RDMA/cxgb4: Remove kref accounting for sync operation

Ucontext allocation and release aren't async events and don't need kref
accounting. The common layer of RDMA subsystem ensures that dealloc
ucontext will be called after all other objects are released.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/cxgb4/iw_cxgb4.h

@@ -589,7 +589,6 @@ struct c4iw_ucontext {
 	u32 key;
 	spinlock_t mmap_lock;
 	struct list_head mmaps;
-	struct kref kref;
 	bool is_32b_cqe;
 };
 
@@ -598,18 +597,6 @@ static inline struct c4iw_ucontext *to_c4iw_ucontext(struct ib_ucontext *c)
 	return container_of(c, struct c4iw_ucontext, ibucontext);
 }
 
-void _c4iw_free_ucontext(struct kref *kref);
-
-static inline void c4iw_put_ucontext(struct c4iw_ucontext *ucontext)
-{
-	kref_put(&ucontext->kref, _c4iw_free_ucontext);
-}
-
-static inline void c4iw_get_ucontext(struct c4iw_ucontext *ucontext)
-{
-	kref_get(&ucontext->kref);
-}
-
 struct c4iw_mm_entry {
 	struct list_head entry;
 	u64 addr;

drivers/infiniband/hw/cxgb4/provider.c

@@ -58,28 +58,19 @@ static int fastreg_support = 1;
 module_param(fastreg_support, int, 0644);
 MODULE_PARM_DESC(fastreg_support, "Advertise fastreg support (default=1)");
 
-void _c4iw_free_ucontext(struct kref *kref)
+static int c4iw_dealloc_ucontext(struct ib_ucontext *context)
 {
-	struct c4iw_ucontext *ucontext;
+	struct c4iw_ucontext *ucontext = to_c4iw_ucontext(context);
 	struct c4iw_dev *rhp;
 	struct c4iw_mm_entry *mm, *tmp;
 
-	ucontext = container_of(kref, struct c4iw_ucontext, kref);
+	pr_debug("context %p\n", context);
 	rhp = to_c4iw_dev(ucontext->ibucontext.device);
 
-	pr_debug("ucontext %p\n", ucontext);
 	list_for_each_entry_safe(mm, tmp, &ucontext->mmaps, entry)
 		kfree(mm);
 	c4iw_release_dev_ucontext(&rhp->rdev, &ucontext->uctx);
 	kfree(ucontext);
-}
-
-static int c4iw_dealloc_ucontext(struct ib_ucontext *context)
-{
-	struct c4iw_ucontext *ucontext = to_c4iw_ucontext(context);
-
-	pr_debug("context %p\n", context);
-	c4iw_put_ucontext(ucontext);
 	return 0;
 }
 
@@ -102,7 +93,6 @@ static struct ib_ucontext *c4iw_alloc_ucontext(struct ib_device *ibdev,
 	c4iw_init_dev_ucontext(&rhp->rdev, &context->uctx);
 	INIT_LIST_HEAD(&context->mmaps);
 	spin_lock_init(&context->mmap_lock);
-	kref_init(&context->kref);
 
 	if (udata->outlen < sizeof(uresp) - sizeof(uresp.reserved)) {
 		pr_err_once("Warning - downlevel libcxgb4 (non-fatal), device status page disabled\n");

drivers/infiniband/hw/cxgb4/qp.c

@@ -904,8 +904,6 @@ static void free_qp_work(struct work_struct *work)
 	destroy_qp(&rhp->rdev, &qhp->wq,
 		   ucontext ? &ucontext->uctx : &rhp->rdev.uctx, !qhp->srq);
 
-	if (ucontext)
-		c4iw_put_ucontext(ucontext);
 	c4iw_put_wr_wait(qhp->wr_waitp);
 	kfree(qhp);
 }
@@ -2338,7 +2336,6 @@ struct ib_qp *c4iw_create_qp(struct ib_pd *pd, struct ib_qp_init_attr *attrs,
 			insert_mmap(ucontext, ma_sync_key_mm);
 		}
 
-		c4iw_get_ucontext(ucontext);
 		qhp->ucontext = ucontext;
 	}
 	if (!attrs->srq) {