From: Tom St Denis <tom.stdenis@amd.com>
Date: Fri, 26 Jan 2018 09:22:05 -0500
Subject: drm/ttm: Remove unncessary retval from ttm_bo_vm_fault()
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Git-commit: de8dfb8e3449c704e2c67680b9226a058e6dc663
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

The dual ret/retval was more complex than need be.  Now
we drop the retval variable and assign the appropriate VM
codes to ret instead.

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/ttm/ttm_bo_vm.c |   28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -118,7 +118,6 @@ static int ttm_bo_vm_fault(struct vm_fau
 	int ret;
 	int i;
 	unsigned long address = vmf->address;
-	int retval = VM_FAULT_NOPAGE;
 	struct ttm_mem_type_manager *man =
 		&bdev->man[bo->mem.mem_type];
 	struct vm_area_struct cvma;
@@ -158,7 +157,7 @@ static int ttm_bo_vm_fault(struct vm_fau
 	 * (if at all) by redirecting mmap to the exporter.
 	 */
 	if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
-		retval = VM_FAULT_SIGBUS;
+		ret = VM_FAULT_SIGBUS;
 		goto out_unlock;
 	}
 
@@ -169,10 +168,10 @@ static int ttm_bo_vm_fault(struct vm_fau
 			break;
 		case -EBUSY:
 		case -ERESTARTSYS:
-			retval = VM_FAULT_NOPAGE;
+			ret = VM_FAULT_NOPAGE;
 			goto out_unlock;
 		default:
-			retval = VM_FAULT_SIGBUS;
+			ret = VM_FAULT_SIGBUS;
 			goto out_unlock;
 		}
 	}
@@ -183,12 +182,10 @@ static int ttm_bo_vm_fault(struct vm_fau
 	 */
 	ret = ttm_bo_vm_fault_idle(bo, vmf);
 	if (unlikely(ret != 0)) {
-		retval = ret;
-
-		if (retval == VM_FAULT_RETRY &&
+		if (ret == VM_FAULT_RETRY &&
 		    !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
 			/* The BO has already been unreserved. */
-			return retval;
+			return ret;
 		}
 
 		goto out_unlock;
@@ -196,12 +193,12 @@ static int ttm_bo_vm_fault(struct vm_fau
 
 	ret = ttm_mem_io_lock(man, true);
 	if (unlikely(ret != 0)) {
-		retval = VM_FAULT_NOPAGE;
+		ret = VM_FAULT_NOPAGE;
 		goto out_unlock;
 	}
 	ret = ttm_mem_io_reserve_vm(bo);
 	if (unlikely(ret != 0)) {
-		retval = VM_FAULT_SIGBUS;
+		ret = VM_FAULT_SIGBUS;
 		goto out_io_unlock;
 	}
 
@@ -211,7 +208,7 @@ static int ttm_bo_vm_fault(struct vm_fau
 		drm_vma_node_start(&bo->vma_node);
 
 	if (unlikely(page_offset >= bo->num_pages)) {
-		retval = VM_FAULT_SIGBUS;
+		ret = VM_FAULT_SIGBUS;
 		goto out_io_unlock;
 	}
 
@@ -238,7 +235,7 @@ static int ttm_bo_vm_fault(struct vm_fau
 
 		/* Allocate all page at once, most common usage */
 		if (ttm->bdev->driver->ttm_tt_populate(ttm, &ctx)) {
-			retval = VM_FAULT_OOM;
+			ret = VM_FAULT_OOM;
 			goto out_io_unlock;
 		}
 	}
@@ -255,7 +252,7 @@ static int ttm_bo_vm_fault(struct vm_fau
 		} else {
 			page = ttm->pages[page_offset];
 			if (unlikely(!page && i == 0)) {
-				retval = VM_FAULT_OOM;
+				ret = VM_FAULT_OOM;
 				goto out_io_unlock;
 			} else if (unlikely(!page)) {
 				break;
@@ -280,7 +277,7 @@ static int ttm_bo_vm_fault(struct vm_fau
 		if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 			break;
 		else if (unlikely(ret != 0)) {
-			retval =
+			ret =
 			    (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 			goto out_io_unlock;
 		}
@@ -289,11 +286,12 @@ static int ttm_bo_vm_fault(struct vm_fau
 		if (unlikely(++page_offset >= page_last))
 			break;
 	}
+	ret = VM_FAULT_NOPAGE;
 out_io_unlock:
 	ttm_mem_io_unlock(man);
 out_unlock:
 	ttm_bo_unreserve(bo);
-	return retval;
+	return ret;
 }
 
 static void ttm_bo_vm_open(struct vm_area_struct *vma)