drm/i915: Disentangle i915_drv.h includes

Separate out the layers of includes (linux, drm, intel, i915) so that it
is a little easier to order our definitions between our multiple
reentrant headers. A couple of headers needed fixes to make them more
standalone (forgotten includes, forward declarations etc).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460565315-7748-2-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -33,27 +33,32 @@
 #include <uapi/drm/i915_drm.h>
 #include <uapi/drm/drm_fourcc.h>
 
-#include <drm/drmP.h>
-#include "i915_params.h"
-#include "i915_reg.h"
-#include "intel_bios.h"
-#include "intel_ringbuffer.h"
-#include "intel_lrc.h"
-#include "i915_gem_gtt.h"
-#include "i915_gem_render_state.h"
 #include <linux/io-mapping.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
-#include <drm/intel-gtt.h>
-#include <drm/drm_legacy.h> /* for struct drm_dma_handle */
-#include <drm/drm_gem.h>
 #include <linux/backlight.h>
 #include <linux/hashtable.h>
 #include <linux/intel-iommu.h>
 #include <linux/kref.h>
 #include <linux/pm_qos.h>
-#include "intel_guc.h"
+#include <linux/shmem_fs.h>
+
+#include <drm/drmP.h>
+#include <drm/intel-gtt.h>
+#include <drm/drm_legacy.h> /* for struct drm_dma_handle */
+#include <drm/drm_gem.h>
+
+#include "i915_params.h"
+#include "i915_reg.h"
+
+#include "intel_bios.h"
 #include "intel_dpll_mgr.h"
+#include "intel_guc.h"
+#include "intel_lrc.h"
+#include "intel_ringbuffer.h"
+
+#include "i915_gem_gtt.h"
+#include "i915_gem_render_state.h"
 
 /* General customization:
  */

drivers/gpu/drm/i915/intel_guc.h

@@ -27,6 +27,8 @@
 #include "intel_guc_fwif.h"
 #include "i915_guc_reg.h"
 
+struct drm_i915_gem_request;
+
 struct i915_guc_client {
 	struct drm_i915_gem_object *client_obj;
 	struct intel_context *owner;

drivers/gpu/drm/i915/intel_lrc.h

@@ -24,6 +24,8 @@
 #ifndef _INTEL_LRC_H_
 #define _INTEL_LRC_H_
 
+#include "intel_ringbuffer.h"
+
 #define GEN8_LR_CONTEXT_ALIGN 4096
 
 /* Execlists regs */