Re: [PATCH v2 2/3] arch: Remove struct fb_info from video helpers

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

Hi

Am 28.03.24 um 12:04 schrieb Helge Deller:
> On 3/27/24 21:41, Thomas Zimmermann wrote:
> > The per-architecture video helpers do not depend on struct fb_info
> > or anything else from fbdev. Remove it from the interface and replace
> > fb_is_primary_device() with video_is_primary_device(). The new helper
>
> Since you rename this function, wouldn't something similar to
>
> device_is_primary_display()
>     or
> device_is_primary_console()
>     or
> is_primary_graphics_device()
>     or
> is_primary_display_device()
>
> be a better name?

The video_ prefix is there to signal that the code is part of the video 
subsystem.

But there's too much code that tried to figure out a default video 
device. So I actually have different plans for this function. I'd like 
to replace it with a helper that returns the default device instead of 
just testing for it. Sample code for x86 is already in vgaarb.c. [1] The 
function's name would then be video_default_device() and return the 
appropriate struct device*. video_is_primary device() will be removed. 
This rename here is the easiest step towards the new helper. Ok?

Best regards
Thomas

[1] https://elixir.bootlin.com/linux/v6.8/source/drivers/pci/vgaarb.c#L559

> Helge
>
> > is similar in functionality, but can operate on non-fbdev devices.
> >
> > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> > Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> > Cc: Helge Deller <deller@xxxxxx>
> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> > Cc: Andreas Larsson <andreas@xxxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: Borislav Petkov <bp@xxxxxxxxx>
> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> > Cc: x86@xxxxxxxxxx
> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> > ---
> >   arch/parisc/include/asm/fb.h     |  8 +++++---
> >   arch/parisc/video/fbdev.c        |  9 +++++----
> >   arch/sparc/include/asm/fb.h      |  7 ++++---
> >   arch/sparc/video/fbdev.c         | 17 ++++++++---------
> >   arch/x86/include/asm/fb.h        |  8 +++++---
> >   arch/x86/video/fbdev.c           | 18 +++++++-----------
> >   drivers/video/fbdev/core/fbcon.c |  2 +-
> >   include/asm-generic/fb.h         | 11 ++++++-----
> >   8 files changed, 41 insertions(+), 39 deletions(-)
> >
> > diff --git a/arch/parisc/include/asm/fb.h b/arch/parisc/include/asm/fb.h
> > index 658a8a7dc5312..ed2a195a3e762 100644
> > --- a/arch/parisc/include/asm/fb.h
> > +++ b/arch/parisc/include/asm/fb.h
> > @@ -2,11 +2,13 @@
> >   #ifndef _ASM_FB_H_
> >   #define _ASM_FB_H_
> >
> > -struct fb_info;
> > +#include <linux/types.h>
> > +
> > +struct device;
> >
> >   #if defined(CONFIG_STI_CORE)
> > -int fb_is_primary_device(struct fb_info *info);
> > -#define fb_is_primary_device fb_is_primary_device
> > +bool video_is_primary_device(struct device *dev);
> > +#define video_is_primary_device video_is_primary_device
> >   #endif
> >
> >   #include <asm-generic/fb.h>
> > diff --git a/arch/parisc/video/fbdev.c b/arch/parisc/video/fbdev.c
> > index e4f8ac99fc9e0..540fa0c919d59 100644
> > --- a/arch/parisc/video/fbdev.c
> > +++ b/arch/parisc/video/fbdev.c
