Reduce the per-packet allocation costs for crypto operations (cryptop)

by pre-allocating two cryptodesc objects and storing them in an array
instead of a linked list.  If more than two cryptodesc objects are
required use mallocarray to fetch them.  Adapt the drivers to the new
API.

This change results in one pool-get per ESP packet instead of three.
It also simplifies softraid crypto where more cryptodesc objects are
allocated than used.

From, with and ok markus@, ok bluhm@
"looks sane" mpi@

14 files changed, 102 insertions, 90 deletions

diff --git a/sys/arch/amd64/amd64/aesni.c b/sys/arch/amd64/amd64/aesni.c
index b712cdceaef..dd8dbfd3ed9 100644
--- a/sys/arch/amd64/amd64/aesni.c
+++ b/sys/arch/amd64/amd64/aesni.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: aesni.c,v 1.39 2016/09/15 02:00:16 dlg Exp $	*/
+/*	$OpenBSD: aesni.c,v 1.40 2017/02/07 17:25:45 patrick Exp $	*/
 /*-
  * Copyright (c) 2003 Jason Wright
  * Copyright (c) 2003, 2004 Theo de Raadt
@@ -616,9 +616,12 @@ aesni_process(struct cryptop *crp)
 	struct aesni_session *ses;
 	struct cryptodesc *crd, *crda, *crde;
 	int err = 0;
+	int i;
 
 	if (crp == NULL || crp->crp_callback == NULL)
 		return (EINVAL);
+	if (crp->crp_ndesc < 1)
+		return (EINVAL);
 
 	mtx_enter(&aesni_sc->sc_mtx);
 	LIST_FOREACH(ses, &aesni_sc->sc_sessions, ses_entries) {
@@ -633,7 +636,8 @@ aesni_process(struct cryptop *crp)
 	}
 
 	crda = crde = NULL;
-	for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+	for (i = 0; i < crp->crp_ndesc; i++) {
+		crd = &crp->crp_desc[i];
 		switch (crd->crd_alg) {
 		case CRYPTO_AES_CBC:
 		case CRYPTO_AES_CTR:
diff --git a/sys/arch/amd64/amd64/via.c b/sys/arch/amd64/amd64/via.c
index f631f5aa303..53cfe1813f5 100644
--- a/sys/arch/amd64/amd64/via.c
+++ b/sys/arch/amd64/amd64/via.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: via.c,v 1.21 2015/08/28 00:03:53 deraadt Exp $	*/
+/*	$OpenBSD: via.c,v 1.22 2017/02/07 17:25:45 patrick Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -441,9 +441,12 @@ viac3_crypto_process(struct cryptop *crp)
 	struct viac3_session *ses;
 	struct cryptodesc *crd;
 	int sesn, err = 0;
+	int i;
 
 	if (crp == NULL || crp->crp_callback == NULL)
 		return (EINVAL);
+	if (crp->crp_ndesc < 1)
+		return (EINVAL);
 
 	sesn = VIAC3_SESSION(crp->crp_sid);
 	if (sesn >= sc->sc_nsessions) {
@@ -456,7 +459,8 @@ viac3_crypto_process(struct cryptop *crp)
 		goto out;
 	}
 
-	for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+	for (i = 0; i < crp->crp_ndesc; i++) {
+		crd = &crp->crp_desc[i];
 		switch (crd->crd_alg) {
 		case CRYPTO_AES_CBC:
 			if ((err = viac3_crypto_encdec(crp, crd, ses, sc,
diff --git a/sys/arch/i386/i386/via.c b/sys/arch/i386/i386/via.c
index 3e007c4ba80..2765dc596ec 100644
--- a/sys/arch/i386/i386/via.c
+++ b/sys/arch/i386/i386/via.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: via.c,v 1.35 2015/09/08 07:12:56 deraadt Exp $	*/
+/*	$OpenBSD: via.c,v 1.36 2017/02/07 17:25:45 patrick Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -444,9 +444,12 @@ viac3_crypto_process(struct cryptop *crp)
 	struct viac3_session *ses;
 	struct cryptodesc *crd;
 	int sesn, err = 0;
+	int i;
 
