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@xxxxxxxxxx> --- crypto/drbg.c | 11 +++++++---- include/crypto/drbg.h | 1 + 2 files changed, 8 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); diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h index 8f941102af36..54b9f5d375f5 100644 --- a/include/crypto/drbg.h +++ b/include/crypto/drbg.h @@ -127,6 +127,7 @@ struct drbg_state { __u8 *outscratchpadbuf; /* CTR mode output scratchpad */ __u8 *outscratchpad; /* CTR mode aligned outbuf */ struct crypto_wait ctr_wait; /* CTR mode async wait obj */ + struct scatterlist sg_in, sg_out; /* CTR mode SGLs */ bool seeded; /* DRBG fully seeded? */ bool pr; /* Prediction resistance enabled? */ -- 2.17.1