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[2603:8081:140c:1a00:2c78:b015:8039:f06c]) by smtp.gmail.com with ESMTPSA id r138-20020acaa890000000b00387367989d7sm6411402oie.23.2023.03.27.14.58.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Mar 2023 14:58:29 -0700 (PDT) From: Bob Pearson To: jgg@nvidia.com, zyjzyj2000@gmail.com, BMT@zurich.ibm.com, linux-rdma@vger.kernel.org Cc: Bob Pearson Subject: [PATCH] RDMA/rxe: Remove tasklet call from rxe_cq.c Date: Mon, 27 Mar 2023 16:56:44 -0500 Message-Id: <20230327215643.10410-1-rpearsonhpe@gmail.com> X-Mailer: git-send-email 2.37.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Remove the tasklet call in rxe_cq.c and also the is_dying in the cq struct. There is no reason for the rxe driver to defer the call to the cq completion handler by scheduling a tasklet. rxe_cq_post() is not called in a hard irq context. The rxe driver currently is incorrect because the tasklet call is made without protecting the cq pointer with a reference from having the underlying memory freed before the deferred routine is called. Executing the comp_handler inline fixes this problem. Fixes: 8700e3e7c485 ("Soft RoCE driver") Signed-off-by: Bob Pearson --- drivers/infiniband/sw/rxe/rxe_cq.c | 32 +++------------------------ drivers/infiniband/sw/rxe/rxe_verbs.c | 2 -- drivers/infiniband/sw/rxe/rxe_verbs.h | 2 -- 3 files changed, 3 insertions(+), 33 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_cq.c b/drivers/infiniband/sw/rxe/rxe_cq.c index 66a13c935d50..20ff0c0c4605 100644 --- a/drivers/infiniband/sw/rxe/rxe_cq.c +++ b/drivers/infiniband/sw/rxe/rxe_cq.c @@ -39,21 +39,6 @@ int rxe_cq_chk_attr(struct rxe_dev *rxe, struct rxe_cq *cq, return -EINVAL; } -static void rxe_send_complete(struct tasklet_struct *t) -{ - struct rxe_cq *cq = from_tasklet(cq, t, comp_task); - unsigned long flags; - - spin_lock_irqsave(&cq->cq_lock, flags); - if (cq->is_dying) { - spin_unlock_irqrestore(&cq->cq_lock, flags); - return; - } - spin_unlock_irqrestore(&cq->cq_lock, flags); - - cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context); -} - int rxe_cq_from_init(struct rxe_dev *rxe, struct rxe_cq *cq, int cqe, int comp_vector, struct ib_udata *udata, struct rxe_create_cq_resp __user *uresp) @@ -79,10 +64,6 @@ int rxe_cq_from_init(struct rxe_dev *rxe, struct rxe_cq *cq, int cqe, cq->is_user = uresp; - cq->is_dying = false; - - tasklet_setup(&cq->comp_task, rxe_send_complete); - spin_lock_init(&cq->cq_lock); cq->ibcq.cqe = cqe; return 0; @@ -103,6 +84,7 @@ int rxe_cq_resize_queue(struct rxe_cq *cq, int cqe, return err; } +/* caller holds reference to cq */ int rxe_cq_post(struct rxe_cq *cq, struct rxe_cqe *cqe, int solicited) { struct ib_event ev; @@ -136,21 +118,13 @@ int rxe_cq_post(struct rxe_cq *cq, struct rxe_cqe *cqe, int solicited) if ((cq->notify == IB_CQ_NEXT_COMP) || (cq->notify == IB_CQ_SOLICITED && solicited)) { cq->notify = 0; - tasklet_schedule(&cq->comp_task); + + cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context); } return 0; } -void rxe_cq_disable(struct rxe_cq *cq) -{ - unsigned long flags; - - spin_lock_irqsave(&cq->cq_lock, flags); - cq->is_dying = true; - spin_unlock_irqrestore(&cq->cq_lock, flags); -} - void rxe_cq_cleanup(struct rxe_pool_elem *elem) { struct rxe_cq *cq = container_of(elem, typeof(*cq), elem); diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c index 84b53c070fc5..090d5bfb1e18 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.c +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c @@ -1178,8 +1178,6 @@ static int rxe_destroy_cq(struct ib_cq *ibcq, struct ib_udata *udata) goto err_out; } - rxe_cq_disable(cq); - err = rxe_cleanup(cq); if (err) rxe_err_cq(cq, "cleanup failed, err = %d", err); diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h index 84994a474e9a..dab6fa305bf2 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.h +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h @@ -63,9 +63,7 @@ struct rxe_cq { struct rxe_queue *queue; spinlock_t cq_lock; u8 notify; - bool is_dying; bool is_user; - struct tasklet_struct comp_task; atomic_t num_wq; }; -- 2.37.2