driver, but that implementation
appears to be wrong here (and probably also wrong for the machine
it was meant for)

There is the regular memcpy_toio(), but on big-endian Arm that
turns into a per-byte copy, which might either not work on your
hardware or be too slow.

There is also __iowrite32_copy(), which is not what I had remembered
but does seem to do what you want here.

> Or does it is better to use directly __raw_writel() ?

__raw_writel() is not very portable, so I would avoid that in normal
device drivers even when you only run them on specific hardware.

      Arnd
diff mbox series

Patch

diff --git a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
index c6c25204780d..a05889745097 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++)
+		writel(cpu_to_le32(op->key[i]), ss->base + SS_KEY0 + i * 4);
 
 	if (areq->iv) {
 		for (i = 0; i < 4 && i < ivsize / 4; i++) {
 			v = *(u32 *)(areq->iv + i * 4);
-			writel(v, ss->base + SS_IV0 + i * 4);
+			writel(cpu_to_le32(v), ss->base + SS_IV0 + i * 4);
 		}
 	}
 	writel(mode, ss->base + SS_CTL);
@@ -225,13 +225,13 @@  static int sun4i_ss_cipher_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++)
+		writel(cpu_to_le32(op->key[i]), ss->base + SS_KEY0 + i * 4);
 
 	if (areq->iv) {
 		for (i = 0; i < 4 && i < ivsize / 4; i++) {
 			v = *(u32 *)(areq->iv + i * 4);
-			writel(v, ss->base + SS_IV0 + i * 4);
+			writel(cpu_to_le32(v), ss->base + SS_IV0 + i * 4);
 		}
 	}
 	writel(mode, ss->base + SS_CTL);