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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/gpu/drm/drm_gem_framebuffer_helper.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/drm_gem_framebuffer_helper.c')
-rw-r--r--drivers/gpu/drm/drm_gem_framebuffer_helper.c328
1 files changed, 328 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..2810d4131
--- /dev/null
+++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
@@ -0,0 +1,328 @@
+/*
+ * drm gem framebuffer helper functions
+ *
+ * Copyright (C) 2017 Noralf Trønnes
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-fence.h>
+#include <linux/reservation.h>
+#include <linux/slab.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic.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>
+
+/**
+ * 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 struct drm_framebuffer *
+drm_gem_fb_alloc(struct drm_device *dev,
+ const struct drm_mode_fb_cmd2 *mode_cmd,
+ struct drm_gem_object **obj, unsigned int num_planes,
+ const struct drm_framebuffer_funcs *funcs)
+{
+ struct drm_framebuffer *fb;
+ int ret, i;
+
+ fb = kzalloc(sizeof(*fb), GFP_KERNEL);
+ if (!fb)
+ return ERR_PTR(-ENOMEM);
+
+ 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_DEV_ERROR(dev->dev, "Failed to init framebuffer: %d\n",
+ ret);
+ kfree(fb);
+ return ERR_PTR(ret);
+ }
+
+ return fb;
+}
+
+/**
+ * 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_unlocked(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_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 can be used to set &drm_framebuffer_funcs for drivers that need the
+ * &drm_framebuffer_funcs.dirty callback. 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)
+{
+ const struct drm_format_info *info;
+ struct drm_gem_object *objs[4];
+ struct drm_framebuffer *fb;
+ int ret, i;
+
+ info = drm_get_format_info(dev, mode_cmd);
+ if (!info)
+ return ERR_PTR(-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_DEBUG_KMS("Failed to lookup GEM object\n");
+ ret = -ENOENT;
+ goto err_gem_object_put;
+ }
+
+ min_size = (height - 1) * mode_cmd->pitches[i]
+ + width * info->cpp[i]
+ + mode_cmd->offsets[i];
+
+ if (objs[i]->size < min_size) {
+ drm_gem_object_put_unlocked(objs[i]);
+ ret = -EINVAL;
+ goto err_gem_object_put;
+ }
+ }
+
+ fb = drm_gem_fb_alloc(dev, mode_cmd, objs, i, funcs);
+ if (IS_ERR(fb)) {
+ ret = PTR_ERR(fb);
+ goto err_gem_object_put;
+ }
+
+ return fb;
+
+err_gem_object_put:
+ for (i--; i >= 0; i--)
+ drm_gem_object_put_unlocked(objs[i]);
+
+ return ERR_PTR(ret);
+}
+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_funcs() if you need to set
+ * &drm_framebuffer_funcs.dirty.
+ *
+ * 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);
+
+/**
+ * drm_gem_fb_prepare_fb() - Prepare a GEM backed framebuffer
+ * @plane: Plane
+ * @state: Plane state the fence will be attached to
+ *
+ * This function prepares a GEM backed framebuffer for scanout by checking if
+ * the plane framebuffer has a DMA-BUF attached. If it does, it extracts the
+ * exclusive fence and attaches it to the plane state for the atomic helper to
+ * wait on. 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.
+ */
+int drm_gem_fb_prepare_fb(struct drm_plane *plane,
+ struct drm_plane_state *state)
+{
+ struct dma_buf *dma_buf;
+ struct dma_fence *fence;
+
+ if (!state->fb)
+ return 0;
+
+ dma_buf = drm_gem_fb_get_obj(state->fb, 0)->dma_buf;
+ if (dma_buf) {
+ fence = reservation_object_get_excl_rcu(dma_buf->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 check if the plane FB has a
+ * &dma_buf attached, extracts the exclusive fence and attaches it to plane
+ * state for the atomic helper to wait on. Drivers can use this as their
+ * &drm_simple_display_pipe_funcs.prepare_fb callback.
+ */
+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);
+
+/**
+ * drm_gem_fbdev_fb_create - Create a GEM backed &drm_framebuffer for fbdev
+ * emulation
+ * @dev: DRM device
+ * @sizes: fbdev size description
+ * @pitch_align: Optional pitch alignment
+ * @obj: GEM object backing the framebuffer
+ * @funcs: Optional vtable to be used for the new framebuffer object when the
+ * dirty callback is needed.
+ *
+ * This function creates a framebuffer from a &drm_fb_helper_surface_size
+ * description for use in the &drm_fb_helper_funcs.fb_probe callback.
+ *
+ * Returns:
+ * Pointer to a &drm_framebuffer on success or an error pointer on failure.
+ */
+struct drm_framebuffer *
+drm_gem_fbdev_fb_create(struct drm_device *dev,
+ struct drm_fb_helper_surface_size *sizes,
+ unsigned int pitch_align, struct drm_gem_object *obj,
+ const struct drm_framebuffer_funcs *funcs)
+{
+ struct drm_mode_fb_cmd2 mode_cmd = { 0 };
+
+ mode_cmd.width = sizes->surface_width;
+ mode_cmd.height = sizes->surface_height;
+ mode_cmd.pitches[0] = sizes->surface_width *
+ DIV_ROUND_UP(sizes->surface_bpp, 8);
+ if (pitch_align)
+ mode_cmd.pitches[0] = roundup(mode_cmd.pitches[0],
+ pitch_align);
+ mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
+ sizes->surface_depth);
+ if (obj->size < mode_cmd.pitches[0] * mode_cmd.height)
+ return ERR_PTR(-EINVAL);
+
+ if (!funcs)
+ funcs = &drm_gem_fb_funcs;
+
+ return drm_gem_fb_alloc(dev, &mode_cmd, &obj, 1, funcs);
+}
+EXPORT_SYMBOL(drm_gem_fbdev_fb_create);