drivers/firmware: move x86 Generic System Framebuffers support

The x86 architecture has generic support to register a system framebuffer
platform device. It either registers a "simple-framebuffer" if the config
option CONFIG_X86_SYSFB is enabled, or a legacy VGA/VBE/EFI FB device.

But the code is generic enough to be reused by other architectures and can
be moved out of the arch/x86 directory.

This will allow to also support the simple{fb,drm} drivers on non-x86 EFI
platforms, such as aarch64 where these drivers are only supported with DT.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625130947.1803678-2-javierm@redhat.com

arch/x86/Kconfig

@@ -2806,32 +2806,6 @@ config AMD_NB
 	def_bool y
 	depends on CPU_SUP_AMD && PCI
 
-config X86_SYSFB
-	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
-	help
-	  Firmwares often provide initial graphics framebuffers so the BIOS,
-	  bootloader or kernel can show basic video-output during boot for
-	  user-guidance and debugging. Historically, x86 used the VESA BIOS
-	  Extensions and EFI-framebuffers for this, which are mostly limited
-	  to x86.
-	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
-	  framebuffers so the new generic system-framebuffer drivers can be
-	  used on x86. If the framebuffer is not compatible with the generic
-	  modes, it is advertised as fallback platform framebuffer so legacy
-	  drivers like efifb, vesafb and uvesafb can pick it up.
-	  If this option is not selected, all system framebuffers are always
-	  marked as fallback platform framebuffers as usual.
-
-	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
-	  not be able to pick up generic system framebuffers if this option
-	  is selected. You are highly encouraged to enable simplefb as
-	  replacement if you select this option. simplefb can correctly deal
-	  with generic system framebuffers. But you should still keep vesafb
-	  and others enabled as fallback if a system framebuffer is
-	  incompatible with simplefb.
-
-	  If unsure, say Y.
-
 endmenu
 
 

arch/x86/kernel/Makefile

@@ -135,9 +135,6 @@ obj-$(CONFIG_X86_CHECK_BIOS_CORRUPTION) += check.o
 obj-$(CONFIG_SWIOTLB)			+= pci-swiotlb.o
 obj-$(CONFIG_OF)			+= devicetree.o
 obj-$(CONFIG_UPROBES)			+= uprobes.o
-obj-y					+= sysfb.o
-obj-$(CONFIG_X86_SYSFB)			+= sysfb_simplefb.o
-obj-$(CONFIG_EFI)			+= sysfb_efi.o
 
 obj-$(CONFIG_PERF_EVENTS)		+= perf_regs.o
 obj-$(CONFIG_TRACING)			+= tracepoint.o

drivers/firmware/Kconfig

@@ -251,6 +251,38 @@ config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
 
 	  Say Y here to enable "download mode" by default.
 
+config SYSFB
+	bool
+	default y
+	depends on X86 || COMPILE_TEST
+
+config X86_SYSFB
+	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
+	depends on SYSFB
+	help
+	  Firmwares often provide initial graphics framebuffers so the BIOS,
+	  bootloader or kernel can show basic video-output during boot for
+	  user-guidance and debugging. Historically, x86 used the VESA BIOS
+	  Extensions and EFI-framebuffers for this, which are mostly limited
+	  to x86.
+	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
+	  framebuffers so the new generic system-framebuffer drivers can be
+	  used on x86. If the framebuffer is not compatible with the generic
+	  modes, it is advertised as fallback platform framebuffer so legacy
+	  drivers like efifb, vesafb and uvesafb can pick it up.
+	  If this option is not selected, all system framebuffers are always
+	  marked as fallback platform framebuffers as usual.
+
+	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
+	  not be able to pick up generic system framebuffers if this option
+	  is selected. You are highly encouraged to enable simplefb as
+	  replacement if you select this option. simplefb can correctly deal
+	  with generic system framebuffers. But you should still keep vesafb
+	  and others enabled as fallback if a system framebuffer is
+	  incompatible with simplefb.
+
+	  If unsure, say Y.
+
 config TI_SCI_PROTOCOL
 	tristate "TI System Control Interface (TISCI) Message Protocol"
 	depends on TI_MESSAGE_MANAGER

drivers/firmware/Makefile

@@ -18,6 +18,8 @@ obj-$(CONFIG_FIRMWARE_MEMMAP)	+= memmap.o
 obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o
 obj-$(CONFIG_FW_CFG_SYSFS)	+= qemu_fw_cfg.o
 obj-$(CONFIG_QCOM_SCM)		+= qcom_scm.o qcom_scm-smc.o qcom_scm-legacy.o
+obj-$(CONFIG_SYSFB)		+= sysfb.o
+obj-$(CONFIG_X86_SYSFB)		+= sysfb_simplefb.o
 obj-$(CONFIG_TI_SCI_PROTOCOL)	+= ti_sci.o
 obj-$(CONFIG_TRUSTED_FOUNDATIONS) += trusted_foundations.o
 obj-$(CONFIG_TURRIS_MOX_RWTM)	+= turris-mox-rwtm.o

drivers/firmware/efi/Makefile

@@ -36,6 +36,8 @@ obj-$(CONFIG_LOAD_UEFI_KEYS)		+= mokvar-table.o
 fake_map-y				+= fake_mem.o
 fake_map-$(CONFIG_X86)			+= x86_fake_mem.o
 
+obj-$(CONFIG_SYSFB)			+= sysfb_efi.o
+
 arm-obj-$(CONFIG_EFI)			:= efi-init.o arm-runtime.o
 obj-$(CONFIG_ARM)			+= $(arm-obj-y)
 obj-$(CONFIG_ARM64)			+= $(arm-obj-y)

drivers/firmware/efi/sysfb_efi.c

@@ -21,10 +21,10 @@
 #include <linux/mm.h>
 #include <linux/pci.h>
 #include <linux/screen_info.h>
+#include <linux/sysfb.h>
 #include <video/vga.h>
 
 #include <asm/efi.h>
-#include <asm/sysfb.h>
 
 enum {
 	OVERRIDE_NONE = 0x0,

drivers/firmware/sysfb.c

@@ -32,7 +32,7 @@
 #include <linux/platform_data/simplefb.h>
 #include <linux/platform_device.h>
 #include <linux/screen_info.h>
-#include <asm/sysfb.h>
+#include <linux/sysfb.h>
 
 static __init int sysfb_init(void)
 {

drivers/firmware/sysfb_simplefb.c

@@ -18,7 +18,7 @@
 #include <linux/platform_data/simplefb.h>
 #include <linux/platform_device.h>
 #include <linux/screen_info.h>
-#include <asm/sysfb.h>
+#include <linux/sysfb.h>
 
 static const char simplefb_resname[] = "BOOTFB";
 static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;

include/linux/sysfb.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
-#ifndef _ARCH_X86_KERNEL_SYSFB_H
+#ifndef _LINUX_SYSFB_H
-#define _ARCH_X86_KERNEL_SYSFB_H
+#define _LINUX_SYSFB_H
 
 /*
  * Generic System Framebuffers on x86
@@ -91,4 +91,4 @@ static inline int create_simplefb(const struct screen_info *si,
 
 #endif /* CONFIG_X86_SYSFB */
 
-#endif /* _ARCH_X86_KERNEL_SYSFB_H */
+#endif /* _LINUX_SYSFB_H */