git: 6d587ff04b71 - main - cxgbe: Don't cache nsegs for KTLS requests

The branch main has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=6d587ff04b71cb82a1e98fd84b5e0257dd65fec9

commit 6d587ff04b71cb82a1e98fd84b5e0257dd65fec9
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2026-09-30 19:19:11 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2026-09-30 19:19:11 +0000

    cxgbe: Don't cache nsegs for KTLS requests
    
    KTLS mbufs are initially parsed when they are first enqueued to
    estimate the number of transmit descriptors needed so that the mbuf is
    queued until enough descriptors are available.  As part of this
    estimate, the number of DSGL segments required by each KTLS mbuf is
    calculated.  Originally, the count for the first TLS record in a chain
    was cached in the header mbuf to avoid having to recalculate it when
    writing out the actual work request for the first TLS record, but this
    requires duplicating fairly complex logic both when parsing and
    transmitting requests.
    
    Sponsored by:   Chelsio Communications
---
 sys/dev/cxgbe/crypto/t7_kern_tls.c | 27 +++++----------------------
 1 file changed, 5 insertions(+), 22 deletions(-)

diff --git a/sys/dev/cxgbe/crypto/t7_kern_tls.c b/sys/dev/cxgbe/crypto/t7_kern_tls.c
index a539a6793f16..3ba4c47235f1 100644
--- a/sys/dev/cxgbe/crypto/t7_kern_tls.c
+++ b/sys/dev/cxgbe/crypto/t7_kern_tls.c
@@ -854,7 +854,6 @@ t7_ktls_parse_pkt(struct mbuf *m)
 	MPASS(m->m_next->m_flags & M_EXTPG);
 
 	tot_len = 0;
-	nsegs = -1;
 
 	/*
 	 * Each of the remaining mbufs in the chain should reference a
@@ -871,13 +870,6 @@ t7_ktls_parse_pkt(struct mbuf *m)
 		if (wr_len > SGE_MAX_WR_LEN || nsegs > TX_SGL_SEGS)
 			return (EFBIG);
 		tot_len += roundup2(wr_len, EQ_ESIZE);
-
-		/*
-		 * Store 'nsegs' for the first TLS record in the
-		 * header mbuf's metadata.
-		 */
-		if (m_tls == m->m_next)
-			set_mbuf_nsegs(m, nsegs);
 	}
 
 	MPASS(tot_len != 0);
@@ -891,9 +883,9 @@ t7_ktls_parse_pkt(struct mbuf *m)
 			if (error == 0) {
 #ifdef VERBOSE_TRACES
 				CTR(KTR_CXGBE,
-				    "%s: %p len16 %d nsegs %d TCP seq %u deferred",
+				    "%s: %p len16 %d TCP seq %u deferred",
 				    __func__, tlsp, mbuf_len16(m),
-				    nsegs, ntohl(tcp->th_seq));
+				    ntohl(tcp->th_seq));
 #endif
 			}
 			TXQ_UNLOCK(tlsp->txq);
@@ -904,8 +896,7 @@ t7_ktls_parse_pkt(struct mbuf *m)
 	}
 
 #ifdef VERBOSE_TRACES
-	CTR(KTR_CXGBE, "%s: %p len16 %d nsegs %d", __func__, tlsp,
-	    mbuf_len16(m), nsegs);
+	CTR(KTR_CXGBE, "%s: %p len16 %d", __func__, tlsp, mbuf_len16(m));
 #endif
 	items[0] = m;
 	error = mp_ring_enqueue(tlsp->txq->r, items, 1, 256);
@@ -1461,16 +1452,8 @@ ktls_write_tls_wr(struct tlspcb *tlsp, struct sge_txq *txq,
 #endif
 	}
 
-	/*
-	 * Use cached value for first record in chain if not using
-	 * partial GCM mode. ktls_parse_pkt() calculates nsegs based
-	 * on send_partial_ghash being false.
-	 */
-	if (m->m_next == m_tls && !send_partial_ghash)
-		nsegs = mbuf_nsegs(m);
-	else
-		nsegs = sglist_count_mbuf_epg(m_tls,
-		    m_tls->m_epg_hdrlen + offset, plen);
+	nsegs = sglist_count_mbuf_epg(m_tls, m_tls->m_epg_hdrlen + offset,
+	    plen);
 
 	/* Determine if we need an LSO header. */
 	need_lso = (m_tls->m_len > mss);