RDMA/rxe: Change mcg_lock to a _bh lock

rxe_mcast.c currently uses _irqsave spinlocks for rxe->mcg_lock while
rxe_recv.c uses _bh spinlocks for the same lock.

As there is no case where the mcg_lock can be taken from an IRQ, change
these all to bh locks so we don't have confusing mismatched lock types on
the same spinlock.

Fixes: 6090a0c4c7c6 ("RDMA/rxe: Cleanup rxe_mcast.c")
Link: https://lore.kernel.org/r/20220504202817.98247-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/infiniband/sw/rxe/rxe_mcast.c b/drivers/infiniband/sw/rxe/rxe_mcast.c
index 77e45cabd8ea0f3b22e7e0eb1c5bb1138a81ff8c..873a9b10307c0ac0131b8ffcb77a01e72dc9f190 100644 (file)
--- a/drivers/infiniband/sw/rxe/rxe_mcast.c
+++ b/drivers/infiniband/sw/rxe/rxe_mcast.c
@@ -143,11 +143,10 @@ static struct rxe_mcg *__rxe_lookup_mcg(struct rxe_dev *rxe,
 struct rxe_mcg *rxe_lookup_mcg(struct rxe_dev *rxe, union ib_gid *mgid)
 {
        struct rxe_mcg *mcg;
-       unsigned long flags;
 
-       spin_lock_irqsave(&rxe->mcg_lock, flags);
+       spin_lock_bh(&rxe->mcg_lock);
        mcg = __rxe_lookup_mcg(rxe, mgid);
-       spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+       spin_unlock_bh(&rxe->mcg_lock);
 
        return mcg;
 }
@@ -189,7 +188,6 @@ static void __rxe_init_mcg(struct rxe_dev *rxe, union ib_gid *mgid,
 static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, union ib_gid *mgid)
 {
        struct rxe_mcg *mcg, *tmp;
-       unsigned long flags;
        int err;
 
        if (rxe->attr.max_mcast_grp == 0)
@@ -211,18 +209,18 @@ static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, union ib_gid *mgid)
        if (!mcg)
                return ERR_PTR(-ENOMEM);
 
-       spin_lock_irqsave(&rxe->mcg_lock, flags);
+       spin_lock_bh(&rxe->mcg_lock);
        /* re-check to see if someone else just added it */
        tmp = __rxe_lookup_mcg(rxe, mgid);
        if (tmp) {
-               spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+               spin_unlock_bh(&rxe->mcg_lock);
                atomic_dec(&rxe->mcg_num);
                kfree(mcg);
                return tmp;
        }
 
        __rxe_init_mcg(rxe, mgid, mcg);
-       spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+       spin_unlock_bh(&rxe->mcg_lock);
 
        /* add mcast address outside of lock */
        err = rxe_mcast_add(rxe, mgid);
@@ -272,14 +270,12 @@ static void __rxe_destroy_mcg(struct rxe_mcg *mcg)
  */
 static void rxe_destroy_mcg(struct rxe_mcg *mcg)
 {
-       unsigned long flags;
-
        /* delete mcast address outside of lock */
        rxe_mcast_del(mcg->rxe, &mcg->mgid);
 
-       spin_lock_irqsave(&mcg->rxe->mcg_lock, flags);
+       spin_lock_bh(&mcg->rxe->mcg_lock);
        __rxe_destroy_mcg(mcg);
-       spin_unlock_irqrestore(&mcg->rxe->mcg_lock, flags);
+       spin_unlock_bh(&mcg->rxe->mcg_lock);
 }
 
 /**
@@ -334,25 +330,24 @@ static int rxe_attach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
 {
        struct rxe_dev *rxe = mcg->rxe;
        struct rxe_mca *mca, *tmp;
-       unsigned long flags;
        int err;
 
        /* check to see if the qp is already a member of the group */
-       spin_lock_irqsave(&rxe->mcg_lock, flags);
+       spin_lock_bh(&rxe->mcg_lock);
        list_for_each_entry(mca, &mcg->qp_list, qp_list) {
                if (mca->qp == qp) {
-                       spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+                       spin_unlock_bh(&rxe->mcg_lock);
                        return 0;
                }
        }
-       spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+       spin_unlock_bh(&rxe->mcg_lock);
 
        /* speculative alloc new mca without using GFP_ATOMIC */
        mca = kzalloc(sizeof(*mca), GFP_KERNEL);
        if (!mca)
                return -ENOMEM;
 
-       spin_lock_irqsave(&rxe->mcg_lock, flags);
+       spin_lock_bh(&rxe->mcg_lock);
        /* re-check to see if someone else just attached qp */
        list_for_each_entry(tmp, &mcg->qp_list, qp_list) {
                if (tmp->qp == qp) {
@@ -366,7 +361,7 @@ static int rxe_attach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
        if (err)
                kfree(mca);
 out:
-       spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+       spin_unlock_bh(&rxe->mcg_lock);
        return err;
 }
 
@@ -400,9 +395,8 @@ static int rxe_detach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
 {
        struct rxe_dev *rxe = mcg->rxe;
        struct rxe_mca *mca, *tmp;
-       unsigned long flags;
 
-       spin_lock_irqsave(&rxe->mcg_lock, flags);
+       spin_lock_bh(&rxe->mcg_lock);
        list_for_each_entry_safe(mca, tmp, &mcg->qp_list, qp_list) {
                if (mca->qp == qp) {
                        __rxe_cleanup_mca(mca, mcg);
@@ -416,13 +410,13 @@ static int rxe_detach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp)
                        if (atomic_read(&mcg->qp_num) <= 0)
                                __rxe_destroy_mcg(mcg);
 
-                       spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+                       spin_unlock_bh(&rxe->mcg_lock);
                        return 0;
                }
        }
 
        /* we didn't find the qp on the list */
-       spin_unlock_irqrestore(&rxe->mcg_lock, flags);
+       spin_unlock_bh(&rxe->mcg_lock);
        return -EINVAL;
 }