Re: [PATCH v2 0/4] crypto: rockchip: Add RK356x/RK3588 cryptographic offloader

["Diederik de Haas" <diederik@cknow-tech.com>]

On Tue Aug 18, 2026 at 8:58 PM CEST, Eric Biggers wrote:
> On Mon, Aug 03, 2026 at 12:42:03PM +0200, Diederik de Haas wrote:
>> crypto-rk3566-test-no-crypto-module-log.txt:
>> https://paste.sr.ht/~diederik/bb5dbfd59f244a6422b965b30f9796ebbfdb1fcb
>> crypto-rk3566-test-with-crypto-module-log.txt:
>> https://paste.sr.ht/~diederik/ea72297678e19cbbc987de9548f9884382e1d1cc
>> crypto-rk3568-test-no-crypto-module-log.txt:
>> https://paste.sr.ht/~diederik/309e519e6b1c31f4c1c5bcb1ea16cc8569a54830
>> crypto-rk3568-test-with-crypto-module-log.txt:
>> https://paste.sr.ht/~diederik/1e1e938ebbbae75128974fe0a7c240843bce04c8
>> crypto-rk3588-test-no-crypto-module-log.txt:
>> https://paste.sr.ht/~diederik/9a2adc2b2e42131445ce4576589e00ecf51ccb4b
>> crypto-rk3588-test-with-crypto-module-log.txt:
>> https://paste.sr.ht/~diederik/e04c11c8809031ca45662f7d4c227c1ba6162b65
>
> Thanks for running some benchmarks!
>
> Looking at your results for rk3566 for example, SHA-256 on 4096-byte
> blocks is 115 cycles/operation for sha256-lib (i.e. ARMv8 CE) or 3027
> cycles/operation for rk2-sha256.  So the Rockchip driver is 26 times
> slower than simply using the existing well-tested CPU-based code.

I shared the results because:
1) I figured it might be useful to have these numbers
2) I didn't know how to interpret the results.

Because a lower cycles/operations would IMO *logically* be better and
your response above seems to confirm that.

Which makes the following results a 'bit' concerning?
``modprobe tcrypt mode=404``

[255753.686837] tcrypt: testing speed of async sha256 (sha256-lib)
[255753.686841] tcrypt: test  0 (   16 byte blocks,   16 bytes per update,   1 updates):    703 cycles/operation,   43 cycles/byte
[255753.686848] tcrypt: test  1 (   64 byte blocks,   16 bytes per update,   4 updates):   1101 cycles/operation,   17 cycles/byte
[255753.686856] tcrypt: test  2 (   64 byte blocks,   64 bytes per update,   1 updates):    869 cycles/operation,   13 cycles/byte
[255753.686861] tcrypt: test  3 (  256 byte blocks,   16 bytes per update,  16 updates):   1676 cycles/operation,    6 cycles/byte
[255753.686871] tcrypt: test  4 (  256 byte blocks,   64 bytes per update,   4 updates):   1059 cycles/operation,    4 cycles/byte
[255753.686877] tcrypt: test  5 (  256 byte blocks,  256 bytes per update,   1 updates):   1249 cycles/operation,    4 cycles/byte
[255753.686884] tcrypt: test  6 ( 1024 byte blocks,   16 bytes per update,  64 updates):   4156 cycles/operation,    4 cycles/byte
[255753.686904] tcrypt: test  7 ( 1024 byte blocks,  256 bytes per update,   4 updates):   1054 cycles/operation,    1 cycles/byte
[255753.686911] tcrypt: test  8 ( 1024 byte blocks, 1024 bytes per update,   1 updates):   2826 cycles/operation,    2 cycles/byte
[255753.686923] tcrypt: test  9 ( 2048 byte blocks,   16 bytes per update, 128 updates):   7438 cycles/operation,    3 cycles/byte
[255753.686957] tcrypt: test 10 ( 2048 byte blocks,  256 bytes per update,   8 updates):   1263 cycles/operation,    0 cycles/byte
[255753.686966] tcrypt: test 11 ( 2048 byte blocks, 1024 bytes per update,   2 updates):    940 cycles/operation,    0 cycles/byte
[255753.686973] tcrypt: test 12 ( 2048 byte blocks, 2048 bytes per update,   1 updates):   4887 cycles/operation,    2 cycles/byte
[255753.686991] tcrypt: test 13 ( 4096 byte blocks,   16 bytes per update, 256 updates):  14017 cycles/operation,    3 cycles/byte
[255753.687054] tcrypt: test 14 ( 4096 byte blocks,  256 bytes per update,  16 updates):   1681 cycles/operation,    0 cycles/byte
[255753.687065] tcrypt: test 15 ( 4096 byte blocks, 1024 bytes per update,   4 updates):   1059 cycles/operation,    0 cycles/byte
[255753.687074] tcrypt: test 16 ( 4096 byte blocks, 4096 bytes per update,   1 updates):   9044 cycles/operation,    2 cycles/byte
[255753.687105] tcrypt: test 17 ( 8192 byte blocks,   16 bytes per update, 512 updates):  27155 cycles/operation,    3 cycles/byte
[255753.687224] tcrypt: test 18 ( 8192 byte blocks,  256 bytes per update,  32 updates):   2489 cycles/operation,    0 cycles/byte
[255753.687241] tcrypt: test 19 ( 8192 byte blocks, 1024 bytes per update,   8 updates):   1268 cycles/operation,    0 cycles/byte
[255753.687253] tcrypt: test 20 ( 8192 byte blocks, 4096 bytes per update,   2 updates):    959 cycles/operation,    0 cycles/byte
[255753.687263] tcrypt: test 21 ( 8192 byte blocks, 8192 bytes per update,   1 updates):  17812 cycles/operation,    2 cycles/byte

This is on my AMD Ryzen 7 5800X which I would've expected to blow
a simple RK3566 SBC out of the water ... :-/

> Don't you love "accelerators" that make things 26 times slower?
>
> I guess we'll get the usual argument that this driver is really just for
> "testing" or whatever.

Or someone spend a significant time implementing it trying to improve and
extend SoC support in good faith, but without your insight. 
Which is 'coincidentally' the exact reason why I suggested the patch series
author to explicitly put you in To or CC.
I would not have used "pushing the driver as a checkbox feature" as argument.
Especially since, apparently, the numbers show it performs poorly.

My 0.02