[PATCH 1/1] RDMA/ionic: map PHC state into user space
From: Abhijit Gangurde
Date: Tue Jul 07 2026 - 05:56:57 EST
Enable user space applications to access the PHC state page when
firmware RDMA completion timestamp is supported.
This mapping allows user space to convert RDMA completion timestamps
to system wall time without kernel transitions, minimizing latency
overhead. Applications can directly read the PHC state through mmap,
enabling efficient timestamp correlation for precision timing
applications.
Co-developed-by: Allen Hubbe <allen.hubbe@xxxxxxx>
Signed-off-by: Allen Hubbe <allen.hubbe@xxxxxxx>
Signed-off-by: Abhijit Gangurde <abhijit.gangurde@xxxxxxx>
---
.../infiniband/hw/ionic/ionic_controlpath.c | 36 +++++++++++++++-
drivers/infiniband/hw/ionic/ionic_datapath.c | 43 ++++++++++---------
drivers/infiniband/hw/ionic/ionic_fw.h | 12 ++++--
drivers/infiniband/hw/ionic/ionic_ibdev.h | 2 +
drivers/infiniband/hw/ionic/ionic_lif_cfg.c | 2 +
drivers/infiniband/hw/ionic/ionic_lif_cfg.h | 1 +
include/uapi/rdma/ionic-abi.h | 1 +
7 files changed, 72 insertions(+), 25 deletions(-)
diff --git a/drivers/infiniband/hw/ionic/ionic_controlpath.c b/drivers/infiniband/hw/ionic/ionic_controlpath.c
index ea12d9b8e125..c04e02d41535 100644
--- a/drivers/infiniband/hw/ionic/ionic_controlpath.c
+++ b/drivers/infiniband/hw/ionic/ionic_controlpath.c
@@ -391,6 +391,16 @@ int ionic_alloc_ucontext(struct ib_ucontext *ibctx, struct ib_udata *udata)
goto err_mmap_dbell;
}
+ if (dev->lif_cfg.phc_state) {
+ ctx->mmap_phc = ionic_mmap_entry_insert(ctx, PAGE_SIZE, 0,
+ IONIC_MMAP_PHC,
+ &resp.phc_offset);
+ if (!ctx->mmap_phc) {
+ rc = -ENOMEM;
+ goto err_mmap_phc;
+ }
+ }
+
resp.page_shift = PAGE_SHIFT;
resp.dbell_offset = db_phys & ~PAGE_MASK;
@@ -414,13 +424,15 @@ int ionic_alloc_ucontext(struct ib_ucontext *ibctx, struct ib_udata *udata)
if (dev->lif_cfg.rq_expdb)
resp.expdb_qtypes |= IONIC_EXPDB_RQ;
- rc = ib_copy_to_udata(udata, &resp, sizeof(resp));
+ rc = ib_copy_to_udata(udata, &resp, min(sizeof(resp), udata->outlen));
if (rc)
goto err_resp;
return 0;
err_resp:
+ rdma_user_mmap_entry_remove(ctx->mmap_phc);
+err_mmap_phc:
rdma_user_mmap_entry_remove(ctx->mmap_dbell);
err_mmap_dbell:
ionic_put_dbid(dev, ctx->dbid);
@@ -433,10 +445,26 @@ void ionic_dealloc_ucontext(struct ib_ucontext *ibctx)
struct ionic_ibdev *dev = to_ionic_ibdev(ibctx->device);
struct ionic_ctx *ctx = to_ionic_ctx(ibctx);
+ rdma_user_mmap_entry_remove(ctx->mmap_phc);
rdma_user_mmap_entry_remove(ctx->mmap_dbell);
ionic_put_dbid(dev, ctx->dbid);
}
+static int ionic_mmap_phc_stage(struct ionic_ibdev *dev,
+ struct vm_area_struct *vma)
+{
+ if (!(vma->vm_flags & VM_SHARED))
