octeontx2-af: NIX LSO config for TSOv4/v6 offload

Config LSO formats for TSOv4 and TSOv6 offloads.
These formats tell HW which fields in the TCP packet's
headers have to be updated while performing segmentation
offload.

Also report PF/VF drivers the LSO format indices as part
of response to NIX_LF_ALLOC mbox msg. These indices are
used in SQE extension headers while framing SQE for pkt
transmission with TSO offload.
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/af/common.h

@@ -132,6 +132,12 @@ struct npa_aq_pool_res {
 	struct	npa_pool_s	ctx_mask;
 };
 
+/* NIX LSO format indices.
+ * As of now TSO is the only one using, so statically assigning indices.
+ */
+#define NIX_LSO_FORMAT_IDX_TSOV4	0
+#define NIX_LSO_FORMAT_IDX_TSOV6	1
+
 /* RSS info */
 #define MAX_RSS_GROUPS			8
 /* Group 0 has to be used in default pkt forwarding MCAM entries

drivers/net/ethernet/marvell/octeontx2/af/mbox.h

@@ -374,6 +374,8 @@ struct nix_lf_alloc_req {
 struct nix_lf_alloc_rsp {
 	struct mbox_msghdr hdr;
 	u16	sqb_size;
+	u8	lso_tsov4_idx;
+	u8	lso_tsov6_idx;
 	u8      mac_addr[ETH_ALEN];
 };
 

drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c

@@ -16,6 +16,96 @@
 #include "rvu.h"
 #include "cgx.h"
 
+static void nix_setup_lso_tso_l3(struct rvu *rvu, int blkaddr,
+				 u64 format, bool v4, u64 *fidx)
+{
+	struct nix_lso_format field = {0};
+
+	/* IP's Length field */
+	field.layer = NIX_TXLAYER_OL3;
+	/* In ipv4, length field is at offset 2 bytes, for ipv6 it's 4 */
+	field.offset = v4 ? 2 : 4;
+	field.sizem1 = 1; /* i.e 2 bytes */
+	field.alg = NIX_LSOALG_ADD_PAYLEN;
+	rvu_write64(rvu, blkaddr,
+		    NIX_AF_LSO_FORMATX_FIELDX(format, (*fidx)++),
+		    *(u64 *)&field);
+
+	/* No ID field in IPv6 header */
+	if (!v4)
+		return;
+
+	/* IP's ID field */
+	field.layer = NIX_TXLAYER_OL3;
+	field.offset = 4;
+	field.sizem1 = 1; /* i.e 2 bytes */
+	field.alg = NIX_LSOALG_ADD_SEGNUM;
+	rvu_write64(rvu, blkaddr,
+		    NIX_AF_LSO_FORMATX_FIELDX(format, (*fidx)++),
+		    *(u64 *)&field);
+}
+
+static void nix_setup_lso_tso_l4(struct rvu *rvu, int blkaddr,
+				 u64 format, u64 *fidx)
+{
+	struct nix_lso_format field = {0};
+
+	/* TCP's sequence number field */
+	field.layer = NIX_TXLAYER_OL4;
+	field.offset = 4;
+	field.sizem1 = 3; /* i.e 4 bytes */
+	field.alg = NIX_LSOALG_ADD_OFFSET;
+	rvu_write64(rvu, blkaddr,
+		    NIX_AF_LSO_FORMATX_FIELDX(format, (*fidx)++),
+		    *(u64 *)&field);
+
+	/* TCP's flags field */
+	field.layer = NIX_TXLAYER_OL4;
+	field.offset = 12;
+	field.sizem1 = 0; /* not needed */
+	field.alg = NIX_LSOALG_TCP_FLAGS;
+	rvu_write64(rvu, blkaddr,
+		    NIX_AF_LSO_FORMATX_FIELDX(format, (*fidx)++),
+		    *(u64 *)&field);
+}
+
+static void nix_setup_lso(struct rvu *rvu, int blkaddr)
+{
+	u64 cfg, idx, fidx = 0;
+
+	/* Enable LSO */
+	cfg = rvu_read64(rvu, blkaddr, NIX_AF_LSO_CFG);
+	/* For TSO, set first and middle segment flags to
+	 * mask out PSH, RST & FIN flags in TCP packet
+	 */
+	cfg &= ~((0xFFFFULL << 32) | (0xFFFFULL << 16));
+	cfg |= (0xFFF2ULL << 32) | (0xFFF2ULL << 16);
+	rvu_write64(rvu, blkaddr, NIX_AF_LSO_CFG, cfg | BIT_ULL(63));
+
+	/* Configure format fields for TCPv4 segmentation offload */
+	idx = NIX_LSO_FORMAT_IDX_TSOV4;
+	nix_setup_lso_tso_l3(rvu, blkaddr, idx, true, &fidx);
+	nix_setup_lso_tso_l4(rvu, blkaddr, idx, &fidx);
+
+	/* Set rest of the fields to NOP */
+	for (; fidx < 8; fidx++) {
+		rvu_write64(rvu, blkaddr,
+			    NIX_AF_LSO_FORMATX_FIELDX(idx, fidx), 0x0ULL);
+	}
+
+	/* Configure format fields for TCPv6 segmentation offload */
+	idx = NIX_LSO_FORMAT_IDX_TSOV6;
+	fidx = 0;
+	nix_setup_lso_tso_l3(rvu, blkaddr, idx, false, &fidx);
+	nix_setup_lso_tso_l4(rvu, blkaddr, idx, &fidx);
+
+	/* Set rest of the fields to NOP */
+	for (; fidx < 8; fidx++) {
+		rvu_write64(rvu, blkaddr,
+			    NIX_AF_LSO_FORMATX_FIELDX(idx, fidx), 0x0ULL);
+	}
+}
+
 static void nix_ctx_free(struct rvu *rvu, struct rvu_pfvf *pfvf)
 {
 	if (pfvf->rq_ctx)
@@ -219,6 +309,8 @@ int rvu_mbox_handler_NIX_LF_ALLOC(struct rvu *rvu,
 	/* set SQB size info */
 	cfg = rvu_read64(rvu, blkaddr, NIX_AF_SQ_CONST);
 	rsp->sqb_size = (cfg >> 34) & 0xFFFF;
+	rsp->lso_tsov4_idx = NIX_LSO_FORMAT_IDX_TSOV4;
+	rsp->lso_tsov6_idx = NIX_LSO_FORMAT_IDX_TSOV6;
 	return rc;
 }
 
