[PATCH 3.12 025/235] crypto: caam - fix AEAD givenc descriptors

From: Jiri Slaby
Date: Fri Jan 27 2017 - 05:59:04 EST

From: Alex Porosanu <alexandru.porosanu@xxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.


commit d128af17876d79b87edf048303f98b35f6a53dbc upstream.

The AEAD givenc descriptor relies on moving the IV through the
output FIFO and then back to the CTX2 for authentication. The
SEQ FIFO STORE could be scheduled before the data can be
read from OFIFO, especially since the SEQ FIFO LOAD needs
to wait for the SEQ FIFO LOAD SKIP to finish first. The
SKIP takes more time when the input is SG than when it's
a contiguous buffer. If the SEQ FIFO LOAD is not scheduled
before the STORE, the DECO will hang waiting for data
to be available in the OFIFO so it can be transferred to C2.
In order to overcome this, first force transfer of IV to C2
by starting the "cryptlen" transfer first and then starting to
store data from OFIFO to the output buffer.

Fixes: 1acebad3d8db8 ("crypto: caam - faster aead implementation")
Signed-off-by: Alex Porosanu <alexandru.porosanu@xxxxxxx>
Signed-off-by: Horia GeantÄ <horia.geanta@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
drivers/crypto/caam/caamalg.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index 7c63b72ecd75..66f549399dc4 100644
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -418,7 +418,9 @@ static int aead_set_sh_desc(struct crypto_aead *aead)

/* Will read cryptlen */
append_math_add(desc, VARSEQINLEN, SEQINLEN, REG0, CAAM_CMD_SZ);
- aead_append_src_dst(desc, FIFOLD_TYPE_MSG1OUT2);
+ append_seq_fifo_load(desc, 0, FIFOLD_CLASS_BOTH | KEY_VLF |
+ append_seq_fifo_store(desc, 0, FIFOST_TYPE_MESSAGE_DATA | KEY_VLF);

/* Write ICV */
append_seq_store(desc, ctx->authsize, LDST_CLASS_2_CCB |