[PATCH RFC v2 1/3] drm: client: add splash client

Francesco Valla
2026-01-06T14:26:10Z

Add a DRM client that draws a simple splash, with possibility to show:

- a colored background;
- a static BMP image (loaded as firmware);
- the logo provided by EFI BGRT.

The client is not meant to replace a full-featured bootsplash, but
rather to remove some complexity (and hopefully boot time) on small
embedded platforms or on systems with a limited scope (e.g: recovery
or manufacturing images).

The background color can be set either at build time from a dedicated
config option or at runtime through the drm_client_lib.splash_color
command line parameter. Any color in RGB888 format can be used.

If enabled, the static BMP image is loaded using the kernel firmware
infrastructure; a valid BMP image with 24bpp color and no compression
is expected. The name of the image can be set through the
drm_client_lib.splash_bmp kernel command line parameter, with the
default being 'drm_splash.bmp'.

Just like the existing DRM clients, the splash can be enabled from the
kernel command line using drm_client_lib.active=splash.

Signed-off-by: Francesco Valla <francesco@valla.it>
---
drivers/gpu/drm/clients/Kconfig | 79 ++-
drivers/gpu/drm/clients/Makefile | 1 +
drivers/gpu/drm/clients/drm_client_internal.h | 9 +
drivers/gpu/drm/clients/drm_client_setup.c | 8 +
drivers/gpu/drm/clients/drm_splash.c | 883 ++++++++++++++++++++++++++
5 files changed, 979 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/clients/Kconfig b/drivers/gpu/drm/clients/Kconfig
index 6096c623d9d5b1a3d4a40d986c45aad2f8277767..dd8cd6cacd1166932eb3890dd816b9ae2d26330f 100644
--- a/drivers/gpu/drm/clients/Kconfig
+++ b/drivers/gpu/drm/clients/Kconfig
@@ -12,6 +12,7 @@ config DRM_CLIENT_LIB
config DRM_CLIENT_SELECTION
tristate
depends on DRM
+ select DRM_CLIENT_LIB if DRM_CLIENT_SPLASH
select DRM_CLIENT_LIB if DRM_CLIENT_LOG
select DRM_CLIENT_LIB if DRM_FBDEV_EMULATION
help
@@ -85,10 +86,79 @@ config DRM_CLIENT_LOG
If you only need logs, but no terminal, or if you prefer userspace
terminal, say "Y".

+config DRM_CLIENT_SPLASH
+ bool "Display graphic splash"
+ depends on DRM_CLIENT_SELECTION
+ select DRM_CLIENT
+ select DRM_CLIENT_SETUP
+ select DRM_DRAW
+ help
+ This enables a splash drm client, able to display either a plain
+ color or a static image until the userspace is ready to take over.
+ The splash will be displayed on all screens available at boot, if
+ any, or on the ones part of the first hotplug event.
+
+config DRM_CLIENT_SPLASH_BACKGROUND_COLOR
+ hex "Splash background color"
+ depends on DRM_CLIENT_SPLASH
+ default 0x000000
+ help
+ The default splash background color, in RGB888 format.
+
+ The color can be overridden through the drm_client_lib.splash_color
+ kernel command line parameter.
+
+config DRM_CLIENT_SPLASH_BMP_SUPPORT
+ bool
+
+choice
+ prompt "Splash source"
+ depends on DRM_CLIENT_SPLASH
+ default DRM_CLIENT_SPLASH_SRC_COLOR
+ help
+ Selects the source for the splash graphic.
+
+config DRM_CLIENT_SPLASH_SRC_COLOR
+ bool "Solid color"
+ help
+ Use a solid color as splash. The color is selected through the
+ DRM_CLIENT_SPLASH_BACKGROUND_COLOR config option.
+
+ The image will be loaded using the firmware loading facility the
+ kernel provides.
+
+config DRM_CLIENT_SPLASH_SRC_BMP
+ bool "BMP image"
+ select DRM_CLIENT_SPLASH_BMP_SUPPORT
+ select FW_LOADER
+ help
+ Use a BMP (bitmap) image as splash. If the image is smaller than the
+ display(s), it will be centered and the color specified through the
+ DRM_CLIENT_SPLASH_BACKGROUND_COLOR config option will be used as
+ background.
+
+ The image will be loaded using the firmware loading facility the
+ kernel provides; it shall use 24 bits per pixel and shall not be
+ compressed. The name of the file can be set through the
+ drm_client_lib.splash_bmp command line parameter, with the default
+ being 'drm_splash.bmp'.
+
+config DRM_CLIENT_SPLASH_SRC_BGRT
+ bool "EFI BGRT"
+ select DRM_CLIENT_SPLASH_BMP_SUPPORT
+ depends on EFI
+ help
+ Use the BGRT image provided by the EFI bootloader. If the image is
+ smaller than the display(s), it will be centered and the color
+ specified through the DRM_CLIENT_SPLASH_BACKGROUND_COLOR config
+ option will be used as background.
