diff mbox series

[v4,38/41] video: handle HAS_IOPORT dependencies

Message ID 20230516110038.2413224-39-schnelle@linux.ibm.com
State New
Headers
Series treewide: Remove I/O port accessors for HAS_IOPORT=n |

Commit Message

Niklas Schnelle May 16, 2023, 11 a.m. UTC 
  In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
not being declared. We thus need to add HAS_IOPORT as dependency for
those drivers using them and guard inline code in headers.

Co-developed-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
Note: The HAS_IOPORT Kconfig option was added in v6.4-rc1 so
      per-subsystem patches may be applied independently

 drivers/video/console/Kconfig |  1 +
 drivers/video/fbdev/Kconfig   | 21 +++++++++++----------
 include/video/vga.h           |  8 ++++++++
 3 files changed, 20 insertions(+), 10 deletions(-)

Comments

Thomas Zimmermann May 16, 2023, 5:21 p.m. UTC | #1 
Hi

Am 16.05.23 um 13:00 schrieb Niklas Schnelle:
> In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> not being declared. We thus need to add HAS_IOPORT as dependency for
> those drivers using them and guard inline code in headers.
> 
> Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> ---
> Note: The HAS_IOPORT Kconfig option was added in v6.4-rc1 so
>        per-subsystem patches may be applied independently
> 
>   drivers/video/console/Kconfig |  1 +
>   drivers/video/fbdev/Kconfig   | 21 +++++++++++----------
>   include/video/vga.h           |  8 ++++++++

Those are 3 different things. It might be preferable to not handle them 
under the video/ umbrella.

>   3 files changed, 20 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
> index 22cea5082ac4..64974eaa3ac5 100644
> --- a/drivers/video/console/Kconfig
> +++ b/drivers/video/console/Kconfig
> @@ -10,6 +10,7 @@ config VGA_CONSOLE
>   	depends on !4xx && !PPC_8xx && !SPARC && !M68K && !PARISC &&  !SUPERH && \
>   		(!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER) && \
>   		!ARM64 && !ARC && !MICROBLAZE && !OPENRISC && !S390 && !UML
> +	depends on HAS_IOPORT
>   	select APERTURE_HELPERS if (DRM || FB || VFIO_PCI_CORE)
>   	default y
>   	help
> diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
> index 96e91570cdd3..a56c57dd839b 100644
> --- a/drivers/video/fbdev/Kconfig
> +++ b/drivers/video/fbdev/Kconfig
> @@ -335,7 +335,7 @@ config FB_IMX
>   
>   config FB_CYBER2000
>   	tristate "CyberPro 2000/2010/5000 support"
> -	depends on FB && PCI && (BROKEN || !SPARC64)
> +	depends on FB && PCI && HAS_IOPORT && (BROKEN || !SPARC64)
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> @@ -429,6 +429,7 @@ config FB_FM2
>   config FB_ARC
>   	tristate "Arc Monochrome LCD board support"
>   	depends on FB && (X86 || COMPILE_TEST)
> +	depends on HAS_IOPORT
>   	select FB_SYS_FILLRECT
>   	select FB_SYS_COPYAREA
>   	select FB_SYS_IMAGEBLIT
> @@ -1332,7 +1333,7 @@ config FB_ATY_BACKLIGHT
>   
>   config FB_S3
>   	tristate "S3 Trio/Virge support"
> -	depends on FB && PCI
> +	depends on FB && PCI && HAS_IOPORT
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> @@ -1393,7 +1394,7 @@ config FB_SAVAGE_ACCEL
>   
>   config FB_SIS
>   	tristate "SiS/XGI display support"
> -	depends on FB && PCI
> +	depends on FB && PCI && HAS_IOPORT
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> @@ -1424,7 +1425,7 @@ config FB_SIS_315
>   
>   config FB_VIA
>   	tristate "VIA UniChrome (Pro) and Chrome9 display support"
> -	depends on FB && PCI && GPIOLIB && I2C && (X86 || COMPILE_TEST)
> +	depends on FB && PCI && GPIOLIB && I2C && HAS_IOPORT && (X86 || COMPILE_TEST)
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> @@ -1463,7 +1464,7 @@ endif
>   
>   config FB_NEOMAGIC
>   	tristate "NeoMagic display support"
> -	depends on FB && PCI
> +	depends on FB && PCI && HAS_IOPORT
>   	select FB_MODE_HELPERS
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
> @@ -1493,7 +1494,7 @@ config FB_KYRO
>   
>   config FB_3DFX
>   	tristate "3Dfx Banshee/Voodoo3/Voodoo5 display support"
> -	depends on FB && PCI
> +	depends on FB && PCI && HAS_IOPORT
>   	select FB_CFB_IMAGEBLIT
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
> @@ -1543,7 +1544,7 @@ config FB_VOODOO1
>   
>   config FB_VT8623
>   	tristate "VIA VT8623 support"
> -	depends on FB && PCI
> +	depends on FB && PCI && HAS_IOPORT
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> @@ -1558,7 +1559,7 @@ config FB_VT8623
>   
>   config FB_TRIDENT
>   	tristate "Trident/CyberXXX/CyberBlade support"
> -	depends on FB && PCI
> +	depends on FB && PCI && HAS_IOPORT
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> @@ -1581,7 +1582,7 @@ config FB_TRIDENT
>   
>   config FB_ARK
>   	tristate "ARK 2000PV support"
> -	depends on FB && PCI
> +	depends on FB && PCI && HAS_IOPORT
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> @@ -2195,7 +2196,7 @@ config FB_SSD1307
>   
>   config FB_SM712
>   	tristate "Silicon Motion SM712 framebuffer support"
> -	depends on FB && PCI
> +	depends on FB && PCI && HAS_IOPORT
>   	select FB_CFB_FILLRECT
>   	select FB_CFB_COPYAREA
>   	select FB_CFB_IMAGEBLIT
> diff --git a/include/video/vga.h b/include/video/vga.h
> index 947c0abd04ef..f4b806b85c86 100644
> --- a/include/video/vga.h
> +++ b/include/video/vga.h
> @@ -203,18 +203,26 @@ extern int restore_vga(struct vgastate *state);
>   
>   static inline unsigned char vga_io_r (unsigned short port)
>   {
> +#ifdef CONFIG_HAS_IOPORT
>   	return inb_p(port);
> +#else
> +	return 0xff;
> +#endif
>   }
>   
>   static inline void vga_io_w (unsigned short port, unsigned char val)
>   {
> +#ifdef CONFIG_HAS_IOPORT
>   	outb_p(val, port);
> +#endif
>   }
>   
>   static inline void vga_io_w_fast (unsigned short port, unsigned char reg,
>   				  unsigned char val)
>   {
> +#ifdef CONFIG_HAS_IOPORT
>   	outw(VGA_OUT16VAL (val, reg), port);
> +#endif
>   }

