drm: move to kref per-master structures.

This is step one towards having multiple masters sharing a drm
device in order to get fast-user-switching to work.

It splits out the information associated with the drm master
into a separate kref counted structure, and allocates this when
a master opens the device node. It also allows the current master
to abdicate (say while VT switched), and a new master to take over
the hardware.

It moves the Intel and radeon drivers to using the sarea from
within the new master structures.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b3cc473..ba096f9 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -103,15 +103,18 @@
 	int enabled;
 };
 
+struct drm_i915_master_private {
+	drm_local_map_t *sarea;
+	struct _drm_i915_sarea *sarea_priv;
+};
+
 typedef struct drm_i915_private {
 	struct drm_device *dev;
 
 	int has_gem;
 
 	void __iomem *regs;
-	drm_local_map_t *sarea;
 
-	drm_i915_sarea_t *sarea_priv;
 	drm_i915_ring_buffer_t ring;
 
 	drm_dma_handle_t *status_page_dmah;
@@ -417,6 +420,9 @@
 extern struct drm_ioctl_desc i915_ioctls[];
 extern int i915_max_ioctl;
 
+extern int i915_master_create(struct drm_device *dev, struct drm_master *master);
+extern void i915_master_destroy(struct drm_device *dev, struct drm_master *master);
+
 				/* i915_dma.c */
 extern void i915_kernel_lost_context(struct drm_device * dev);
 extern int i915_driver_load(struct drm_device *, unsigned long flags);