+ return -EINVAL;
+
+ if (vma->vm_flags & (VM_WRITE | VM_EXEC))
+ return -EPERM;
+
+ vm_flags_clear(vma, VM_MAYWRITE);
+
+ return vm_insert_page(vma, vma->vm_start,
+ virt_to_page(dev->lif_cfg.phc_state));
+}
+
int ionic_mmap(struct ib_ucontext *ibctx, struct vm_area_struct *vma)
{
struct ionic_ibdev *dev = to_ionic_ibdev(ibctx->device);
@@ -455,6 +483,12 @@ int ionic_mmap(struct ib_ucontext *ibctx, struct vm_area_struct *vma)
ionic_entry = container_of(rdma_entry, struct ionic_mmap_entry,
rdma_entry);
+ if (ionic_entry->mmap_flags & IONIC_MMAP_PHC) {
+ rc = ionic_mmap_phc_stage(dev, vma);
+ rdma_user_mmap_entry_put(rdma_entry);
+ return rc;
+ }
+
ibdev_dbg(&dev->ibdev, "writecombine? %d\n",
ionic_entry->mmap_flags & IONIC_MMAP_WC);
if (ionic_entry->mmap_flags & IONIC_MMAP_WC)
diff --git a/drivers/infiniband/hw/ionic/ionic_datapath.c b/drivers/infiniband/hw/ionic/ionic_datapath.c
index aa2944887f23..3e2300f7ea10 100644
--- a/drivers/infiniband/hw/ionic/ionic_datapath.c
+++ b/drivers/infiniband/hw/ionic/ionic_datapath.c
@@ -32,6 +32,7 @@ static int ionic_flush_recv(struct ionic_qp *qp, struct ib_wc *wc)
{
struct ionic_rq_meta *meta;
struct ionic_v1_wqe *wqe;
+ u64 wqe_idx;
if (!qp->rq_flush)
return 0;
@@ -40,21 +41,22 @@ static int ionic_flush_recv(struct ionic_qp *qp, struct ib_wc *wc)
return 0;
wqe = ionic_queue_at_cons(&qp->rq);
+ wqe_idx = le64_to_cpu(wqe->base.wqe_idx);
- /* wqe_id must be a valid queue index */
- if (unlikely(wqe->base.wqe_id >> qp->rq.depth_log2)) {
+ /* wqe_idx must be a valid queue index */
+ if (unlikely(wqe_idx >> qp->rq.depth_log2)) {
ibdev_warn(qp->ibqp.device,
"flush qp %u recv index %llu invalid\n",
- qp->qpid, (unsigned long long)wqe->base.wqe_id);
+ qp->qpid, (unsigned long long)wqe_idx);
return -EIO;
}
- /* wqe_id must indicate a request that is outstanding */
- meta = &qp->rq_meta[wqe->base.wqe_id];
+ /* wqe_idx must indicate a request that is outstanding */
+ meta = &qp->rq_meta[wqe_idx];
if (unlikely(meta->next != IONIC_META_POSTED)) {
ibdev_warn(qp->ibqp.device,
"flush qp %u recv index %llu not posted\n",
- qp->qpid, (unsigned long long)wqe->base.wqe_id);
+ qp->qpid, (unsigned long long)wqe_idx);
return -EIO;
}
@@ -133,8 +135,8 @@ static int ionic_poll_recv(struct ionic_ibdev *dev, struct ionic_cq *cq,
{
struct ionic_qp *qp = NULL;
struct ionic_rq_meta *meta;
+ u16 vlan_tag, wqe_idx;
u32 src_qpn, st_len;
- u16 vlan_tag;
u8 op;
if (cqe_qp->rq_flush)
@@ -144,7 +146,7 @@ static int ionic_poll_recv(struct ionic_ibdev *dev, struct ionic_cq *cq,
st_len = be32_to_cpu(cqe->status_length);
- /* ignore wqe_id in case of flush error */
+ /* ignore wqe_idx in case of flush error */