+
+endchoice
+
choice
prompt "Default DRM Client"
depends on DRM_CLIENT_SELECTION
- depends on DRM_FBDEV_EMULATION || DRM_CLIENT_LOG
+ depends on DRM_FBDEV_EMULATION || DRM_CLIENT_LOG || DRM_CLIENT_SPLASH
default DRM_CLIENT_DEFAULT_FBDEV
help
Selects the default drm client.
@@ -111,6 +181,12 @@ config DRM_CLIENT_DEFAULT_LOG
screen, but doesn't implement a full terminal. For that you will need
a userspace terminal using drm/kms.

+config DRM_CLIENT_DEFAULT_SPLASH
+ bool "splash"
+ depends on DRM_CLIENT_SPLASH
+ help
+ Use splash as default drm client.
+
endchoice

config DRM_CLIENT_DEFAULT
@@ -118,6 +194,7 @@ config DRM_CLIENT_DEFAULT
depends on DRM_CLIENT
default "fbdev" if DRM_CLIENT_DEFAULT_FBDEV
default "log" if DRM_CLIENT_DEFAULT_LOG
+ default "splash" if DRM_CLIENT_DEFAULT_SPLASH
default ""

endmenu
diff --git a/drivers/gpu/drm/clients/Makefile b/drivers/gpu/drm/clients/Makefile
index c16addbc327f09572aa3142cbf0d1d13f172a9e9..3df02d10cd18a47d7e8d7cee70163b0ef0129b51 100644
--- a/drivers/gpu/drm/clients/Makefile
+++ b/drivers/gpu/drm/clients/Makefile
@@ -5,4 +5,5 @@ subdir-ccflags-y += -I$(src)/..
drm_client_lib-y := drm_client_setup.o
drm_client_lib-$(CONFIG_DRM_CLIENT_LOG) += drm_log.o
drm_client_lib-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fbdev_client.o
+drm_client_lib-$(CONFIG_DRM_CLIENT_SPLASH) += drm_splash.o
obj-$(CONFIG_DRM_CLIENT_LIB) += drm_client_lib.o
diff --git a/drivers/gpu/drm/clients/drm_client_internal.h b/drivers/gpu/drm/clients/drm_client_internal.h
index 6dc078bf6503b902cbb3267b64ea42d9f1c23375..48ee0c1c2529882b2bf5dc786788390823e25cd6 100644
--- a/drivers/gpu/drm/clients/drm_client_internal.h
+++ b/drivers/gpu/drm/clients/drm_client_internal.h
@@ -22,4 +22,13 @@ void drm_log_register(struct drm_device *dev);
static inline void drm_log_register(struct drm_device *dev) {}
#endif

+#ifdef CONFIG_DRM_CLIENT_SPLASH
+void drm_splash_register(struct drm_device *dev,
+ const struct drm_format_info *format);
+#else
+static inline void drm_splash_register(struct drm_device *dev,
+ const struct drm_format_info *format)
+{}
+#endif
+
#endif
diff --git a/drivers/gpu/drm/clients/drm_client_setup.c b/drivers/gpu/drm/clients/drm_client_setup.c
index 515aceac22b18161a14bd60be4acedc1ddd05bc5..c19498938ee3ba442f7502b27a9c33dfff45a203 100644
--- a/drivers/gpu/drm/clients/drm_client_setup.c
+++ b/drivers/gpu/drm/clients/drm_client_setup.c
@@ -56,6 +56,14 @@ void drm_client_setup(struct drm_device *dev, const struct drm_format_info *form
return;
}
#endif
+
+#ifdef CONFIG_DRM_CLIENT_SPLASH
+ if (!strcmp(drm_client_default, "splash")) {
+ drm_splash_register(dev, format);
+ return;
+ }
+#endif
+
if (strcmp(drm_client_default, ""))
drm_warn(dev, "Unknown DRM client %s\n", drm_client_default);
}
diff --git a/drivers/gpu/drm/clients/drm_splash.c b/drivers/gpu/drm/clients/drm_splash.c
new file mode 100644
index 0000000000000000000000000000000000000000..204a5256ef03b6edb81e5dc8c49b5929cb51ff92
--- /dev/null
+++ b/drivers/gpu/drm/clients/drm_splash.c
@@ -0,0 +1,883 @@
+// SPDX-License-Identifier: GPL-2.0 or MIT
+/*
+ * Copyright (c) 2025-2026 Francesco Valla <francesco@valla.it>
+ *
+ */
+
+#include <linux/atomic.h>
+#include <linux/device.h>
+#include <linux/efi-bgrt.h>
+#include <linux/firmware.h>
+#include <linux/init.h>
+#include <linux/iosys-map.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include <drm/drm_client.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_plane.h>
+#include <drm/drm_print.h>
+
+#include "drm_client_internal.h"
+#include "drm_draw_internal.h"
+#include "drm_internal.h"
+
+/**
+ * DOC: overview
+ *
+ * This is a simple graphic bootsplash, able to display either a plain color or
+ * a static image.
