tree 69353b8d8a6c390fccc526f83f0cc0d828aeb1b0
parent 15b2455ab4e6434a53c639bd2a168cd2a3e1eb47
author Horia Geantă <horia.geanta@nxp.com> 1564465713 +0300
committer Herbert Xu <herbert@gondor.apana.org.au> 1565327134 +1000

crypto: caam - fix concurrency issue in givencrypt descriptor

IV transfer from ofifo to class2 (set up at [29][30]) is not guaranteed
to be scheduled before the data transfer from ofifo to external memory
(set up at [38]:

[29] 10FA0004           ld: ind-nfifo (len=4) imm
[30] 81F00010               <nfifo_entry: ofifo->class2 type=msg len=16>
[31] 14820004           ld: ccb2-datasz len=4 offs=0 imm
[32] 00000010               data:0x00000010
[33] 8210010D    operation: cls1-op aes cbc init-final enc
[34] A8080B04         math: (seqin + math0)->vseqout len=4
[35] 28000010    seqfifold: skip len=16
[36] A8080A04         math: (seqin + math0)->vseqin len=4
[37] 2F1E0000    seqfifold: both msg1->2-last2-last1 len=vseqinsz
[38] 69300000   seqfifostr: msg len=vseqoutsz
[39] 5C20000C      seqstr: ccb2 ctx len=12 offs=0

If ofifo -> external memory transfer happens first, DECO will hang
(issuing a Watchdog Timeout error, if WDOG is enabled) waiting for
data availability in ofifo for the ofifo -> c2 ififo transfer.

Make sure IV transfer happens first by waiting for all CAAM internal
transfers to end before starting payload transfer.

New descriptor with jump command inserted at [37]:

[..]
[36] A8080A04         math: (seqin + math0)->vseqin len=4
[37] A1000401         jump: jsl1 all-match[!nfifopend] offset=[01] local->[38]
[38] 2F1E0000    seqfifold: both msg1->2-last2-last1 len=vseqinsz
[39] 69300000   seqfifostr: msg len=vseqoutsz
[40] 5C20000C      seqstr: ccb2 ctx len=12 offs=0

[Note: the issue is present in the descriptor from the very beginning
(cf. Fixes tag). However I've marked it v4.19+ since it's the oldest
maintained kernel that the patch applies clean against.]

Cc: <stable@vger.kernel.org> # v4.19+
Fixes: 1acebad3d8db8 ("crypto: caam - faster aead implementation")
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>