From: Leon Romanovsky <leonro@mellanox.com>
Date: Tue, 12 Feb 2019 20:39:15 +0200
Subject: RDMA/cxgb4: Remove kref accounting for sync operation
Patch-mainline: v5.1-rc1
Git-commit: cfe876d8e6b0491170d44c8040c518b121957104
References: bsc#1136348 jsc#SLE-4684

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/cxgb4/iw_cxgb4.h |   13 -------------
 drivers/infiniband/hw/cxgb4/provider.c |   16 +++-------------
 drivers/infiniband/hw/cxgb4/qp.c       |    3 ---
 3 files changed, 3 insertions(+), 29 deletions(-)

--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -590,7 +590,6 @@ struct c4iw_ucontext {
 	u32 key;
 	spinlock_t mmap_lock;
 	struct list_head mmaps;
-	struct kref kref;
 	bool is_32b_cqe;
 };
 
@@ -599,18 +598,6 @@ static inline struct c4iw_ucontext *to_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;
--- a/drivers/infiniband/hw/cxgb4/provider.c
+++ b/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_uc
 	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");
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -903,8 +903,6 @@ static void free_qp_work(struct work_str
 	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_p
 			insert_mmap(ucontext, ma_sync_key_mm);
 		}
 
-		c4iw_get_ucontext(ucontext);
 		qhp->ucontext = ucontext;
 	}
 	if (!attrs->srq) {