+ */
+
+static unsigned int splash_color = CONFIG_DRM_CLIENT_SPLASH_BACKGROUND_COLOR;
+module_param(splash_color, uint, 0400);
+MODULE_PARM_DESC(splash_color, "Splash background color (RGB888)");
+
+#if IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_SRC_BMP)
+#define DEFAULT_SPLASH_BMP "drm_splash.bmp"
+static char *splash_bmp = DEFAULT_SPLASH_BMP;
+module_param(splash_bmp, charp, 0400);
+MODULE_PARM_DESC(splash_bmp, "Name of splash image (default: \"" DEFAULT_SPLASH_BMP "\")");
+#endif // CONFIG_DRM_CLIENT_SPLASH_SRC_BMP
+
+#if IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_BMP_SUPPORT)
+#define BMP_FILE_MAGIC_ID 0x4d42
+
+/* BMP header structures copied from drivers/video/fbdev/efifb.c */
+struct bmp_file_header {
+ u16 id;
+ u32 file_size;
+ u32 reserved;
+ u32 bitmap_offset;
+} __packed;
+
+struct bmp_dib_header {
+ u32 dib_header_size;
+ s32 width;
+ s32 height;
+ u16 planes;
+ u16 bpp;
+ u32 compression;
+ u32 bitmap_size;
+ u32 horz_resolution;
+ u32 vert_resolution;
+ u32 colors_used;
+ u32 colors_important;
+} __packed;
+#endif // CONFIG_DRM_CLIENT_SPLASH_BMP_SUPPORT
+
+typedef int (*drm_splash_data_get_func_t)(void *priv, const u8 **data, size_t *size);
+typedef void (*drm_splash_data_release_func_t)(void *priv);
+
+struct drm_splash_scanout {
+ int id;
+ u32 format;
+ unsigned int width;
+ unsigned int height;
+ struct drm_client_buffer *buffer;
+ bool bg_drawn;
+};
+
+struct drm_splash {
+ struct drm_client_dev client;
+ u32 preferred_format;
+ struct device dev;
+
+ struct task_struct *thread;
+ atomic_t pending;
+
+ struct mutex hotplug_lock;
+ bool initialized;
+
+ u32 n_scanout;
+ struct drm_splash_scanout *scanout;
+
+ spinlock_t data_lock;
+ drm_splash_data_get_func_t data_get;
+ drm_splash_data_release_func_t data_release;
+ void *data_priv;
+};
+
+static struct drm_splash *client_to_drm_splash(struct drm_client_dev *client)
+{
+ return container_of_const(client, struct drm_splash, client);
+}
+
+static void __maybe_unused
+drm_splash_data_source_push(struct drm_splash *splash,
+ drm_splash_data_get_func_t get,
+ drm_splash_data_release_func_t release,
+ void *priv)
+{
+ guard(spinlock)(&splash->data_lock);
+
+ /* Release previous data */
+ if (splash->data_release)
+ splash->data_release(splash->data_priv);
+
+ splash->data_get = get;
+ splash->data_release = release;
+ splash->data_priv = priv;
+}
+
+static void drm_splash_data_source_pop(struct drm_splash *splash,
+ drm_splash_data_get_func_t *get,
+ drm_splash_data_release_func_t *release,
+ void **priv)
+{
+ guard(spinlock)(&splash->data_lock);
+
+ *get = splash->data_get;
+ splash->data_get = NULL;
+
+ *release = splash->data_release;
+ splash->data_release = NULL;
+
+ *priv = splash->data_priv;
+ splash->data_priv = NULL;
+}
+
+static struct drm_splash_scanout *
+get_scanout_from_tile_group(struct drm_splash *splash, int id)
+{
+ int j;
+
+ for (j = 0; j < splash->n_scanout; j++)
+ if (splash->scanout[j].id == id)
+ return &splash->scanout[j];
+
+ return NULL;
+}
+
+static u32 drm_splash_find_usable_format(struct drm_plane *plane,
+ u32 preferred_format)
+{
+ int i;
+
+ /* Check if the preferred format can be used */
+ for (i = 0; i < plane->format_count; i++)
+ if (plane->format_types[i] == preferred_format)
+ return preferred_format;
+
+ /* Otherwise, find the first format that can be converted from XRGB8888 */
+ for (i = 0; i < plane->format_count; i++)
+ if (drm_draw_color_from_xrgb8888(0xffffffff, plane->format_types[i]) != 0)
+ return plane->format_types[i];
+
+ return DRM_FORMAT_INVALID;
+}
+
+static void drm_splash_fill(struct iosys_map *map, unsigned int dst_pitch,
+ unsigned int height, unsigned int width,
+ u32 px_width, u32 color)
+{
+ switch (px_width) {
+ case 2:
+ drm_draw_fill16(map, dst_pitch, height, width, color);