It feels wrong that these helpers silently do nothing. I'd enclose them 
in CONFIG_HAS_IOPORT entirely. The drivers that use them unconditionally 
would then fail to build.

Best regards
Thomas

>   
>   static inline unsigned char vga_mm_r (void __iomem *regbase, unsigned short port)

-- 
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)
Niklas Schnelle May 17, 2023, 12:41 p.m. UTC | #2 
On Tue, 2023-05-16 at 19:21 +0200, Thomas Zimmermann wrote:
> Hi
> 
> Am 16.05.23 um 13:00 schrieb Niklas Schnelle:
> > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > not being declared. We thus need to add HAS_IOPORT as dependency for
> > those drivers using them and guard inline code in headers.
> > 
> > Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> > Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> > ---
> > Note: The HAS_IOPORT Kconfig option was added in v6.4-rc1 so
> >        per-subsystem patches may be applied independently
> > 
> >   drivers/video/console/Kconfig |  1 +
> >   drivers/video/fbdev/Kconfig   | 21 +++++++++++----------
> >   include/video/vga.h           |  8 ++++++++
> 
> Those are 3 different things. It might be preferable to not handle them 
> under the video/ umbrella.
> 
> >   3 files changed, 20 insertions(+), 10 deletions(-)
> > 
> > diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
> > index 22cea5082ac4..64974eaa3ac5 100644
> > --- a/drivers/video/console/Kconfig
> > +++ b/drivers/video/console/Kconfig
> > @@ -10,6 +10,7 @@ config VGA_CONSOLE
> >   	depends on !4xx && !PPC_8xx && !SPARC && !M68K && !PARISC &&  !SUPERH && \
> >   		(!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER) && \
> >   		!ARM64 && !ARC && !MICROBLAZE && !OPENRISC && !S390 && !UML
> > +	depends on HAS_IOPORT
> >   	select APERTURE_HELPERS if (DRM || FB || VFIO_PCI_CORE)
> >   	default y
> >   	help
> > diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
> > index 96e91570cdd3..a56c57dd839b 100644
> > --- a/drivers/video/fbdev/Kconfig
> > +++ b/drivers/video/fbdev/Kconfig
> > @@ -335,7 +335,7 @@ config FB_IMX
> >   
> >   config FB_CYBER2000
> >   	tristate "CyberPro 2000/2010/5000 support"
> > -	depends on FB && PCI && (BROKEN || !SPARC64)
> > +	depends on FB && PCI && HAS_IOPORT && (BROKEN || !SPARC64)
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> >   	select FB_CFB_IMAGEBLIT
> > @@ -429,6 +429,7 @@ config FB_FM2
> >   config FB_ARC
> >   	tristate "Arc Monochrome LCD board support"
> >   	depends on FB && (X86 || COMPILE_TEST)
> > +	depends on HAS_IOPORT
> >   	select FB_SYS_FILLRECT
> >   	select FB_SYS_COPYAREA
> >   	select FB_SYS_IMAGEBLIT
> > @@ -1332,7 +1333,7 @@ config FB_ATY_BACKLIGHT
> >   
> >   config FB_S3
> >   	tristate "S3 Trio/Virge support"
> > -	depends on FB && PCI
> > +	depends on FB && PCI && HAS_IOPORT
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> >   	select FB_CFB_IMAGEBLIT
> > @@ -1393,7 +1394,7 @@ config FB_SAVAGE_ACCEL
> >   
> >   config FB_SIS
> >   	tristate "SiS/XGI display support"
> > -	depends on FB && PCI
> > +	depends on FB && PCI && HAS_IOPORT
