[PATCH v3 1/2] drivers/firmware: move x86 Generic System Framebuffers support

Javier Martinez Canillas
2021-06-25T13:10:13Z

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>
---

Changes in v3:
- Add Borislav and Greg Acked-by tags.

Changes in v2:
- Use default y and depends on X86 instead doing a select in arch/x86/Kconfig.
- Also enable the SYSFB Kconfig option when COMPILE_TEST.
- Improve commit message to explain why is useful for other arches to use this.

arch/x86/Kconfig | 26 ---------------
arch/x86/kernel/Makefile | 3 --
drivers/firmware/Kconfig | 32 +++++++++++++++++++
drivers/firmware/Makefile | 2 ++
drivers/firmware/efi/Makefile | 2 ++
.../firmware/efi}/sysfb_efi.c | 2 +-
{arch/x86/kernel => drivers/firmware}/sysfb.c | 2 +-
.../firmware}/sysfb_simplefb.c | 2 +-
.../x86/include/asm => include/linux}/sysfb.h | 6 ++--
9 files changed, 42 insertions(+), 35 deletions(-)
rename {arch/x86/kernel => drivers/firmware/efi}/sysfb_efi.c (99%)
rename {arch/x86/kernel => drivers/firmware}/sysfb.c (98%)
rename {arch/x86/kernel => drivers/firmware}/sysfb_simplefb.c (99%)
rename {arch/x86/include/asm => include/linux}/sysfb.h (95%)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0ae3eccfec52..f169a30db768 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2766,32 +2766,6 @@ 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

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 0f66682ac02a..4114ea47def2 100644
--- a/arch/x86/kernel/Makefile
+++ b/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
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 1db738d5b301..5991071e9d7f 100644
--- a/drivers/firmware/Kconfig
+++ b/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
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 546ac8e7f6d0..946dda07443d 100644
--- a/drivers/firmware/Makefile
+++ b/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-$(CONFIG_TURRIS_MOX_RWTM) += turris-mox-rwtm.o
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 467e94259679..c02ff25dd477 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -36,6 +36,8 @@ obj-$(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)
diff --git a/arch/x86/kernel/sysfb_efi.c b/drivers/firmware/efi/sysfb_efi.c
similarity index 99%
rename from arch/x86/kernel/sysfb_efi.c
rename to drivers/firmware/efi/sysfb_efi.c
index 8a56a6d80098..9f035b15501c 100644
--- a/arch/x86/kernel/sysfb_efi.c
+++ b/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,
diff --git a/arch/x86/kernel/sysfb.c b/drivers/firmware/sysfb.c
similarity index 98%
rename from arch/x86/kernel/sysfb.c
rename to drivers/firmware/sysfb.c
index 014ebd8ca869..1337515963d5 100644
--- a/arch/x86/kernel/sysfb.c
+++ b/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)
{
diff --git a/arch/x86/kernel/sysfb_simplefb.c b/drivers/firmware/sysfb_simplefb.c
similarity index 99%
rename from arch/x86/kernel/sysfb_simplefb.c
rename to drivers/firmware/sysfb_simplefb.c
index 298fc1edd9c9..df892444ea17 100644
--- a/arch/x86/kernel/sysfb_simplefb.c
+++ b/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;
diff --git a/arch/x86/include/asm/sysfb.h b/include/linux/sysfb.h
similarity index 95%
rename from arch/x86/include/asm/sysfb.h
rename to include/linux/sysfb.h
index 9834eef7f034..3e5355769dc3 100644
--- a/arch/x86/include/asm/sysfb.h
+++ b/include/linux/sysfb.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
-#ifndef _ARCH_X86_KERNEL_SYSFB_H
-#define _ARCH_X86_KERNEL_SYSFB_H
+#ifndef _LINUX_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 */
--
2.31.1