0001-bootsplash.patch

diff --git a/MAINTAINERS b/MAINTAINERS
index a74227ad082e..b5633b56391e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2705,6 +2705,14 @@ S:	Supported
 F:	drivers/net/bonding/
 F:	include/uapi/linux/if_bonding.h
 
+BOOTSPLASH
+M:	Max Staudt <[email protected]>
+L:	[email protected]
+S:	Maintained
+F:	drivers/video/fbdev/core/bootsplash*.*
+F:	drivers/video/fbdev/core/dummycon.c
+F:	include/linux/bootsplash.h
+
 BPF (Safe dynamic programs and tools)
 M:	Alexei Starovoitov <[email protected]>
 M:	Daniel Borkmann <[email protected]>
diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index 7f1f1fbcef9e..f3ff976266fe 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -151,6 +151,30 @@ config FRAMEBUFFER_CONSOLE_ROTATION
          such that other users of the framebuffer will remain normally
          oriented.
 
+config BOOTSPLASH
+	bool "Bootup splash screen"
+	depends on FRAMEBUFFER_CONSOLE
+	---help---
+	  This option enables the Linux bootsplash screen.
+
+	  The bootsplash is a full-screen logo or animation indicating a
+	  booting system. It replaces the classic scrolling text with a
+	  graphical alternative, similar to other systems.
+
+	  Since this is technically implemented as a hook on top of fbcon,
+	  it can only work if the FRAMEBUFFER_CONSOLE is enabled and a
+	  framebuffer driver is active. Thus, to get a text-free boot,
+	  the system needs to boot with vesafb, efifb, or similar.
+
+	  Once built into the kernel, the bootsplash needs to be enabled
+	  with bootsplash.enabled=1 and a splash file needs to be supplied.
+
+	  Further documentation can be found in:
+	    Documentation/fb/bootsplash.txt
+
+	  If unsure, say N.
+	  This is typically used by distributors and system integrators.
+
 config STI_CONSOLE
         bool "STI text console"
         depends on PARISC
diff --git a/drivers/video/fbdev/core/Makefile b/drivers/video/fbdev/core/Makefile
index 73493bbd7a15..66895321928e 100644
--- a/drivers/video/fbdev/core/Makefile
+++ b/drivers/video/fbdev/core/Makefile
@@ -29,3 +29,6 @@ obj-$(CONFIG_FB_SYS_IMAGEBLIT) += sysimgblt.o
 obj-$(CONFIG_FB_SYS_FOPS)      += fb_sys_fops.o
 obj-$(CONFIG_FB_SVGALIB)       += svgalib.o
 obj-$(CONFIG_FB_DDC)           += fb_ddc.o
+
+obj-$(CONFIG_BOOTSPLASH)       += bootsplash.o bootsplash_render.o \
+                                  dummyblit.o
diff --git a/drivers/video/fbdev/core/bootsplash.c b/drivers/video/fbdev/core/bootsplash.c
new file mode 100644
index 000000000000..e449755af268
--- /dev/null
+++ b/drivers/video/fbdev/core/bootsplash.c
@@ -0,0 +1,294 @@
+/*
+ * Kernel based bootsplash.
+ *
+ * (Main file: Glue code, workers, timer, PM, kernel and userland API)
+ *
+ * Authors:
+ * Max Staudt <[email protected]>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#define pr_fmt(fmt) "bootsplash: " fmt
+
+
+#include <linux/atomic.h>
+#include <linux/bootsplash.h>
+#include <linux/console.h>
+#include <linux/device.h> /* dev_warn() */
+#include <linux/fb.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/selection.h> /* console_blanked */
+#include <linux/stringify.h>
+#include <linux/types.h>
+#include <linux/vmalloc.h>
+#include <linux/vt_kern.h>
+#include <linux/workqueue.h>
+
+#include "bootsplash_internal.h"
+
+
+/*
+ * We only have one splash screen, so let's keep a single
+ * instance of the internal state.
+ */
+static struct splash_priv splash_state;
+
+
+static void splash_callback_redraw_vc(struct work_struct *ignored)
+{
+	if (console_blanked)
+		return;
+
+	console_lock();
+	if (vc_cons[fg_console].d)
+		update_screen(vc_cons[fg_console].d);
+	console_unlock();
+}
+
+
+static bool is_fb_compatible(const struct fb_info *info)
+{
