On Fri, May 09, 2025 at 10:33:08PM -0700, Eric Biggers wrote:
>
> Yes, the PowerPC Poly1305 code incorrectly uses VSX without first checking
> crypto_simd_usable().  And PowerPC also doesn't support VSX in softirqs, or at
> least it doesn't claim to (it doesn't override may_use_simd(), so it gets the
> default from include/asm-generic/simd.h which returns false in softirq 
> context).
> Maybe add 'depends on BROKEN' to CRYPTO_POLY1305_P10 for now, and give the
> PowerPC folks (Cc'ed) a chance to fix this before removing the code.

I just noticed something weird with this code, running a speed
test using "modprobe tcrypt mode=217" shows that the p10 version
of poly1305 is way slower than the generic:

qemu P9 CPU:

May 10 13:36:46 test-p10 kernel: [   59.585264][  T374] tcrypt: testing speed 
of multibuffer rfc7539esp(chacha20,poly1305) 
(rfc7539esp(chacha20-generic,poly1305-generic)) encryption
May 10 13:36:46 test-p10 kernel: [   59.586011][  T374] tcrypt: test 0 (288 bit 
key, 16 byte blocks): 1 operation in 1374 cycles (16 bytes)
May 10 13:36:46 test-p10 kernel: [   59.587446][  T374] tcrypt: test 1 (288 bit 
key, 64 byte blocks): 1 operation in 1359 cycles (64 bytes)
May 10 13:36:46 test-p10 kernel: [   59.588025][  T374] tcrypt: test 2 (288 bit 
key, 256 byte blocks): 1 operation in 1778 cycles (256 bytes)
May 10 13:36:46 test-p10 kernel: [   59.588639][  T374] tcrypt: test 3 (288 bit 
key, 512 byte blocks): 1 operation in 2323 cycles (512 bytes)
May 10 13:36:46 test-p10 kernel: [   59.589342][  T374] tcrypt: test 4 (288 bit 
key, 1024 byte blocks): 1 operation in 31624 cycles (1024 bytes)
May 10 13:36:46 test-p10 kernel: [   59.594178][  T374] tcrypt: test 5 (288 bit 
key, 1420 byte blocks): 1 operation in 4408 cycles (1420 bytes)
May 10 13:36:46 test-p10 kernel: [   59.595317][  T374] tcrypt: test 6 (288 bit 
key, 4096 byte blocks): 1 operation in 9719 cycles (4096 bytes)
May 10 13:36:46 test-p10 kernel: [   59.597512][  T374] tcrypt: test 7 (288 bit 
key, 8192 byte blocks): 1 operation in 20168 cycles (8192 bytes)
May 10 13:36:46 test-p10 kernel: [   59.604616][  T374] tcrypt: testing speed 
of multibuffer rfc7539esp(chacha20,poly1305) 
(rfc7539esp(chacha20-generic,poly1305-generic)) decryption
May 10 13:36:46 test-p10 kernel: [   59.604916][  T374] tcrypt: test 0 (288 bit 
key, 16 byte blocks): 1 operation in 1356 cycles (16 bytes)
May 10 13:36:46 test-p10 kernel: [   59.605564][  T374] tcrypt: test 1 (288 bit 
key, 64 byte blocks): 1 operation in 1393 cycles (64 bytes)
May 10 13:36:46 test-p10 kernel: [   59.608308][  T374] tcrypt: test 2 (288 bit 
key, 256 byte blocks): 1 operation in 1845 cycles (256 bytes)
May 10 13:36:46 test-p10 kernel: [   59.609002][  T374] tcrypt: test 3 (288 bit 
key, 512 byte blocks): 1 operation in 2392 cycles (512 bytes)
May 10 13:36:46 test-p10 kernel: [   59.612109][  T374] tcrypt: test 4 (288 bit 
key, 1024 byte blocks): 1 operation in 3349 cycles (1024 bytes)
May 10 13:36:46 test-p10 kernel: [   59.613289][  T374] tcrypt: test 5 (288 bit 
key, 1420 byte blocks): 1 operation in 4418 cycles (1420 bytes)
May 10 13:36:46 test-p10 kernel: [   59.616233][  T374] tcrypt: test 6 (288 bit 
key, 4096 byte blocks): 1 operation in 21600 cycles (4096 bytes)
May 10 13:36:46 test-p10 kernel: [   59.620221][  T374] tcrypt: test 7 (288 bit 
key, 8192 byte blocks): 1 operation in 20013 cycles (8192 bytes)

qemu P10 CPU:

