| Message ID | 1372940714-12470-4-git-send-email-dh.herrmann@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Any comments on this? On Thu, Jul 4, 2013 at 2:25 PM, David Herrmann <dh.herrmann@gmail.com> wrote: > The current situation regarding boot-framebuffers (VGA, VESA/VBE, EFI) on > x86 causes troubles when loading multiple fbdev drivers. The global > "struct screen_info" does not provide any state-tracking about which > drivers use the FBs. request_mem_region() theoretically works, but > unfortunately vesafb/efifb ignore it due to quirks for broken boards. > > Avoid this by creating a platform framebuffer devices with a pointer > to the "struct screen_info" as platform-data. Drivers can now create > platform-drivers and the driver-core will refuse multiple drivers being > active simultaneously. > > We keep the screen_info available for backwards-compatibility. Drivers > can be converted in follow-up patches. > > Different devices are created for VGA/VESA/EFI FBs to allow multiple > drivers to be loaded on distro kernels. We create: > - "vesa-framebuffer" for VBE/VESA graphics FBs > - "efi-framebuffer" for EFI FBs > - "platform-framebuffer" for everything else > This allows to load vesafb, efifb and others simultaneously and each > picks up only the supported FB types. > > Apart from platform-framebuffer devices, this also introduces a > compatibility option for "simple-framebuffer" drivers which recently got > introduced for OF based systems. If CONFIG_X86_SYSFB is selected, we > try to match the screen_info against a simple-framebuffer supported > format. If we succeed, we create a "simple-framebuffer" device instead > of a platform-framebuffer. > This allows to reuse the simplefb.c driver across architectures and also > to introduce a SimpleDRM driver. There is no need to have vesafb.c, > efifb.c, simplefb.c and more just to have architecture specific quirks > in their setup-routines. > > Instead, we now move the architecture specific quirks into x86-setup and > provide a generic simple-framebuffer. For backwards-compatibility (if > strange formats are used), we still allow vesafb/efifb to be loaded > simultaneously and pick up all remaining devices. > > Signed-off-by: David Herrmann <dh.herrmann@gmail.com> > --- > arch/x86/Kconfig | 26 +++++++++++ > arch/x86/include/asm/sysfb.h | 41 +++++++++++++++++ > arch/x86/kernel/Makefile | 2 + > arch/x86/kernel/sysfb.c | 71 ++++++++++++++++++++++++++++++ > arch/x86/kernel/sysfb_simplefb.c | 95 ++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 235 insertions(+) > create mode 100644 arch/x86/include/asm/sysfb.h > create mode 100644 arch/x86/kernel/sysfb.c > create mode 100644 arch/x86/kernel/sysfb_simplefb.c > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index fe120da..54a93a5 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -2255,6 +2255,32 @@ config RAPIDIO > > source "drivers/rapidio/Kconfig" > > +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 adverticed 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/include/asm/sysfb.h b/arch/x86/include/asm/sysfb.h > new file mode 100644 > index 0000000..2395fe0 > --- /dev/null > +++ b/arch/x86/include/asm/sysfb.h > @@ -0,0 +1,41 @@ > +#ifndef _ARCH_X86_KERNEL_SYSFB_H > +#define _ARCH_X86_KERNEL_SYSFB_H > + > +/* > + * Generic System Framebuffers on x86 > + * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> > + * > + * 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/kernel.h> > +#include <linux/platform_data/simplefb.h> > +#include <linux/screen_info.h> > + > +#ifdef CONFIG_X86_SYSFB > + > +bool parse_mode(const struct screen_info *si, > + struct simplefb_platform_data *mode); > +int create_simplefb(const struct screen_info *si, > + const struct simplefb_platform_data *mode); > + > +#else /* CONFIG_X86_SYSFB */ > + > +static