git: 5a3885768490 - main - cxgbe tom: Halve the size of offload transmit software descriptors
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Date: Thu, 11 Sep 2025 21:10:50 UTC
The branch main has been updated by jhb:
URL: https://cgit.FreeBSD.org/src/commit/?id=5a38857684907c52982787dbac2c5e5c8abfd4f8
commit 5a38857684907c52982787dbac2c5e5c8abfd4f8
Author: John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2025-09-11 21:10:39 +0000
Commit: John Baldwin <jhb@FreeBSD.org>
CommitDate: 2025-09-11 21:10:39 +0000
cxgbe tom: Halve the size of offload transmit software descriptors
Use bitfields to pack tx_credits and plen into a single 32-bit word.
Reviewed by: np
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D47759
---
sys/dev/cxgbe/cxgbei/icl_cxgbei.c | 2 ++
sys/dev/cxgbe/iw_cxgbe/qp.c | 2 ++
sys/dev/cxgbe/tom/t4_cpl_io.c | 16 ++++++++++++++++
sys/dev/cxgbe/tom/t4_tls.c | 4 ++++
sys/dev/cxgbe/tom/t4_tom.c | 2 ++
sys/dev/cxgbe/tom/t4_tom.h | 7 +++++--
6 files changed, 31 insertions(+), 2 deletions(-)
diff --git a/sys/dev/cxgbe/cxgbei/icl_cxgbei.c b/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
index c8592807f843..d805642541d3 100644
--- a/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
+++ b/sys/dev/cxgbe/cxgbei/icl_cxgbei.c
@@ -1053,6 +1053,8 @@ send_iscsi_flowc_wr(struct adapter *sc, struct toepcb *toep, int maxlen)
flowc->mnemval[0].mnemonic = FW_FLOWC_MNEM_TXDATAPLEN_MAX;
flowc->mnemval[0].val = htobe32(maxlen);
+ KASSERT(howmany(flowclen, 16) <= MAX_OFLD_TX_SDESC_CREDITS,
+ ("%s: tx_credits %u too large", __func__, howmany(flowclen, 16)));
txsd->tx_credits = howmany(flowclen, 16);
txsd->plen = 0;
KASSERT(toep->tx_credits >= txsd->tx_credits && toep->txsd_avail > 0,
diff --git a/sys/dev/cxgbe/iw_cxgbe/qp.c b/sys/dev/cxgbe/iw_cxgbe/qp.c
index 0e374bc961c4..cbf4bae00a60 100644
--- a/sys/dev/cxgbe/iw_cxgbe/qp.c
+++ b/sys/dev/cxgbe/iw_cxgbe/qp.c
@@ -1326,6 +1326,8 @@ creds(struct toepcb *toep, struct inpcb *inp, size_t wrsize)
return (EINVAL);
}
txsd = &toep->txsd[toep->txsd_pidx];
+ KASSERT(howmany(wrsize, 16) <= MAX_OFLD_TX_SDESC_CREDITS,
+ ("%s: tx_credits %zu too large", __func__, howmany(wrsize, 16)));
txsd->tx_credits = howmany(wrsize, 16);
txsd->plen = 0;
KASSERT(toep->tx_credits >= txsd->tx_credits && toep->txsd_avail > 0,
diff --git a/sys/dev/cxgbe/tom/t4_cpl_io.c b/sys/dev/cxgbe/tom/t4_cpl_io.c
index 7a6b1cbdd736..9ecb4aeee939 100644
--- a/sys/dev/cxgbe/tom/t4_cpl_io.c
+++ b/sys/dev/cxgbe/tom/t4_cpl_io.c
@@ -148,6 +148,8 @@ send_flowc_wr(struct toepcb *toep, struct tcpcb *tp)
KASSERT(paramidx == nparams, ("nparams mismatch"));
+ KASSERT(howmany(flowclen, 16) <= MAX_OFLD_TX_SDESC_CREDITS,
+ ("%s: tx_credits %u too large", __func__, howmany(flowclen, 16)));
txsd->tx_credits = howmany(flowclen, 16);
txsd->plen = 0;
KASSERT(toep->tx_credits >= txsd->tx_credits && toep->txsd_avail > 0,
@@ -215,6 +217,8 @@ update_tx_rate_limit(struct adapter *sc, struct toepcb *toep, u_int Bps)
else
flowc->mnemval[0].val = htobe32(tc_idx);
+ KASSERT(flowclen16 <= MAX_OFLD_TX_SDESC_CREDITS,
+ ("%s: tx_credits %u too large", __func__, flowclen16));
txsd->tx_credits = flowclen16;
txsd->plen = 0;
toep->tx_credits -= txsd->tx_credits;
@@ -491,6 +495,9 @@ t4_close_conn(struct adapter *sc, struct toepcb *toep)
#define MIN_TX_CREDITS(iso) \
(MIN_OFLD_TX_CREDITS + ((iso) ? MIN_ISO_TX_CREDITS : 0))
+_Static_assert(MAX_OFLD_TX_CREDITS <= MAX_OFLD_TX_SDESC_CREDITS,
+ "MAX_OFLD_TX_SDESC_CREDITS too small");