+	if (!(info->flags & FBINFO_BE_MATH)
+	    != !fb_be_math((struct fb_info *)info)) {
+		dev_warn(info->device,
+			 "Can't draw on foreign endianness framebuffer.\n");
+
+		return false;
+	}
+
+	if (info->flags & FBINFO_MISC_TILEBLITTING) {
+		dev_warn(info->device,
+			 "Can't draw splash on tiling framebuffer.\n");
+
+		return false;
+	}
+
+	if (info->fix.type != FB_TYPE_PACKED_PIXELS
+	    || (info->fix.visual != FB_VISUAL_TRUECOLOR
+		&& info->fix.visual != FB_VISUAL_DIRECTCOLOR)) {
+		dev_warn(info->device,
+			 "Can't draw splash on non-packed or non-truecolor framebuffer.\n");
+
+		dev_warn(info->device,
+			 "  type: %u   visual: %u\n",
+			 info->fix.type, info->fix.visual);
+
+		return false;
+	}
+
+	if (info->var.bits_per_pixel != 16
+	    && info->var.bits_per_pixel != 24
+	    && info->var.bits_per_pixel != 32) {
+		dev_warn(info->device,
+			 "We only support drawing on framebuffers with 16, 24, or 32 bpp, not %d.\n",
+			 info->var.bits_per_pixel);
+
+		return false;
+	}
+
+	return true;
+}
+
+
+/*
+ * Called by fbcon_switch() when an instance is activated or refreshed.
+ */
+void bootsplash_render_full(struct fb_info *info)
+{
+	if (!is_fb_compatible(info))
+		return;
+
+	bootsplash_do_render_background(info);
+}
+
+
+/*
+ * External status enquiry and on/off switch
+ */
+bool bootsplash_would_render_now(void)
+{
+	return !oops_in_progress
+		&& !console_blanked
+		&& bootsplash_is_enabled();
+}
+
+bool bootsplash_is_enabled(void)
+{
+	bool was_enabled;
+
+	/* Make sure we have the newest state */
+	smp_rmb();
+
+	was_enabled = test_bit(0, &splash_state.enabled);
+
+	return was_enabled;
+}
+
+void bootsplash_disable(void)
+{
+	int was_enabled;
+
+	was_enabled = test_and_clear_bit(0, &splash_state.enabled);
+
+	if (was_enabled) {
+		if (oops_in_progress) {
+			/* Redraw screen now so we can see a panic */
+			if (vc_cons[fg_console].d)
+				update_screen(vc_cons[fg_console].d);
+		} else {
+			/* No urgency, redraw at next opportunity */
+			schedule_work(&splash_state.work_redraw_vc);
+		}
+	}
+}
+
+void bootsplash_enable(void)
+{
+	bool was_enabled;
+
+	if (oops_in_progress)
+		return;
+
+	was_enabled = test_and_set_bit(0, &splash_state.enabled);
+
+	if (!was_enabled)
+		schedule_work(&splash_state.work_redraw_vc);
+}
+
+
+/*
+ * Userland API via platform device in sysfs
+ */
+static ssize_t splash_show_enabled(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", bootsplash_is_enabled());
+}
+
+static ssize_t splash_store_enabled(struct device *device,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	bool enable;
+	int err;
+
+	if (!buf || !count)
+		return -EFAULT;
+
+	err = kstrtobool(buf, &enable);
+	if (err)
+		return err;
+
+	if (enable)
+		bootsplash_enable();
+	else
+		bootsplash_disable();
+
+	return count;
+}
+
+static DEVICE_ATTR(enabled, 0644, splash_show_enabled, splash_store_enabled);
+
+
+static struct attribute *splash_dev_attrs[] = {
+	&dev_attr_enabled.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(splash_dev);
+
+
+
+
+/*
+ * Power management fixup via platform device
+ *
+ * When the system is woken from sleep or restored after hibernating, we
+ * cannot expect the screen contents to still be present in video RAM.
+ * Thus, we have to redraw the splash if we're currently active.
+ */
+static int splash_resume(struct device *device)
+{
+	if (bootsplash_would_render_now())
+		schedule_work(&splash_state.work_redraw_vc);
+
+	return 0;
+}
+
+static int splash_suspend(struct device *device)
+{
+	cancel_work_sync(&splash_state.work_redraw_vc);
+
+	return 0;
+}
+
+
+static const struct dev_pm_ops splash_pm_ops = {
+	.thaw = splash_resume,
+	.restore = splash_resume,
+	.resume = splash_resume,
