1 files changed, 464 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
new file mode 100644
index 000000000000..a82d741e6630
--- /dev/null
+++ b/drivers/gpu/drm/drm_client.c
@@ -0,0 +1,464 @@
+// SPDX-License-Identifier: GPL-2.0 or MIT
+/*
+ * Copyright 2018 Noralf Trønnes
+ */
+
+#include <linux/export.h>
+#include <linux/iosys-map.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+
+#include <drm/drm_client.h>
+#include <drm/drm_client_event.h>
+#include <drm/drm_device.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_file.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_mode.h>
+#include <drm/drm_print.h>
+
+#include "drm_crtc_internal.h"
+#include "drm_internal.h"
+
+/**
+ * DOC: overview
+ *
+ * This library provides support for clients running in the kernel like fbdev and bootsplash.
+ *
+ * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
+ */
+
+static int drm_client_open(struct drm_client_dev *client)
+{
+	struct drm_device *dev = client->dev;
+	struct drm_file *file;
+
+	file = drm_file_alloc(dev->primary);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	mutex_lock(&dev->filelist_mutex);
+	list_add(&file->lhead, &dev->filelist_internal);
+	mutex_unlock(&dev->filelist_mutex);
+
+	client->file = file;
+
+	return 0;
+}
+
+static void drm_client_close(struct drm_client_dev *client)
+{
+	struct drm_device *dev = client->dev;
+
+	mutex_lock(&dev->filelist_mutex);
+	list_del(&client->file->lhead);
+	mutex_unlock(&dev->filelist_mutex);
+
+	drm_file_free(client->file);
+}
+
+/**
+ * drm_client_init - Initialise a DRM client
+ * @dev: DRM device
+ * @client: DRM client
+ * @name: Client name
+ * @funcs: DRM client functions (optional)
+ *
+ * This initialises the client and opens a &drm_file.
+ * Use drm_client_register() to complete the process.
+ * The caller needs to hold a reference on @dev before calling this function.
+ * The client is freed when the &drm_device is unregistered. See drm_client_release().
+ *
+ * Returns:
+ * Zero on success or negative error code on failure.
+ */
+int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
+		    const char *name, const struct drm_client_funcs *funcs)
+{
+	int ret;
+
+	if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create)
+		return -EOPNOTSUPP;
+
+	client->dev = dev;
+	client->name = name;
+	client->funcs = funcs;
+
+	ret = drm_client_modeset_create(client);
+	if (ret)
+		return ret;
+
+	ret = drm_client_open(client);
+	if (ret)
+		goto err_free;
+
+	drm_dev_get(dev);
+
+	return 0;
+
+err_free:
+	drm_client_modeset_free(client);
+	return ret;
+}
+EXPORT_SYMBOL(drm_client_init);
+
+/**
+ * drm_client_register - Register client
+ * @client: DRM client
+ *
+ * Add the client to the &drm_device client list to activate its callbacks.
+ * @client must be initialized by a call to drm_client_init(). After
+ * drm_client_register() it is no longer permissible to call drm_client_release()
+ * directly (outside the unregister callback), instead cleanup will happen
+ * automatically on driver unload.
+ *
+ * Registering a client generates a hotplug event that allows the client
+ * to set up its display from pre-existing outputs. The client must have
+ * initialized its state to able to handle the hotplug event successfully.
+ */
+void drm_client_register(struct drm_client_dev *client)
+{
+	struct drm_device *dev = client->dev;
+	int ret;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_add(&client->list, &dev->clientlist);
+
+	if (client->funcs && client->funcs->hotplug) {
+		/*
+		 * Perform an initial hotplug event to pick up the
+		 * display configuration for the client. This step
+		 * has to be performed *after* registering the client
+		 * in the list of clients, or a concurrent hotplug
+		 * event might be lost; leaving the display off.
+		 *
+		 * Hold the clientlist_mutex as for a regular hotplug
+		 * event.
+		 */
+		ret = client->funcs->hotplug(client);
+		if (ret)
+			drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
+	}
+	mutex_unlock(&dev->clientlist_mutex);
+}
+EXPORT_SYMBOL(drm_client_register);
+
+/**
+ * drm_client_release - Release DRM client resources
+ * @client: DRM client
+ *
+ * Releases resources by closing the &drm_file that was opened by drm_client_init().
+ * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
+ *
+ * This function should only be called from the unregister callback. An exception
+ * is fbdev which cannot free the buffer if userspace has open file descriptors.
+ *
+ * Note:
+ * Clients cannot initiate a release by themselves. This is done to keep the code simple.
+ * The driver has to be unloaded before the client can be unloaded.
