[14/17] crypto/cnxk: add CTX for non IPsec operations

Message ID 20221220143232.2519650-15-ktejasree@marvell.com (mailing list archive)
State Accepted, archived
Delegated to: akhil goyal
Headers
Series fixes and improvements to cnxk crytpo PMD |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Tejasree Kondoj Dec. 20, 2022, 2:32 p.m. UTC
  Support context cache with non IPsec operations.

Signed-off-by: Tejasree Kondoj <ktejasree@marvell.com>
Signed-off-by: Anoob Joseph <anoobj@marvell.com>
---
 drivers/common/cnxk/roc_platform.h        |  3 +-
 drivers/common/cnxk/roc_se.c              | 47 +++++++++++++++++++++++
 drivers/common/cnxk/roc_se.h              | 42 +++++++++++++-------
 drivers/common/cnxk/version.map           |  1 +
 drivers/crypto/cnxk/cn10k_cryptodev_ops.c | 17 ++++----
 drivers/crypto/cnxk/cn9k_cryptodev_ops.c  | 14 +++----
 drivers/crypto/cnxk/cnxk_cryptodev_ops.c  | 38 +++++++++++++-----
 drivers/crypto/cnxk/cnxk_cryptodev_ops.h  | 13 +++----
 drivers/crypto/cnxk/cnxk_se.h             | 10 +++--
 9 files changed, 134 insertions(+), 51 deletions(-)
  

Patch

diff --git a/drivers/common/cnxk/roc_platform.h b/drivers/common/cnxk/roc_platform.h
index 1a48ff3db4..8ba28e69fa 100644
--- a/drivers/common/cnxk/roc_platform.h
+++ b/drivers/common/cnxk/roc_platform.h
@@ -57,9 +57,10 @@ 
 #define PLT_ALIGN		 RTE_ALIGN
 #define PLT_ALIGN_MUL_CEIL	 RTE_ALIGN_MUL_CEIL
 #define PLT_MODEL_MZ_NAME	 "roc_model_mz"
-#define PLT_CACHE_LINE_SIZE      RTE_CACHE_LINE_SIZE
+#define PLT_CACHE_LINE_SIZE	 RTE_CACHE_LINE_SIZE
 #define BITMASK_ULL		 GENMASK_ULL
 #define PLT_ALIGN_CEIL		 RTE_ALIGN_CEIL
+#define PLT_ALIGN_FLOOR		 RTE_ALIGN_FLOOR
 #define PLT_INIT		 RTE_INIT
 #define PLT_MAX_ETHPORTS	 RTE_MAX_ETHPORTS
 #define PLT_TAILQ_FOREACH_SAFE	 RTE_TAILQ_FOREACH_SAFE
diff --git a/drivers/common/cnxk/roc_se.c b/drivers/common/cnxk/roc_se.c
index aba7f9416d..8c19c5fccc 100644
--- a/drivers/common/cnxk/roc_se.c
+++ b/drivers/common/cnxk/roc_se.c
@@ -726,3 +726,50 @@  roc_se_ctx_swap(struct roc_se_ctx *se_ctx)
 
