drm/i915: Add main atomic entrypoints (v2)

Add the top-level atomic entrypoints for check/commit.  These won't get
called yet; we still need to either enable the atomic ioctl or switch to
using the non-transitional atomic helpers for legacy operations.

v2:
 - Use plane->pipe rather than plane->possible_crtcs while ensuring that
   only a single CRTC is in use.  Either way will work fine since i915
   drm_plane's are always tied to a single CRTC, but plane->pipe is
   slightly more intuitive. (Ander)
 - Simplify crtc/connector checking logic. (Ander)

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/Makefile

@@ -66,6 +66,7 @@ i915-y += dvo_ch7017.o \
 	  dvo_ns2501.o \
 	  dvo_sil164.o \
 	  dvo_tfp410.o \
+	  intel_atomic.o \
 	  intel_atomic_plane.o \
 	  intel_crt.o \
 	  intel_ddi.o \

drivers/gpu/drm/i915/intel_atomic.c

@@ -0,0 +1,164 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * DOC: atomic modeset support
+ *
+ * The functions here implement the state management and hardware programming
+ * dispatch required by the atomic modeset infrastructure.
+ * See intel_atomic_plane.c for the plane-specific atomic functionality.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_plane_helper.h>
+#include "intel_drv.h"
+
+
+/**
+ * intel_atomic_check - validate state object
+ * @dev: drm device
+ * @state: state to validate
+ */
+int intel_atomic_check(struct drm_device *dev,
+		       struct drm_atomic_state *state)
+{
+	int nplanes = dev->mode_config.num_total_plane;
+	int ncrtcs = dev->mode_config.num_crtc;
+	int nconnectors = dev->mode_config.num_connector;
+	enum pipe nuclear_pipe = INVALID_PIPE;
+	int ret;
+	int i;
+	bool not_nuclear = false;
+
+	/*
+	 * FIXME:  At the moment, we only support "nuclear pageflip" on a
+	 * single CRTC.  Cross-crtc updates will be added later.
+	 */
+	for (i = 0; i < nplanes; i++) {
+		struct intel_plane *plane = to_intel_plane(state->planes[i]);
+		if (!plane)
+			continue;
+
+		if (nuclear_pipe == INVALID_PIPE) {
+			nuclear_pipe = plane->pipe;
+		} else if (nuclear_pipe != plane->pipe) {
+			DRM_DEBUG_KMS("i915 only support atomic plane operations on a single CRTC at the moment\n");
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * FIXME:  We only handle planes for now; make sure there are no CRTC's
+	 * or connectors involved.
+	 */
+	state->allow_modeset = false;
+	for (i = 0; i < ncrtcs; i++) {
+		struct intel_crtc *crtc = to_intel_crtc(state->crtcs[i]);
+		if (crtc && crtc->pipe != nuclear_pipe)
+			not_nuclear = true;
+	}
+	for (i = 0; i < nconnectors; i++)
+		if (state->connectors[i] != NULL)
+			not_nuclear = true;
+
+	if (not_nuclear) {
+		DRM_DEBUG_KMS("i915 only supports atomic plane operations at the moment\n");
+		return -EINVAL;
+	}
+
+	ret = drm_atomic_helper_check_planes(dev, state);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+
+
+/**
+ * intel_atomic_commit - commit validated state object
+ * @dev: DRM device
+ * @state: the top-level driver state object
+ * @async: asynchronous commit
+ *
+ * This function commits a top-level state object that has been validated
+ * with drm_atomic_helper_check().
+ *
+ * FIXME:  Atomic modeset support for i915 is not yet complete.  At the moment
+ * we can only handle plane-related operations and do not yet support
+ * asynchronous commit.
+ *
+ * RETURNS
+ * Zero for success or -errno.
+ */
+int intel_atomic_commit(struct drm_device *dev,
+			struct drm_atomic_state *state,
+			bool async)
+{
+	int ret;
+	int i;
+
+	if (async) {
+		DRM_DEBUG_KMS("i915 does not yet support async commit\n");
+		return -EINVAL;
+	}
+
+	ret = drm_atomic_helper_prepare_planes(dev, state);
+	if (ret)
+		return ret;
+
+	/* Point of no return */
+
+	/*
+	 * FIXME:  The proper sequence here will eventually be:
+	 *
+	 * drm_atomic_helper_swap_state(dev, state)
+	 * drm_atomic_helper_commit_pre_planes(dev, state);
+	 * drm_atomic_helper_commit_planes(dev, state);
+	 * drm_atomic_helper_commit_post_planes(dev, state);
+	 * drm_atomic_helper_wait_for_vblanks(dev, state);
+	 * drm_atomic_helper_cleanup_planes(dev, state);
+	 * drm_atomic_state_free(state);
+	 *
+	 * once we have full atomic modeset.  For now, just manually update
+	 * plane states to avoid clobbering good states with dummy states
+	 * while nuclear pageflipping.
+	 */
+	for (i = 0; i < dev->mode_config.num_total_plane; i++) {
+		struct drm_plane *plane = state->planes[i];
+
+		if (!plane)
+			continue;
+
+		plane->state->state = state;
+		swap(state->plane_states[i], plane->state);
+		plane->state->state = NULL;
+	}
+	drm_atomic_helper_commit_planes(dev, state);
+	drm_atomic_helper_wait_for_vblanks(dev, state);
+	drm_atomic_helper_cleanup_planes(dev, state);
+	drm_atomic_state_free(state);
+
+	return 0;
+}

drivers/gpu/drm/i915/intel_display.c

@@ -12752,6 +12752,8 @@ static inline void intel_fbdev_output_poll_changed(struct drm_device *dev)
 static const struct drm_mode_config_funcs intel_mode_funcs = {
 	.fb_create = intel_user_framebuffer_create,
 	.output_poll_changed = intel_fbdev_output_poll_changed,
+	.atomic_check = intel_atomic_check,
+	.atomic_commit = intel_atomic_commit,
 };
 
 /* Set up chip specific display functions */

drivers/gpu/drm/i915/intel_drv.h

@@ -1249,6 +1249,13 @@ void intel_pre_disable_primary(struct drm_crtc *crtc);
 void intel_tv_init(struct drm_device *dev);
 
 /* intel_atomic.c */
+int intel_atomic_check(struct drm_device *dev,
+		       struct drm_atomic_state *state);
+int intel_atomic_commit(struct drm_device *dev,
+			struct drm_atomic_state *state,
+			bool async);
+
+/* intel_atomic_plane.c */
 struct intel_plane_state *intel_create_plane_state(struct drm_plane *plane);
 struct drm_plane_state *intel_plane_duplicate_state(struct drm_plane *plane);
 void intel_plane_destroy_state(struct drm_plane *plane,