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| author | Stephan Mueller <smueller@chronox.de> | 2018-07-10 17:56:33 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-07-20 13:51:21 +0800 |
| commit | cf862cbc831982a27f14a08adf82ad9ca8d86205 (patch) | |
| tree | 84b26e66645be295e8e91bace8bcd793daf4c51b /crypto/drbg.c | |
| parent | 3fd8093b41e745448ffeb0a0d3becc2cd1f9d7ad (diff) | |
| download | lwn-cf862cbc831982a27f14a08adf82ad9ca8d86205.tar.gz lwn-cf862cbc831982a27f14a08adf82ad9ca8d86205.zip | |
crypto: drbg - eliminate constant reinitialization of SGL
The CTR DRBG requires two SGLs pointing to input/output buffers for the
CTR AES operation. The used SGLs always have only one entry. Thus, the
SGL can be initialized during allocation time, preventing a
re-initialization of the SGLs during each call.
The performance is increased by about 1 to 3 percent depending on the
size of the requested buffer size.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/drbg.c')
| -rw-r--r-- | crypto/drbg.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/crypto/drbg.c b/crypto/drbg.c index 466a112a4446..ee302fd229ad 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1715,6 +1715,9 @@ static int drbg_init_sym_kernel(struct drbg_state *drbg) drbg->outscratchpad = (u8 *)PTR_ALIGN(drbg->outscratchpadbuf, alignmask + 1); + sg_init_table(&drbg->sg_in, 1); + sg_init_table(&drbg->sg_out, 1); + return alignmask; } @@ -1743,17 +1746,17 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg, u8 *inbuf, u32 inlen, u8 *outbuf, u32 outlen) { - struct scatterlist sg_in, sg_out; + struct scatterlist *sg_in = &drbg->sg_in, *sg_out = &drbg->sg_out; int ret; - sg_init_one(&sg_in, inbuf, inlen); - sg_init_one(&sg_out, drbg->outscratchpad, DRBG_OUTSCRATCHLEN); + sg_set_buf(sg_in, inbuf, inlen); + sg_set_buf(sg_out, drbg->outscratchpad, DRBG_OUTSCRATCHLEN); while (outlen) { u32 cryptlen = min3(inlen, outlen, (u32)DRBG_OUTSCRATCHLEN); /* Output buffer may not be valid for SGL, use scratchpad */ - skcipher_request_set_crypt(drbg->ctr_req, &sg_in, &sg_out, + skcipher_request_set_crypt(drbg->ctr_req, sg_in, sg_out, cryptlen, drbg->V); ret = crypto_wait_req(crypto_skcipher_encrypt(drbg->ctr_req), &drbg->ctr_wait); |