 	zs_ctx->zuc.otk_ctx.w0.u64 = htobe64(zs_ctx->zuc.otk_ctx.w0.u64);
 }
+
+void
+roc_se_ctx_init(struct roc_se_ctx *roc_se_ctx)
+{
+	struct se_ctx_s *ctx = &roc_se_ctx->se_ctx;
+	uint64_t ctx_len, *uc_ctx;
+	uint8_t i;
+
+	switch (roc_se_ctx->fc_type) {
+	case ROC_SE_FC_GEN:
+		ctx_len = sizeof(struct roc_se_context);
+		break;
+	case ROC_SE_PDCP:
+		ctx_len = sizeof(struct roc_se_zuc_snow3g_ctx);
+		break;
+	case ROC_SE_KASUMI:
+		ctx_len = sizeof(struct roc_se_kasumi_ctx);
+		break;
+	case ROC_SE_PDCP_CHAIN:
+		ctx_len = sizeof(struct roc_se_zuc_snow3g_chain_ctx);
+		break;
+	default:
+		ctx_len = 0;
+	}
+
+	ctx_len = PLT_ALIGN_CEIL(ctx_len, 8);
+
+	/* Skip w0 for swap */
+	uc_ctx = PLT_PTR_ADD(ctx, sizeof(ctx->w0));
+	for (i = 0; i < (ctx_len / 8); i++)
+		uc_ctx[i] = plt_cpu_to_be_64(((uint64_t *)uc_ctx)[i]);
+
+	/* Include w0 */
+	ctx_len += sizeof(ctx->w0);
+	ctx_len = PLT_ALIGN_CEIL(ctx_len, 8);
+
+	ctx->w0.s.aop_valid = 1;
+	ctx->w0.s.ctx_hdr_size = 0;
+
+	ctx->w0.s.ctx_size = PLT_ALIGN_FLOOR(ctx_len, 128);
+	if (ctx->w0.s.ctx_size == 0)
+		ctx->w0.s.ctx_size = 1;
+
+	ctx->w0.s.ctx_push_size = ctx_len / 8;
+	if (ctx->w0.s.ctx_push_size > 32)
+		ctx->w0.s.ctx_push_size = 32;
+}
diff --git a/drivers/common/cnxk/roc_se.h b/drivers/common/cnxk/roc_se.h
index a8f0f49479..d1ef71577c 100644
--- a/drivers/common/cnxk/roc_se.h
+++ b/drivers/common/cnxk/roc_se.h
@@ -300,14 +300,31 @@  struct roc_se_ctx {
 	uint64_t rsvd : 17;
 	union cpt_inst_w4 template_w4;
 	/* Below fields are accessed by hardware */
-	union {
-		struct roc_se_context fctx;
-		struct roc_se_zuc_snow3g_ctx zs_ctx;
-		struct roc_se_zuc_snow3g_chain_ctx zs_ch_ctx;
-		struct roc_se_kasumi_ctx k_ctx;
-	} se_ctx;
+	struct se_ctx_s {
+		/* Word0 */
+		union {
+			struct {
+				uint64_t rsvd : 48;
+
+				uint64_t ctx_push_size : 7;
+				uint64_t rsvd1 : 1;
+
+				uint64_t ctx_hdr_size : 2;
+				uint64_t aop_valid : 1;
+				uint64_t rsvd2 : 1;
+				uint64_t ctx_size : 4;
+			} s;
+			uint64_t u64;
+		} w0;
+		union {
+			struct roc_se_context fctx;
+			struct roc_se_zuc_snow3g_ctx zs_ctx;
+			struct roc_se_zuc_snow3g_chain_ctx zs_ch_ctx;
+			struct roc_se_kasumi_ctx k_ctx;
+		};
+	} se_ctx __plt_aligned(ROC_ALIGN);
 	uint8_t *auth_key;
-};
+} __plt_aligned(ROC_ALIGN);
 
 struct roc_se_fc_params {
 	union {
@@ -349,14 +366,13 @@  roc_se_zuc_bytes_swap(uint8_t *arr, int len)
 	}
 }
 
-int __roc_api roc_se_auth_key_set(struct roc_se_ctx *se_ctx,
-				  roc_se_auth_type type, const uint8_t *key,
-				  uint16_t key_len, uint16_t mac_len);
+int __roc_api roc_se_auth_key_set(struct roc_se_ctx *se_ctx, roc_se_auth_type type,
+				  const uint8_t *key, uint16_t key_len, uint16_t mac_len);
 
-int __roc_api roc_se_ciph_key_set(struct roc_se_ctx *se_ctx,
-				  roc_se_cipher_type type, const uint8_t *key,
-				  uint16_t key_len, uint8_t *salt);
+int __roc_api roc_se_ciph_key_set(struct roc_se_ctx *se_ctx, roc_se_cipher_type type,
+				  const uint8_t *key, uint16_t key_len, uint8_t *salt);
 
 void __roc_api roc_se_ctx_swap(struct roc_se_ctx *se_ctx);
+void __roc_api roc_se_ctx_init(struct roc_se_ctx *se_ctx);
 
