1 files changed, 491 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
new file mode 100644
index 000000000..109d11fb4
--- /dev/null
+++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * drm gem framebuffer helper functions
+ *
+ * Copyright (C) 2017 Noralf Trønnes
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-fence.h>
+#include <linux/dma-resv.h>
+#include <linux/slab.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_uapi.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_fb_helper.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_modeset_helper.h>
+#include <drm/drm_simple_kms_helper.h>
+
+#define AFBC_HEADER_SIZE		16
+#define AFBC_TH_LAYOUT_ALIGNMENT	8
+#define AFBC_HDR_ALIGN			64
+#define AFBC_SUPERBLOCK_PIXELS		256
+#define AFBC_SUPERBLOCK_ALIGNMENT	128
+#define AFBC_TH_BODY_START_ALIGNMENT	4096
+
+/**
+ * DOC: overview
+ *
+ * This library provides helpers for drivers that don't subclass
+ * &drm_framebuffer and use &drm_gem_object for their backing storage.
+ *
+ * Drivers without additional needs to validate framebuffers can simply use
+ * drm_gem_fb_create() and everything is wired up automatically. Other drivers
+ * can use all parts independently.
+ */
+
+/**
+ * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer
+ * @fb: Framebuffer
+ * @plane: Plane index
+ *
+ * No additional reference is taken beyond the one that the &drm_frambuffer
+ * already holds.
+ *
+ * Returns:
+ * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL
+ * if it does not exist.
+ */
+struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb,
+					  unsigned int plane)
+{
+	if (plane >= 4)
+		return NULL;
+
+	return fb->obj[plane];
+}
+EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj);
+
+static int
+drm_gem_fb_init(struct drm_device *dev,
+		 struct drm_framebuffer *fb,
+		 const struct drm_mode_fb_cmd2 *mode_cmd,
+		 struct drm_gem_object **obj, unsigned int num_planes,
+		 const struct drm_framebuffer_funcs *funcs)
+{
+	int ret, i;
+
+	drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);
+
+	for (i = 0; i < num_planes; i++)
+		fb->obj[i] = obj[i];
+
+	ret = drm_framebuffer_init(dev, fb, funcs);
+	if (ret)
+		drm_err(dev, "Failed to init framebuffer: %d\n", ret);
+
+	return ret;
+}
+
+/**
+ * drm_gem_fb_destroy - Free GEM backed framebuffer
+ * @fb: Framebuffer
+ *
+ * Frees a GEM backed framebuffer with its backing buffer(s) and the structure
+ * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy
+ * callback.
+ */
+void drm_gem_fb_destroy(struct drm_framebuffer *fb)
+{
+	int i;
+
+	for (i = 0; i < 4; i++)
+		drm_gem_object_put(fb->obj[i]);
+
+	drm_framebuffer_cleanup(fb);
+	kfree(fb);
+}
+EXPORT_SYMBOL(drm_gem_fb_destroy);
+
+/**
+ * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer
+ * @fb: Framebuffer
+ * @file: DRM file to register the handle for
+ * @handle: Pointer to return the created handle
+ *
+ * This function creates a handle for the GEM object backing the framebuffer.
+ * Drivers can use this as their &drm_framebuffer_funcs->create_handle
+ * callback. The GETFB IOCTL calls into this callback.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file,
+			     unsigned int *handle)
+{
+	return drm_gem_handle_create(file, fb->obj[0], handle);
+}
+EXPORT_SYMBOL(drm_gem_fb_create_handle);
+
+/**
+ * drm_gem_fb_init_with_funcs() - Helper function for implementing
+ *				  &drm_mode_config_funcs.fb_create
+ *				  callback in cases when the driver
+ *				  allocates a subclass of
+ *				  struct drm_framebuffer
+ * @dev: DRM device
+ * @fb: framebuffer object
+ * @file: DRM file that holds the GEM handle(s) backing the framebuffer
+ * @mode_cmd: Metadata from the userspace framebuffer creation request
+ * @funcs: vtable to be used for the new framebuffer object
+ *
+ * This function can be used to set &drm_framebuffer_funcs for drivers that need
+ * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
+ * change &drm_framebuffer_funcs. The function does buffer size validation.