+ break;
+ case 3:
+ drm_draw_fill24(map, dst_pitch, height, width, color);
+ break;
+ case 4:
+ drm_draw_fill32(map, dst_pitch, height, width, color);
+ break;
+ default:
+ WARN_ONCE(1, "Can't fill with pixel width %d", px_width);
+ }
+}
+
+static int drm_splash_fill_solid_color(struct drm_client_buffer *buffer, u32 color)
+{
+ struct drm_client_dev *client = buffer->client;
+ struct drm_framebuffer *fb = buffer->fb;
+ struct drm_rect r = DRM_RECT_INIT(0, 0, fb->width, fb->height);
+ u32 px_width = fb->format->cpp[0];
+ struct iosys_map map;
+ int ret;
+
+ ret = drm_client_buffer_vmap_local(buffer, &map);
+ if (ret) {
+ drm_err(client->dev, "splash: cannot vmap buffer: %d", ret);
+ return ret;
+ }
+
+ drm_splash_fill(&map, fb->pitches[0], drm_rect_height(&r),
+ drm_rect_width(&r), px_width, color);
+
+ drm_client_buffer_vunmap_local(buffer);
+
+ return drm_client_buffer_flush(buffer, &r);
+}
+
+#if IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_BMP_SUPPORT)
+static void drm_splash_blit_pix16(struct iosys_map *map, unsigned int dpitch,
+ unsigned int x_pad, unsigned int y_pad,
+ const u8 *sbuf8, unsigned int spitch,
+ unsigned int width, unsigned int height,
+ bool invert_y, u32 format)
+{
+ unsigned int x, y, src_offset, dst_offset;
+ u32 scolor, dcolor, wr_off;
+
+ for (y = 0; y < height; y++) {
+ src_offset = (invert_y ? (height - y - 1) : y) * spitch;
+ dst_offset = (y_pad + y) * dpitch;
+
+ for (x = 0; x < width; x++) {
+ scolor = *(const u32 *)(&sbuf8[src_offset + 3 * x]);
+ dcolor = drm_draw_color_from_xrgb8888(scolor, format);
+ wr_off = dst_offset + (x_pad + x) * sizeof(u16);
+
+ iosys_map_wr(map, wr_off, u16, dcolor);
+ }
+ }
+}
+
+static void drm_splash_blit_pix24(struct iosys_map *map, unsigned int dpitch,
+ unsigned int x_pad, unsigned int y_pad,
+ const u8 *sbuf8, unsigned int spitch,
+ unsigned int width, unsigned int height,
+ bool invert_y, u32 format)
+{
+ unsigned int x, y, src_offset, dst_offset;
+ u32 scolor, dcolor, wr_off;
+
+ for (y = 0; y < height; y++) {
+ src_offset = (invert_y ? (height - y - 1) : y) * spitch;
+ dst_offset = (y_pad + y) * dpitch;
+
+ for (x = 0; x < width; x++) {
+ scolor = *(const u32 *)(&sbuf8[src_offset + 3 * x]);
+ dcolor = drm_draw_color_from_xrgb8888(scolor, format);
+ wr_off = dst_offset + (x_pad + x) * 3;
+
+ iosys_map_wr(map, wr_off, u8, (dcolor & 0x000000FF) >> 0);
+ iosys_map_wr(map, wr_off + 1, u8, (dcolor & 0x0000FF00) >> 8);
+ iosys_map_wr(map, wr_off + 2, u8, (dcolor & 0x00FF0000) >> 16);
+ }
+ }
+}
+
+static void drm_splash_blit_pix32(struct iosys_map *map, unsigned int dpitch,
+ unsigned int x_pad, unsigned int y_pad,
+ const u8 *sbuf8, unsigned int spitch,
+ unsigned int width, unsigned int height,
+ bool invert_y, u32 format)
+{
+ unsigned int x, y, src_offset, dst_offset;
+ u32 scolor, dcolor, wr_off;
+
+ for (y = 0; y < height; y++) {
+ src_offset = (invert_y ? (height - y - 1) : y) * spitch;
+ dst_offset = (y_pad + y) * dpitch;
+
+ for (x = 0; x < width; x++) {
+ scolor = *(const u32 *)(&sbuf8[src_offset + 3 * x]);
+ dcolor = drm_draw_color_from_xrgb8888(scolor, format);
+ wr_off = dst_offset + (x_pad + x) * sizeof(u32);
+
+ iosys_map_wr(map, wr_off, u32, dcolor);
+ }
+ }
+}
+
+static void drm_splash_blit_rgb888(struct iosys_map *map, unsigned int dpitch,
+ unsigned int x_pad, unsigned int y_pad,
+ const u8 *sbuf8, unsigned int spitch,
+ unsigned int width, unsigned int height,
+ bool invert_y)
+{
+ unsigned int y, src_offset, dst_offset;
+
+ for (y = 0; y < height; y++) {
+ src_offset = (invert_y ? (height - y - 1) : y) * spitch;
+ dst_offset = (y_pad + y) * dpitch + x_pad * 3;
+
+ iosys_map_memcpy_to(map, dst_offset, &sbuf8[src_offset], width * 3);
+ }
+}
+
+static int drm_splash_bmp_to_scanout(struct drm_splash_scanout *scanout,