+	.suspend = splash_suspend,
+	.freeze = splash_suspend,
+};
+
+static struct platform_driver splash_driver = {
+	.driver = {
+		.name = "bootsplash",
+		.pm = &splash_pm_ops,
+	},
+};
+
+
+/*
+ * Main init
+ */
+void bootsplash_init(void)
+{
+	int ret;
+
+	/* Initialized already? */
+	if (splash_state.splash_device)
+		return;
+
+
+	/* Register platform device to export user API */
+	ret = platform_driver_register(&splash_driver);
+	if (ret) {
+		pr_err("platform_driver_register() failed: %d\n", ret);
+		goto err;
+	}
+
+	splash_state.splash_device
+		= platform_device_alloc("bootsplash", 0);
+
+	if (!splash_state.splash_device)
+		goto err_driver;
+
+	splash_state.splash_device->dev.groups = splash_dev_groups;
+
+	ret = platform_device_add(splash_state.splash_device);
+	if (ret) {
+		pr_err("platform_device_add() failed: %d\n", ret);
+		goto err_device;
+	}
+
+
+	INIT_WORK(&splash_state.work_redraw_vc, splash_callback_redraw_vc);
+
+	return;
+
+err_device:
+	platform_device_put(splash_state.splash_device);
+	splash_state.splash_device = NULL;
+err_driver:
+	platform_driver_unregister(&splash_driver);
+err:
+	pr_err("Failed to initialize.\n");
+}
diff --git a/drivers/video/fbdev/core/bootsplash_internal.h b/drivers/video/fbdev/core/bootsplash_internal.h
new file mode 100644
index 000000000000..b11da5cb90bf
--- /dev/null
+++ b/drivers/video/fbdev/core/bootsplash_internal.h
@@ -0,0 +1,55 @@
+/*
+ * Kernel based bootsplash.
+ *
+ * (Internal data structures used at runtime)
+ *
+ * Authors:
+ * Max Staudt <[email protected]>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __BOOTSPLASH_INTERNAL_H
+#define __BOOTSPLASH_INTERNAL_H
+
+
+#include <linux/types.h>
+#include <linux/fb.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+
+
+/*
+ * Runtime types
+ */
+struct splash_priv {
+	/*
+	 * Enabled/disabled state, to be used with atomic bit operations.
+	 *   Bit 0: 0 = Splash hidden
+	 *          1 = Splash shown
+	 *
+	 * Note: fbcon.c uses this twice, by calling
+	 *       bootsplash_would_render_now() in set_blitting_type() and
+	 *       in fbcon_switch().
+	 *       This is racy, but eventually consistent: Turning the
+	 *       splash on/off will cause a redraw, which calls
+	 *       fbcon_switch(), which calls set_blitting_type().
+	 *       So the last on/off toggle will make things consistent.
+	 */
+	unsigned long enabled;
+
+	/* Our gateway to userland via sysfs */
+	struct platform_device *splash_device;
+
+	struct work_struct work_redraw_vc;
+};
+
+
+
+/*
+ * Rendering functions
+ */
+void bootsplash_do_render_background(struct fb_info *info);
+
+#endif
diff --git a/drivers/video/fbdev/core/bootsplash_render.c b/drivers/video/fbdev/core/bootsplash_render.c
new file mode 100644
index 000000000000..4d7e0117f653
--- /dev/null
+++ b/drivers/video/fbdev/core/bootsplash_render.c
@@ -0,0 +1,93 @@
+/*
+ * Kernel based bootsplash.
+ *
+ * (Rendering functions)
+ *
+ * Authors:
+ * Max Staudt <[email protected]>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#define pr_fmt(fmt) "bootsplash: " fmt
+
+
+#include <linux/bootsplash.h>
+#include <linux/fb.h>
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+
+#include "bootsplash_internal.h"
+
+
+
+
+/*
+ * Rendering: Internal drawing routines
+ */
+
+
+/*
+ * Pack pixel into target format and do Big/Little Endian handling.
+ * This would be a good place to handle endianness conversion if necessary.
+ */
+static inline u32 pack_pixel(const struct fb_var_screeninfo *dst_var,
+			     u8 red, u8 green, u8 blue)
+{
+	u32 dstpix;
+
+	/* Quantize pixel */
+	red = red >> (8 - dst_var->red.length);
+	green = green >> (8 - dst_var->green.length);
+	blue = blue >> (8 - dst_var->blue.length);
