drm: Extract drm_atomic_state_helper.[hc]

We already have a separate overview doc for this, makes sense to
untangle it from the overall atomic helpers.

v2: Rebase

v3: Rebase more.

Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181004202446.22905-4-daniel.vetter@ffwll.ch

1 files changed, 601 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
new file mode 100644
index 000000000000..3ba996069d69
--- /dev/null
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -0,0 +1,601 @@
+/*
+ * Copyright (C) 2018 Intel Corp.
+ *
+ * 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
+ *
+ * Authors:
+ * Rob Clark <robdclark@gmail.com>
+ * Daniel Vetter <daniel.vetter@ffwll.ch>
+ */
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_plane.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_device.h>
+
+#include <linux/slab.h>
+#include <linux/dma-fence.h>
+
+/**
+ * DOC: atomic state reset and initialization
+ *
+ * Both the drm core and the atomic helpers assume that there is always the full
+ * and correct atomic software state for all connectors, CRTCs and planes
+ * available. Which is a bit a problem on driver load and also after system
+ * suspend. One way to solve this is to have a hardware state read-out
+ * infrastructure which reconstructs the full software state (e.g. the i915
+ * driver).
+ *
+ * The simpler solution is to just reset the software state to everything off,
+ * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
+ * the atomic helpers provide default reset implementations for all hooks.
+ *
+ * On the upside the precise state tracking of atomic simplifies system suspend
+ * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
+ * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
+ * For other drivers the building blocks are split out, see the documentation
+ * for these functions.
+ */
+
+/**
+ * drm_atomic_helper_crtc_reset - default &drm_crtc_funcs.reset hook for CRTCs
+ * @crtc: drm CRTC
+ *
+ * Resets the atomic state for @crtc by freeing the state pointer (which might
+ * be NULL, e.g. at driver load time) and allocating a new empty state object.
+ */
+void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
+{
+	if (crtc->state)
+		__drm_atomic_helper_crtc_destroy_state(crtc->state);
+
+	kfree(crtc->state);
+	crtc->state = kzalloc(sizeof(*crtc->state), GFP_KERNEL);
+
+	if (crtc->state)
+		crtc->state->crtc = crtc;
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
+
+/**
+ * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
+ * @crtc: CRTC object
+ * @state: atomic CRTC state
+ *
+ * Copies atomic state from a CRTC's current state and resets inferred values.
+ * This is useful for drivers that subclass the CRTC state.
+ */
+void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
+					      struct drm_crtc_state *state)
+{
+	memcpy(state, crtc->state, sizeof(*state));
+
+	if (state->mode_blob)
+		drm_property_blob_get(state->mode_blob);
+	if (state->degamma_lut)
+		drm_property_blob_get(state->degamma_lut);
+	if (state->ctm)
+		drm_property_blob_get(state->ctm);
+	if (state->gamma_lut)
+		drm_property_blob_get(state->gamma_lut);
+	state->mode_changed = false;
+	state->active_changed = false;
+	state->planes_changed = false;
+	state->connectors_changed = false;
+	state->color_mgmt_changed = false;
+	state->zpos_changed = false;
+	state->commit = NULL;
+	state->event = NULL;
+	state->pageflip_flags = 0;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
+
+/**
+ * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
+ * @crtc: drm CRTC
+ *
+ * Default CRTC state duplicate hook for drivers which don't have their own
+ * subclassed CRTC state structure.
+ */
+struct drm_crtc_state *
+drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
+{
+	struct drm_crtc_state *state;
+
+	if (WARN_ON(!crtc->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_crtc_duplicate_state(crtc, state);
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
+
+/**
+ * __drm_atomic_helper_crtc_destroy_state - release CRTC state
+ * @state: CRTC state object to release
+ *
+ * Releases all resources stored in the CRTC state without actually freeing
+ * the memory of the CRTC state. This is useful for drivers that subclass the
+ * CRTC state.