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> >   	select FB_CFB_IMAGEBLIT
> > @@ -1424,7 +1425,7 @@ config FB_SIS_315
> >   
> >   config FB_VIA
> >   	tristate "VIA UniChrome (Pro) and Chrome9 display support"
> > -	depends on FB && PCI && GPIOLIB && I2C && (X86 || COMPILE_TEST)
> > +	depends on FB && PCI && GPIOLIB && I2C && HAS_IOPORT && (X86 || COMPILE_TEST)
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> >   	select FB_CFB_IMAGEBLIT
> > @@ -1463,7 +1464,7 @@ endif
> >   
> >   config FB_NEOMAGIC
> >   	tristate "NeoMagic display support"
> > -	depends on FB && PCI
> > +	depends on FB && PCI && HAS_IOPORT
> >   	select FB_MODE_HELPERS
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> > @@ -1493,7 +1494,7 @@ config FB_KYRO
> >   
> >   config FB_3DFX
> >   	tristate "3Dfx Banshee/Voodoo3/Voodoo5 display support"
> > -	depends on FB && PCI
> > +	depends on FB && PCI && HAS_IOPORT
> >   	select FB_CFB_IMAGEBLIT
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> > @@ -1543,7 +1544,7 @@ config FB_VOODOO1
> >   
> >   config FB_VT8623
> >   	tristate "VIA VT8623 support"
> > -	depends on FB && PCI
> > +	depends on FB && PCI && HAS_IOPORT
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> >   	select FB_CFB_IMAGEBLIT
> > @@ -1558,7 +1559,7 @@ config FB_VT8623
> >   
> >   config FB_TRIDENT
> >   	tristate "Trident/CyberXXX/CyberBlade support"
> > -	depends on FB && PCI
> > +	depends on FB && PCI && HAS_IOPORT
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> >   	select FB_CFB_IMAGEBLIT
> > @@ -1581,7 +1582,7 @@ config FB_TRIDENT
> >   
> >   config FB_ARK
> >   	tristate "ARK 2000PV support"
> > -	depends on FB && PCI
> > +	depends on FB && PCI && HAS_IOPORT
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> >   	select FB_CFB_IMAGEBLIT
> > @@ -2195,7 +2196,7 @@ config FB_SSD1307
> >   
> >   config FB_SM712
> >   	tristate "Silicon Motion SM712 framebuffer support"
> > -	depends on FB && PCI
> > +	depends on FB && PCI && HAS_IOPORT
> >   	select FB_CFB_FILLRECT
> >   	select FB_CFB_COPYAREA
> >   	select FB_CFB_IMAGEBLIT
> > diff --git a/include/video/vga.h b/include/video/vga.h
> > index 947c0abd04ef..f4b806b85c86 100644
> > --- a/include/video/vga.h
> > +++ b/include/video/vga.h
> > @@ -203,18 +203,26 @@ extern int restore_vga(struct vgastate *state);
> >   
> >   static inline unsigned char vga_io_r (unsigned short port)
> >   {
> > +#ifdef CONFIG_HAS_IOPORT
> >   	return inb_p(port);
> > +#else
> > +	return 0xff;
> > +#endif
> >   }
> >   
> >   static inline void vga_io_w (unsigned short port, unsigned char val)
> >   {
> > +#ifdef CONFIG_HAS_IOPORT
> >   	outb_p(val, port);
> > +#endif
> >   }
> >   
> >   static inline void vga_io_w_fast (unsigned short port, unsigned char reg,
> >   				  unsigned char val)
> >   {
> > +#ifdef CONFIG_HAS_IOPORT
> >   	outw(VGA_OUT16VAL (val, reg), port);
> > +#endif
> >   }
> 
> It feels wrong that these helpers silently do nothing. I'd enclose them 
> in CONFIG_HAS_IOPORT entirely. The drivers that use them unconditionally 
> would then fail to build.
> 
> Best regards
> Thomas

