RE: [PATCH v1 2/7] AES for PPC/SPE - aes tables

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From:  Markus Stockhausen
> 4K AES tables for big endian

I can't help feeling that you could give more information about how the
values are generated.

...
> + * These big endian AES encryption/decryption tables are designed to be simply
> + * accessed by a combination of rlwimi/lwz instructions with a minimum
> + * of table registers (usually only one required). Thus they are aligned to
> + * 4K. The locality of rotated values is derived from the reduced offsets that
> + * are available in the SPE load instructions. E.g. evldw, evlwwsplat, ...
> + *
> + */
> +.data
> +.align 12
> +.globl PPC_AES_4K_ENCTAB
> +PPC_AES_4K_ENCTAB:
> +	.long 0xc66363a5,0xa5c66363,0x63a5c663,0x6363a5c6

These seem to be byte rotates (all down the table).
If so then use a CPP define to generate the rotated values.

I'd like to see a reference to where the values themselves come from.

> +	.long 0xf87c7c84,0x84f87c7c,0x7c84f87c,0x7c7c84f8
...
> +	.long 0x6dbbbbd6,0xd66dbbbb,0xbbd66dbb,0xbbbbd66d
> +	.long 0x2c16163a,0x3a2c1616,0x163a2c16,0x16163a2c
> +.globl PPC_AES_4K_DECTAB
> +PPC_AES_4K_DECTAB:
> +	.long 0x51f4a750,0x5051f4a7,0xa75051f4,0xf4a75051
...
> +	.long 0xd0b85742,0x42d0b857,0x5742d0b8,0xb85742d0

Some explanation of this third dataset is also needed.

> +	.byte 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38
...
> +	.byte 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d

	David

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