 	if (crp == NULL || crp->crp_callback == NULL)
 		return (EINVAL);
+	if (crp->crp_ndesc < 1)
+		return (EINVAL);
 
 	sesn = VIAC3_SESSION(crp->crp_sid);
 	if (sesn >= sc->sc_nsessions) {
@@ -459,7 +462,8 @@ viac3_crypto_process(struct cryptop *crp)
 		goto out;
 	}
 
-	for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+	for (i = 0; i < crp->crp_ndesc; i++) {
+		crd = &crp->crp_desc[i];
 		switch (crd->crd_alg) {
 		case CRYPTO_AES_CBC:
 			if ((err = viac3_crypto_encdec(crp, crd, ses, sc,
diff --git a/sys/arch/i386/pci/glxsb.c b/sys/arch/i386/pci/glxsb.c
index c93a86452b4..21786ab4ece 100644
--- a/sys/arch/i386/pci/glxsb.c
+++ b/sys/arch/i386/pci/glxsb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: glxsb.c,v 1.30 2015/09/08 08:33:26 deraadt Exp $	*/
+/*	$OpenBSD: glxsb.c,v 1.31 2017/02/07 17:25:45 patrick Exp $	*/
 
 /*
  * Copyright (c) 2006 Tom Cosgrove <tom@openbsd.org>
@@ -778,7 +778,7 @@ glxsb_crypto_process(struct cryptop *crp)
 	struct glxsb_session *ses;
 	struct cryptodesc *crd;
 	int sesn,err = 0;
-	int s;
+	int s, i;
 
 	s = splnet();
 
@@ -786,8 +786,7 @@ glxsb_crypto_process(struct cryptop *crp)
 		err = EINVAL;
 		goto out;
 	}
-	crd = crp->crp_desc;
-	if (crd == NULL) {
+	if (crp->crp_ndesc < 1) {
 		err = EINVAL;
 		goto out;
 	}
@@ -803,7 +802,8 @@ glxsb_crypto_process(struct cryptop *crp)
 		goto out;
 	}
 
-	for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+	for (i = 0; i < crp->crp_ndesc; i++) {
+		crd = &crp->crp_desc[i];
 		switch (crd->crd_alg) {
 		case CRYPTO_AES_CBC:
 			if (ses->ses_swd_enc) {
diff --git a/sys/crypto/crypto.c b/sys/crypto/crypto.c
index 650eda28826..2ee1cb6d887 100644
--- a/sys/crypto/crypto.c
+++ b/sys/crypto/crypto.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: crypto.c,v 1.78 2016/09/19 18:09:40 tedu Exp $	*/
+/*	$OpenBSD: crypto.c,v 1.79 2017/02/07 17:25:46 patrick Exp $	*/
 /*
  * The author of this code is Angelos D. Keromytis (angelos@cis.upenn.edu)
  *
@@ -400,18 +400,17 @@ crypto_dispatch(struct cryptop *crp)
 int
 crypto_invoke(struct cryptop *crp)
 {
-	struct cryptodesc *crd;
 	u_int64_t nid;
 	u_int32_t hid;
 	int error;
-	int s;
+	int s, i;
 