+
+	/* Pack pixel */
+	dstpix = red << (dst_var->red.offset)
+		| green << (dst_var->green.offset)
+		| blue << (dst_var->blue.offset);
+
+	/*
+	 * Move packed pixel to the beginning of the memory cell,
+	 * so we can memcpy() it out easily
+	 */
+#ifdef __BIG_ENDIAN
+	switch (dst_var->bits_per_pixel) {
+	case 16:
+		dstpix <<= 16;
+		break;
+	case 24:
+		dstpix <<= 8;
+		break;
+	case 32:
+		break;
+	}
+#else
+	/* This is intrinsically unnecessary on Little Endian */
+#endif
+
+	return dstpix;
+}
+
+
+void bootsplash_do_render_background(struct fb_info *info)
+{
+	unsigned int x, y;
+	u32 dstpix;
+	u32 dst_octpp = info->var.bits_per_pixel / 8;
+
+	dstpix = pack_pixel(&info->var,
+			    0,
+			    0,
+			    0);
+
+	for (y = 0; y < info->var.yres_virtual; y++) {
+		u8 *dstline = info->screen_buffer + (y * info->fix.line_length);
+
+		for (x = 0; x < info->var.xres_virtual; x++) {
+			memcpy(dstline, &dstpix, dst_octpp);
+
+			dstline += dst_octpp;
+		}
+	}
+}
diff --git a/drivers/video/fbdev/core/dummyblit.c b/drivers/video/fbdev/core/dummyblit.c
new file mode 100644
index 000000000000..8c22ff92ce24
--- /dev/null
+++ b/drivers/video/fbdev/core/dummyblit.c
@@ -0,0 +1,89 @@
+/*
+ *  linux/drivers/video/fbdev/core/dummyblit.c -- Dummy Blitting Operation
+ *
+ *  Authors:
+ *  Max Staudt <[email protected]>
+ *
+ *  These functions are used in place of blitblit/tileblit to suppress
+ *  fbcon's text output while a splash is shown.
+ *
+ *  Only suppressing actual rendering keeps the text buffer in the VC layer
+ *  intact and makes it easy to switch back from the bootsplash to a full
+ *  text console with a simple redraw (with the original functions in place).
+ *
+ *  Based on linux/drivers/video/fbdev/core/bitblit.c
+ *       and linux/drivers/video/fbdev/core/tileblit.c
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/module.h>
+#include <linux/fb.h>
+#include <linux/vt_kern.h>
+#include <linux/console.h>
+#include <asm/types.h>
+#include "fbcon.h"
+
+static void dummy_bmove(struct vc_data *vc, struct fb_info *info, int sy,
+			int sx, int dy, int dx, int height, int width)
+{
+	;
+}
+
+static void dummy_clear(struct vc_data *vc, struct fb_info *info, int sy,
+			int sx, int height, int width)
+{
+	;
+}
+
+static void dummy_putcs(struct vc_data *vc, struct fb_info *info,
+			const unsigned short *s, int count, int yy, int xx,
+			int fg, int bg)
+{
+	;
+}
+
+static void dummy_clear_margins(struct vc_data *vc, struct fb_info *info,
+				int color, int bottom_only)
+{
+	;
+}
+
+static void dummy_cursor(struct vc_data *vc, struct fb_info *info, int mode,
+			int softback_lines, int fg, int bg)
+{
+	;
+}
+
+static int dummy_update_start(struct fb_info *info)
+{
+	/*
+	 * Copied from bitblit.c and tileblit.c
+	 *
+	 * As of Linux 4.12, nobody seems to care about our return value.
+	 */
+	struct fbcon_ops *ops = info->fbcon_par;
+	int err;
+
+	err = fb_pan_display(info, &ops->var);
+	ops->var.xoffset = info->var.xoffset;
+	ops->var.yoffset = info->var.yoffset;
+	ops->var.vmode = info->var.vmode;
+	return err;
+}
+
+void fbcon_set_dummyops(struct fbcon_ops *ops)
+{
+	ops->bmove = dummy_bmove;
+	ops->clear = dummy_clear;
+	ops->putcs = dummy_putcs;
+	ops->clear_margins = dummy_clear_margins;
+	ops->cursor = dummy_cursor;
+	ops->update_start = dummy_update_start;
+	ops->rotate_font = NULL;
+}
+EXPORT_SYMBOL_GPL(fbcon_set_dummyops);
+
+MODULE_AUTHOR("Max Staudt <[email protected]>");
+MODULE_DESCRIPTION("Dummy Blitting Operation");
+MODULE_LICENSE("GPL");
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 04612f938bab..9a39a6fcfe98 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -80,6 +80,7 @@
 #include <asm/irq.h>
 
