The current mv_cesa driver lacks DMA support and the speedups are rather small. Nevertheless, we have a reduced CPU utilization.
$this->bbcode_second_pass_quote('', 'O')penSSL uses a dedicated buffer to pass to the engine, which has to be filled (the userspace memcopy you're seeing). Mainline mv_cesa on the other hand does not use the DMA engine (yet), so the data has to be moved into the engine's SRAM by the CPU (the kernelspace memcopy).
-- Phil Sutter (cryptodev-linux)
New crypto driver: mv_cesa with DMA support
10 posts
• Page 1 of 1
New crypto driver: mv_cesa with DMA support
by CapJo » Tue Apr 14, 2015 10:55 pm
https://mail.gna.org/public/cryptodev-linux-devel/2012-09/threads.html#00012
Phil Sutter started to implement DMA support in 2012, but stopped after having some issues with different DMA engines in Marvel SoCs.
http://comments.gmane.org/gmane.linux.kernel.cryptoapi/7077
In 2014 the issue came up again, and was discussed.
http://comments.gmane.org/gmane.linux.kernel.cryptoapi/11892
Last week a new set of patches were send to the linux-crypto mailing list. Hopefully, they will be merged soon to benefit from the better crypto/ssh performance.
$this->bbcode_second_pass_quote('', 'H')ello,
This is an attempt to replace the mv_cesa driver by a new one to address some limitations of the existing driver. From a performance and CPU load point of view the most important limitation is the lack of DMA support, thus preventing us from chaining crypto operations.
I know we usually try to adapt existing drivers instead of replacing them by new ones, but after trying to refactor the mv_cesa driver I realized it would take longer than writing an new one from scratch.
Here are the main features brought by this new driver:
- support for armada SoCs (up to 38x) while keeping support for older ones (Orion and Kirkwood)
- DMA mode to offload the CPU in case of intensive crypto usage
- new algorithms: SHA256, DES and 3DES
-- Boris Brezillon (free-electrons.com)
http://lwn.net/Articles/639892/
Here are some benchmark results from the mailing list.
$this->bbcode_second_pass_code('', 'Here are some tests on 2 Marvell SoC (I do not have dove platforms at hand and did not collect the results for A370):
- Kirkwood 88F6282 (Feroceon 88FR131 rev 1) at 1.6GHz
- Armada XP (mv78230, i.e. 2 core <at> 1.2GHz)
The targets are AES ECB and CBC encryption (decryption is similar performance-wise), done w/ tcrypt (mode=500 passed to tcrypt module).
For each SoC, the various tests done by tcrypt are the following:
AES ECB/CBC encryption:
t 0 (128 bit key, 16 byte blocks)
t 1 (128 bit key, 64 byte blocks)
t 2 (128 bit key, 256 byte blocks)
t 3 (128 bit key, 1024 byte blocks)
t 4 (128 bit key, 8192 byte blocks)
t 5 (192 bit key, 16 byte blocks)
t 6 (192 bit key, 64 byte blocks)
t 7 (192 bit key, 256 byte blocks)
t 8 (192 bit key, 1024 byte blocks)
t 9 (192 bit key, 8192 byte blocks)
t 10 (256 bit key, 16 byte blocks)
t 11 (256 bit key, 64 byte blocks)
t 12 (256 bit key, 256 byte blocks)
t 13 (256 bit key, 1024 byte blocks)
t 14 (256 bit key, 8192 byte blocks)
The three columns provide the value for software implementation (aes-asm), current driver (if available for that SoC), submitted v0. The percentage is the improvement against software implementation.