> > @@ -5,12 +5,13 @@
> >    * Copyright (C) 2001-2002 Thomas Bogendoerfer 
> > <tsbogend@xxxxxxxxxxxxxxxx>
> >    */
> >
> > -#include <linux/fb.h>
> >   #include <linux/module.h>
> >
> >   #include <video/sticore.h>
> >
> > -int fb_is_primary_device(struct fb_info *info)
> > +#include <asm/fb.h>
> > +
> > +bool video_is_primary_device(struct device *dev)
> >   {
> >       struct sti_struct *sti;
> >
> > @@ -21,6 +22,6 @@ int fb_is_primary_device(struct fb_info *info)
> >           return true;
> >
> >       /* return true if it's the default built-in framebuffer driver */
> > -    return (sti->dev == info->device);
> > +    return (sti->dev == dev);
> >   }
> > -EXPORT_SYMBOL(fb_is_primary_device);
> > +EXPORT_SYMBOL(video_is_primary_device);
> > diff --git a/arch/sparc/include/asm/fb.h b/arch/sparc/include/asm/fb.h
> > index 24440c0fda490..07f0325d6921c 100644
> > --- a/arch/sparc/include/asm/fb.h
> > +++ b/arch/sparc/include/asm/fb.h
> > @@ -3,10 +3,11 @@
> >   #define _SPARC_FB_H_
> >
> >   #include <linux/io.h>
> > +#include <linux/types.h>
> >
> >   #include <asm/page.h>
> >
> > -struct fb_info;
> > +struct device;
> >
> >   #ifdef CONFIG_SPARC32
> >   static inline pgprot_t pgprot_framebuffer(pgprot_t prot,
> > @@ -18,8 +19,8 @@ static inline pgprot_t pgprot_framebuffer(pgprot_t 
> > prot,
> >   #define pgprot_framebuffer pgprot_framebuffer
> >   #endif
> >
> > -int fb_is_primary_device(struct fb_info *info);
> > -#define fb_is_primary_device fb_is_primary_device
> > +bool video_is_primary_device(struct device *dev);
> > +#define video_is_primary_device video_is_primary_device
> >
> >   static inline void fb_memcpy_fromio(void *to, const volatile void 
> > __iomem *from, size_t n)
> >   {
> > diff --git a/arch/sparc/video/fbdev.c b/arch/sparc/video/fbdev.c
> > index bff66dd1909a4..e46f0499c2774 100644
> > --- a/arch/sparc/video/fbdev.c
> > +++ b/arch/sparc/video/fbdev.c
> > @@ -1,26 +1,25 @@
> >   // SPDX-License-Identifier: GPL-2.0
> >
> >   #include <linux/console.h>
> > -#include <linux/fb.h>
> > +#include <linux/device.h>
> >   #include <linux/module.h>
> >
> > +#include <asm/fb.h>
> >   #include <asm/prom.h>
> >
> > -int fb_is_primary_device(struct fb_info *info)
> > +bool video_is_primary_device(struct device *dev)
> >   {
> > -    struct device *dev = info->device;
> > -    struct device_node *node;
> > +    struct device_node *node = dev->of_node;
> >
> >       if (console_set_on_cmdline)
> > -        return 0;
> > +        return false;
> >
> > -    node = dev->of_node;
> >       if (node && node == of_console_device)
> > -        return 1;
> > +        return true;
> >
> > -    return 0;
> > +    return false;
> >   }
> > -EXPORT_SYMBOL(fb_is_primary_device);
> > +EXPORT_SYMBOL(video_is_primary_device);
> >
> >   MODULE_DESCRIPTION("Sparc fbdev helpers");
> >   MODULE_LICENSE("GPL");
> > diff --git a/arch/x86/include/asm/fb.h b/arch/x86/include/asm/fb.h
> > index c3b9582de7efd..999db33792869 100644
> > --- a/arch/x86/include/asm/fb.h
> > +++ b/arch/x86/include/asm/fb.h
> > @@ -2,17 +2,19 @@
> >   #ifndef _ASM_X86_FB_H
> >   #define _ASM_X86_FB_H
> >
> > +#include <linux/types.h>
> > +
> >   #include <asm/page.h>
> >
> > -struct fb_info;
> > +struct device;
> >