@@ -358,6 +450,9 @@ int rvu_nix_init(struct rvu *rvu)
 	/* Restore CINT timer delay to HW reset values */
 	rvu_write64(rvu, blkaddr, NIX_AF_CINT_DELAY, 0x0ULL);
 
+	/* Configure segmentation offload formats */
+	nix_setup_lso(rvu, blkaddr);
+
 	return 0;
 }
 

drivers/net/ethernet/marvell/octeontx2/af/rvu_struct.h

@@ -426,4 +426,39 @@ struct nix_aq_res_s {
 	u64 reserved_64_127;		/* W1 */
 };
 
+enum nix_lsoalg {
+	NIX_LSOALG_NOP,
+	NIX_LSOALG_ADD_SEGNUM,
+	NIX_LSOALG_ADD_PAYLEN,
+	NIX_LSOALG_ADD_OFFSET,
+	NIX_LSOALG_TCP_FLAGS,
+};
+
+enum nix_txlayer {
+	NIX_TXLAYER_OL3,
+	NIX_TXLAYER_OL4,
+	NIX_TXLAYER_IL3,
+	NIX_TXLAYER_IL4,
+};
+
+struct nix_lso_format {
+#if defined(__BIG_ENDIAN_BITFIELD)
+	u64 rsvd_19_63		: 45;
+	u64 alg			: 3;
+	u64 rsvd_14_15		: 2;
+	u64 sizem1		: 2;
+	u64 rsvd_10_11		: 2;
+	u64 layer		: 2;
+	u64 offset		: 8;
+#else
+	u64 offset		: 8;
+	u64 layer		: 2;
+	u64 rsvd_10_11		: 2;
+	u64 sizem1		: 2;
+	u64 rsvd_14_15		: 2;
+	u64 alg			: 3;
+	u64 rsvd_19_63		: 45;
+#endif
+};
+
 #endif /* RVU_STRUCT_H */