+ const u8 *data, size_t data_len)
+
+{
+ struct drm_client_buffer *buffer = scanout->buffer;
+ struct drm_client_dev *client = buffer->client;
+ struct drm_framebuffer *fb = buffer->fb;
+ u32 px_width = fb->format->cpp[0];
+ const struct bmp_file_header *file_header;
+ const struct bmp_dib_header *dib_header;
+ u32 bmp_width, bmp_height, bmp_pitch;
+ bool bmp_invert_y;
+ unsigned int x_pad, y_pad;
+ const u8 *image_data;
+ struct iosys_map map;
+ struct drm_rect r;
+ int ret;
+
+ if (data_len < (sizeof(*file_header) + sizeof(*dib_header))) {
+ drm_err(client->dev, "splash: BMP file too short");
+ return -EINVAL;
+ }
+
+ file_header = (const struct bmp_file_header *)data;
+ if (file_header->id != BMP_FILE_MAGIC_ID) {
+ drm_err(client->dev, "splash: invalid BMP magic 0x%04X",
+ file_header->id);
+ return -EINVAL;
+ }
+
+ dib_header = (const struct bmp_dib_header *)(data + sizeof(*file_header));
+
+ /* Restrict supported format to uncompressed, 24bit RGB888 */
+ if (dib_header->dib_header_size != 40 || dib_header->width < 0 ||
+ dib_header->planes != 1 || dib_header->compression != 0 ||
+ dib_header->bpp != 24) {
+ drm_err(client->dev, "splash: invalid BMP format");
+ return -EINVAL;
+ }
+
+ bmp_width = dib_header->width;
+ bmp_height = abs(dib_header->height);
+ bmp_pitch = round_up(3 * bmp_width, 4);
+ bmp_invert_y = (dib_header->height > 0);
+
+ if ((file_header->bitmap_offset + bmp_pitch * bmp_height) > data_len) {
+ drm_err(client->dev, "splash: invalid BMP size");
+ return -EINVAL;
+ }
+
+ if (bmp_width > scanout->width || bmp_height > scanout->height) {
+ drm_err(client->dev, "splash: BMP image is too big for the screen");
+ return -EINVAL;
+ }
+
+ image_data = data + file_header->bitmap_offset;
+
+ ret = drm_client_buffer_vmap_local(buffer, &map);
+ if (ret) {
+ drm_err(client->dev, "splash: cannot vmap buffer: %d", ret);
+ return ret;
+ }
+
+ /* Center X and Y */
+ x_pad = (scanout->width - bmp_width) / 2;
+ y_pad = (scanout->height - bmp_height) / 2;
+ r = DRM_RECT_INIT(x_pad, y_pad, bmp_width, bmp_height);
+
+ /* In case the target format is RGB888, source data can be copied to
+ * the video buffer line by line, avoiding some overhead.
+ */
+ if (scanout->format == DRM_FORMAT_RGB888) {
+ drm_splash_blit_rgb888(&map, fb->pitches[0], x_pad, y_pad,
+ image_data, bmp_pitch, bmp_width,
+ bmp_height, bmp_invert_y);
+ } else {
+ switch (px_width) {
+ case 2:
+ drm_splash_blit_pix16(&map, fb->pitches[0], x_pad,
+ y_pad, image_data, bmp_pitch,
+ bmp_width, bmp_height,
+ bmp_invert_y, scanout->format);
+ break;
+ case 3:
+ drm_splash_blit_pix24(&map, fb->pitches[0], x_pad,
+ y_pad, image_data, bmp_pitch,
+ bmp_width, bmp_height,
+ bmp_invert_y, scanout->format);
+ break;
+ case 4:
+ drm_splash_blit_pix32(&map, fb->pitches[0], x_pad,
+ y_pad, image_data, bmp_pitch,
+ bmp_width, bmp_height,
+ bmp_invert_y, scanout->format);
+ break;
+ default:
+ drm_warn_once(client->dev,
+ "splash: can't blit with pixel width %d",
+ px_width);
+ }
+ }
+
+ drm_client_buffer_vunmap_local(buffer);
+
+ return drm_client_buffer_flush(buffer, &r);
+}
+#else
+static inline int drm_splash_bmp_to_scanout(struct drm_splash_scanout *scanout,
+ const u8 *data, size_t data_len)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
+static int drm_splash_draw_scanout(struct drm_splash *splash,
+ struct drm_splash_scanout *scanout,
+ const u8 *data, size_t data_len)
+{
+ if (!scanout->buffer)
+ return -ENODEV;
+
+ if (!scanout->bg_drawn) {
+ u32 color = drm_draw_color_from_xrgb8888(splash_color,
+ scanout->format);
+ drm_splash_fill_solid_color(scanout->buffer, color);
+ scanout->bg_drawn = true;
+ }
+
+ if (data != NULL) {
+ /* Ignore the return value, since the solid color has already
+ * been drawn to screen.