+ */
+void drm_client_release(struct drm_client_dev *client)
+{
+	struct drm_device *dev = client->dev;
+
+	drm_dbg_kms(dev, "%s\n", client->name);
+
+	drm_client_modeset_free(client);
+	drm_client_close(client);
+
+	if (client->funcs && client->funcs->free)
+		client->funcs->free(client);
+
+	drm_dev_put(dev);
+}
+EXPORT_SYMBOL(drm_client_release);
+
+/**
+ * drm_client_buffer_delete - Delete a client buffer
+ * @buffer: DRM client buffer
+ */
+void drm_client_buffer_delete(struct drm_client_buffer *buffer)
+{
+	struct drm_gem_object *gem;
+	int ret;
+
+	if (!buffer)
+		return;
+
+	gem = buffer->fb->obj[0];
+	drm_gem_vunmap(gem, &buffer->map);
+
+	ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
+	if (ret)
+		drm_err(buffer->client->dev,
+			"Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
+
+	drm_gem_object_put(buffer->gem);
+
+	kfree(buffer);
+}
+EXPORT_SYMBOL(drm_client_buffer_delete);
+
+static struct drm_client_buffer *
+drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height,
+			 u32 format, u32 handle, u32 pitch)
+{
+	struct drm_mode_fb_cmd2 fb_req = {
+		.width = width,
+		.height = height,
+		.pixel_format = format,
+		.handles = {
+			handle,
+		},
+		.pitches = {
+			pitch,
+		},
+	};
+	struct drm_device *dev = client->dev;
+	struct drm_client_buffer *buffer;
+	struct drm_gem_object *obj;
+	struct drm_framebuffer *fb;
+	int ret;
+
+	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+	if (!buffer)
+		return ERR_PTR(-ENOMEM);
+
+	buffer->client = client;
+
+	obj = drm_gem_object_lookup(client->file, handle);
+	if (!obj)  {
+		ret = -ENOENT;
+		goto err_delete;
+	}
+
+	ret = drm_mode_addfb2(dev, &fb_req, client->file);
+	if (ret)
+		goto err_drm_gem_object_put;
+
+	fb = drm_framebuffer_lookup(dev, client->file, fb_req.fb_id);
+	if (drm_WARN_ON(dev, !fb)) {
+		ret = -ENOENT;
+		goto err_drm_mode_rmfb;
+	}
+
+	/* drop the reference we picked up in framebuffer lookup */
+	drm_framebuffer_put(fb);
+
+	strscpy(fb->comm, client->name, TASK_COMM_LEN);
+
+	buffer->gem = obj;
+	buffer->fb = fb;
+
+	return buffer;
+
+err_drm_mode_rmfb:
+	drm_mode_rmfb(dev, fb_req.fb_id, client->file);
+err_drm_gem_object_put:
+	drm_gem_object_put(obj);
+err_delete:
+	kfree(buffer);
+	return ERR_PTR(ret);
+}
+
+/**
+ * drm_client_buffer_vmap_local - Map DRM client buffer into address space
+ * @buffer: DRM client buffer
+ * @map_copy: Returns the mapped memory's address
+ *
+ * This function maps a client buffer into kernel address space. If the
+ * buffer is already mapped, it returns the existing mapping's address.
+ *
+ * Client buffer mappings are not ref'counted. Each call to
+ * drm_client_buffer_vmap_local() should be closely followed by a call to
+ * drm_client_buffer_vunmap_local(). See drm_client_buffer_vmap() for
+ * long-term mappings.
+ *
+ * The returned address is a copy of the internal value. In contrast to
+ * other vmap interfaces, you don't need it for the client's vunmap
+ * function. So you can modify it at will during blit and draw operations.
+ *
+ * Returns:
+ *	0 on success, or a negative errno code otherwise.
+ */
+int drm_client_buffer_vmap_local(struct drm_client_buffer *buffer,
+				 struct iosys_map *map_copy)
+{
+	struct drm_gem_object *gem = buffer->fb->obj[0];
+	struct iosys_map *map = &buffer->map;
+	int ret;
+
+	drm_gem_lock(gem);
+
+	ret = drm_gem_vmap_locked(gem, map);
+	if (ret)
+		goto err_drm_gem_vmap_unlocked;
+	*map_copy = *map;
+
+	return 0;
+
+err_drm_gem_vmap_unlocked:
+	drm_gem_unlock(gem);
+	return ret;
+}
+EXPORT_SYMBOL(drm_client_buffer_vmap_local);
+
+/**
+ * drm_client_buffer_vunmap_local - Unmap DRM client buffer
+ * @buffer: DRM client buffer
+ *
+ * This function removes a client buffer's memory mapping established
+ * with drm_client_buffer_vunmap_local(). Calling this function is only
+ * required by clients that manage their buffer mappings by themselves.