> >   pgprot_t pgprot_framebuffer(pgprot_t prot,
> >                   unsigned long vm_start, unsigned long vm_end,
> >                   unsigned long offset);
> >   #define pgprot_framebuffer pgprot_framebuffer
> >
> > -int fb_is_primary_device(struct fb_info *info);
> > -#define fb_is_primary_device fb_is_primary_device
> > +bool video_is_primary_device(struct device *dev);
> > +#define video_is_primary_device video_is_primary_device
> >
> >   #include <asm-generic/fb.h>
> >
> > diff --git a/arch/x86/video/fbdev.c b/arch/x86/video/fbdev.c
> > index 1dd6528cc947c..4d87ce8e257fe 100644
> > --- a/arch/x86/video/fbdev.c
> > +++ b/arch/x86/video/fbdev.c
> > @@ -7,7 +7,6 @@
> >    *
> >    */
> >
> > -#include <linux/fb.h>
> >   #include <linux/module.h>
> >   #include <linux/pci.h>
> >   #include <linux/vgaarb.h>
> > @@ -25,20 +24,17 @@ pgprot_t pgprot_framebuffer(pgprot_t prot,
> >   }
> >   EXPORT_SYMBOL(pgprot_framebuffer);
> >
> > -int fb_is_primary_device(struct fb_info *info)
> > +bool video_is_primary_device(struct device *dev)
> >   {
> > -    struct device *device = info->device;
> > -    struct pci_dev *pci_dev;
> > +    struct pci_dev *pdev;
> >
> > -    if (!device || !dev_is_pci(device))
> > -        return 0;
> > +    if (!dev_is_pci(dev))
> > +        return false;
> >
> > -    pci_dev = to_pci_dev(device);
> > +    pdev = to_pci_dev(dev);
> >
> > -    if (pci_dev == vga_default_device())
> > -        return 1;
> > -    return 0;
> > +    return (pdev == vga_default_device());
> >   }
> > -EXPORT_SYMBOL(fb_is_primary_device);
> > +EXPORT_SYMBOL(video_is_primary_device);
> >
> >   MODULE_LICENSE("GPL");
> > diff --git a/drivers/video/fbdev/core/fbcon.c 
> > b/drivers/video/fbdev/core/fbcon.c
> > index 46823c2e2ba12..85c5c8cbc680a 100644
> > --- a/drivers/video/fbdev/core/fbcon.c
> > +++ b/drivers/video/fbdev/core/fbcon.c
> > @@ -2939,7 +2939,7 @@ void fbcon_remap_all(struct fb_info *info)
> >   static void fbcon_select_primary(struct fb_info *info)
> >   {
> >       if (!map_override && primary_device == -1 &&
> > -        fb_is_primary_device(info)) {
> > +        video_is_primary_device(info->device)) {
> >           int i;
> >
> >           printk(KERN_INFO "fbcon: %s (fb%i) is primary device\n",
> > diff --git a/include/asm-generic/fb.h b/include/asm-generic/fb.h
> > index 6ccabb400aa66..4788c1e1c6bc0 100644
> > --- a/include/asm-generic/fb.h
> > +++ b/include/asm-generic/fb.h
> > @@ -10,8 +10,9 @@
> >   #include <linux/io.h>
> >   #include <linux/mm_types.h>
> >   #include <linux/pgtable.h>
> > +#include <linux/types.h>
> >
> > -struct fb_info;
> > +struct device;
> >
> >   #ifndef pgprot_framebuffer
> >   #define pgprot_framebuffer pgprot_framebuffer
> > @@ -23,11 +24,11 @@ static inline pgprot_t 
> > pgprot_framebuffer(pgprot_t prot,
> >   }
> >   #endif
> >
> > -#ifndef fb_is_primary_device
> > -#define fb_is_primary_device fb_is_primary_device
> > -static inline int fb_is_primary_device(struct fb_info *info)
> > +#ifndef video_is_primary_device
> > +#define video_is_primary_device video_is_primary_device
> > +static inline bool video_is_primary_device(struct device *dev)
> >   {
> > -    return 0;
> > +    return false;
> >   }
> >   #endif

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)