+ */
+ drm_splash_bmp_to_scanout(scanout, data, data_len);
+ }
+
+ return 0;
+}
+
+static int drm_splash_render_thread(void *data)
+{
+ struct drm_splash *splash = data;
+ struct drm_client_dev *client = &splash->client;
+
+ while (!kthread_should_stop()) {
+ unsigned int draw_count = 0;
+ drm_splash_data_get_func_t get_fn = NULL;
+ drm_splash_data_release_func_t release_fn = NULL;
+ void *priv = NULL;
+ const u8 *img_data = NULL;
+ size_t img_data_len = 0;
+ int i, ret;
+
+ drm_splash_data_source_pop(splash, &get_fn, &release_fn, &priv);
+
+ if (get_fn) {
+ ret = get_fn(priv, &img_data, &img_data_len);
+ if (ret) {
+ drm_err(client->dev,
+ "splash: failed to get image data: %d",
+ ret);
+ }
+ }
+
+ for (i = 0; i < splash->n_scanout; i++) {
+ ret = drm_splash_draw_scanout(splash,
+ &splash->scanout[i],
+ img_data, img_data_len);
+ if (ret) {
+ drm_err(client->dev,
+ "splash: failed to fill scanout %d: %d",
+ i, ret);
+ continue;
+ }
+
+ draw_count++;
+ }
+
+ if (release_fn)
+ release_fn(priv);
+
+ if (draw_count > 0) {
+ ret = drm_client_modeset_commit(client);
+ /* If commit returns EBUSY, another master showed up.
+ * This means that the splash is no more required.
+ */
+ if (ret == -EBUSY) {
+ drm_info(client->dev,
+ "splash: not master anymore, exiting");
+ break;
+ }
+ }
+
+ /* If no changes arrived in the mean time, wait to be awaken,
+ * e.g.by a firmware callback.
+ */
+ if (atomic_xchg(&splash->pending, 0) == 0)
+ set_current_state(TASK_UNINTERRUPTIBLE);
+
+ schedule();
+ }
+
+ return 0;
+}
+
+static inline void drm_splash_wake_render_thread(struct drm_splash *splash)
+{
+ atomic_set(&splash->pending, 1);
+ wake_up_process(splash->thread);
+}
+
+#if IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_SRC_BMP)
+static int drm_splash_fw_get(void *priv, const u8 **data, size_t *size)
+{
+ const struct firmware *fw = priv;
+
+ if (!fw)
+ return -ENODATA;
+
+ *data = fw->data;
+ *size = fw->size;
+
+ return 0;
+}
+
+static void drm_splash_fw_release(void *priv)
+{
+ const struct firmware *fw = priv;
+
+ if (fw)
+ release_firmware(fw);
+}
+
+static void drm_splash_fw_callback(const struct firmware *fw, void *context)
+{
+ struct drm_splash *splash = context;
+ struct drm_client_dev *client = &splash->client;
+
+ if (!fw || !fw->data) {
+ drm_err(client->dev, "splash: no firmware");
+ return;
+ }
+
+ drm_splash_data_source_push(splash, drm_splash_fw_get,
+ drm_splash_fw_release, (void *)fw);
+
+ /* Wake the render thread */
+ drm_dbg(client->dev, "splash: firmware loaded, wake up drawing thread");
+ drm_splash_wake_render_thread(splash);
+}
+
+static int drm_splash_fw_request_bmp(struct drm_splash *splash)
+{
+ struct drm_client_dev *client = &splash->client;
+
+ drm_info(client->dev, "splash: request %s as firmware", splash_bmp);
+
+ return request_firmware_nowait(THIS_MODULE, FW_ACTION_UEVENT,
+ splash_bmp, client->dev->dev, GFP_KERNEL,
+ splash, drm_splash_fw_callback);
+}
+#else
+static inline int drm_splash_fw_request_bmp(struct drm_splash *splash)
+{
+ return -EOPNOTSUPP;
+}
+#endif // CONFIG_DRM_CLIENT_SPLASH_SRC_BMP
+
+#if IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_SRC_BGRT)
+static int drm_splash_bgrt_get_data(void *priv, const u8 **data, size_t *size)
+{
+ void *bgrt_image = priv;
+
+ *data = bgrt_image;
+ *size = bgrt_image_size;
+
+ return 0;
+}
+
+static void drm_splash_bgrt_release(void *priv)
+{
+ void *bgrt_image = priv;
+
+ if (bgrt_image)
+ memunmap(bgrt_image);
+}
+
+static int drm_splash_bgrt_load(struct drm_splash *splash)
+{
+ struct drm_client_dev *client = &splash->client;
+ void *bgrt_image = NULL;
+
+ drm_info(client->dev, "splash: using EFI BGRT");