+ */
+void drm_client_buffer_vunmap_local(struct drm_client_buffer *buffer)
+{
+	struct drm_gem_object *gem = buffer->fb->obj[0];
+	struct iosys_map *map = &buffer->map;
+
+	drm_gem_vunmap_locked(gem, map);
+	drm_gem_unlock(gem);
+}
+EXPORT_SYMBOL(drm_client_buffer_vunmap_local);
+
+/**
+ * drm_client_buffer_vmap - Map DRM client buffer into address space
+ * @buffer: DRM client buffer
+ * @map_copy: Returns the mapped memory's address
+ *
+ * This function maps a client buffer into kernel address space. If the
+ * buffer is already mapped, it returns the existing mapping's address.
+ *
+ * Client buffer mappings are not ref'counted. Each call to
+ * drm_client_buffer_vmap() should be followed by a call to
+ * drm_client_buffer_vunmap(); or the client buffer should be mapped
+ * throughout its lifetime.
+ *
+ * The returned address is a copy of the internal value. In contrast to
+ * other vmap interfaces, you don't need it for the client's vunmap
+ * function. So you can modify it at will during blit and draw operations.
+ *
+ * Returns:
+ *	0 on success, or a negative errno code otherwise.
+ */
+int drm_client_buffer_vmap(struct drm_client_buffer *buffer,
+			   struct iosys_map *map_copy)
+{
+	struct drm_gem_object *gem = buffer->fb->obj[0];
+	int ret;
+
+	ret = drm_gem_vmap(gem, &buffer->map);
+	if (ret)
+		return ret;
+	*map_copy = buffer->map;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_client_buffer_vmap);
+
+/**
+ * drm_client_buffer_vunmap - Unmap DRM client buffer
+ * @buffer: DRM client buffer
+ *
+ * This function removes a client buffer's memory mapping. Calling this
+ * function is only required by clients that manage their buffer mappings
+ * by themselves.
+ */
+void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
+{
+	struct drm_gem_object *gem = buffer->fb->obj[0];
+
+	drm_gem_vunmap(gem, &buffer->map);
+}
+EXPORT_SYMBOL(drm_client_buffer_vunmap);
+
+/**
+ * drm_client_buffer_create_dumb - Create a client buffer backed by a dumb buffer
+ * @client: DRM client
+ * @width: Framebuffer width
+ * @height: Framebuffer height
+ * @format: Buffer format
+ *
+ * This function creates a &drm_client_buffer which consists of a
+ * &drm_framebuffer backed by a dumb buffer.
+ * Call drm_client_buffer_delete() to free the buffer.
+ *
+ * Returns:
+ * Pointer to a client buffer or an error pointer on failure.
+ */
+struct drm_client_buffer *
+drm_client_buffer_create_dumb(struct drm_client_dev *client, u32 width, u32 height, u32 format)
+{
+	const struct drm_format_info *info = drm_format_info(format);
+	struct drm_device *dev = client->dev;
+	struct drm_mode_create_dumb dumb_args = { };
+	struct drm_client_buffer *buffer;
+	int ret;
+
+	dumb_args.width = width;
+	dumb_args.height = height;
+	dumb_args.bpp = drm_format_info_bpp(info, 0);
+	ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
+	if (ret)
+		return ERR_PTR(ret);
+
+	buffer = drm_client_buffer_create(client, width, height, format,
+					  dumb_args.handle, dumb_args.pitch);
+	if (IS_ERR(buffer)) {
+		ret = PTR_ERR(buffer);
+		goto err_drm_mode_destroy_dumb;
+	}
+
+	/*
+	 * The handle is only needed for creating the framebuffer, destroy it
+	 * again to solve a circular dependency should anybody export the GEM
+	 * object as DMA-buf. The framebuffer and our buffer structure are still
+	 * holding references to the GEM object to prevent its destruction.
+	 */
+	drm_mode_destroy_dumb(client->dev, dumb_args.handle, client->file);
+
+	return buffer;
+
+err_drm_mode_destroy_dumb:
+	drm_mode_destroy_dumb(client->dev, dumb_args.handle, client->file);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(drm_client_buffer_create_dumb);
+
+/**
+ * drm_client_buffer_flush - Manually flush client buffer
+ * @buffer: DRM client buffer
+ * @rect: Damage rectangle (if NULL flushes all)
+ *
+ * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes
+ * for drivers that need it.
+ *
+ * Returns:
+ * Zero on success or negative error code on failure.
+ */
+int drm_client_buffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect)
+{
+	if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty)
+		return 0;
+
+	if (rect) {
+		struct drm_clip_rect clip = {
+			.x1 = rect->x1,
+			.y1 = rect->y1,
+			.x2 = rect->x2,
+			.y2 = rect->y2,
+		};
+
+		return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
+						0, 0, &clip, 1);
+	}
+
+	return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
+					0, 0, NULL, 0);
+}
+EXPORT_SYMBOL(drm_client_buffer_flush);