drm: remove dev->vma_count

This is just used for a debugfs file, and we can easily reconstruct
this number by just walking the list twice. Which isn't really bad for
a debugfs file anyway.

So let's rip this out.

There's the other issue that the dev->vmalist itself is a bit useless,
since that can be reconstructed with all the memory mapping
information from proc. But remove that is a different topic entirely.

Signed-off-by: Daniel Vetter <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/drm_fops.c

···
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		return;
 
-	atomic_set(&dev->vma_count, 0);
-
 	dev->sigdata.lock = NULL;
 
 	dev->context_flag = 0;

drivers/gpu/drm/drm_info.c

···
 	struct drm_device *dev = node->minor->dev;
 	struct drm_vma_entry *pt;
 	struct vm_area_struct *vma;
+	unsigned long vma_count = 0;
 #if defined(__i386__)
 	unsigned int pgprot;
 #endif
 
 	mutex_lock(&dev->struct_mutex);
-	seq_printf(m, "vma use count: %d, high_memory = %pK, 0x%pK\n",
-		   atomic_read(&dev->vma_count),
-		   high_memory, (void *)(unsigned long)virt_to_phys(high_memory));
+	list_for_each_entry(pt, &dev->vmalist, head)
+		vma_count++;
+
+	seq_printf(m, "vma use count: %lu, high_memory = %pK, 0x%pK\n",
+		   vma_count, high_memory,
+		   (void *)(unsigned long)virt_to_phys(high_memory));
 
 	list_for_each_entry(pt, &dev->vmalist, head) {
 		vma = pt->vma;

drivers/gpu/drm/drm_vm.c

···
 
 	DRM_DEBUG("0x%08lx,0x%08lx\n",
 		  vma->vm_start, vma->vm_end - vma->vm_start);
-	atomic_dec(&dev->vma_count);
 
 	map = vma->vm_private_data;
 
···
 
 	DRM_DEBUG("0x%08lx,0x%08lx\n",
 		  vma->vm_start, vma->vm_end - vma->vm_start);
-	atomic_inc(&dev->vma_count);
 
 	vma_entry = kmalloc(sizeof(*vma_entry), GFP_KERNEL);
 	if (vma_entry) {
···
 
 	DRM_DEBUG("0x%08lx,0x%08lx\n",
 		  vma->vm_start, vma->vm_end - vma->vm_start);
-	atomic_dec(&dev->vma_count);
 
 	list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
 		if (pt->vma == vma) {

include/drm/drmP.h

···
 	/** \name Usage Counters */
 	/*@{ */
 	int open_count;			/**< Outstanding files open */
-	atomic_t vma_count;		/**< Outstanding vma areas open */
 	int buf_use;			/**< Buffers in use -- cannot alloc */
 	atomic_t buf_alloc;		/**< Buffer allocation in progress */
 	/*@} */