[PATCH] drm: pass dev to drm_vm_{open,close}_locked()

[Rob Clark]

From: Rob Clark <rob at ti.com>

Previously these functions would assume that vma->vm_file was the
drm_file.  Although if in some cases if the drm driver needs to use
something else for the backing file (such as the tmpfs filp) then this
assumption is no longer true.  But vma->vm_private_data is still the
GEM object.

With this change, now the drm_device comes from the GEM object rather
than the drm_file so the driver is more free to play with vma->vm_file.

The scenario where this comes up is for mmap'ing of cached dmabuf's
for non-coherent systems, where the driver needs to use fault handling
and PTE shootdown to simulate coherency.  We can't use the vma->vm_file
of the dmabuf, which is using anon_inode's address_space.  The most
straightforward thing to do is to use the GEM object's obj->filp for
vma->vm_file in all cases, for which we need this patch.

Signed-off-by: Rob Clark <rob at ti.com>
---
 drivers/gpu/drm/drm_gem.c |    6 +++---
 drivers/gpu/drm/drm_vm.c  |   18 ++++++++----------
 include/drm/drmP.h        |    4 ++--
 3 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 83114b5..475b300 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -628,7 +628,7 @@ void drm_gem_vm_open(struct vm_area_struct *vma)
 	drm_gem_object_reference(obj);
 
 	mutex_lock(&obj->dev->struct_mutex);
-	drm_vm_open_locked(vma);
+	drm_vm_open_locked(obj->dev, vma);
 	mutex_unlock(&obj->dev->struct_mutex);
 }
 EXPORT_SYMBOL(drm_gem_vm_open);
@@ -639,7 +639,7 @@ void drm_gem_vm_close(struct vm_area_struct *vma)
 	struct drm_device *dev = obj->dev;
 
 	mutex_lock(&dev->struct_mutex);
-	drm_vm_close_locked(vma);
+	drm_vm_close_locked(obj->dev, vma);
 	drm_gem_object_unreference(obj);
 	mutex_unlock(&dev->struct_mutex);
 }
@@ -712,7 +712,7 @@ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 	 */
 	drm_gem_object_reference(obj);
 
-	drm_vm_open_locked(vma);
+	drm_vm_open_locked(dev, vma);
 
 out_unlock:
 	mutex_unlock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index 1495618..961ee08 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -406,10 +406,9 @@ static const struct vm_operations_struct drm_vm_sg_ops = {
  * Create a new drm_vma_entry structure as the \p vma private data entry and
  * add it to drm_device::vmalist.
  */
-void drm_vm_open_locked(struct vm_area_struct *vma)
+void drm_vm_open_locked(struct drm_device *dev,
+		struct vm_area_struct *vma)
 {
-	struct drm_file *priv = vma->vm_file->private_data;
-	struct drm_device *dev = priv->minor->dev;
 	struct drm_vma_entry *vma_entry;
 
 	DRM_DEBUG("0x%08lx,0x%08lx\n",
@@ -430,14 +429,13 @@ static void drm_vm_open(struct vm_area_struct *vma)
 	struct drm_device *dev = priv->minor->dev;
 
 	mutex_lock(&dev->struct_mutex);
-	drm_vm_open_locked(vma);
+	drm_vm_open_locked(dev, vma);
 	mutex_unlock(&dev->struct_mutex);
 }
 
-void drm_vm_close_locked(struct vm_area_struct *vma)
+void drm_vm_close_locked(struct drm_device *dev,
+		struct vm_area_struct *vma)
 {
-	struct drm_file *priv = vma->vm_file->private_data;
-	struct drm_device *dev = priv->minor->dev;
 	struct drm_vma_entry *pt, *temp;
 
 	DRM_DEBUG("0x%08lx,0x%08lx\n",
@@ -467,7 +465,7 @@ static void drm_vm_close(struct vm_area_struct *vma)
 	struct drm_device *dev = priv->minor->dev;
 
 	mutex_lock(&dev->struct_mutex);
-	drm_vm_close_locked(vma);
+	drm_vm_close_locked(dev, vma);
 	mutex_unlock(&dev->struct_mutex);
 }
 
@@ -519,7 +517,7 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
 	vma->vm_flags |= VM_RESERVED;	/* Don't swap */
 	vma->vm_flags |= VM_DONTEXPAND;
 
-	drm_vm_open_locked(vma);
+	drm_vm_open_locked(dev, vma);
 	return 0;
 }
 
@@ -670,7 +668,7 @@ int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
 	vma->vm_flags |= VM_RESERVED;	/* Don't swap */
 	vma->vm_flags |= VM_DONTEXPAND;
 
-	drm_vm_open_locked(vma);
+	drm_vm_open_locked(dev, vma);
 	return 0;
 }
 
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index dd73104..213a85a 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1309,8 +1309,8 @@ extern int drm_release(struct inode *inode, struct file *filp);
 				/* Mapping support (drm_vm.h) */
 extern int drm_mmap(struct file *filp, struct vm_area_struct *vma);
 extern int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma);
-extern void drm_vm_open_locked(struct vm_area_struct *vma);
-extern void drm_vm_close_locked(struct vm_area_struct *vma);
+extern void drm_vm_open_locked(struct drm_device *dev, struct vm_area_struct *vma);
+extern void drm_vm_close_locked(struct drm_device *dev, struct vm_area_struct *vma);
 extern unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait);
 
 				/* Memory management support (drm_memory.h) */
-- 
1.7.9.5