+ */
+void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
+{
+	if (state->commit) {
+		/*
+		 * In the event that a non-blocking commit returns
+		 * -ERESTARTSYS before the commit_tail work is queued, we will
+		 * have an extra reference to the commit object. Release it, if
+		 * the event has not been consumed by the worker.
+		 *
+		 * state->event may be freed, so we can't directly look at
+		 * state->event->base.completion.
+		 */
+		if (state->event && state->commit->abort_completion)
+			drm_crtc_commit_put(state->commit);
+
+		kfree(state->commit->event);
+		state->commit->event = NULL;
+
+		drm_crtc_commit_put(state->commit);
+	}
+
+	drm_property_blob_put(state->mode_blob);
+	drm_property_blob_put(state->degamma_lut);
+	drm_property_blob_put(state->ctm);
+	drm_property_blob_put(state->gamma_lut);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
+
+/**
+ * drm_atomic_helper_crtc_destroy_state - default state destroy hook
+ * @crtc: drm CRTC
+ * @state: CRTC state object to release
+ *
+ * Default CRTC state destroy hook for drivers which don't have their own
+ * subclassed CRTC state structure.
+ */
+void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
+					  struct drm_crtc_state *state)
+{
+	__drm_atomic_helper_crtc_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
+
+/**
+ * __drm_atomic_helper_plane_reset - resets planes state to default values
+ * @plane: plane object, must not be NULL
+ * @state: atomic plane state, must not be NULL
+ *
+ * Initializes plane state to default. This is useful for drivers that subclass
+ * the plane state.
+ */
+void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
+				     struct drm_plane_state *state)
+{
+	state->plane = plane;
+	state->rotation = DRM_MODE_ROTATE_0;
+
+	state->alpha = DRM_BLEND_ALPHA_OPAQUE;
+	state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;
+
+	plane->state = state;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);
+
+/**
+ * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
+ * @plane: drm plane
+ *
+ * Resets the atomic state for @plane by freeing the state pointer (which might
+ * be NULL, e.g. at driver load time) and allocating a new empty state object.
+ */
+void drm_atomic_helper_plane_reset(struct drm_plane *plane)
+{
+	if (plane->state)
+		__drm_atomic_helper_plane_destroy_state(plane->state);
+
+	kfree(plane->state);
+	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
+	if (plane->state)
+		__drm_atomic_helper_plane_reset(plane, plane->state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
+
+/**
+ * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
+ * @plane: plane object
+ * @state: atomic plane state
+ *
+ * Copies atomic state from a plane's current state. This is useful for
+ * drivers that subclass the plane state.
+ */
+void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
+					       struct drm_plane_state *state)
+{
+	memcpy(state, plane->state, sizeof(*state));
+
+	if (state->fb)
+		drm_framebuffer_get(state->fb);
+
+	state->fence = NULL;
+	state->commit = NULL;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
+
+/**
+ * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
+ * @plane: drm plane
+ *
+ * Default plane state duplicate hook for drivers which don't have their own
+ * subclassed plane state structure.
+ */
+struct drm_plane_state *
+drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
+{
+	struct drm_plane_state *state;
+
+	if (WARN_ON(!plane->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_plane_duplicate_state(plane, state);
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
+
+/**
+ * __drm_atomic_helper_plane_destroy_state - release plane state
+ * @state: plane state object to release
+ *
+ * Releases all resources stored in the plane state without actually freeing
+ * the memory of the plane state. This is useful for drivers that subclass the
+ * plane state.
+ */
+void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
+{
+	if (state->fb)
+		drm_framebuffer_put(state->fb);
+
+	if (state->fence)
+		dma_fence_put(state->fence);
+
+	if (state->commit)
+		drm_crtc_commit_put(state->commit);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
+
+/**
+ * drm_atomic_helper_plane_destroy_state - default state destroy hook
+ * @plane: drm plane
+ * @state: plane state object to release
+ *
+ * Default plane state destroy hook for drivers which don't have their own
+ * subclassed plane state structure.