 	/* Sanity checks. */
 	if (crp == NULL || crp->crp_callback == NULL)
 		return EINVAL;
 
 	s = splvm();
-	if (crp->crp_desc == NULL || crypto_drivers == NULL) {
+	if (crp->crp_ndesc < 1 || crypto_drivers == NULL) {
 		crp->crp_etype = EINVAL;
 		crypto_done(crp);
 		splx(s);
@@ -449,8 +448,9 @@ crypto_invoke(struct cryptop *crp)
 
  migrate:
 	/* Migrate session. */
-	for (crd = crp->crp_desc; crd->crd_next; crd = crd->crd_next)
-		crd->CRD_INI.cri_next = &(crd->crd_next->CRD_INI);
+	for (i = 0; i < crp->crp_ndesc - 1; i++)
+		crp->crp_desc[i].CRD_INI.cri_next = &crp->crp_desc[i+1].CRD_INI;
+	crp->crp_desc[crp->crp_ndesc].CRD_INI.cri_next = NULL;
 
 	if (crypto_newsession(&nid, &(crp->crp_desc->CRD_INI), 0) == 0)
 		crp->crp_sid = nid;
@@ -467,16 +467,12 @@ crypto_invoke(struct cryptop *crp)
 void
 crypto_freereq(struct cryptop *crp)
 {
-	struct cryptodesc *crd;
-
 	if (crp == NULL)
 		return;
 
-	while ((crd = crp->crp_desc) != NULL) {
-		crp->crp_desc = crd->crd_next;
-		pool_put(&cryptodesc_pool, crd);
-	}
-
+	if (crp->crp_ndescalloc > 2)
+		free(crp->crp_desc, M_CRYPTO_DATA,
+		    crp->crp_ndescalloc * sizeof(struct cryptodesc));
 	pool_put(&cryptop_pool, crp);
 }
 
@@ -486,22 +482,22 @@ crypto_freereq(struct cryptop *crp)
 struct cryptop *
 crypto_getreq(int num)
 {
-	struct cryptodesc *crd;
 	struct cryptop *crp;
-	
+
 	crp = pool_get(&cryptop_pool, PR_NOWAIT | PR_ZERO);
 	if (crp == NULL)
 		return NULL;
 
-	while (num--) {
-		crd = pool_get(&cryptodesc_pool, PR_NOWAIT | PR_ZERO);
-		if (crd == NULL) {
-			crypto_freereq(crp);
+	crp->crp_desc = crp->crp_sdesc;
+	crp->crp_ndescalloc = crp->crp_ndesc = num;
+
+	if (num > 2) {
+		crp->crp_desc = mallocarray(num, sizeof(struct cryptodesc),
+		    M_CRYPTO_DATA, M_NOWAIT | M_ZERO);
+		if (crp->crp_desc == NULL) {
+			pool_put(&cryptop_pool, crp);
 			return NULL;
 		}
-
-		crd->crd_next = crp->crp_desc;
-		crp->crp_desc = crd;
 	}
 
 	return crp;
@@ -515,8 +511,6 @@ crypto_init(void)
 
 	pool_init(&cryptop_pool, sizeof(struct cryptop), 0, IPL_VM, 0,
 	    "cryptop", NULL);
-	pool_init(&cryptodesc_pool, sizeof(struct cryptodesc), 0, IPL_VM, 0,
-	    "cryptodesc", NULL);
 }
 
 /*
diff --git a/sys/crypto/cryptodev.h b/sys/crypto/cryptodev.h
index bd915817ebd..c64f74ff663 100644
--- a/sys/crypto/cryptodev.h
+++ b/sys/crypto/cryptodev.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cryptodev.h,v 1.69 2017/02/07 15:10:48 bluhm Exp $	*/
+/*	$OpenBSD: cryptodev.h,v 1.70 2017/02/07 17:25:46 patrick Exp $	*/
 
 /*
  * The author of this code is Angelos D. Keromytis (angelos@cis.upenn.edu)
@@ -147,8 +147,6 @@ struct cryptodesc {
 #define crd_rnd		CRD_INI.cri_rnd
 #define crd_alg		CRD_INI.cri_alg
 #define crd_klen	CRD_INI.cri_klen
-
-	struct cryptodesc *crd_next;
 };
 
