Date: Mon, 11 Nov 2024 16:39:40 GMT From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 4d3b659f24a8 - main - nvmf: Track SQ flow control Message-ID: <202411111639.4ABGde9B070491@gitrepo.freebsd.org>
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The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=4d3b659f24a88f76557019e6f3192760bdebfbdf commit 4d3b659f24a88f76557019e6f3192760bdebfbdf Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2024-11-11 16:39:05 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2024-11-11 16:39:05 +0000 nvmf: Track SQ flow control This isn't really needed since the host driver never submits more commands to a queue than it can hold, but I noticed that the recently-added SQ head and tail sysctl nodes were not updating. This fixes that and also uses these values to assert that there we never submit a command while a queue pair is full. Sponsored by: Chelsio Communications --- sys/dev/nvmf/host/nvmf_qpair.c | 33 ++++++++++++++++++++++++++++----- sys/dev/nvmf/nvmf_transport.c | 8 ++++++++ sys/dev/nvmf/nvmf_transport.h | 1 + 3 files changed, 37 insertions(+), 5 deletions(-) diff --git a/sys/dev/nvmf/host/nvmf_qpair.c b/sys/dev/nvmf/host/nvmf_qpair.c index 1aeb0535eacf..b03ecfa081d3 100644 --- a/sys/dev/nvmf/host/nvmf_qpair.c +++ b/sys/dev/nvmf/host/nvmf_qpair.c @@ -115,8 +115,23 @@ nvmf_dispatch_command(struct nvmf_host_qpair *qp, struct nvmf_host_command *cmd) struct nvmf_softc *sc = qp->sc; struct nvme_command *sqe; struct nvmf_capsule *nc; + uint16_t new_sqtail; int error; + mtx_assert(&qp->lock, MA_OWNED); + + qp->submitted++; + + /* + * Update flow control tracking. This is just a sanity check. + * Since num_commands == qsize - 1, there can never be too + * many commands in flight. + */ + new_sqtail = (qp->sqtail + 1) % (qp->num_commands + 1); + KASSERT(new_sqtail != qp->sqhd, ("%s: qp %p is full", __func__, qp)); + qp->sqtail = new_sqtail; + mtx_unlock(&qp->lock); + nc = cmd->req->nc; sqe = nvmf_capsule_sqe(nc); @@ -180,11 +195,23 @@ nvmf_receive_capsule(void *arg, struct nvmf_capsule *nc) return; } + /* Update flow control tracking. */ + mtx_lock(&qp->lock); + if (qp->sq_flow_control) { + if (nvmf_sqhd_valid(nc)) + qp->sqhd = le16toh(cqe->sqhd); + } else { + /* + * If SQ FC is disabled, just advance the head for + * each response capsule received. + */ + qp->sqhd = (qp->sqhd + 1) % (qp->num_commands + 1); + } + /* * If the queue has been shutdown due to an error, silently * drop the response. */ - mtx_lock(&qp->lock); if (qp->qp == NULL) { device_printf(sc->dev, "received completion for CID %u on shutdown %s\n", cid, @@ -215,8 +242,6 @@ nvmf_receive_capsule(void *arg, struct nvmf_capsule *nc) } else { cmd->req = STAILQ_FIRST(&qp->pending_requests); STAILQ_REMOVE_HEAD(&qp->pending_requests, link); - qp->submitted++; - mtx_unlock(&qp->lock); nvmf_dispatch_command(qp, cmd); } @@ -420,7 +445,5 @@ nvmf_submit_request(struct nvmf_request *req) ("%s: CID already busy", __func__)); qp->active_commands[cmd->cid] = cmd; cmd->req = req; - qp->submitted++; - mtx_unlock(&qp->lock); nvmf_dispatch_command(qp, cmd); } diff --git a/sys/dev/nvmf/nvmf_transport.c b/sys/dev/nvmf/nvmf_transport.c index ea4aee8cc7ae..316d1571e61d 100644 --- a/sys/dev/nvmf/nvmf_transport.c +++ b/sys/dev/nvmf/nvmf_transport.c @@ -180,6 +180,14 @@ nvmf_capsule_cqe(struct nvmf_capsule *nc) return (&nc->nc_cqe); } +bool +nvmf_sqhd_valid(struct nvmf_capsule *nc) +{ + KASSERT(nc->nc_qe_len == sizeof(struct nvme_completion), + ("%s: capsule %p is not a response capsule", __func__, nc)); + return (nc->nc_sqhd_valid); +} + uint8_t nvmf_validate_command_capsule(struct nvmf_capsule *nc) { diff --git a/sys/dev/nvmf/nvmf_transport.h b/sys/dev/nvmf/nvmf_transport.h index 549170b25940..bbd830eba576 100644 --- a/sys/dev/nvmf/nvmf_transport.h +++ b/sys/dev/nvmf/nvmf_transport.h @@ -78,6 +78,7 @@ int nvmf_transmit_capsule(struct nvmf_capsule *nc); void nvmf_abort_capsule_data(struct nvmf_capsule *nc, int error); void *nvmf_capsule_sqe(struct nvmf_capsule *nc); void *nvmf_capsule_cqe(struct nvmf_capsule *nc); +bool nvmf_sqhd_valid(struct nvmf_capsule *nc); /* Controller-specific APIs. */
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