 #endif /* __ROC_SE_H__ */
diff --git a/drivers/common/cnxk/version.map b/drivers/common/cnxk/version.map
index 17f0ec6b48..ee283d2392 100644
--- a/drivers/common/cnxk/version.map
+++ b/drivers/common/cnxk/version.map
@@ -99,6 +99,7 @@  INTERNAL {
 	roc_model;
 	roc_se_auth_key_set;
 	roc_se_ciph_key_set;
+	roc_se_ctx_init;
 	roc_nix_bpf_alloc;
 	roc_nix_bpf_config;
 	roc_nix_bpf_connect;
diff --git a/drivers/crypto/cnxk/cn10k_cryptodev_ops.c b/drivers/crypto/cnxk/cn10k_cryptodev_ops.c
index 5a098ffcf2..57b44210c2 100644
--- a/drivers/crypto/cnxk/cn10k_cryptodev_ops.c
+++ b/drivers/crypto/cnxk/cn10k_cryptodev_ops.c
@@ -52,14 +52,13 @@  cn10k_cpt_sym_temp_sess_create(struct cnxk_cpt_qp *qp, struct rte_crypto_op *op)
 	if (rte_mempool_get(qp->sess_mp, (void **)&sess) < 0)
 		return NULL;
 
-	ret = sym_session_configure(qp->lf.roc_cpt, sym_op->xform,
-				    sess);
+	ret = sym_session_configure(qp->lf.roc_cpt, sym_op->xform, sess, true);
 	if (ret) {
 		rte_mempool_put(qp->sess_mp, (void *)sess);
 		goto sess_put;
 	}
 
-	priv = (void *)sess->driver_priv_data;
+	priv = (void *)sess;
 	sym_op->session = sess;
 
 	return priv;
@@ -121,13 +120,13 @@  cn10k_cpt_fill_inst(struct cnxk_cpt_qp *qp, struct rte_crypto_op *ops[], struct
 
 	if (op->type == RTE_CRYPTO_OP_TYPE_SYMMETRIC) {
 		if (op->sess_type == RTE_CRYPTO_OP_SECURITY_SESSION) {
-			sec_sess = (struct cn10k_sec_session *)(sym_op->session);
+			sec_sess = (struct cn10k_sec_session *)sym_op->session;
 			ret = cpt_sec_inst_fill(qp, op, sec_sess, &inst[0]);
 			if (unlikely(ret))
 				return 0;
 			w7 = sec_sess->inst.w7;
 		} else if (op->sess_type == RTE_CRYPTO_OP_WITH_SESSION) {
-			sess = CRYPTODEV_GET_SYM_SESS_PRIV(sym_op->session);
+			sess = (struct cnxk_se_sess *)(sym_op->session);
 			ret = cpt_sym_inst_fill(qp, op, sess, infl_req, &inst[0], is_sg_ver2);
 			if (unlikely(ret))
 				return 0;
@@ -141,7 +140,7 @@  cn10k_cpt_fill_inst(struct cnxk_cpt_qp *qp, struct rte_crypto_op *ops[], struct
 
 			ret = cpt_sym_inst_fill(qp, op, sess, infl_req, &inst[0], is_sg_ver2);
 			if (unlikely(ret)) {
-				sym_session_clear(op->sym->session);
+				sym_session_clear(op->sym->session, true);
 				rte_mempool_put(qp->sess_mp, op->sym->session);
 				return 0;
 			}
@@ -316,7 +315,7 @@  cn10k_cpt_crypto_adapter_ev_mdata_set(struct rte_cryptodev *dev __rte_unused, vo
 		} else if (sess_type == RTE_CRYPTO_OP_WITH_SESSION) {
 			struct cnxk_se_sess *priv;
 
-			priv = CRYPTODEV_GET_SYM_SESS_PRIV(sess);
+			priv = (struct cnxk_se_sess *)sess;
 			priv->qp = qp;
 			priv->cpt_inst_w2 = w2;
 		} else
@@ -351,7 +350,7 @@  cn10k_ca_meta_info_extract(struct rte_crypto_op *op, struct cnxk_cpt_qp **qp, ui
 		} else if (op->sess_type == RTE_CRYPTO_OP_WITH_SESSION) {
 			struct cnxk_se_sess *priv;
 