 /* Structure describing complete operation */
@@ -179,7 +177,11 @@ struct cryptop {
 
 	void 		*crp_buf;	/* Data to be processed */
 	void 		*crp_opaque;	/* Opaque pointer, passed along */
-	struct cryptodesc *crp_desc;	/* Linked list of processing descriptors */
+
+	struct cryptodesc *crp_desc;	/* List of processing descriptors */
+	struct cryptodesc crp_sdesc[2];	/* Static array for small ops */
+	int		 crp_ndesc;	/* Amount of descriptors to use */
+	int		 crp_ndescalloc;/* Amount of descriptors allocated */
 
 	void (*crp_callback)(struct cryptop *); /* Callback function */
 
diff --git a/sys/crypto/cryptosoft.c b/sys/crypto/cryptosoft.c
index 06792eb0a9a..315210c5407 100644
--- a/sys/crypto/cryptosoft.c
+++ b/sys/crypto/cryptosoft.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cryptosoft.c,v 1.81 2016/09/02 09:12:49 tom Exp $	*/
+/*	$OpenBSD: cryptosoft.c,v 1.82 2017/02/07 17:25:46 patrick Exp $	*/
 
 /*
  * The author of this code is Angelos D. Keromytis (angelos@cis.upenn.edu)
@@ -495,7 +495,8 @@ swcr_authenc(struct cryptop *crp)
 
 	ivlen = blksz = iskip = oskip = 0;
 
-	for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+	for (i = 0; i < crp->crp_ndesc; i++) {
+		crd = &crp->crp_desc[i];
 		for (sw = swcr_sessions[crp->crp_sid & 0xffffffff];
 		     sw && sw->sw_alg != crd->crd_alg;
 		     sw = sw->sw_next)
@@ -1020,12 +1021,13 @@ swcr_process(struct cryptop *crp)
 	struct swcr_data *sw;
 	u_int32_t lid;
 	int type;
+	int i;
 
 	/* Sanity check */
 	if (crp == NULL)
 		return EINVAL;
 
-	if (crp->crp_desc == NULL || crp->crp_buf == NULL) {
+	if (crp->crp_ndesc < 1 || crp->crp_buf == NULL) {
 		crp->crp_etype = EINVAL;
 		goto done;
 	}
@@ -1042,7 +1044,8 @@ swcr_process(struct cryptop *crp)
 		type = CRYPTO_BUF_IOV;
 
 	/* Go through crypto descriptors, processing as we go */
-	for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+	for (i = 0; i < crp->crp_ndesc; i++) {
+		crd = &crp->crp_desc[i];
 		/*
 		 * Find the crypto context.
 		 *
diff --git a/sys/dev/pci/hifn7751.c b/sys/dev/pci/hifn7751.c
index 3814bdcf545..6f55e6783e5 100644
--- a/sys/dev/pci/hifn7751.c
+++ b/sys/dev/pci/hifn7751.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hifn7751.c,v 1.176 2017/01/19 10:20:29 jsg Exp $	*/
+/*	$OpenBSD: hifn7751.c,v 1.177 2017/02/07 17:25:46 patrick Exp $	*/
 
 /*
  * Invertex AEON / Hifn 7751 driver
@@ -1927,7 +1927,7 @@ hifn_process(struct cryptop *crp)
 	struct hifn_command *cmd = NULL;
 	int card, session, err = 0, ivlen;
 	struct hifn_softc *sc;
-	struct cryptodesc *crd1, *crd2, *maccrd, *enccrd;
+	struct cryptodesc *crd1, *crd2 = NULL, *maccrd, *enccrd;
 
 	if (crp == NULL || crp->crp_callback == NULL) {
 		hifnstats.hst_invalid++;
@@ -1969,12 +1969,13 @@ hifn_process(struct cryptop *crp)
 		goto errout;	/* XXX we don't handle contiguous buffers! */
 	}
 