+
+ if (!bgrt_tab.image_address) {
+ drm_info(client->dev, "splash: no BGRT found");
+ return -ENOENT;
+ }
+
+ if (bgrt_tab.status & 0x06) {
+ drm_info(client->dev, "splash: BGRT rotation bits set, skipping");
+ return -EOPNOTSUPP;
+ }
+
+ drm_dbg(client->dev, "splash: BGRT image is at 0x%016llx, size=%zX",
+ bgrt_tab.image_address, bgrt_image_size);
+
+ bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
+ MEMREMAP_WB);
+ if (!bgrt_image) {
+ drm_warn(client->dev, "splash: failed to map BGRT image memory");
+ return -ENOMEM;
+ }
+
+ drm_splash_data_source_push(splash, drm_splash_bgrt_get_data,
+ drm_splash_bgrt_release, bgrt_image);
+
+ drm_splash_wake_render_thread(splash);
+
+ return 0;
+}
+#else
+static inline int drm_splash_bgrt_load(struct drm_splash *splash)
+{
+ return -EOPNOTSUPP;
+}
+#endif // CONFIG_DRM_CLIENT_SPLASH_SRC_BGRT
+
+static int drm_splash_init_client(struct drm_splash *splash)
+{
+ struct drm_client_dev *client = &splash->client;
+ struct drm_mode_set *modeset;
+ unsigned int modeset_mask = 0;
+ unsigned int fb_count = 0;
+ int j;
+
+ if (drm_client_modeset_probe(client, 0, 0))
+ return -1;
+
+ j = 0;
+ drm_client_for_each_modeset(modeset, client) {
+ struct drm_splash_scanout *tmp;
+ struct drm_splash_scanout *scanout;
+ u32 format;
+ int id = -1;
+
+ /* Skip modesets without a mode */
+ if (!modeset->mode)
+ continue;
+
+ if (modeset->connectors[0]->has_tile) {
+ struct drm_splash_scanout *tiled;
+ int new_id = modeset->connectors[0]->tile_group->id;
+
+ /* Tiled modesets contribute to a single framebuffer,
+ * check if this tiled group has already been seen.
+ */
+ tiled = get_scanout_from_tile_group(splash, new_id);
+ if (tiled != NULL) {
+ if (!modeset->x)
+ tiled->width += modeset->mode->vdisplay;
+ if (!modeset->y)
+ tiled->height += modeset->mode->hdisplay;
+ modeset->fb = tiled->buffer->fb;
+ continue;
+ }
+
+ /* New tile group, save its ID for later */
+ id = new_id;
+ }
+
+ format = drm_splash_find_usable_format(modeset->crtc->primary,
+ splash->preferred_format);
+ if (format == DRM_FORMAT_INVALID) {
+ drm_warn(client->dev,
+ "splash: can't find a usable format for modeset");
+ continue;
+ }
+
+ tmp = krealloc(splash->scanout,
+ (splash->n_scanout + 1) * sizeof(*splash->scanout),
+ GFP_KERNEL);
+ if (!tmp) {
+ drm_warn(client->dev,
+ "splash: can't reallocate the scanout array");
+ break;
+ }
+
+ splash->scanout = tmp;
+ scanout = &splash->scanout[splash->n_scanout];
+ splash->n_scanout++;
+
+ memset(scanout, 0, sizeof(*scanout));
+ scanout->id = id;
+ scanout->format = format;
+ scanout->width = modeset->mode->hdisplay;
+ scanout->height = modeset->mode->vdisplay;
+
+ modeset_mask |= BIT(j);
+ j++;
+ }
+
+ /* Now that all sensible modesets have been collected, allocate buffers */
+ j = 0;
+ drm_client_for_each_modeset(modeset, client) {
+ struct drm_splash_scanout *scanout;
+
+ if (!(modeset_mask & BIT(j)))
+ continue;
+
+ scanout = &splash->scanout[j];
+ j++;
+
+ scanout->buffer = drm_client_buffer_create_dumb(client,
+ scanout->width,
+ scanout->height,
+ scanout->format);
+ if (IS_ERR(scanout->buffer)) {
+ drm_warn(client->dev,
+ "splash: can't create dumb buffer %d %d %p4cc",
+ scanout->width, scanout->height, &scanout->format);
+ continue;
+ }
+
+ drm_info(client->dev, "splash: created dumb buffer %d %d %p4cc",
+ scanout->width, scanout->height, &scanout->format);
+
+ modeset->fb = scanout->buffer->fb;
+ fb_count++;
+ }
+
+ return (fb_count == 0) ? -ENODEV : 0;
+}
+
+static void drm_splash_free_scanout(struct drm_client_dev *client)
+{
+ struct drm_splash *splash = client_to_drm_splash(client);
+ int i;
+
