RDMA/hns: Use mutex instead of spinlock for ida allocation

GFP_KERNEL may cause ida_alloc_range() to sleep, but the spinlock covering
this function is not allowed to sleep, so the spinlock needs to be changed
to mutex.

As there is a certain chance of memory allocation failure, GFP_ATOMIC is
not suitable for QP allocation scenarios.

Fixes: 71586dd20010 ("RDMA/hns: Create QP with selected QPN for bank load balance")
Link: https://lore.kernel.org/r/1611048513-28663-1-git-send-email-liweihang@huawei.com
Signed-off-by: Yangyang Li <liyangyang20@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 55d538625e36139c40ab93122944699816b0d95d..ad8253245a85fd73963c4c9d78034d5de2344884 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_device.h
+++ b/drivers/infiniband/hw/hns/hns_roce_device.h
@@ -532,7 +532,7 @@ struct hns_roce_qp_table {
        struct hns_roce_hem_table       sccc_table;
        struct mutex                    scc_mutex;
        struct hns_roce_bank bank[HNS_ROCE_QP_BANK_NUM];
-       spinlock_t bank_lock;
+       struct mutex bank_mutex;
 };
 
 struct hns_roce_cq_table {

diff --git a/drivers/infiniband/hw/hns/hns_roce_qp.c b/drivers/infiniband/hw/hns/hns_roce_qp.c
index d8e2fe5558d29d371ac31776a564f8638e21c17c..1116371adf74f4bc267aa5b7e2c8085a5c54356e 100644 (file)
--- a/drivers/infiniband/hw/hns/hns_roce_qp.c
+++ b/drivers/infiniband/hw/hns/hns_roce_qp.c
@@ -209,7 +209,7 @@ static int alloc_qpn(struct hns_roce_dev *hr_dev, struct hns_roce_qp *hr_qp)
 
                hr_qp->doorbell_qpn = 1;
        } else {
-               spin_lock(&qp_table->bank_lock);
+               mutex_lock(&qp_table->bank_mutex);
                bankid = get_least_load_bankid_for_qp(qp_table->bank);
 
                ret = alloc_qpn_with_bankid(&qp_table->bank[bankid], bankid,
@@ -217,12 +217,12 @@ static int alloc_qpn(struct hns_roce_dev *hr_dev, struct hns_roce_qp *hr_qp)
                if (ret) {
                        ibdev_err(&hr_dev->ib_dev,
                                  "failed to alloc QPN, ret = %d\n", ret);
-                       spin_unlock(&qp_table->bank_lock);
+                       mutex_unlock(&qp_table->bank_mutex);
                        return ret;
                }
 
                qp_table->bank[bankid].inuse++;
-               spin_unlock(&qp_table->bank_lock);
+               mutex_unlock(&qp_table->bank_mutex);
 
                hr_qp->doorbell_qpn = (u32)num;
        }
@@ -408,9 +408,9 @@ static void free_qpn(struct hns_roce_dev *hr_dev, struct hns_roce_qp *hr_qp)
 
        ida_free(&hr_dev->qp_table.bank[bankid].ida, hr_qp->qpn >> 3);
 
-       spin_lock(&hr_dev->qp_table.bank_lock);
+       mutex_lock(&hr_dev->qp_table.bank_mutex);
        hr_dev->qp_table.bank[bankid].inuse--;
-       spin_unlock(&hr_dev->qp_table.bank_lock);
+       mutex_unlock(&hr_dev->qp_table.bank_mutex);
 }
 
 static int set_rq_size(struct hns_roce_dev *hr_dev, struct ib_qp_cap *cap,
@@ -1371,6 +1371,7 @@ int hns_roce_init_qp_table(struct hns_roce_dev *hr_dev)
        unsigned int i;
 
        mutex_init(&qp_table->scc_mutex);
+       mutex_init(&qp_table->bank_mutex);
        xa_init(&hr_dev->qp_table_xa);
 
        reserved_from_bot = hr_dev->caps.reserved_qps;