if (ionic_v1_cqe_error(cqe) && st_len == IONIC_STS_WQE_FLUSHED_ERR) {
cqe_qp->rq_flush = true;
cq->flush = true;
@@ -160,20 +162,19 @@ static int ionic_poll_recv(struct ionic_ibdev *dev, struct ionic_cq *cq,
return -EIO;
}
- /* wqe_id must be a valid queue index */
- if (unlikely(cqe->recv.wqe_id >> qp->rq.depth_log2)) {
+ wqe_idx = le64_to_cpu(cqe->recv.wqe_idx_timestamp) & IONIC_V1_CQE_WQE_IDX_MASK;
+ /* wqe_idx must be a valid queue index */
+ if (unlikely(wqe_idx >> qp->rq.depth_log2)) {
ibdev_warn(&dev->ibdev,
- "qp %u recv index %llu invalid\n",
- qp->qpid, (unsigned long long)cqe->recv.wqe_id);
+ "qp %u recv index %u invalid\n", qp->qpid, wqe_idx);
return -EIO;
}
- /* wqe_id must indicate a request that is outstanding */
- meta = &qp->rq_meta[cqe->recv.wqe_id];
+ /* wqe_idx must indicate a request that is outstanding */
+ meta = &qp->rq_meta[wqe_idx];
if (unlikely(meta->next != IONIC_META_POSTED)) {
ibdev_warn(&dev->ibdev,
- "qp %u recv index %llu not posted\n",
- qp->qpid, (unsigned long long)cqe->recv.wqe_id);
+ "qp %u recv index %u not posted\n", qp->qpid, wqe_idx);
return -EIO;
}
@@ -408,7 +409,7 @@ static int ionic_comp_msn(struct ionic_qp *qp, struct ionic_v1_cqe *cqe)
static int ionic_comp_npg(struct ionic_qp *qp, struct ionic_v1_cqe *cqe)
{
struct ionic_sq_meta *meta;
- u16 cqe_idx;
+ u16 wqe_idx;
u32 st_len;
if (qp->sq_flush)
@@ -430,8 +431,8 @@ static int ionic_comp_npg(struct ionic_qp *qp, struct ionic_v1_cqe *cqe)
return 0;
}
- cqe_idx = cqe->send.npg_wqe_id & qp->sq.mask;
- meta = &qp->sq_meta[cqe_idx];
+ wqe_idx = le64_to_cpu(cqe->send.npg_wqe_idx_timestamp) & qp->sq.mask;
+ meta = &qp->sq_meta[wqe_idx];
meta->local_comp = true;
if (ionic_v1_cqe_error(cqe)) {
@@ -811,7 +812,7 @@ static void ionic_prep_base(struct ionic_qp *qp,
meta->signal = false;
meta->local_comp = false;
- wqe->base.wqe_id = qp->sq.prod;
+ wqe->base.wqe_idx = cpu_to_le64(qp->sq.prod);
if (wr->send_flags & IB_SEND_FENCE)
wqe->base.flags |= cpu_to_be16(IONIC_V1_FLAG_FENCE);
@@ -1205,7 +1206,7 @@ static int ionic_prep_recv(struct ionic_qp *qp,
meta->wrid = wr->wr_id;
- wqe->base.wqe_id = meta - qp->rq_meta;
+ wqe->base.wqe_idx = cpu_to_le64(meta - qp->rq_meta);
wqe->base.num_sge_key = wr->num_sge;
/* total length for recv goes in base imm_data_key */
diff --git a/drivers/infiniband/hw/ionic/ionic_fw.h b/drivers/infiniband/hw/ionic/ionic_fw.h
index adfbb89d856c..ee23062a1762 100644
--- a/drivers/infiniband/hw/ionic/ionic_fw.h
+++ b/drivers/infiniband/hw/ionic/ionic_fw.h
@@ -332,7 +332,7 @@ struct ionic_v1_cqe {
__le16 old_rq_cq_cindex;
} admin;
struct {
- __u64 wqe_id;
+ __le64 wqe_idx_timestamp;