inline bool parse_mode(const struct screen_info *si, > + struct simplefb_platform_data *mode) > +{ > + return false; > +} > + > +static inline int create_simplefb(const struct screen_info *si, > + const struct simplefb_platform_data *mode) > +{ > + return -EINVAL; > +} > + > +#endif /* CONFIG_X86_SYSFB */ > + > +#endif /* _ARCH_X86_KERNEL_SYSFB_H */ > diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile > index 7bd3bd3..c5e7677 100644 > --- a/arch/x86/kernel/Makefile > +++ b/arch/x86/kernel/Makefile > @@ -100,6 +100,8 @@ 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_PERF_EVENTS) += perf_regs.o > > diff --git a/arch/x86/kernel/sysfb.c b/arch/x86/kernel/sysfb.c > new file mode 100644 > index 0000000..7f30e19 > --- /dev/null > +++ b/arch/x86/kernel/sysfb.c > @@ -0,0 +1,71 @@ > +/* > + * Generic System Framebuffers on x86 > + * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> > + * > + * 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. > + */ > + > +/* > + * Simple-Framebuffer support for x86 systems > + * Create a platform-device for any available boot framebuffer. The > + * simple-framebuffer platform device is already available on DT systems, so > + * this module parses the global "screen_info" object and creates a suitable > + * platform device compatible with the "simple-framebuffer" DT object. If > + * the framebuffer is incompatible, we instead create a legacy > + * "vesa-framebuffer", "efi-framebuffer" or "platform-framebuffer" device and > + * pass the screen_info as platform_data. This allows legacy drivers > + * to pick these devices up without messing with simple-framebuffer drivers. > + * The global "screen_info" is still valid at all times. > + * > + * If CONFIG_X86_SYSFB is not selected, we never register "simple-framebuffer" > + * platform devices, but only use legacy framebuffer devices for > + * backwards compatibility. > + * > + * TODO: We set the dev_id field of all platform-devices to 0. This allows > + * other x86 OF/DT parsers to create such devices, too. However, they must > + * start at offset 1 for this to work. > + */ > + > +#include <linux/err.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/mm.h> > +#include <linux/platform_data/simplefb.h> > +#include <linux/platform_device.h> > +#include <linux/screen_info.h> > +#include <asm/sysfb.h> > + > +static __init int sysfb_init(void) > +{ > + struct screen_info *si = &screen_info; > + struct simplefb_platform_data mode; > + struct platform_device *pd; > + const char *name; > + bool compatible; > + int ret; > + > + /* try to create a simple-framebuffer device */ > + compatible = parse_mode(si, &mode); > + if (compatible) { > + ret = create_simplefb(si, &mode); > + if (!ret) > + return 0; > + } > + > + /* if the FB is incompatible, create a legacy framebuffer device */ > + if (si->orig_video_isVGA == VIDEO_TYPE_EFI) > + name = "efi-framebuffer"; > + else if (si->orig_video_isVGA == VIDEO_TYPE_VLFB) > + name = "vesa-framebuffer"; > + else > + name = "platform-framebuffer"; > + > + pd = platform_device_register_resndata(NULL, name, 0, > + NULL, 0, si, sizeof(*si)); > + return IS_ERR(pd) ? PTR_ERR(pd) : 0; > +} > + > +device_initcall(sysfb_init); > diff --git a/arch/x86/kernel/sysfb_simplefb.c b/arch/x86/kernel/sysfb_simplefb.c > new file mode 100644 > index 0000000..22513e9 > --- /dev/null > +++ b/arch/x86/kernel/sysfb_simplefb.c > @@ -0,0 +1,95 @@ > +/* > + * Generic System Framebuffers on x86 > + * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> > + * > + * 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. > + */ > + > +/* > + * simple-framebuffer probing > + * Try to convert "screen_info" into a "simple-framebuffer" compatible mode. > + * If the mode is incompatible, we return "false" and let the caller create > + * legacy nodes instead. > + */ > + > +#include <linux/err.h> > +#include <linux/init.h> > +#include <linux/kernel.h> > +#include <linux/mm.h> > +#include <linux/platform_data/simplefb.h> > +#include <linux/platform_device.h> > +#include <linux/screen_info.h> > +#include <asm/sysfb.h> > + > +static const char simplefb_resname[] = "BOOTFB"; > +static const struct simplefb_format formats[] = SIMPLEFB_FORMATS; > + > +/* try parsing x86 screen_info into a simple-framebuffer mode struct */ > +__init bool parse_mode(const struct screen_info *si, > + struct simplefb_platform_data *mode) > +{ > + const struct simplefb_format *f; > + __u8 type; > + unsigned int i; > + > + type = si->orig_video_isVGA; > + if (type != VIDEO_TYPE_VLFB && type != VIDEO_TYPE_EFI) > + return false; > + > + for (i = 0; i < ARRAY_SIZE(formats); ++i) { > + f = &formats[i]; > + if (si->lfb_depth == f->bits_per_pixel && > + si->red_size == f->red.length && > + si->red_pos == f->red.offset && > + si->green_size == f->green.length && > + si->green_pos == f->green.offset && > + si->blue_size == f->blue.length && > + si->blue_pos == f->blue.offset && > + si->rsvd_size == f->transp.length && > + si->rsvd_pos == f->transp.offset) { > + mode->format = f->name; > + mode->width = si->lfb_width; > + mode->height = si->lfb_height; > + mode->stride = si->lfb_linelength; > + return true; > + } > + } > + > + return false; > +} > + > +__init int create_simplefb(const struct screen_info *si, > + const struct simplefb_platform_data *mode) > +{ > + struct platform_device *pd; > + struct resource res; > + unsigned long len; > + > + /* don't use lfb_size as it may contain the whole VMEM instead of only > + * the part that is occupied by the framebuffer */ > + len = mode->height * mode->stride; > + len = PAGE_ALIGN(len); > + if (len > si->lfb_size << 16) { > + printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n"); > + return -EINVAL; > + } > + > + /* setup IORESOURCE_MEM as framebuffer memory */ > + memset(&res, 0, sizeof(res)); > + res.flags = IORESOURCE_MEM; > + res.name = simplefb_resname; > + res.start = si->lfb_base; > + res.end = si->lfb_base + len - 1; > + if (res.end <= res.start) > + return -EINVAL; > + > + pd = platform_device_register_resndata(NULL, "simple-framebuffer", 0, > + &res, 1, mode, sizeof(*mode)); > + if (IS_ERR(pd)) > + return PTR_ERR(pd); > + > + return 0; > +} > -- > 1.8.3.2 >
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index fe120da..54a93a5 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2255,6 +2255,32 @@ config RAPIDIO source "drivers/rapidio/Kconfig" +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 adverticed 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/include/asm/sysfb.h b/arch/x86/include/asm/sysfb.h new file mode 100644 index 0000000..2395fe0 --- /dev/null +++ b/arch/x86/include/asm/sysfb.h @@ -0,0 +1,41 @@ +#ifndef _ARCH_X86_KERNEL_SYSFB_H +#define _ARCH_X86_KERNEL_SYSFB_H + +/* + * Generic System Framebuffers on x86 + * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> + * + * 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/kernel.h> +#include <linux/platform_data/simplefb.h> +#include <linux/screen_info.h> + +#ifdef CONFIG_X86_SYSFB + +bool parse_mode(const struct screen_info *si, + struct simplefb_platform_data *mode); +int create_simplefb(const struct screen_info *si, + const struct simplefb_platform_data *mode); + +#else /* CONFIG_X86_SYSFB */ + +static inline bool parse_mode(const struct screen_info *si, + struct simplefb_platform_data *mode) +{ + return false; +} + +static inline int create_simplefb(const struct screen_info *si, + const struct simplefb_platform_data *mode) +{ + return -EINVAL; +} + +#endif /* CONFIG_X86_SYSFB */ + +#endif /* _ARCH_X86_KERNEL_SYSFB_H */ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 7bd3bd3..c5e7677 