+ */
+void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
+					   struct drm_plane_state *state)
+{
+	__drm_atomic_helper_plane_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
+
+/**
+ * __drm_atomic_helper_connector_reset - reset state on connector
+ * @connector: drm connector
+ * @conn_state: connector state to assign
+ *
+ * Initializes the newly allocated @conn_state and assigns it to
+ * the &drm_conector->state pointer of @connector, usually required when
+ * initializing the drivers or when called from the &drm_connector_funcs.reset
+ * hook.
+ *
+ * This is useful for drivers that subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_reset(struct drm_connector *connector,
+				    struct drm_connector_state *conn_state)
+{
+	if (conn_state)
+		conn_state->connector = connector;
+
+	connector->state = conn_state;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
+
+/**
+ * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
+ * @connector: drm connector
+ *
+ * Resets the atomic state for @connector by freeing the state pointer (which
+ * might be NULL, e.g. at driver load time) and allocating a new empty state
+ * object.
+ */
+void drm_atomic_helper_connector_reset(struct drm_connector *connector)
+{
+	struct drm_connector_state *conn_state =
+		kzalloc(sizeof(*conn_state), GFP_KERNEL);
+
+	if (connector->state)
+		__drm_atomic_helper_connector_destroy_state(connector->state);
+
+	kfree(connector->state);
+	__drm_atomic_helper_connector_reset(connector, conn_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
+
+/**
+ * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
+ * @connector: connector object
+ * @state: atomic connector state
+ *
+ * Copies atomic state from a connector's current state. This is useful for
+ * drivers that subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
+					    struct drm_connector_state *state)
+{
+	memcpy(state, connector->state, sizeof(*state));
+	if (state->crtc)
+		drm_connector_get(connector);
+	state->commit = NULL;
+
+	/* Don't copy over a writeback job, they are used only once */
+	state->writeback_job = NULL;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
+
+/**
+ * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
+ * @connector: drm connector
+ *
+ * Default connector state duplicate hook for drivers which don't have their own
+ * subclassed connector state structure.
+ */
+struct drm_connector_state *
+drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
+{
+	struct drm_connector_state *state;
+
+	if (WARN_ON(!connector->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_connector_duplicate_state(connector, state);
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
+
+/**
+ * drm_atomic_helper_duplicate_state - duplicate an atomic state object
+ * @dev: DRM device
+ * @ctx: lock acquisition context
+ *
+ * Makes a copy of the current atomic state by looping over all objects and
+ * duplicating their respective states. This is used for example by suspend/
+ * resume support code to save the state prior to suspend such that it can
+ * be restored upon resume.
+ *
+ * Note that this treats atomic state as persistent between save and restore.
+ * Drivers must make sure that this is possible and won't result in confusion
+ * or erroneous behaviour.
