From 13f5c3c4e7802a3812fcb18ee8b36c662eaf048c Mon Sep 17 00:00:00 2001
From: hselasky <hselasky@FreeBSD.org>
Date: Wed, 7 Mar 2018 14:03:31 +0000
Subject: [PATCH] Disable unsupported disassociate ucontext functionality in
 mlx5ib(4).

MFC after:	1 week
Sponsored by:	Mellanox Technologies
---
 sys/dev/mlx5/mlx5_ib/mlx5_ib_main.c | 58 -----------------------------
 1 file changed, 58 deletions(-)

diff --git a/sys/dev/mlx5/mlx5_ib/mlx5_ib_main.c b/sys/dev/mlx5/mlx5_ib/mlx5_ib_main.c
index e40139a9aa0e..79aa7e653b3d 100644
--- a/sys/dev/mlx5/mlx5_ib/mlx5_ib_main.c
+++ b/sys/dev/mlx5/mlx5_ib/mlx5_ib_main.c
@@ -1241,62 +1241,6 @@ static int mlx5_ib_set_vma_data(struct vm_area_struct *vma,
 	return 0;
 }
 
-static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext)
-{
-	int ret;
-	struct vm_area_struct *vma;
-	struct mlx5_ib_vma_private_data *vma_private, *n;
-	struct mlx5_ib_ucontext *context = to_mucontext(ibcontext);
-	struct task_struct *owning_process  = NULL;
-	struct mm_struct   *owning_mm       = NULL;
-
-	owning_process = get_pid_task(ibcontext->tgid, PIDTYPE_PID);
-	if (!owning_process)
-		return;
-
-	owning_mm = get_task_mm(owning_process);
-	if (!owning_mm) {
-		pr_info("no mm, disassociate ucontext is pending task termination\n");
-		while (1) {
-			put_task_struct(owning_process);
-			usleep_range(1000, 2000);
-			owning_process = get_pid_task(ibcontext->tgid,
-						      PIDTYPE_PID);
-			if (!owning_process /* ||
-			    owning_process->state == TASK_DEAD */) {
-				pr_info("disassociate ucontext done, task was terminated\n");
-				/* in case task was dead need to release the
-				 * task struct.
-				 */
-				if (owning_process)
-					put_task_struct(owning_process);
-				return;
-			}
-		}
-	}
-
-	/* need to protect from a race on closing the vma as part of
-	 * mlx5_ib_vma_close.
-	 */
-	down_read(&owning_mm->mmap_sem);
-	list_for_each_entry_safe(vma_private, n, &context->vma_private_list,
-				 list) {
-		vma = vma_private->vma;
-		ret = zap_vma_ptes(vma, vma->vm_start,
-				   PAGE_SIZE);
-		WARN_ONCE(ret, "%s: zap_vma_ptes failed", __func__);
-		/* context going to be destroyed, should
-		 * not access ops any more.
-		 */
-		vma->vm_ops = NULL;
-		list_del(&vma_private->list);
-		kfree(vma_private);
-	}
-	up_read(&owning_mm->mmap_sem);
-	mmput(owning_mm);
-	put_task_struct(owning_process);
-}
-
 static inline char *mmap_cmd2str(enum mlx5_ib_mmap_cmd cmd)
 {
 	switch (cmd) {
@@ -3056,8 +3000,6 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev)
 		dev->ib_dev.set_vf_guid		= mlx5_ib_set_vf_guid;
 	}
 
-	dev->ib_dev.disassociate_ucontext = mlx5_ib_disassociate_ucontext;
-
 	mlx5_ib_internal_fill_odp_caps(dev);
 
 	if (MLX5_CAP_GEN(mdev, imaicl)) {