+
/* Maximum amount of immediate data we could stuff in a WR */
static inline int
max_imm_payload(int tx_credits, int iso)
@@ -705,6 +712,8 @@ t4_push_frames(struct adapter *sc, struct toepcb *toep, int drop)
if ((m->m_flags & M_NOTREADY) != 0)
break;
+ if (plen + m->m_len > MAX_OFLD_TX_SDESC_PLEN)
+ break;
if (m->m_flags & M_EXTPG) {
#ifdef KERN_TLS
if (m->m_epg_tls != NULL) {
@@ -870,6 +879,8 @@ t4_push_frames(struct adapter *sc, struct toepcb *toep, int drop)
toep->flags |= TPF_TX_SUSPENDED;
KASSERT(toep->txsd_avail > 0, ("%s: no txsd", __func__));
+ KASSERT(plen <= MAX_OFLD_TX_SDESC_PLEN,
+ ("%s: plen %u too large", __func__, plen));
txsd->plen = plen;
txsd->tx_credits = credits;
txsd++;
@@ -1211,6 +1222,8 @@ t4_push_pdus(struct adapter *sc, struct toepcb *toep, int drop)
toep->flags |= TPF_TX_SUSPENDED;
KASSERT(toep->txsd_avail > 0, ("%s: no txsd", __func__));
+ KASSERT(plen <= MAX_OFLD_TX_SDESC_PLEN,
+ ("%s: plen %u too large", __func__, plen));
txsd->plen = plen;
txsd->tx_credits = credits;
txsd++;
@@ -1969,6 +1982,9 @@ t4_set_tcb_field(struct adapter *sc, struct sge_wrq *wrq, struct toepcb *toep,
req->val = htobe64(val);
if (wrq->eq.type == EQ_OFLD) {
txsd = &toep->txsd[toep->txsd_pidx];
+ _Static_assert(howmany(sizeof(*req), 16) <=
+ MAX_OFLD_TX_SDESC_CREDITS,
+ "MAX_OFLD_TX_SDESC_CREDITS too small");
txsd->tx_credits = howmany(sizeof(*req), 16);
txsd->plen = 0;
KASSERT(toep->tx_credits >= txsd->tx_credits &&
diff --git a/sys/dev/cxgbe/tom/t4_tls.c b/sys/dev/cxgbe/tom/t4_tls.c
index 27c16b9988ae..857832aafa5c 100644
--- a/sys/dev/cxgbe/tom/t4_tls.c
+++ b/sys/dev/cxgbe/tom/t4_tls.c
@@ -191,6 +191,8 @@ tls_program_key_id(struct toepcb *toep, struct ktls_session *tls,
t4_tls_key_ctx(tls, direction, kctx);
txsd = &toep->txsd[toep->txsd_pidx];
+ _Static_assert(DIV_ROUND_UP(TLS_KEY_WR_SZ, 16) <=
+ MAX_OFLD_TX_SDESC_CREDITS, "MAX_OFLD_TX_SDESC_CREDITS too small");
txsd->tx_credits = DIV_ROUND_UP(TLS_KEY_WR_SZ, 16);
txsd->plen = 0;
toep->tx_credits -= txsd->tx_credits;
@@ -694,6 +696,8 @@ t4_push_ktls(struct adapter *sc, struct toepcb *toep, int drop)
toep->flags |= TPF_TX_SUSPENDED;
KASSERT(toep->txsd_avail > 0, ("%s: no txsd", __func__));
+ KASSERT(m->m_len <= MAX_OFLD_TX_SDESC_PLEN,
+ ("%s: plen %u too large", __func__, m->m_len));
txsd->plen = m->m_len;
txsd->tx_credits = credits;
txsd++;
diff --git a/sys/dev/cxgbe/tom/t4_tom.c b/sys/dev/cxgbe/tom/t4_tom.c
index 9b09facd05a7..0b54fdaa5c80 100644
--- a/sys/dev/cxgbe/tom/t4_tom.c
+++ b/sys/dev/cxgbe/tom/t4_tom.c
@@ -882,6 +882,8 @@ send_mss_flowc_wr(struct adapter *sc, struct toepcb *toep)
flowc->mnemval[0].val = htobe32(toep->params.emss);
txsd = &toep->txsd[toep->txsd_pidx];
+ _Static_assert(flowclen16 <= MAX_OFLD_TX_SDESC_CREDITS,
+ "MAX_OFLD_TX_SDESC_CREDITS too small");
txsd->tx_credits = flowclen16;
txsd->plen = 0;
toep->tx_credits -= txsd->tx_credits;
diff --git a/sys/dev/cxgbe/tom/t4_tom.h b/sys/dev/cxgbe/tom/t4_tom.h
index 6295a3484b9f..3b2243aeb69f 100644
--- a/sys/dev/cxgbe/tom/t4_tom.h
+++ b/sys/dev/cxgbe/tom/t4_tom.h
@@ -122,10 +122,13 @@ struct conn_params {
};
struct ofld_tx_sdesc {
- uint32_t plen; /* payload length */
- uint8_t tx_credits; /* firmware tx credits (unit is 16B) */
+ uint32_t plen : 26; /* payload length */
+ uint32_t tx_credits : 6; /* firmware tx credits (unit is 16B) */
};
+#define MAX_OFLD_TX_SDESC_PLEN ((1u << 26) - 1)
+#define MAX_OFLD_TX_SDESC_CREDITS ((1u << 6) - 1)
+
struct ppod_region {
u_int pr_start;
u_int pr_len;