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -100,6 +100,8 @@ 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_PERF_EVENTS) += perf_regs.o diff --git a/arch/x86/kernel/sysfb.c b/arch/x86/kernel/sysfb.c new file mode 100644 index 0000000..7f30e19 --- /dev/null +++ b/arch/x86/kernel/sysfb.c @@ -0,0 +1,71 @@ +/* + * Generic System Framebuffers on x86 + * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> + * + * 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. + */ + +/* + * Simple-Framebuffer support for x86 systems + * Create a platform-device for any available boot framebuffer. The + * simple-framebuffer platform device is already available on DT systems, so + * this module parses the global "screen_info" object and creates a suitable + * platform device compatible with the "simple-framebuffer" DT object. If + * the framebuffer is incompatible, we instead create a legacy + * "vesa-framebuffer", "efi-framebuffer" or "platform-framebuffer" device and + * pass the screen_info as platform_data. This allows legacy drivers + * to pick these devices up without messing with simple-framebuffer drivers. + * The global "screen_info" is still valid at all times. + * + * If CONFIG_X86_SYSFB is not selected, we never register "simple-framebuffer" + * platform devices, but only use legacy framebuffer devices for + * backwards compatibility. + * + * TODO: We set the dev_id field of all platform-devices to 0. This allows + * other x86 OF/DT parsers to create such devices, too. However, they must + * start at offset 1 for this to work. + */ + +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/platform_data/simplefb.h> +#include <linux/platform_device.h> +#include <linux/screen_info.h> +#include <asm/sysfb.h> + +static __init int sysfb_init(void) +{ + struct screen_info *si = &screen_info; + struct simplefb_platform_data mode; + struct platform_device *pd; + const char *name; + bool compatible; + int ret; + + /* try to create a simple-framebuffer device */ + compatible = parse_mode(si, &mode); + if (compatible) { + ret = create_simplefb(si, &mode); + if (!ret) + return 0; + } + + /* if the FB is incompatible, create a legacy framebuffer device */ + if (si->orig_video_isVGA == VIDEO_TYPE_EFI) + name = "efi-framebuffer"; + else if (si->orig_video_isVGA == VIDEO_TYPE_VLFB) + name = "vesa-framebuffer"; + else + name = "platform-framebuffer"; + + pd = platform_device_register_resndata(NULL, name, 0, + NULL, 0, si, sizeof(*si)); + return IS_ERR(pd) ? PTR_ERR(pd) : 0; +} + +device_initcall(sysfb_init); diff --git a/arch/x86/kernel/sysfb_simplefb.c b/arch/x86/kernel/sysfb_simplefb.c new file mode 100644 index 0000000..22513e9 --- /dev/null +++ b/arch/x86/kernel/sysfb_simplefb.c @@ -0,0 +1,95 @@ +/* + * Generic System Framebuffers on x86 + * Copyright (c) 2012-2013 David Herrmann <dh.herrmann@gmail.com> + * + * 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. + */ + +/* + * simple-framebuffer probing + * Try to convert "screen_info" into a "simple-framebuffer" compatible mode. + * If the mode is incompatible, we return "false" and let the caller create + * legacy nodes instead. + */ + +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/platform_data/simplefb.h> +#include <linux/platform_device.h> +#include <linux/screen_info.h> +#include <asm/sysfb.h> + +static const char simplefb_resname[] = "BOOTFB"; +static const struct simplefb_format formats[] = SIMPLEFB_FORMATS; + +/* try parsing x86 screen_info into a simple-framebuffer mode struct */ +__init bool parse_mode(const struct screen_info *si, + struct simplefb_platform_data *mode) +{ + const struct simplefb_format *f; + __u8 type; + unsigned int i; + + type = si->orig_video_isVGA; + if (type != VIDEO_TYPE_VLFB && type != VIDEO_TYPE_EFI) + return false; + + for (i = 0; i < ARRAY_SIZE(formats); ++i) { + f = &formats[i]; + if (si->lfb_depth == f->bits_per_pixel && + si->red_size == f->red.length && + si->red_pos == f->red.offset && + si->green_size == f->green.length && + si->green_pos == f->green.offset && + si->blue_size == f->blue.length && + si->blue_pos == f->blue.offset && + si->rsvd_size == f->transp.length && + si->rsvd_pos == f->transp.offset) { + mode->format = f->name; + mode->width = si->lfb_width; + mode->height = si->lfb_height; + mode->stride = si->lfb_linelength; + return true; + } + } + + return false; +} + +__init int create_simplefb(const struct screen_info *si, + const struct simplefb_platform_data *mode) +{ + struct platform_device *pd; + struct resource res; + unsigned long len; + + /* don't use lfb_size as it may contain the whole VMEM instead of only + * the part that is occupied by the framebuffer */ + len = mode->height * mode->stride; + len = PAGE_ALIGN(len); + if (len > si->lfb_size << 16) { + printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n"); + return -EINVAL; + } + + /* setup IORESOURCE_MEM as framebuffer memory */ + memset(&res, 0, sizeof(res)); + res.flags = IORESOURCE_MEM; + res.name = simplefb_resname; + res.start = si->lfb_base; + res.end = si->lfb_base + len - 1; + if (res.end <= res.start) + return -EINVAL; + + pd = platform_device_register_resndata(NULL, "simple-framebuffer", 0, + &res, 1, mode, sizeof(*mode)); + if (IS_ERR(pd)) + return PTR_ERR(pd); + + return 0; +}
The current situation regarding boot-framebuffers (VGA, VESA/VBE, EFI) on x86 causes troubles when loading multiple fbdev drivers. The global "struct screen_info" does not provide any state-tracking about which drivers use the FBs. request_mem_region() theoretically works, but unfortunately vesafb/efifb ignore it due to quirks for broken boards. Avoid this by creating a platform framebuffer devices with a pointer to the "struct screen_info" as platform-data. Drivers can now create platform-drivers and the driver-core will refuse multiple drivers being active simultaneously. We keep the screen_info available for backwards-compatibility. Drivers can be converted in follow-up patches. Different devices are created for VGA/VESA/EFI FBs to allow multiple drivers to be loaded on distro kernels. We create: - "vesa-framebuffer" for VBE/VESA graphics FBs - "efi-framebuffer" for EFI FBs - "platform-framebuffer" for everything else This allows to load vesafb, efifb and others simultaneously and each picks up only the supported FB types. Apart from platform-framebuffer devices, this also introduces a compatibility option for "simple-framebuffer" drivers which recently got introduced for OF based systems. If CONFIG_X86_SYSFB is selected, we try to match the screen_info against a simple-framebuffer supported format. If we succeed, we create a "simple-framebuffer" device instead of a platform-framebuffer. This allows to reuse the simplefb.c driver across architectures and also to introduce a SimpleDRM driver. There is no need to have vesafb.c, efifb.c, simplefb.c and more just to have architecture specific quirks in their setup-routines. Instead, we now move the architecture specific quirks into x86-setup and provide a generic simple-framebuffer. For backwards-compatibility (if strange formats are used), we still allow vesafb/efifb to be loaded simultaneously and pick up all remaining devices. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> --- arch/x86/Kconfig | 26 +++++++++++ arch/x86/include/asm/sysfb.h | 41 +++++++++++++++++ arch/x86/kernel/Makefile | 2 + arch/x86/kernel/sysfb.c | 71 ++++++++++++++++++++++++++++++ arch/x86/kernel/sysfb_simplefb.c | 95 ++++++++++++++++++++++++++++++++++++++++ 5 files changed, 235 insertions(+) create mode 100644 arch/x86/include/asm/sysfb.h create mode 100644 arch/x86/kernel/sysfb.c create mode 100644 arch/x86/kernel/sysfb_simplefb.c