soft current driver submitted v0
(if available)
KW:
ECB
t 0: 5.23 MB/s 1.01 MB/s (-80.58%) 1.11 MB/s (-78.75%)
t 1: 12.40 MB/s 3.70 MB/s (-70.16%) 4.14 MB/s (-66.59%)
t 2: 18.94 MB/s 10.81 MB/s (-42.94%) 13.86 MB/s (-26.78%)
t 3: 21.79 MB/s 20.69 MB/s (-5.05%) 33.80 MB/s (55.12%)
t 4: 22.54 MB/s 25.97 MB/s (15.23%) 50.27 MB/s (123.05%)
t 5: 5.00 MB/s 1.01 MB/s (-79.75%) 1.10 MB/s (-78.02%)
t 6: 11.35 MB/s 3.70 MB/s (-67.41%) 3.84 MB/s (-66.17%)
t 7: 16.60 MB/s 10.66 MB/s (-35.81%) 13.59 MB/s (-18.14%)
t 8: 18.76 MB/s 20.13 MB/s (7.29%) 32.30 MB/s (72.15%)
t 9: 19.20 MB/s 25.10 MB/s (30.74%) 47.11 MB/s (145.37%)
t10: 4.85 MB/s 1.02 MB/s (-79.02%) 1.10 MB/s (-77.25%)
t11: 10.50 MB/s 3.74 MB/s (-64.35%) 4.10 MB/s (-60.89%)
t12: 14.80 MB/s 4.65 MB/s (-68.55%) 13.40 MB/s (-9.43%)
t13: 16.47 MB/s 19.22 MB/s (16.69%) 31.14 MB/s (89.02%)
t14: 16.89 MB/s 24.36 MB/s (44.18%) 44.33 MB/s (162.40%)
CBC
t 0: 4.78 MB/s 0.98 MB/s (-79.50%) 1.09 MB/s (-77.12%)
t 1: 11.44 MB/s 3.59 MB/s (-68.62%) 4.07 MB/s (-64.41%)
t 2: 17.66 MB/s 10.53 MB/s (-40.38%) 13.67 MB/s (-22.58%)
t 3: 20.41 MB/s 20.42 MB/s (0.00%) 33.50 MB/s (64.10%)
t 4: 21.14 MB/s 25.86 MB/s (22.36%) 50.02 MB/s (136.63%)
t 5: 4.58 MB/s 0.98 MB/s (-78.64%) 1.08 MB/s (-76.31%)
t 6: 10.54 MB/s 3.58 MB/s (-66.00%) 4.04 MB/s (-61.68%)
t 7: 15.61 MB/s 10.39 MB/s (-33.49%) 13.40 MB/s (-14.16%)
t 8: 17.73 MB/s 19.88 MB/s (12.10%) 32.04 MB/s (80.69%)
t 9: 18.18 MB/s 25.02 MB/s (37.60%) 46.90 MB/s (157.97%)
t10: 4.45 MB/s 0.98 MB/s (-77.96%) 1.09 MB/s (-75.62%)
t11: 9.80 MB/s 3.60 MB/s (-63.28%) 4.03 MB/s (-58.83%)
t12: 14.01 MB/s 4.34 MB/s (-69.01%) 13.24 MB/s (-5.48%)
t13: 15.67 MB/s 19.44 MB/s (24.01%) 30.90 MB/s (97.17%)
t14: 16.09 MB/s 24.28 MB/s (50.85%) 44.15 MB/s (174.34%)
XP:
ECB
t 0: 8.85 MB/s 0.77 MB/s (-91.25%)
t 1: 21.73 MB/s 3.09 MB/s (-85.79%)
t 2: 34.81 MB/s 12.35 MB/s (-64.52%)
t 3: 40.81 MB/s 38.68 MB/s (-5.22%)
t 4: 42.69 MB/s 84.52 MB/s (98.00%)
t 5: 8.55 MB/s 0.78 MB/s (-90.92%)
t 6: 20.63 MB/s 3.11 MB/s (-84.92%)
t 7: 31.47 MB/s 12.43 MB/s (-60.52%)
t 8: 36.07 MB/s 38.08 MB/s (5.58%)
t 9: 37.09 MB/s 80.43 MB/s (116.85%)
t10: 8.25 MB/s 0.78 MB/s (-90.56%)
t11: 19.19 MB/s 3.11 MB/s (-83.80%)
t12: 28.61 MB/s 12.42 MB/s (-56.59%)
t13: 32.49 MB/s 37.28 MB/s (14.74%)
t14: 33.56 MB/s 77.11 MB/s (129.79%)
CBC
t 0: 8.20 MB/s 0.78 MB/s (-90.53%)
t 1: 19.85 MB/s 3.10 MB/s (-84.36%)
t 2: 31.60 MB/s 12.42 MB/s (-60.69%)
t 3: 37.03 MB/s 38.70 MB/s (4.51%)
t 4: 38.76 MB/s 84.05 MB/s (116.87%)
t 5: 7.69 MB/s 0.78 MB/s (-89.90%)
t 6: 18.62 MB/s 3.10 MB/s (-83.32%)
t 7: 28.47 MB/s 12.40 MB/s (-56.44%)
t 8: 32.73 MB/s 37.97 MB/s (16.02%)
t 9: 33.73 MB/s 79.96 MB/s (137.07%)
t10: 7.58 MB/s 0.77 MB/s (-89.88%)
t11: 17.59 MB/s 3.07 MB/s (-82.56%)
t12: 26.26 MB/s 12.28 MB/s (-53.23%)
t13: 29.89 MB/s 37.02 MB/s (23.87%)
t14: 30.87 MB/s 76.70 MB/s (148.45%)')
- CapJo
- Posts: 9
- Joined: Tue Apr 14, 2015 10:21 pm