 #include "fbcon.h"
+#include <linux/bootsplash.h>
 
 #ifdef FBCONDEBUG
 #  define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __func__ , ## args)
@@ -542,6 +543,8 @@ static int do_fbcon_takeover(int show_logo)
 	for (i = first_fb_vc; i <= last_fb_vc; i++)
 		con2fb_map[i] = info_idx;
 
+	bootsplash_init();
+
 	err = do_take_over_console(&fb_con, first_fb_vc, last_fb_vc,
 				fbcon_is_default);
 
@@ -661,6 +664,9 @@ static void set_blitting_type(struct vc_data *vc, struct fb_info *info)
 	else {
 		fbcon_set_rotation(info);
 		fbcon_set_bitops(ops);
+
+		if (bootsplash_would_render_now())
+			fbcon_set_dummyops(ops);
 	}
 }
 
@@ -683,6 +689,19 @@ static void set_blitting_type(struct vc_data *vc, struct fb_info *info)
 	ops->p = &fb_display[vc->vc_num];
 	fbcon_set_rotation(info);
 	fbcon_set_bitops(ops);
+
+	/*
+	 * Note:
+	 * This is *eventually correct*.
+	 * Setting the fbcon operations and drawing the splash happen at
+	 * different points in time. If the splash is enabled/disabled
+	 * in between, then bootsplash_{en,dis}able will schedule a
+	 * redraw, which will again render the splash (or not) and set
+	 * the correct fbcon ops.
+	 * The last run will then be the right one.
+	 */
+	if (bootsplash_would_render_now())
+		fbcon_set_dummyops(ops);
 }
 
 static int fbcon_invalid_charcount(struct fb_info *info, unsigned charcount)
@@ -2184,6 +2203,9 @@ static int fbcon_switch(struct vc_data *vc)
 	info = registered_fb[con2fb_map[vc->vc_num]];
 	ops = info->fbcon_par;
 
+	if (bootsplash_would_render_now())
+		bootsplash_render_full(info);
+
 	if (softback_top) {
 		if (softback_lines)
 			fbcon_set_origin(vc);
diff --git a/drivers/video/fbdev/core/fbcon.h b/drivers/video/fbdev/core/fbcon.h
index 18f3ac144237..45f94347fe5e 100644
--- a/drivers/video/fbdev/core/fbcon.h
+++ b/drivers/video/fbdev/core/fbcon.h
@@ -214,6 +214,11 @@ static inline int attr_col_ec(int shift, struct vc_data *vc,
 #define SCROLL_REDRAW	   0x004
 #define SCROLL_PAN_REDRAW  0x005
 
+#ifdef CONFIG_BOOTSPLASH
+extern void fbcon_set_dummyops(struct fbcon_ops *ops);
+#else /* CONFIG_BOOTSPLASH */
+#define fbcon_set_dummyops(x)
+#endif /* CONFIG_BOOTSPLASH */
 #ifdef CONFIG_FB_TILEBLITTING
 extern void fbcon_set_tileops(struct vc_data *vc, struct fb_info *info);
 #endif
diff --git a/include/linux/bootsplash.h b/include/linux/bootsplash.h
new file mode 100644
index 000000000000..c6dd0b43180d
--- /dev/null
+++ b/include/linux/bootsplash.h
@@ -0,0 +1,43 @@
+/*
+ * Kernel based bootsplash.
+ *
+ * Authors:
+ * Max Staudt <[email protected]>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __LINUX_BOOTSPLASH_H
+#define __LINUX_BOOTSPLASH_H
+
+#include <linux/fb.h>
+
+
+#ifdef CONFIG_BOOTSPLASH
+
+extern void bootsplash_render_full(struct fb_info *info);
+
+extern bool bootsplash_would_render_now(void);
+
+extern bool bootsplash_is_enabled(void);
+extern void bootsplash_disable(void);
+extern void bootsplash_enable(void);
+
+extern void bootsplash_init(void);
+
+#else /* CONFIG_BOOTSPLASH */
+
+#define bootsplash_render_full(x)
+
+#define bootsplash_would_render_now() (false)
+
+#define bootsplash_is_enabled() (false)
+#define bootsplash_disable()
+#define bootsplash_enable()
+
+#define bootsplash_init()
+
+#endif /* CONFIG_BOOTSPLASH */
+
+
+#endif