-	crd1 = crp->crp_desc;
-	if (crd1 == NULL) {
+	if (crp->crp_ndesc < 1) {
 		err = EINVAL;
 		goto errout;
 	}
-	crd2 = crd1->crd_next;
+	crd1 = &crp->crp_desc[0];
+	if (crp->crp_ndesc >= 2)
+		crd2 = &crp->crp_desc[1];
 
 	if (crd2 == NULL) {
 		if (crd1->crd_alg == CRYPTO_MD5_HMAC ||
@@ -2291,9 +2292,11 @@ hifn_callback(struct hifn_softc *sc, struct hifn_command *cmd,
 			macbuf += sizeof(struct hifn_comp_result);
 		macbuf += sizeof(struct hifn_mac_result);
 
-		for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+		for (i = 0; i < crp->crp_ndesc; i++) {
 			int len;
 
+			crd = &crp->crp_desc[i];
+
 			if (crd->crd_alg == CRYPTO_MD5_HMAC ||
 			    crd->crd_alg == CRYPTO_SHA1_HMAC)
 				len = 12;
@@ -2326,7 +2329,7 @@ int
 hifn_compression(struct hifn_softc *sc, struct cryptop *crp,
     struct hifn_command *cmd)
 {
-	struct cryptodesc *crd = crp->crp_desc;
+	struct cryptodesc *crd = &crp->crp_desc[0];
 	int s, err = 0;
 
 	cmd->compcrd = crd;
diff --git a/sys/dev/pci/safe.c b/sys/dev/pci/safe.c
index 44bf9f0edc9..0a4c0de75a5 100644
--- a/sys/dev/pci/safe.c
+++ b/sys/dev/pci/safe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: safe.c,v 1.41 2015/12/10 21:00:51 naddy Exp $	*/
+/*	$OpenBSD: safe.c,v 1.42 2017/02/07 17:25:46 patrick Exp $	*/
 
 /*-
  * Copyright (c) 2003 Sam Leffler, Errno Consulting
@@ -301,7 +301,7 @@ safe_process(struct cryptop *crp)
 {
 	int err = 0, i, nicealign, uniform, s;
 	struct safe_softc *sc;
-	struct cryptodesc *crd1, *crd2, *maccrd, *enccrd;
+	struct cryptodesc *crd1, *crd2 = NULL, *maccrd, *enccrd;
 	int bypass, oplen, ivsize, card;
 	int16_t coffset;
 	struct safe_session *ses;
@@ -360,13 +360,14 @@ safe_process(struct cryptop *crp)
 	sa = &re->re_sa;
 	ses = &sc->sc_sessions[re->re_sesn];
 
-	crd1 = crp->crp_desc;
-	if (crd1 == NULL) {
+	if (crp->crp_ndesc < 1) {
 		safestats.st_nodesc++;
 		err = EINVAL;
 		goto errout;
 	}
-	crd2 = crd1->crd_next;
+	crd1 = &crp->crp_desc[0];
+	if (crp->crp_ndesc >= 2)
+		crd2 = &crp->crp_desc[1];
 
 	cmd0 = SAFE_SA_CMD0_BASIC;		/* basic group operation */
 	cmd1 = 0;
@@ -1608,6 +1609,7 @@ safe_callback(struct safe_softc *sc, struct safe_ringentry *re)
 {
 	struct cryptop *crp = (struct cryptop *)re->re_crp;
 	struct cryptodesc *crd;
+	int i;
 
 	safestats.st_opackets++;
 	safestats.st_obytes += (re->re_dst_map == NULL) ?
@@ -1644,7 +1646,8 @@ safe_callback(struct safe_softc *sc, struct safe_ringentry *re)
 
 	if (re->re_flags & SAFE_QFLAGS_COPYOUTICV) {
 		/* copy out ICV result */
-		for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+		for (i = 0; i < crp->crp_ndesc; i++) {
+			crd = &crp->crp_desc[i];
 			if (!(crd->crd_alg == CRYPTO_MD5_HMAC ||
 			    crd->crd_alg == CRYPTO_SHA1_HMAC))
 				continue;
diff --git a/sys/dev/pci/ubsec.c b/sys/dev/pci/ubsec.c
index cbefa8576ca..70517670e7b 100644
--- a/sys/dev/pci/ubsec.c
+++ b/sys/dev/pci/ubsec.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ubsec.c,v 1.162 2016/05/30 23:38:21 dlg Exp $	*/
+/*	$OpenBSD: ubsec.c,v 1.163 2017/02/07 17:25:46 patrick Exp $	*/
 