__be32 src_qpn_op;
__u8 src_mac[6];
__be16 vlan_tag;
@@ -342,13 +342,19 @@ struct ionic_v1_cqe {
__u8 rsvd[4];
__be32 msg_msn;
__u8 rsvd2[8];
- __u64 npg_wqe_id;
+ __le64 npg_wqe_idx_timestamp;
} send;
};
__be32 status_length;
__be32 qid_type_flags;
};
+/* bits for cqe wqe_idx and timestamp */
+enum ionic_v1_cqe_wqe_idx_timestamp_bits {
+ IONIC_V1_CQE_WQE_IDX_MASK = 0xffff,
+ IONIC_V1_CQE_TIMESTAMP_SHIFT = 16,
+};
+
/* bits for cqe recv */
enum ionic_v1_cqe_src_qpn_bits {
IONIC_V1_CQE_RECV_QPN_MASK = 0xffffff,
@@ -423,7 +429,7 @@ static inline u32 ionic_v1_cqe_qtf_qid(u32 qtf)
/* v1 base wqe header */
struct ionic_v1_base_hdr {
- __u64 wqe_id;
+ __le64 wqe_idx;
__u8 op;
__u8 num_sge_key;
__be16 flags;
diff --git a/drivers/infiniband/hw/ionic/ionic_ibdev.h b/drivers/infiniband/hw/ionic/ionic_ibdev.h
index 82fda1e3cdb6..de23376267f5 100644
--- a/drivers/infiniband/hw/ionic/ionic_ibdev.h
+++ b/drivers/infiniband/hw/ionic/ionic_ibdev.h
@@ -72,6 +72,7 @@ enum ionic_admin_flags {
enum ionic_mmap_flag {
IONIC_MMAP_WC = BIT(0),
+ IONIC_MMAP_PHC = BIT(1),
};
struct ionic_mmap_entry {
@@ -173,6 +174,7 @@ struct ionic_ctx {
struct ib_ucontext ibctx;
u32 dbid;
struct rdma_user_mmap_entry *mmap_dbell;
+ struct rdma_user_mmap_entry *mmap_phc;
};
struct ionic_tbl_buf {
diff --git a/drivers/infiniband/hw/ionic/ionic_lif_cfg.c b/drivers/infiniband/hw/ionic/ionic_lif_cfg.c
index f3cd281c3a2f..54eaa30cce78 100644
--- a/drivers/infiniband/hw/ionic/ionic_lif_cfg.c
+++ b/drivers/infiniband/hw/ionic/ionic_lif_cfg.c
@@ -40,6 +40,8 @@ void ionic_fill_lif_cfg(struct ionic_lif *lif, struct ionic_lif_cfg *cfg)
cfg->dbid_count = le32_to_cpu(lif->ionic->ident.dev.ndbpgs_per_lif);
cfg->dbpage = lif->kern_dbpage;
cfg->intr_ctrl = lif->ionic->idev.intr_ctrl;
+ if (le64_to_cpu(ident->eth.config.features) & IONIC_ETH_HW_RDMA_TIMESTAMP)
+ cfg->phc_state = lif->phc->state_page;
cfg->db_phys = lif->ionic->bars[IONIC_PCI_BAR_DBELL].bus_addr;
diff --git a/drivers/infiniband/hw/ionic/ionic_lif_cfg.h b/drivers/infiniband/hw/ionic/ionic_lif_cfg.h
index 20853429f623..2b29e646c193 100644
--- a/drivers/infiniband/hw/ionic/ionic_lif_cfg.h
+++ b/drivers/infiniband/hw/ionic/ionic_lif_cfg.h
@@ -23,6 +23,7 @@ struct ionic_lif_cfg {
u64 __iomem *dbpage;
struct ionic_intr __iomem *intr_ctrl;
phys_addr_t db_phys;
+ void *phc_state;
u64 page_size_supported;
u32 npts_per_lif;
diff --git a/include/uapi/rdma/ionic-abi.h b/include/uapi/rdma/ionic-abi.h
index 97f695510380..abd1bde0991f 100644
--- a/include/uapi/rdma/ionic-abi.h
+++ b/include/uapi/rdma/ionic-abi.h
@@ -48,6 +48,7 @@ struct ionic_ctx_resp {
__u8 expdb_qtypes;
__u8 rsvd2[3];
+ __aligned_u64 phc_offset;
};
struct ionic_qdesc {
--
2.43.0