+ if (splash->n_scanout) {
+ for (i = 0; i < splash->n_scanout; i++)
+ drm_client_buffer_delete(splash->scanout[i].buffer);
+
+ splash->n_scanout = 0;
+ kfree(splash->scanout);
+ splash->scanout = NULL;
+ }
+}
+
+static int drm_splash_client_hotplug(struct drm_client_dev *client)
+{
+ struct drm_splash *splash = client_to_drm_splash(client);
+ int ret;
+
+ guard(mutex)(&splash->hotplug_lock);
+
+ /* The modesets that get a splash are defined at first hotplug event */
+ if (splash->initialized)
+ return 0;
+
+ ret = drm_splash_init_client(splash);
+ if (ret == -ENODEV) {
+ drm_info(client->dev, "splash: no modeset found");
+ return 0;
+ } else if (ret) {
+ drm_err(client->dev,
+ "splash: failed to init client: %d", ret);
+ return ret;
+ }
+
+ /* Create the render thread, waken later */
+ splash->thread = kthread_create(drm_splash_render_thread,
+ splash, "drm_splash_%s",
+ client->dev->unique);
+ if (IS_ERR(splash->thread)) {
+ ret = PTR_ERR(splash->thread);
+ drm_err(client->dev, "splash: failed to create render thread: %d", ret);
+ drm_splash_free_scanout(client);
+ return ret;
+ }
+
+ if (IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_SRC_BMP))
+ ret = drm_splash_fw_request_bmp(splash);
+ else if (IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_SRC_BGRT))
+ ret = drm_splash_bgrt_load(splash);
+ else
+ ret = 0;
+
+ if (ret) {
+ drm_err(client->dev, "splash: failed to kick image load: %d", ret);
+ kthread_stop(splash->thread);
+ drm_splash_free_scanout(client);
+ return ret;
+ }
+
+ /* Wake the render thread to show initial contents */
+ drm_splash_wake_render_thread(splash);
+
+ splash->initialized = true;
+
+ return 0;
+}
+
+static int drm_splash_client_restore(struct drm_client_dev *client, bool force)
+{
+ int ret;
+
+ if (force)
+ ret = drm_client_modeset_commit_locked(client);
+ else
+ ret = drm_client_modeset_commit(client);
+
+ return ret;
+}
+
+static void drm_splash_client_unregister(struct drm_client_dev *client)
+{
+ struct drm_splash *splash = client_to_drm_splash(client);
+
+ kthread_stop(splash->thread);
+ drm_splash_free_scanout(client);
+ drm_client_release(client);
+
+ if (splash->data_release)
+ splash->data_release(splash->data_priv);
+}
+
+static void drm_splash_client_free(struct drm_client_dev *client)
+{
+ struct drm_splash *splash = client_to_drm_splash(client);
+ struct drm_device *dev = client->dev;
+
+ mutex_destroy(&splash->hotplug_lock);
+ kfree(splash);
+
+ drm_dbg(dev, "Unregistered with drm splash");
+}
+
+static const struct drm_client_funcs drm_splash_client_funcs = {
+ .owner = THIS_MODULE,
+ .hotplug = drm_splash_client_hotplug,
+ .restore = drm_splash_client_restore,
+ .unregister = drm_splash_client_unregister,
+ .free = drm_splash_client_free,
+};
+
+/**
+ * drm_splash_register() - Register a drm device to drm_splash
+ * @dev: the drm device to register.
+ * @format: drm device preferred format.
+ */
+void drm_splash_register(struct drm_device *dev,
+ const struct drm_format_info *format)
+{
+ struct drm_splash *splash;
+
+ splash = kzalloc(sizeof(*splash), GFP_KERNEL);
+ if (!splash)
+ goto err_warn;
+
+ mutex_init(&splash->hotplug_lock);
+ spin_lock_init(&splash->data_lock);
+
+ if (format && format->num_planes == 1)
+ splash->preferred_format = format->format;
+ else
+ splash->preferred_format = DRM_FORMAT_RGB888;
+
+ if (drm_client_init(dev, &splash->client, "drm_splash",
+ &drm_splash_client_funcs))
+ goto err_free;
+
+ drm_client_register(&splash->client);
+ drm_dbg(dev, "Registered with drm splash");
+
+ return;
+
+err_free:
+ kfree(splash);
+err_warn:
+ drm_warn(dev, "Failed to register with drm splash");
+}

--
2.52.0