 /*
  * Copyright (c) 2000 Jason L. Wright (jason@thought.net)
@@ -776,7 +776,7 @@ ubsec_process(struct cryptop *crp)
 	struct ubsec_q *q = NULL;
 	int card, err = 0, i, j, s, nicealign;
 	struct ubsec_softc *sc;
-	struct cryptodesc *crd1, *crd2, *maccrd, *enccrd;
+	struct cryptodesc *crd1, *crd2 = NULL, *maccrd, *enccrd;
 	int encoffset = 0, macoffset = 0, cpskip, cpoffset;
 	int sskip, dskip, stheend, dtheend;
 	int16_t coffset;
@@ -835,12 +835,13 @@ ubsec_process(struct cryptop *crp)
 	dmap->d_dma->d_mcr.mcr_flags = 0;
 	q->q_crp = crp;
 
-	crd1 = crp->crp_desc;
-	if (crd1 == NULL) {
+	if (crp->crp_ndesc < 1) {
 		err = EINVAL;
 		goto errout;
 	}
-	crd2 = crd1->crd_next;
+	crd1 = &crp->crp_desc[0];
+	if (crp->crp_ndesc >= 2)
+		crd2 = &crp->crp_desc[1];
 
 	if (crd2 == NULL) {
 		if (crd1->crd_alg == CRYPTO_MD5_HMAC ||
@@ -1330,6 +1331,7 @@ ubsec_callback(struct ubsec_softc *sc, struct ubsec_q *q)
 	u_int8_t *ctx = (u_int8_t *)(dmap->d_alloc.dma_vaddr +
 		    offsetof(struct ubsec_dmachunk, d_ctx));
 	struct ubsec_pktctx_hdr *ph = (struct ubsec_pktctx_hdr *)ctx;
+	int i;
 
 	ubsecstats.hst_opackets++;
 	ubsecstats.hst_obytes += dmap->d_alloc.dma_size;
@@ -1355,7 +1357,8 @@ ubsec_callback(struct ubsec_softc *sc, struct ubsec_q *q)
 		crp->crp_buf = (caddr_t)q->q_dst_m;
 	}
 
-	for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
+	for (i = 0; i < crp->crp_ndesc; i++) {
+		crd = &crp->crp_desc[i];
 		if (crd->crd_alg != CRYPTO_MD5_HMAC &&
 		    crd->crd_alg != CRYPTO_SHA1_HMAC)
 			continue;
diff --git a/sys/dev/softraid_crypto.c b/sys/dev/softraid_crypto.c
index 2dc4c6b2328..c419686997e 100644
--- a/sys/dev/softraid_crypto.c
+++ b/sys/dev/softraid_crypto.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: softraid_crypto.c,v 1.132 2017/02/07 15:10:48 bluhm Exp $ */
+/* $OpenBSD: softraid_crypto.c,v 1.133 2017/02/07 17:25:46 patrick Exp $ */
 /*
  * Copyright (c) 2007 Marco Peereboom <marco@peereboom.us>
  * Copyright (c) 2008 Hans-Joerg Hoexer <hshoexer@openbsd.org>
@@ -64,7 +64,6 @@ struct sr_crypto_wu {
 	struct uio			 cr_uio;
 	struct iovec			 cr_iov;
 	struct cryptop	 		*cr_crp;
-	struct cryptodesc		*cr_descs;
 	void				*cr_dmabuf;
 };
 
@@ -270,15 +269,11 @@ sr_crypto_prepare(struct sr_workunit *wu, int encrypt)
 