+ * The buffer size validation is for a general case, though, so users should
+ * pay attention to the checks being appropriate for them or, at least,
+ * non-conflicting.
+ *
+ * Returns:
+ * Zero or a negative error code.
+ */
+int drm_gem_fb_init_with_funcs(struct drm_device *dev,
+			       struct drm_framebuffer *fb,
+			       struct drm_file *file,
+			       const struct drm_mode_fb_cmd2 *mode_cmd,
+			       const struct drm_framebuffer_funcs *funcs)
+{
+	const struct drm_format_info *info;
+	struct drm_gem_object *objs[4];
+	int ret, i;
+
+	info = drm_get_format_info(dev, mode_cmd);
+	if (!info)
+		return -EINVAL;
+
+	for (i = 0; i < info->num_planes; i++) {
+		unsigned int width = mode_cmd->width / (i ? info->hsub : 1);
+		unsigned int height = mode_cmd->height / (i ? info->vsub : 1);
+		unsigned int min_size;
+
+		objs[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]);
+		if (!objs[i]) {
+			drm_dbg_kms(dev, "Failed to lookup GEM object\n");
+			ret = -ENOENT;
+			goto err_gem_object_put;
+		}
+
+		min_size = (height - 1) * mode_cmd->pitches[i]
+			 + drm_format_info_min_pitch(info, i, width)
+			 + mode_cmd->offsets[i];
+
+		if (objs[i]->size < min_size) {
+			drm_gem_object_put(objs[i]);
+			ret = -EINVAL;
+			goto err_gem_object_put;
+		}
+	}
+
+	ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs);
+	if (ret)
+		goto err_gem_object_put;
+
+	return 0;
+
+err_gem_object_put:
+	for (i--; i >= 0; i--)
+		drm_gem_object_put(objs[i]);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs);
+
+/**
+ * drm_gem_fb_create_with_funcs() - Helper function for the
+ *                                  &drm_mode_config_funcs.fb_create
+ *                                  callback
+ * @dev: DRM device
+ * @file: DRM file that holds the GEM handle(s) backing the framebuffer
+ * @mode_cmd: Metadata from the userspace framebuffer creation request
+ * @funcs: vtable to be used for the new framebuffer object
+ *
+ * This function can be used to set &drm_framebuffer_funcs for drivers that need
+ * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to
+ * change &drm_framebuffer_funcs. The function does buffer size validation.
+ *
+ * Returns:
+ * Pointer to a &drm_framebuffer on success or an error pointer on failure.
+ */
+struct drm_framebuffer *
+drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file,
+			     const struct drm_mode_fb_cmd2 *mode_cmd,
+			     const struct drm_framebuffer_funcs *funcs)
+{
+	struct drm_framebuffer *fb;
+	int ret;
+
+	fb = kzalloc(sizeof(*fb), GFP_KERNEL);
+	if (!fb)
+		return ERR_PTR(-ENOMEM);
+
+	ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs);
+	if (ret) {
+		kfree(fb);
+		return ERR_PTR(ret);
+	}
+
+	return fb;
+}
+EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs);
+
+static const struct drm_framebuffer_funcs drm_gem_fb_funcs = {
+	.destroy	= drm_gem_fb_destroy,
+	.create_handle	= drm_gem_fb_create_handle,
+};
+
+/**
+ * drm_gem_fb_create() - Helper function for the
+ *                       &drm_mode_config_funcs.fb_create callback
+ * @dev: DRM device
+ * @file: DRM file that holds the GEM handle(s) backing the framebuffer
+ * @mode_cmd: Metadata from the userspace framebuffer creation request
+ *
+ * This function creates a new framebuffer object described by
+ * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
+ * backing the framebuffer.
+ *
+ * If your hardware has special alignment or pitch requirements these should be
+ * checked before calling this function. The function does buffer size
+ * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer
+ * flushing.
+ *
+ * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
+ * The ADDFB2 IOCTL calls into this callback.
+ *
+ * Returns:
+ * Pointer to a &drm_framebuffer on success or an error pointer on failure.
