From 98df2aee1459ee1c62c70cbe9b370d2a532aea36 Mon Sep 17 00:00:00 2001 From: Cheng Xu Date: Thu, 30 Jul 2026 20:43:53 +0800 Subject: [PATCH] RDMA/erdma: Hold CQ references when processing EQ events EQ handlers look up CQs from dev->cq_xa and invoke CQ completion or error callbacks outside the xarray lock. erdma_destroy_cq() can erase the CQ from the xarray and free its queue buffer and doorbell record while a previously scheduled EQ handler is still using the CQ. Add a CQ refcount and take a reference under the xarray lock with refcount_inc_not_zero(). Remove the CQ from the xarray before dropping the destroy-path reference, then wait for in-flight EQ users before releasing CQ resources. Fixes: 155055771704 ("RDMA/erdma: Add verbs implementation") Signed-off-by: Cheng Xu Link: https://patch.msgid.link/20260730124357.12976-1-chengyou@linux.alibaba.com Signed-off-by: Leon Romanovsky --- drivers/infiniband/hw/erdma/erdma_eq.c | 6 ++++-- drivers/infiniband/hw/erdma/erdma_verbs.c | 12 +++++++++-- drivers/infiniband/hw/erdma/erdma_verbs.h | 25 +++++++++++++++++++++-- 3 files changed, 37 insertions(+), 6 deletions(-) diff --git a/drivers/infiniband/hw/erdma/erdma_eq.c b/drivers/infiniband/hw/erdma/erdma_eq.c index a8784e07acd6..96e74fcf417c 100644 --- a/drivers/infiniband/hw/erdma/erdma_eq.c +++ b/drivers/infiniband/hw/erdma/erdma_eq.c @@ -52,7 +52,7 @@ void erdma_aeq_event_handler(struct erdma_dev *dev) if (FIELD_GET(ERDMA_AEQE_HDR_TYPE_MASK, le32_to_cpu(aeqe->hdr)) == ERDMA_AE_TYPE_CQ_ERR) { cqn = le32_to_cpu(aeqe->event_data0); - cq = find_cq_by_cqn(dev, cqn); + cq = erdma_cq_get_by_cqn(dev, cqn); if (!cq) continue; @@ -62,6 +62,7 @@ void erdma_aeq_event_handler(struct erdma_dev *dev) if (cq->ibcq.event_handler) cq->ibcq.event_handler(&event, cq->ibcq.cq_context); + erdma_cq_put(cq); } else { qpn = le32_to_cpu(aeqe->event_data0); qp = find_qp_by_qpn(dev, qpn); @@ -157,7 +158,7 @@ void erdma_ceq_completion_handler(struct erdma_eq_cb *ceq_cb) poll_cnt++; cqn = FIELD_GET(ERDMA_CEQE_HDR_CQN_MASK, READ_ONCE(*ceqe)); - cq = find_cq_by_cqn(dev, cqn); + cq = erdma_cq_get_by_cqn(dev, cqn); if (!cq) continue; @@ -166,6 +167,7 @@ void erdma_ceq_completion_handler(struct erdma_eq_cb *ceq_cb) if (cq->ibcq.comp_handler) cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context); + erdma_cq_put(cq); } notify_eq(&ceq_cb->eq); diff --git a/drivers/infiniband/hw/erdma/erdma_verbs.c b/drivers/infiniband/hw/erdma/erdma_verbs.c index ab6abbab029e..2adcd00c4199 100644 --- a/drivers/infiniband/hw/erdma/erdma_verbs.c +++ b/drivers/infiniband/hw/erdma/erdma_verbs.c @@ -1326,6 +1326,7 @@ int erdma_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata) struct erdma_dev *dev = to_edev(ibcq->device); struct erdma_ucontext *ctx = rdma_udata_to_drv_context( udata, struct erdma_ucontext, ibucontext); + unsigned long flags; int err; struct erdma_cmdq_destroy_cq_req req; @@ -1340,6 +1341,13 @@ int erdma_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata) "failed to destroy CQ %u: %d\n", cq->cqn, err); + xa_lock_irqsave(&dev->cq_xa, flags); + __xa_erase(&dev->cq_xa, cq->cqn); + xa_unlock_irqrestore(&dev->cq_xa, flags); + + erdma_cq_put(cq); + wait_for_completion(&cq->free); + if (rdma_is_kernel_res(&cq->ibcq.res)) { dma_free_coherent(&dev->pdev->dev, cq->depth << CQE_SHIFT, cq->kern_cq.qbuf, cq->kern_cq.qbuf_dma_addr); @@ -1350,8 +1358,6 @@ int erdma_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata) put_mtt_entries(dev, &cq->user_cq.qbuf_mem); } - xa_erase(&dev->cq_xa, cq->cqn); - return 0; } @@ -1980,6 +1986,8 @@ int erdma_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr, cq->ibcq.cqe = depth; cq->depth = depth; cq->assoc_eqn = attr->comp_vector + 1; + refcount_set(&cq->refcount, 1); + init_completion(&cq->free); ret = xa_alloc_cyclic(&dev->cq_xa, &cq->cqn, cq, XA_LIMIT(1, dev->attrs.max_cq - 1), diff --git a/drivers/infiniband/hw/erdma/erdma_verbs.h b/drivers/infiniband/hw/erdma/erdma_verbs.h index 7d8d3fe501d5..894e080435fb 100644 --- a/drivers/infiniband/hw/erdma/erdma_verbs.h +++ b/drivers/infiniband/hw/erdma/erdma_verbs.h @@ -7,6 +7,9 @@ #ifndef __ERDMA_VERBS_H__ #define __ERDMA_VERBS_H__ +#include +#include + #include "erdma.h" /* RDMA Capability. */ @@ -341,6 +344,8 @@ struct erdma_cq { u32 depth; u32 assoc_eqn; + refcount_t refcount; + struct completion free; union { struct erdma_kcq_info kern_cq; @@ -355,9 +360,25 @@ static inline struct erdma_qp *find_qp_by_qpn(struct erdma_dev *dev, int id) return (struct erdma_qp *)xa_load(&dev->qp_xa, id); } -static inline struct erdma_cq *find_cq_by_cqn(struct erdma_dev *dev, int id) +static inline struct erdma_cq *erdma_cq_get_by_cqn(struct erdma_dev *dev, + int id) { - return (struct erdma_cq *)xa_load(&dev->cq_xa, id); + struct erdma_cq *cq; + unsigned long flags; + + xa_lock_irqsave(&dev->cq_xa, flags); + cq = xa_load(&dev->cq_xa, id); + if (cq && !refcount_inc_not_zero(&cq->refcount)) + cq = NULL; + xa_unlock_irqrestore(&dev->cq_xa, flags); + + return cq; +} + +static inline void erdma_cq_put(struct erdma_cq *cq) +{ + if (refcount_dec_and_test(&cq->refcount)) + complete(&cq->free); } void erdma_qp_get(struct erdma_qp *qp);