drm: Protect dev->filelist with its own mutex

amdgpu gained dev->struct_mutex usage, and that's because it's walking
the dev->filelist list. Protect that list with it's own lock to take
one more step towards getting rid of struct_mutex usage in drivers
once and for all.

While doing the conversion I noticed that 2 debugfs files in i915
completely lacked appropriate locking. Fix that up too.

v2: don't forget to switch to drm_gem_object_unreference_unlocked.

Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-9-git-send-email-daniel.vetter@ffwll.ch

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index fa6a27bff298..a087b9638cde 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -93,7 +93,7 @@ void amdgpu_gem_force_release(struct amdgpu_device *adev)
         struct drm_device *ddev = adev->ddev;
         struct drm_file *file;
 
-        mutex_lock(&ddev->struct_mutex);
+        mutex_lock(&ddev->filelist_mutex);
 
         list_for_each_entry(file, &ddev->filelist, lhead) {
                 struct drm_gem_object *gobj;
@@ -103,13 +103,13 @@ void amdgpu_gem_force_release(struct amdgpu_device *adev)
                 spin_lock(&file->table_lock);
                 idr_for_each_entry(&file->object_idr, gobj, handle) {
                         WARN_ONCE(1, "And also active allocations!\n");
-                        drm_gem_object_unreference(gobj);
+                        drm_gem_object_unreference_unlocked(gobj);
                 }
                 idr_destroy(&file->object_idr);
                 spin_unlock(&file->table_lock);
         }
 
-        mutex_unlock(&ddev->struct_mutex);
+        mutex_unlock(&ddev->filelist_mutex);
 }
 
 /*
@@ -769,7 +769,7 @@ static int amdgpu_debugfs_gem_info(struct seq_file *m, void *data)
         struct drm_file *file;
         int r;
 
-        r = mutex_lock_interruptible(&dev->struct_mutex);
+        r = mutex_lock_interruptible(&dev->filelist_mutex);
         if (r)
                 return r;
 
@@ -793,7 +793,7 @@ static int amdgpu_debugfs_gem_info(struct seq_file *m, void *data)
                 spin_unlock(&file->table_lock);
         }
 
-        mutex_unlock(&dev->struct_mutex);
+        mutex_unlock(&dev->filelist_mutex);
         return 0;
 }