This is a note to let you know that I've just added the patch titled RDMA/hns: Bugfix for checking whether the srq is full when post wr to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rdma-hns-bugfix-for-checking-whether-the-srq-is-full.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b1bac9e97160949f03e616692bb04d1bfc2ca330 Author: Wenpeng Liang <liangwenpeng@xxxxxxxxxx> Date: Sat Jan 30 16:58:00 2021 +0800 RDMA/hns: Bugfix for checking whether the srq is full when post wr [ Upstream commit 1620f09b96ec14c1ff1ff64ee0aeabc027c653d5 ] If a user posts WR by wr_list, the head pointer of idx_queue won't be updated until all wqes are filled, so the judgment of whether head equals to tail will get a wrong result. Fix above issue and move the head and tail pointer from the srq structure into the idx_queue structure. After idx_queue is filled with wqe idx, the head pointer of it will increase. Fixes: c7bcb13442e1 ("RDMA/hns: Add SRQ support for hip08 kernel mode") Link: https://lore.kernel.org/r/1611997090-48820-3-git-send-email-liweihang@xxxxxxxxxx Signed-off-by: Wenpeng Liang <liangwenpeng@xxxxxxxxxx> Signed-off-by: Weihang Li <liweihang@xxxxxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h index dd3e3886ab96d..2e42e25957938 100644 --- a/drivers/infiniband/hw/hns/hns_roce_device.h +++ b/drivers/infiniband/hw/hns/hns_roce_device.h @@ -492,6 +492,8 @@ struct hns_roce_idx_que { struct hns_roce_mtr mtr; int entry_shift; unsigned long *bitmap; + u32 head; + u32 tail; }; struct hns_roce_srq { @@ -511,8 +513,6 @@ struct hns_roce_srq { u64 *wrid; struct hns_roce_idx_que idx_que; spinlock_t lock; - u16 head; - u16 tail; struct mutex mutex; void (*event)(struct hns_roce_srq *srq, enum hns_roce_event event); }; diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c index 4d1e4bddf8327..c05e418b6e538 100644 --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c @@ -849,11 +849,20 @@ static void hns_roce_free_srq_wqe(struct hns_roce_srq *srq, int wqe_index) spin_lock(&srq->lock); bitmap_clear(srq->idx_que.bitmap, wqe_index, 1); - srq->tail++; + srq->idx_que.tail++; spin_unlock(&srq->lock); } +int hns_roce_srqwq_overflow(struct hns_roce_srq *srq, int nreq) +{ + struct hns_roce_idx_que *idx_que = &srq->idx_que; + unsigned int cur; + + cur = idx_que->head - idx_que->tail; + return cur + nreq >= srq->wqe_cnt - 1; +} + static int find_empty_entry(struct hns_roce_idx_que *idx_que, unsigned long size) { @@ -889,7 +898,7 @@ static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq, spin_lock_irqsave(&srq->lock, flags); - ind = srq->head & (srq->wqe_cnt - 1); + ind = srq->idx_que.head & (srq->wqe_cnt - 1); max_sge = srq->max_gs - srq->rsv_sge; for (nreq = 0; wr; ++nreq, wr = wr->next) { @@ -902,7 +911,7 @@ static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq, break; } - if (unlikely(srq->head == srq->tail)) { + if (unlikely(hns_roce_srqwq_overflow(srq, nreq))) { ret = -ENOMEM; *bad_wr = wr; break; @@ -938,7 +947,7 @@ static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq, } if (likely(nreq)) { - srq->head += nreq; + srq->idx_que.head += nreq; /* * Make sure that descriptors are written before @@ -950,7 +959,7 @@ static int hns_roce_v2_post_srq_recv(struct ib_srq *ibsrq, cpu_to_le32(HNS_ROCE_V2_SRQ_DB << V2_DB_BYTE_4_CMD_S | (srq->srqn & V2_DB_BYTE_4_TAG_M)); srq_db.parameter = - cpu_to_le32(srq->head & V2_DB_PARAMETER_IDX_M); + cpu_to_le32(srq->idx_que.head & V2_DB_PARAMETER_IDX_M); hns_roce_write64(hr_dev, (__le32 *)&srq_db, srq->db_reg_l); } diff --git a/drivers/infiniband/hw/hns/hns_roce_srq.c b/drivers/infiniband/hw/hns/hns_roce_srq.c index 8e20085b8920a..9f60a0a745e11 100644 --- a/drivers/infiniband/hw/hns/hns_roce_srq.c +++ b/drivers/infiniband/hw/hns/hns_roce_srq.c @@ -247,6 +247,9 @@ static int alloc_srq_idx(struct hns_roce_dev *hr_dev, struct hns_roce_srq *srq, } } + idx_que->head = 0; + idx_que->tail = 0; + return 0; err_idx_mtr: hns_roce_mtr_destroy(hr_dev, &idx_que->mtr); @@ -265,8 +268,6 @@ static void free_srq_idx(struct hns_roce_dev *hr_dev, struct hns_roce_srq *srq) static int alloc_srq_wrid(struct hns_roce_dev *hr_dev, struct hns_roce_srq *srq) { - srq->head = 0; - srq->tail = srq->wqe_cnt - 1; srq->wrid = kvmalloc_array(srq->wqe_cnt, sizeof(u64), GFP_KERNEL); if (!srq->wrid) return -ENOMEM;