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[0/4] crypto: nintendo-aes - add a new AES driver

Message ID 20210921213930.10366-1-linkmauve@linkmauve.fr (mailing list archive)
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Series crypto: nintendo-aes - add a new AES driver | expand

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Emmanuel Gil Peyrot Sept. 21, 2021, 9:39 p.m. UTC 
This engine implements AES in CBC mode, using 128-bit keys only.  It is
present on both the Wii and the Wii U, and is apparently identical in
both consoles.

The hardware is capable of firing an interrupt when the operation is
done, but this driver currently uses a busy loop, I’m not too sure
whether it would be preferable to switch, nor how to achieve that.

It also supports a mode where no operation is done, and thus could be
used as a DMA copy engine, but I don’t know how to expose that to the
kernel or whether it would even be useful.

In my testing, on a Wii U, this driver reaches 80.7 MiB/s, while the
aes-generic driver only reaches 30.9 MiB/s, so it is a quite welcome
speedup.

This driver was written based on reversed documentation, see:
https://wiibrew.org/wiki/Hardware/AES

Emmanuel Gil Peyrot (4):
  crypto: nintendo-aes - add a new AES driver
  dt-bindings: nintendo-aes: Document the Wii and Wii U AES support
  powerpc: wii.dts: Expose the AES engine on this platform
  powerpc: wii_defconfig: Enable AES by default

 .../bindings/crypto/nintendo-aes.yaml         |  34 +++
 arch/powerpc/boot/dts/wii.dts                 |   7 +
 arch/powerpc/configs/wii_defconfig            |   4 +-
 drivers/crypto/Kconfig                        |  11 +
 drivers/crypto/Makefile                       |   1 +
 drivers/crypto/nintendo-aes.c                 | 273 ++++++++++++++++++
 6 files changed, 329 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/crypto/nintendo-aes.yaml
 create mode 100644 drivers/crypto/nintendo-aes.c

Comments

Eric Biggers Sept. 21, 2021, 9:59 p.m. UTC | #1 
On Tue, Sep 21, 2021 at 11:39:26PM +0200, Emmanuel Gil Peyrot wrote:
> This engine implements AES in CBC mode, using 128-bit keys only.  It is
> present on both the Wii and the Wii U, and is apparently identical in
> both consoles.
> 
> The hardware is capable of firing an interrupt when the operation is
> done, but this driver currently uses a busy loop, I’m not too sure
> whether it would be preferable to switch, nor how to achieve that.
> 
> It also supports a mode where no operation is done, and thus could be
> used as a DMA copy engine, but I don’t know how to expose that to the
> kernel or whether it would even be useful.
> 
> In my testing, on a Wii U, this driver reaches 80.7 MiB/s, while the
> aes-generic driver only reaches 30.9 MiB/s, so it is a quite welcome
> speedup.
> 
> This driver was written based on reversed documentation, see:
> https://wiibrew.org/wiki/Hardware/AES
> 
> Emmanuel Gil Peyrot (4):
>   crypto: nintendo-aes - add a new AES driver
>   dt-bindings: nintendo-aes: Document the Wii and Wii U AES support
>   powerpc: wii.dts: Expose the AES engine on this platform
>   powerpc: wii_defconfig: Enable AES by default

Does this pass the self-tests, including the fuzz tests which are enabled by
CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y?

- Eric
Emmanuel Gil Peyrot Sept. 21, 2021, 10:37 p.m. UTC | #2 
On Tue, Sep 21, 2021 at 02:59:37PM -0700, Eric Biggers wrote:
> On Tue, Sep 21, 2021 at 11:39:26PM +0200, Emmanuel Gil Peyrot wrote:
> > This engine implements AES in CBC mode, using 128-bit keys only.  It is
> > present on both the Wii and the Wii U, and is apparently identical in
> > both consoles.
> > 
> > The hardware is capable of firing an interrupt when the operation is
> > done, but this driver currently uses a busy loop, I’m not too sure
> > whether it would be preferable to switch, nor how to achieve that.
> > 
> > It also supports a mode where no operation is done, and thus could be
> > used as a DMA copy engine, but I don’t know how to expose that to the
> > kernel or whether it would even be useful.
> > 
> > In my testing, on a Wii U, this driver reaches 80.7 MiB/s, while the
> > aes-generic driver only reaches 30.9 MiB/s, so it is a quite welcome
> > speedup.
> > 
> > This driver was written based on reversed documentation, see:
> > https://wiibrew.org/wiki/Hardware/AES
> > 
> > Emmanuel Gil Peyrot (4):
> >   crypto: nintendo-aes - add a new AES driver
> >   dt-bindings: nintendo-aes: Document the Wii and Wii U AES support
> >   powerpc: wii.dts: Expose the AES engine on this platform
> >   powerpc: wii_defconfig: Enable AES by default
> 
> Does this pass the self-tests, including the fuzz tests which are enabled by
> CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y?

I wasn’t aware of those, and indeed it doesn’t pass them yet:
[    0.680164] alg: skcipher: cbc-aes-nintendo encryption overran dst buffer on test vector 0, cfg="out-of-place"
[    0.680201] fbcon: Taking over console
[    0.680219] ------------[ cut here ]------------
[    0.680222] alg: self-tests for cbc-aes-nintendo (cbc(aes)) failed (rc=-75)

I’ll try to figure out how to debug this and I’ll send a v2, thanks for
the hint!

> 
> - Eric