-			priv = CRYPTODEV_GET_SYM_SESS_PRIV(op->sym->session);
+			priv = (struct cnxk_se_sess *)op->sym->session;
 			*qp = priv->qp;
 			*w2 = priv->cpt_inst_w2;
 		} else {
@@ -914,7 +913,7 @@  cn10k_cpt_dequeue_post_process(struct cnxk_cpt_qp *qp,
 temp_sess_free:
 	if (unlikely(cop->sess_type == RTE_CRYPTO_OP_SESSIONLESS)) {
 		if (cop->type == RTE_CRYPTO_OP_TYPE_SYMMETRIC) {
-			sym_session_clear(cop->sym->session);
+			sym_session_clear(cop->sym->session, true);
 			rte_mempool_put(qp->sess_mp, cop->sym->session);
 			cop->sym->session = NULL;
 		}
diff --git a/drivers/crypto/cnxk/cn9k_cryptodev_ops.c b/drivers/crypto/cnxk/cn9k_cryptodev_ops.c
index cfe1e08dff..e3784e34c9 100644
--- a/drivers/crypto/cnxk/cn9k_cryptodev_ops.c
+++ b/drivers/crypto/cnxk/cn9k_cryptodev_ops.c
@@ -49,11 +49,11 @@  cn9k_cpt_sym_temp_sess_create(struct cnxk_cpt_qp *qp, struct rte_crypto_op *op)
 	if (rte_mempool_get(qp->sess_mp, (void **)&sess) < 0)
 		return NULL;
 
-	ret = sym_session_configure(qp->lf.roc_cpt, sym_op->xform, sess);
+	ret = sym_session_configure(qp->lf.roc_cpt, sym_op->xform, sess, true);
 	if (ret)
 		goto sess_put;
 
-	priv = CRYPTODEV_GET_SYM_SESS_PRIV(sess);
+	priv = (struct cnxk_se_sess *)sess;
 
 	sym_op->session = sess;
 
@@ -76,7 +76,7 @@  cn9k_cpt_inst_prep(struct cnxk_cpt_qp *qp, struct rte_crypto_op *op,
 
 		if (op->sess_type == RTE_CRYPTO_OP_WITH_SESSION) {
 			sym_op = op->sym;
-			sess = CRYPTODEV_GET_SYM_SESS_PRIV(sym_op->session);
+			sess = (struct cnxk_se_sess *)sym_op->session;
 			ret = cpt_sym_inst_fill(qp, op, sess, infl_req, inst, false);
 			inst->w7.u64 = sess->cpt_inst_w7;
 		} else if (op->sess_type == RTE_CRYPTO_OP_SECURITY_SESSION)
@@ -90,7 +90,7 @@  cn9k_cpt_inst_prep(struct cnxk_cpt_qp *qp, struct rte_crypto_op *op,
 
 			ret = cpt_sym_inst_fill(qp, op, sess, infl_req, inst, false);
 			if (unlikely(ret)) {
-				sym_session_clear(op->sym->session);
+				sym_session_clear(op->sym->session, true);
 				rte_mempool_put(qp->sess_mp, op->sym->session);
 			}
 			inst->w7.u64 = sess->cpt_inst_w7;
@@ -326,7 +326,7 @@  cn9k_cpt_crypto_adapter_ev_mdata_set(struct rte_cryptodev *dev __rte_unused,
 		} else if (sess_type == RTE_CRYPTO_OP_WITH_SESSION) {
 			struct cnxk_se_sess *priv;
 
-			priv = CRYPTODEV_GET_SYM_SESS_PRIV(sess);
+			priv = (struct cnxk_se_sess *)sess;
 			priv->qp = qp;
 			priv->cpt_inst_w2 = w2;
 		} else
@@ -361,7 +361,7 @@  cn9k_ca_meta_info_extract(struct rte_crypto_op *op,
 		} else if (op->sess_type == RTE_CRYPTO_OP_WITH_SESSION) {
 			struct cnxk_se_sess *priv;
 