+ */
+struct drm_framebuffer *
+drm_gem_fb_create(struct drm_device *dev, struct drm_file *file,
+		  const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
+					    &drm_gem_fb_funcs);
+}
+EXPORT_SYMBOL_GPL(drm_gem_fb_create);
+
+static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb = {
+	.destroy	= drm_gem_fb_destroy,
+	.create_handle	= drm_gem_fb_create_handle,
+	.dirty		= drm_atomic_helper_dirtyfb,
+};
+
+/**
+ * drm_gem_fb_create_with_dirty() - Helper function for the
+ *                       &drm_mode_config_funcs.fb_create callback
+ * @dev: DRM device
+ * @file: DRM file that holds the GEM handle(s) backing the framebuffer
+ * @mode_cmd: Metadata from the userspace framebuffer creation request
+ *
+ * This function creates a new framebuffer object described by
+ * &drm_mode_fb_cmd2. This description includes handles for the buffer(s)
+ * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty
+ * callback giving framebuffer flushing through the atomic machinery. Use
+ * drm_gem_fb_create() if you don't need the dirty callback.
+ * The function does buffer size validation.
+ *
+ * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes
+ * to enable userspace to use damage clips also with the ATOMIC IOCTL.
+ *
+ * Drivers can use this as their &drm_mode_config_funcs.fb_create callback.
+ * The ADDFB2 IOCTL calls into this callback.
+ *
+ * Returns:
+ * Pointer to a &drm_framebuffer on success or an error pointer on failure.
+ */
+struct drm_framebuffer *
+drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file,
+			     const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
+					    &drm_gem_fb_funcs_dirtyfb);
+}
+EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty);
+
+static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev,
+				  const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	const struct drm_format_info *info;
+
+	info = drm_get_format_info(dev, mode_cmd);
+
+	/* use whatever a driver has set */
+	if (info->cpp[0])
+		return info->cpp[0] * 8;
+
+	/* guess otherwise */
+	switch (info->format) {
+	case DRM_FORMAT_YUV420_8BIT:
+		return 12;
+	case DRM_FORMAT_YUV420_10BIT:
+		return 15;
+	case DRM_FORMAT_VUY101010:
+		return 30;
+	default:
+		break;
+	}
+
+	/* all attempts failed */
+	return 0;
+}
+
+static int drm_gem_afbc_min_size(struct drm_device *dev,
+				 const struct drm_mode_fb_cmd2 *mode_cmd,
+				 struct drm_afbc_framebuffer *afbc_fb)
+{
+	__u32 n_blocks, w_alignment, h_alignment, hdr_alignment;
+	/* remove bpp when all users properly encode cpp in drm_format_info */
+	__u32 bpp;
+
+	switch (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) {
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16:
+		afbc_fb->block_width = 16;
+		afbc_fb->block_height = 16;
+		break;
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8:
+		afbc_fb->block_width = 32;
+		afbc_fb->block_height = 8;
+		break;
+	/* no user exists yet - fall through */
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4:
+	case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4:
+	default:
+		drm_dbg_kms(dev, "Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n",
+			    mode_cmd->modifier[0]
+			    & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK);
+		return -EINVAL;
+	}
+
+	/* tiled header afbc */
+	w_alignment = afbc_fb->block_width;
+	h_alignment = afbc_fb->block_height;
+	hdr_alignment = AFBC_HDR_ALIGN;
+	if (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_TILED) {
+		w_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
+		h_alignment *= AFBC_TH_LAYOUT_ALIGNMENT;
+		hdr_alignment = AFBC_TH_BODY_START_ALIGNMENT;
+	}
+
+	afbc_fb->aligned_width = ALIGN(mode_cmd->width, w_alignment);
+	afbc_fb->aligned_height = ALIGN(mode_cmd->height, h_alignment);
+	afbc_fb->offset = mode_cmd->offsets[0];
+
+	bpp = drm_gem_afbc_get_bpp(dev, mode_cmd);
+	if (!bpp) {
+		drm_dbg_kms(dev, "Invalid AFBC bpp value: %d\n", bpp);
+		return -EINVAL;
+	}
+
+	n_blocks = (afbc_fb->aligned_width * afbc_fb->aligned_height)
+		   / AFBC_SUPERBLOCK_PIXELS;
+	afbc_fb->afbc_size = ALIGN(n_blocks * AFBC_HEADER_SIZE, hdr_alignment);
+	afbc_fb->afbc_size += n_blocks * ALIGN(bpp * AFBC_SUPERBLOCK_PIXELS / 8,
+					       AFBC_SUPERBLOCK_ALIGNMENT);
+
+	return 0;
+}
+
+/**
+ * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to
+ *			    fill and validate all the afbc-specific
+ *			    struct drm_afbc_framebuffer members
+ *
+ * @dev: DRM device
+ * @afbc_fb: afbc-specific framebuffer
+ * @mode_cmd: Metadata from the userspace framebuffer creation request
+ * @afbc_fb: afbc framebuffer
+ *
+ * This function can be used by drivers which support afbc to complete
+ * the preparation of struct drm_afbc_framebuffer. It must be called after
+ * allocating the said struct and calling drm_gem_fb_init_with_funcs().
