[PATCH 16/48] staging: etnaviv: give etnaviv_gem_mmap_offset() a sane behaviour

[Lucas Stach]

From: Russell King <rmk+kernel at arm.linux.org.uk>

etnaviv_gem_mmap_offset() returned zero if drm_gem_create_mmap_offset()
failed.  This is incorrect behaviour as etnaviv_ioctl_gem_info() does
not detect this condition, so it returns success.

Fix this by re-architecting etnaviv_gem_mmap_offset().  Merge
mmap_offset() into this function, and change its prototype to accept a
pointer to the "offset" return value, thereby allowing it to return a
standard negative errno code.

Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
 drivers/staging/etnaviv/etnaviv_drv.c |  4 ++--
 drivers/staging/etnaviv/etnaviv_drv.h |  2 +-
 drivers/staging/etnaviv/etnaviv_gem.c | 26 +++++++-------------------
 3 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/drivers/staging/etnaviv/etnaviv_drv.c b/drivers/staging/etnaviv/etnaviv_drv.c
index 1071c449f3d4..9962318075c5 100644
--- a/drivers/staging/etnaviv/etnaviv_drv.c
+++ b/drivers/staging/etnaviv/etnaviv_drv.c
@@ -438,7 +438,7 @@ static int etnaviv_ioctl_gem_info(struct drm_device *dev, void *data,
 {
 	struct drm_etnaviv_gem_info *args = data;
 	struct drm_gem_object *obj;
-	int ret = 0;
+	int ret;
 
 	if (args->pad)
 		return -EINVAL;
@@ -447,7 +447,7 @@ static int etnaviv_ioctl_gem_info(struct drm_device *dev, void *data,
 	if (!obj)
 		return -ENOENT;
 
-	args->offset = etnaviv_gem_mmap_offset(obj);
+	ret = etnaviv_gem_mmap_offset(obj, &args->offset);
 
 	drm_gem_object_unreference_unlocked(obj);
 
diff --git a/drivers/staging/etnaviv/etnaviv_drv.h b/drivers/staging/etnaviv/etnaviv_drv.h
index 9abb7f8c2dc0..37992342bbf0 100644
--- a/drivers/staging/etnaviv/etnaviv_drv.h
+++ b/drivers/staging/etnaviv/etnaviv_drv.h
@@ -73,7 +73,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 
 int etnaviv_gem_mmap(struct file *filp, struct vm_area_struct *vma);
 int etnaviv_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
-uint64_t etnaviv_gem_mmap_offset(struct drm_gem_object *obj);
+int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, uint64_t *offset);
 int etnaviv_gem_get_iova_locked(struct etnaviv_gpu *gpu,
 	struct drm_gem_object *obj, uint32_t *iova);
 int etnaviv_gem_get_iova(struct etnaviv_gpu *gpu, struct drm_gem_object *obj,
diff --git a/drivers/staging/etnaviv/etnaviv_gem.c b/drivers/staging/etnaviv/etnaviv_gem.c
index 522e5a6c3612..38dee80d996c 100644
--- a/drivers/staging/etnaviv/etnaviv_gem.c
+++ b/drivers/staging/etnaviv/etnaviv_gem.c
@@ -270,33 +270,21 @@ out:
 }
 
 /** get mmap offset */
-static uint64_t mmap_offset(struct drm_gem_object *obj)
+int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, uint64_t *offset)
 {
 	struct drm_device *dev = obj->dev;
 	int ret;
 
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
+	mutex_lock(&dev->struct_mutex);
 	/* Make it mmapable */
 	ret = drm_gem_create_mmap_offset(obj);
-
-	if (ret) {
+	if (ret)
 		dev_err(dev->dev, "could not allocate mmap offset\n");
-		return 0;
-	}
-
-	return drm_vma_node_offset_addr(&obj->vma_node);
-}
-
-uint64_t etnaviv_gem_mmap_offset(struct drm_gem_object *obj)
-{
-	uint64_t offset;
-
-	mutex_lock(&obj->dev->struct_mutex);
-	offset = mmap_offset(obj);
-	mutex_unlock(&obj->dev->struct_mutex);
+	else
+		*offset = drm_vma_node_offset_addr(&obj->vma_node);
+	mutex_unlock(&dev->struct_mutex);
 
-	return offset;
+	return ret;
 }
 
 /* should be called under struct_mutex.. although it can be called
-- 
2.5.1