-			priv = CRYPTODEV_GET_SYM_SESS_PRIV(op->sym->session);
+			priv = (struct cnxk_se_sess *)op->sym->session;
 			*qp = priv->qp;
 			inst->w2.u64 = priv->cpt_inst_w2;
 		} else {
@@ -630,7 +630,7 @@  cn9k_cpt_dequeue_post_process(struct cnxk_cpt_qp *qp, struct rte_crypto_op *cop,
 temp_sess_free:
 	if (unlikely(cop->sess_type == RTE_CRYPTO_OP_SESSIONLESS)) {
 		if (cop->type == RTE_CRYPTO_OP_TYPE_SYMMETRIC) {
-			sym_session_clear(cop->sym->session);
+			sym_session_clear(cop->sym->session, true);
 			rte_mempool_put(qp->sess_mp, cop->sym->session);
 			cop->sym->session = NULL;
 		}
diff --git a/drivers/crypto/cnxk/cnxk_cryptodev_ops.c b/drivers/crypto/cnxk/cnxk_cryptodev_ops.c
index 92e8755671..2e845afce9 100644
--- a/drivers/crypto/cnxk/cnxk_cryptodev_ops.c
+++ b/drivers/crypto/cnxk/cnxk_cryptodev_ops.c
@@ -626,6 +626,11 @@  cnxk_cpt_inst_w7_get(struct cnxk_se_sess *sess, struct roc_cpt *roc_cpt)
 
 	inst_w7.s.cptr = (uint64_t)&sess->roc_se_ctx.se_ctx;
 
+	if (roc_cpt->cpt_revision == ROC_CPT_REVISION_ID_106XX)
+		inst_w7.s.ctx_val = 1;
+	else
+		inst_w7.s.cptr += 8;
+
 	/* Set the engine group */
 	if (sess->zsk_flag || sess->aes_ctr_eea2 || sess->is_sha3)
 		inst_w7.s.egrp = roc_cpt->eng_grp[CPT_ENG_TYPE_SE];
@@ -636,19 +641,22 @@  cnxk_cpt_inst_w7_get(struct cnxk_se_sess *sess, struct roc_cpt *roc_cpt)
 }
 
 int
-sym_session_configure(struct roc_cpt *roc_cpt,
-		      struct rte_crypto_sym_xform *xform,
-		      struct rte_cryptodev_sym_session *sess)
+sym_session_configure(struct roc_cpt *roc_cpt, struct rte_crypto_sym_xform *xform,
+		      struct rte_cryptodev_sym_session *sess, bool is_session_less)
 {
 	enum cpt_dp_thread_type thr_type;
-	struct cnxk_se_sess *sess_priv = CRYPTODEV_GET_SYM_SESS_PRIV(sess);
+	struct cnxk_se_sess *sess_priv = (struct cnxk_se_sess *)sess;
 	int ret;
 
-	memset(sess_priv, 0, sizeof(struct cnxk_se_sess));
+	if (is_session_less)
+		memset(sess_priv, 0, sizeof(struct cnxk_se_sess));
+
 	ret = cnxk_sess_fill(roc_cpt, xform, sess_priv);
 	if (ret)
 		goto priv_put;
 
+	sess_priv->lf = roc_cpt->lf[0];
+
 	if (sess_priv->cpt_op & ROC_SE_OP_CIPHER_MASK) {
 		switch (sess_priv->roc_se_ctx.fc_type) {
 		case ROC_SE_FC_GEN:
@@ -690,6 +698,10 @@  sym_session_configure(struct roc_cpt *roc_cpt,
 	}
 
 	sess_priv->cpt_inst_w7 = cnxk_cpt_inst_w7_get(sess_priv, roc_cpt);
+
+	if (roc_cpt->cpt_revision == ROC_CPT_REVISION_ID_106XX)
+		roc_se_ctx_init(&sess_priv->roc_se_ctx);
+
 	return 0;
 
 priv_put:
@@ -704,25 +716,31 @@  cnxk_cpt_sym_session_configure(struct rte_cryptodev *dev,
 	struct cnxk_cpt_vf *vf = dev->data->dev_private;
 	struct roc_cpt *roc_cpt = &vf->cpt;
 
-	return sym_session_configure(roc_cpt, xform, sess);
+	return sym_session_configure(roc_cpt, xform, sess, false);
 }
 
 void
-sym_session_clear(struct rte_cryptodev_sym_session *sess)
+sym_session_clear(struct rte_cryptodev_sym_session *sess, bool is_session_less)
 {
-	struct cnxk_se_sess *sess_priv = CRYPTODEV_GET_SYM_SESS_PRIV(sess);
+	struct cnxk_se_sess *sess_priv = (struct cnxk_se_sess *)sess;
+
+	/* Trigger CTX flush + invalidate to remove from CTX_CACHE */
+	roc_cpt_lf_ctx_flush(sess_priv->lf, &sess_priv->roc_se_ctx.se_ctx, true);
+
+	plt_delay_ms(1);
 
 	if (sess_priv->roc_se_ctx.auth_key != NULL)
 		plt_free(sess_priv->roc_se_ctx.auth_key);
 