 	/*
 	 * We preallocated enough crypto descs for up to MAXPHYS of I/O.
-	 * Since there may be less than that we need to tweak the linked list
+	 * Since there may be less than that we need to tweak the amount
 	 * of crypto desc structures to be just long enough for our needs.
 	 */
-	crd = crwu->cr_descs;
-	for (i = 0; i < ((MAXPHYS >> DEV_BSHIFT) - n); i++) {
-		crd = crd->crd_next;
-		KASSERT(crd);
-	}
-	crwu->cr_crp->crp_desc = crd;
+	KASSERT(crwu->cr_crp->crp_ndescalloc >= n);
+	crwu->cr_crp->crp_ndesc = n;
 	flags = (encrypt ? CRD_F_ENCRYPT : 0) |
 	    CRD_F_IV_PRESENT | CRD_F_IV_EXPLICIT;
 
@@ -297,8 +292,8 @@ sr_crypto_prepare(struct sr_workunit *wu, int encrypt)
 	crwu->cr_crp->crp_alloctype = M_DEVBUF;
 	crwu->cr_crp->crp_flags = CRYPTO_F_IOV | CRYPTO_F_NOQUEUE;
 	crwu->cr_crp->crp_buf = &crwu->cr_uio;
-	for (i = 0, crd = crwu->cr_crp->crp_desc; crd;
-	    i++, blkno++, crd = crd->crd_next) {
+	for (i = 0; i < crwu->cr_crp->crp_ndesc; i++, blkno++) {
+		crd = &crwu->cr_crp->crp_desc[i];
 		crd->crd_skip = i << DEV_BSHIFT;
 		crd->crd_len = DEV_BSIZE;
 		crd->crd_inject = 0;
@@ -946,7 +941,6 @@ sr_crypto_alloc_resources(struct sr_discipline *sd)
 		crwu->cr_crp = crypto_getreq(MAXPHYS >> DEV_BSHIFT);
 		if (crwu->cr_crp == NULL)
 			return (ENOMEM);
-		crwu->cr_descs = crwu->cr_crp->crp_desc;
 	}
 
 	memset(&cri, 0, sizeof(cri));
@@ -1005,10 +999,8 @@ sr_crypto_free_resources(struct sr_discipline *sd)
 		crwu = (struct sr_crypto_wu *)wu;
 		if (crwu->cr_dmabuf)
 			dma_free(crwu->cr_dmabuf, MAXPHYS);
-		if (crwu->cr_crp) {
-			crwu->cr_crp->crp_desc = crwu->cr_descs;
+		if (crwu->cr_crp)
 			crypto_freereq(crwu->cr_crp);
-		}
 	}
 
 	sr_wu_free(sd);
diff --git a/sys/netinet/ip_ah.c b/sys/netinet/ip_ah.c
index 425f3ff7ef8..d67711fad7a 100644
--- a/sys/netinet/ip_ah.c
+++ b/sys/netinet/ip_ah.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_ah.c,v 1.126 2017/02/07 15:10:48 bluhm Exp $ */
+/*	$OpenBSD: ip_ah.c,v 1.127 2017/02/07 17:25:46 patrick Exp $ */
 /*
  * The authors of this code are John Ioannidis (ji@tla.org),
  * Angelos D. Keromytis (kermit@csd.uch.gr) and
@@ -629,7 +629,7 @@ ah_input(struct mbuf *m, struct tdb *tdb, int skip, int protoff)
 		return ENOBUFS;
 	}
 
-	crda = crp->crp_desc;
+	crda = &crp->crp_desc[0];
 
 	crda->crd_skip = 0;
 	crda->crd_len = m->m_pkthdr.len;
@@ -1090,7 +1090,7 @@ ah_output(struct mbuf *m, struct tdb *tdb, struct mbuf **mp, int skip,
 		return ENOBUFS;
 	}
 