+ * It is caller's responsibility to put afbc_fb->base.obj objects in case
+ * the call is unsuccessful.
+ *
+ * Returns:
+ * Zero on success or a negative error value on failure.
+ */
+int drm_gem_fb_afbc_init(struct drm_device *dev,
+			 const struct drm_mode_fb_cmd2 *mode_cmd,
+			 struct drm_afbc_framebuffer *afbc_fb)
+{
+	const struct drm_format_info *info;
+	struct drm_gem_object **objs;
+	int ret;
+
+	objs = afbc_fb->base.obj;
+	info = drm_get_format_info(dev, mode_cmd);
+	if (!info)
+		return -EINVAL;
+
+	ret = drm_gem_afbc_min_size(dev, mode_cmd, afbc_fb);
+	if (ret < 0)
+		return ret;
+
+	if (objs[0]->size < afbc_fb->afbc_size)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_gem_fb_afbc_init);
+
+/**
+ * drm_gem_fb_prepare_fb() - Prepare a GEM backed framebuffer
+ * @plane: Plane
+ * @state: Plane state the fence will be attached to
+ *
+ * This function extracts the exclusive fence from &drm_gem_object.resv and
+ * attaches it to plane state for the atomic helper to wait on. This is
+ * necessary to correctly implement implicit synchronization for any buffers
+ * shared as a struct &dma_buf. This function can be used as the
+ * &drm_plane_helper_funcs.prepare_fb callback.
+ *
+ * There is no need for &drm_plane_helper_funcs.cleanup_fb hook for simple
+ * gem based framebuffer drivers which have their buffers always pinned in
+ * memory.
+ *
+ * See drm_atomic_set_fence_for_plane() for a discussion of implicit and
+ * explicit fencing in atomic modeset updates.
+ */
+int drm_gem_fb_prepare_fb(struct drm_plane *plane,
+			  struct drm_plane_state *state)
+{
+	struct drm_gem_object *obj;
+	struct dma_fence *fence;
+
+	if (!state->fb)
+		return 0;
+
+	obj = drm_gem_fb_get_obj(state->fb, 0);
+	fence = dma_resv_get_excl_rcu(obj->resv);
+	drm_atomic_set_fence_for_plane(state, fence);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_gem_fb_prepare_fb);
+
+/**
+ * drm_gem_fb_simple_display_pipe_prepare_fb - prepare_fb helper for
+ *     &drm_simple_display_pipe
+ * @pipe: Simple display pipe
+ * @plane_state: Plane state
+ *
+ * This function uses drm_gem_fb_prepare_fb() to extract the exclusive fence
+ * from &drm_gem_object.resv and attaches it to plane state for the atomic
+ * helper to wait on. This is necessary to correctly implement implicit
+ * synchronization for any buffers shared as a struct &dma_buf. Drivers can use
+ * this as their &drm_simple_display_pipe_funcs.prepare_fb callback.
+ *
+ * See drm_atomic_set_fence_for_plane() for a discussion of implicit and
+ * explicit fencing in atomic modeset updates.
+ */
+int drm_gem_fb_simple_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe,
+					      struct drm_plane_state *plane_state)
+{
+	return drm_gem_fb_prepare_fb(&pipe->plane, plane_state);
+}
+EXPORT_SYMBOL(drm_gem_fb_simple_display_pipe_prepare_fb);