-	memset(sess_priv, 0, cnxk_cpt_sym_session_get_size(NULL));
+	if (is_session_less)
+		memset(sess_priv, 0, cnxk_cpt_sym_session_get_size(NULL));
 }
 
 void
 cnxk_cpt_sym_session_clear(struct rte_cryptodev *dev __rte_unused,
 			   struct rte_cryptodev_sym_session *sess)
 {
-	return sym_session_clear(sess);
+	return sym_session_clear(sess, false);
 }
 
 unsigned int
diff --git a/drivers/crypto/cnxk/cnxk_cryptodev_ops.h b/drivers/crypto/cnxk/cnxk_cryptodev_ops.h
index 5153d334ba..f91ad368ea 100644
--- a/drivers/crypto/cnxk/cnxk_cryptodev_ops.h
+++ b/drivers/crypto/cnxk/cnxk_cryptodev_ops.h
@@ -107,18 +107,15 @@  int cnxk_cpt_queue_pair_release(struct rte_cryptodev *dev, uint16_t qp_id);
 
 unsigned int cnxk_cpt_sym_session_get_size(struct rte_cryptodev *dev);
 
-int cnxk_cpt_sym_session_configure(struct rte_cryptodev *dev,
-				   struct rte_crypto_sym_xform *xform,
+int cnxk_cpt_sym_session_configure(struct rte_cryptodev *dev, struct rte_crypto_sym_xform *xform,
 				   struct rte_cryptodev_sym_session *sess);
 
-int sym_session_configure(struct roc_cpt *roc_cpt,
-			  struct rte_crypto_sym_xform *xform,
-			  struct rte_cryptodev_sym_session *sess);
+int sym_session_configure(struct roc_cpt *roc_cpt, struct rte_crypto_sym_xform *xform,
+			  struct rte_cryptodev_sym_session *sess, bool is_session_less);
 
-void cnxk_cpt_sym_session_clear(struct rte_cryptodev *dev,
-		struct rte_cryptodev_sym_session *sess);
+void cnxk_cpt_sym_session_clear(struct rte_cryptodev *dev, struct rte_cryptodev_sym_session *sess);
 
-void sym_session_clear(struct rte_cryptodev_sym_session *sess);
+void sym_session_clear(struct rte_cryptodev_sym_session *sess, bool is_session_less);
 
 unsigned int cnxk_ae_session_size_get(struct rte_cryptodev *dev __rte_unused);
 
diff --git a/drivers/crypto/cnxk/cnxk_se.h b/drivers/crypto/cnxk/cnxk_se.h
index 092cdd88e7..774efd5879 100644
--- a/drivers/crypto/cnxk/cnxk_se.h
+++ b/drivers/crypto/cnxk/cnxk_se.h
@@ -6,6 +6,8 @@ 
 #define _CNXK_SE_H_
 #include <stdbool.h>
 
+#include <rte_cryptodev.h>
+
 #include "cnxk_cryptodev.h"
 #include "cnxk_cryptodev_ops.h"
 #include "cnxk_sg.h"
@@ -25,6 +27,7 @@  enum cpt_dp_thread_type {
 };
 
 struct cnxk_se_sess {
+	struct rte_cryptodev_sym_session rte_sess;
 	uint16_t cpt_op : 4;
 	uint16_t zsk_flag : 4;
 	uint16_t aes_gcm : 1;
@@ -51,10 +54,11 @@  struct cnxk_se_sess {
 	uint64_t cpt_inst_w2;
 	struct cnxk_cpt_qp *qp;
 	struct roc_se_ctx roc_se_ctx;
-} __rte_cache_aligned;
+	struct roc_cpt_lf *lf;
+} __rte_aligned(ROC_ALIGN);
 
-static __rte_always_inline int
-fill_sess_gmac(struct rte_crypto_sym_xform *xform, struct cnxk_se_sess *sess);
+static __rte_always_inline int fill_sess_gmac(struct rte_crypto_sym_xform *xform,
+					      struct cnxk_se_sess *sess);
 
 static inline void
 cpt_pack_iv(uint8_t *iv_src, uint8_t *iv_dst)