RDMA/hns: Bugfix for checking whether the srq is full when post wr

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@huawei.com
Signed-off-by: Wenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
index 72961e4..916e031 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_device.h
+++ b/drivers/infiniband/hw/hns/hns_roce_device.h
@@ -494,6 +494,8 @@ struct hns_roce_idx_que {
        struct hns_roce_mtr             mtr;
        int                             entry_shift;
        unsigned long                   *bitmap;
+       u32                             head;
+       u32                             tail;
 };
 
 struct hns_roce_srq {
@@ -513,8 +515,6 @@ 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 2245d25..b13775a 100644 (file)
--- 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 1be6812..e622fd1 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_srq.c
+++ b/drivers/infiniband/hw/hns/hns_roce_srq.c
@@ -245,6 +245,9 @@ 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);
@@ -263,8 +266,6 @@ 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;