-	crda = crp->crp_desc;
+	crda = &crp->crp_desc[0];
 
 	crda->crd_skip = 0;
 	crda->crd_inject = skip + rplen;
diff --git a/sys/netinet/ip_esp.c b/sys/netinet/ip_esp.c
index 403b82520f8..0f8d3928eaf 100644
--- a/sys/netinet/ip_esp.c
+++ b/sys/netinet/ip_esp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_esp.c,v 1.144 2017/02/07 15:10:48 bluhm Exp $ */
+/*	$OpenBSD: ip_esp.c,v 1.145 2017/02/07 17:25:46 patrick Exp $ */
 /*
  * The authors of this code are John Ioannidis (ji@tla.org),
  * Angelos D. Keromytis (kermit@csd.uch.gr) and
@@ -461,8 +461,8 @@ esp_input(struct mbuf *m, struct tdb *tdb, int skip, int protoff)
 	}
 
 	if (esph) {
-		crda = crp->crp_desc;
-		crde = crda->crd_next;
+		crda = &crp->crp_desc[0];
+		crde = &crp->crp_desc[1];
 
 		/* Authentication descriptor */
 		crda->crd_skip = skip;
@@ -488,7 +488,7 @@ esp_input(struct mbuf *m, struct tdb *tdb, int skip, int protoff)
 		/* Copy the authenticator */
 		m_copydata(m, m->m_pkthdr.len - alen, alen, (caddr_t)(tc + 1));
 	} else
-		crde = crp->crp_desc;
+		crde = &crp->crp_desc[0];
 
 	/* Crypto operation descriptor */
 	crp->crp_ilen = m->m_pkthdr.len; /* Total input length */
@@ -958,8 +958,8 @@ esp_output(struct mbuf *m, struct tdb *tdb, struct mbuf **mp, int skip,
 	}
 
 	if (espx) {
-		crde = crp->crp_desc;
-		crda = crde->crd_next;
+		crde = &crp->crp_desc[0];
+		crda = &crp->crp_desc[1];
 
 		/* Encryption descriptor. */
 		crde->crd_skip = skip + hlen;
@@ -977,7 +977,7 @@ esp_output(struct mbuf *m, struct tdb *tdb, struct mbuf **mp, int skip,
 		else
 			crde->crd_len = m->m_pkthdr.len - (skip + hlen + alen);
 	} else
-		crda = crp->crp_desc;
+		crda = &crp->crp_desc[0];
 
 	/* IPsec-specific opaque crypto info. */
 	tc = malloc(sizeof(*tc), M_XDATA, M_NOWAIT | M_ZERO);
diff --git a/sys/netinet/ip_ipcomp.c b/sys/netinet/ip_ipcomp.c
index 3717fc212ad..d4dc26c48bc 100644
--- a/sys/netinet/ip_ipcomp.c
+++ b/sys/netinet/ip_ipcomp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ip_ipcomp.c,v 1.51 2017/02/07 15:10:48 bluhm Exp $ */
+/* $OpenBSD: ip_ipcomp.c,v 1.52 2017/02/07 17:25:46 patrick Exp $ */
 
 /*
  * Copyright (c) 2001 Jean-Jacques Bernard-Gundol (jj@wabbitt.org)
@@ -158,7 +158,7 @@ ipcomp_input(struct mbuf *m, struct tdb *tdb, int skip, int protoff)
 		ipcompstat.ipcomps_crypto++;
 		return ENOBUFS;
 	}
-	crdc = crp->crp_desc;
+	crdc = &crp->crp_desc[0];
 
 	crdc->crd_skip = skip + hlen;
 	crdc->crd_len = m->m_pkthdr.len - (skip + hlen);
@@ -474,7 +474,7 @@ ipcomp_output(struct mbuf *m, struct tdb *tdb, struct mbuf **mp, int skip,
 		ipcompstat.ipcomps_crypto++;
 		return ENOBUFS;
 	}
-	crdc = crp->crp_desc;
+	crdc = &crp->crp_desc[0];
 
 	/* Compression descriptor */
 	crdc->crd_skip = skip;