+ *
+ * Note that if callers haven't already acquired all modeset locks this might
+ * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
+ *
+ * Returns:
+ * A pointer to the copy of the atomic state object on success or an
+ * ERR_PTR()-encoded error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
+ */
+struct drm_atomic_state *
+drm_atomic_helper_duplicate_state(struct drm_device *dev,
+				  struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_atomic_state *state;
+	struct drm_connector *conn;
+	struct drm_connector_list_iter conn_iter;
+	struct drm_plane *plane;
+	struct drm_crtc *crtc;
+	int err = 0;
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return ERR_PTR(-ENOMEM);
+
+	state->acquire_ctx = ctx;
+
+	drm_for_each_crtc(crtc, dev) {
+		struct drm_crtc_state *crtc_state;
+
+		crtc_state = drm_atomic_get_crtc_state(state, crtc);
+		if (IS_ERR(crtc_state)) {
+			err = PTR_ERR(crtc_state);
+			goto free;
+		}
+	}
+
+	drm_for_each_plane(plane, dev) {
+		struct drm_plane_state *plane_state;
+
+		plane_state = drm_atomic_get_plane_state(state, plane);
+		if (IS_ERR(plane_state)) {
+			err = PTR_ERR(plane_state);
+			goto free;
+		}
+	}
+
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(conn, &conn_iter) {
+		struct drm_connector_state *conn_state;
+
+		conn_state = drm_atomic_get_connector_state(state, conn);
+		if (IS_ERR(conn_state)) {
+			err = PTR_ERR(conn_state);
+			drm_connector_list_iter_end(&conn_iter);
+			goto free;
+		}
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	/* clear the acquire context so that it isn't accidentally reused */
+	state->acquire_ctx = NULL;
+
+free:
+	if (err < 0) {
+		drm_atomic_state_put(state);
+		state = ERR_PTR(err);
+	}
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_duplicate_state);
+
+/**
+ * __drm_atomic_helper_connector_destroy_state - release connector state
+ * @state: connector state object to release
+ *
+ * Releases all resources stored in the connector state without actually
+ * freeing the memory of the connector state. This is useful for drivers that
+ * subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
+{
+	if (state->crtc)
+		drm_connector_put(state->connector);
+
+	if (state->commit)
+		drm_crtc_commit_put(state->commit);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
+
+/**
+ * drm_atomic_helper_connector_destroy_state - default state destroy hook
+ * @connector: drm connector
+ * @state: connector state object to release
+ *
+ * Default connector state destroy hook for drivers which don't have their own
+ * subclassed connector state structure.
+ */
+void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
+					  struct drm_connector_state *state)
+{
+	__drm_atomic_helper_connector_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
+
+/**
+ * drm_atomic_helper_legacy_gamma_set - set the legacy gamma correction table
+ * @crtc: CRTC object
+ * @red: red correction table
+ * @green: green correction table
+ * @blue: green correction table
+ * @size: size of the tables
+ * @ctx: lock acquire context
+ *
+ * Implements support for legacy gamma correction table for drivers
+ * that support color management through the DEGAMMA_LUT/GAMMA_LUT
+ * properties. See drm_crtc_enable_color_mgmt() and the containing chapter for
+ * how the atomic color management and gamma tables work.
+ */
+int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
+				       u16 *red, u16 *green, u16 *blue,
+				       uint32_t size,
+				       struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_atomic_state *state;
+	struct drm_crtc_state *crtc_state;
+	struct drm_property_blob *blob = NULL;
+	struct drm_color_lut *blob_data;
+	int i, ret = 0;
+	bool replaced;
+
+	state = drm_atomic_state_alloc(crtc->dev);
+	if (!state)
+		return -ENOMEM;
+
+	blob = drm_property_create_blob(dev,
+					sizeof(struct drm_color_lut) * size,
+					NULL);
+	if (IS_ERR(blob)) {
+		ret = PTR_ERR(blob);
+		blob = NULL;
+		goto fail;
+	}
+
+	/* Prepare GAMMA_LUT with the legacy values. */
+	blob_data = blob->data;
+	for (i = 0; i < size; i++) {
+		blob_data[i].red = red[i];
+		blob_data[i].green = green[i];
+		blob_data[i].blue = blue[i];
+	}
+
+	state->acquire_ctx = ctx;
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		goto fail;
+	}
+
+	/* Reset DEGAMMA_LUT and CTM properties. */
+	replaced  = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
+	replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
+	replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
+	crtc_state->color_mgmt_changed |= replaced;
+
+	ret = drm_atomic_commit(state);
+
+fail:
+	drm_atomic_state_put(state);
+	drm_property_blob_put(blob);
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_legacy_gamma_set);
+
+/**
+ * __drm_atomic_helper_private_duplicate_state - copy atomic private state
+ * @obj: CRTC object
+ * @state: new private object state
+ *
+ * Copies atomic state from a private objects's current state and resets inferred values.
+ * This is useful for drivers that subclass the private state.
+ */
+void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
+						     struct drm_private_state *state)
+{
+	memcpy(state, obj->state, sizeof(*state));
+}
+EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);