May 10 13:40:56 test-p10 kernel: [   91.672877][  T392] tcrypt: testing speed 
of multibuffer rfc7539esp(chacha20,poly1305) 
(rfc7539esp(chacha20-powerpc,poly1305-generic)) encryption
May 10 13:40:56 test-p10 kernel: [   91.674615][  T392] tcrypt: test 0 (288 bit 
key, 16 byte blocks): 1 operation in 1471 cycles (16 bytes)
May 10 13:40:56 test-p10 kernel: [   91.680240][  T392] tcrypt: test 1 (288 bit 
key, 64 byte blocks): 1 operation in 1733 cycles (64 bytes)
May 10 13:40:56 test-p10 kernel: [   91.682975][  T392] tcrypt: test 2 (288 bit 
key, 256 byte blocks): 1 operation in 3248 cycles (256 bytes)
May 10 13:40:56 test-p10 kernel: [   91.684445][  T392] tcrypt: test 3 (288 bit 
key, 512 byte blocks): 1 operation in 15211 cycles (512 bytes)
May 10 13:40:56 test-p10 kernel: [   91.687603][  T392] tcrypt: test 4 (288 bit 
key, 1024 byte blocks): 1 operation in 20500 cycles (1024 bytes)
May 10 13:40:56 test-p10 kernel: [   91.690926][  T392] tcrypt: test 5 (288 bit 
key, 1420 byte blocks): 1 operation in 10159 cycles (1420 bytes)
May 10 13:40:56 test-p10 kernel: [   91.695009][  T392] tcrypt: test 6 (288 bit 
key, 4096 byte blocks): 1 operation in 25917 cycles (4096 bytes)
May 10 13:40:56 test-p10 kernel: [   91.701320][  T392] tcrypt: test 7 (288 bit 
key, 8192 byte blocks): 1 operation in 63352 cycles (8192 bytes)
May 10 13:40:56 test-p10 kernel: [   91.713863][  T392] tcrypt: testing speed 
of multibuffer rfc7539esp(chacha20,poly1305) 
(rfc7539esp(chacha20-powerpc,poly1305-generic)) decryption
May 10 13:40:56 test-p10 kernel: [   91.714182][  T392] tcrypt: test 0 (288 bit 
key, 16 byte blocks): 1 operation in 1502 cycles (16 bytes)
May 10 13:40:56 test-p10 kernel: [   91.714871][  T392] tcrypt: test 1 (288 bit 
key, 64 byte blocks): 1 operation in 1778 cycles (64 bytes)
May 10 13:40:56 test-p10 kernel: [   91.715508][  T392] tcrypt: test 2 (288 bit 
key, 256 byte blocks): 1 operation in 3322 cycles (256 bytes)
May 10 13:40:56 test-p10 kernel: [   91.716463][  T392] tcrypt: test 3 (288 bit 
key, 512 byte blocks): 1 operation in 20980 cycles (512 bytes)
May 10 13:40:56 test-p10 kernel: [   91.720775][  T392] tcrypt: test 4 (288 bit 
key, 1024 byte blocks): 1 operation in 8000 cycles (1024 bytes)
May 10 13:40:56 test-p10 kernel: [   91.724348][  T392] tcrypt: test 5 (288 bit 
key, 1420 byte blocks): 1 operation in 10155 cycles (1420 bytes)
May 10 13:40:56 test-p10 kernel: [   91.727952][  T392] tcrypt: test 6 (288 bit 
key, 4096 byte blocks): 1 operation in 27711 cycles (4096 bytes)
May 10 13:40:56 test-p10 kernel: [   91.735306][  T392] tcrypt: test 7 (288 bit 
key, 8192 byte blocks): 1 operation in 52874 cycles (8192 bytes)

Did I do something wrong?

Cheers,
-- 
Email: Herbert Xu <herb...@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

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