Ok yeah, I was looking at the call sites like vga_w_fast() that use
either an HAS_IOPORT dependent function or a writew() based one and so
if I #ifdef the regbase != NULL check we could end up with a NULL
derference but I guess that is kind of what we want since clearly
something is wrong if the driver tries to do I/O port access despite it
not being available.

Thanks,
Niklas
diff mbox series

Patch

diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
index 22cea5082ac4..64974eaa3ac5 100644
--- a/drivers/video/console/Kconfig
+++ b/drivers/video/console/Kconfig
@@ -10,6 +10,7 @@  config VGA_CONSOLE
 	depends on !4xx && !PPC_8xx && !SPARC && !M68K && !PARISC &&  !SUPERH && \
 		(!ARM || ARCH_FOOTBRIDGE || ARCH_INTEGRATOR || ARCH_NETWINDER) && \
 		!ARM64 && !ARC && !MICROBLAZE && !OPENRISC && !S390 && !UML
+	depends on HAS_IOPORT
 	select APERTURE_HELPERS if (DRM || FB || VFIO_PCI_CORE)
 	default y
 	help
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 96e91570cdd3..a56c57dd839b 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -335,7 +335,7 @@  config FB_IMX
 
 config FB_CYBER2000
 	tristate "CyberPro 2000/2010/5000 support"
-	depends on FB && PCI && (BROKEN || !SPARC64)
+	depends on FB && PCI && HAS_IOPORT && (BROKEN || !SPARC64)
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -429,6 +429,7 @@  config FB_FM2
 config FB_ARC
 	tristate "Arc Monochrome LCD board support"
 	depends on FB && (X86 || COMPILE_TEST)
+	depends on HAS_IOPORT
 	select FB_SYS_FILLRECT
 	select FB_SYS_COPYAREA
 	select FB_SYS_IMAGEBLIT
@@ -1332,7 +1333,7 @@  config FB_ATY_BACKLIGHT
 
 config FB_S3
 	tristate "S3 Trio/Virge support"
-	depends on FB && PCI
+	depends on FB && PCI && HAS_IOPORT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -1393,7 +1394,7 @@  config FB_SAVAGE_ACCEL
 
 config FB_SIS
 	tristate "SiS/XGI display support"
-	depends on FB && PCI
+	depends on FB && PCI && HAS_IOPORT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -1424,7 +1425,7 @@  config FB_SIS_315
 
 config FB_VIA
 	tristate "VIA UniChrome (Pro) and Chrome9 display support"
-	depends on FB && PCI && GPIOLIB && I2C && (X86 || COMPILE_TEST)
+	depends on FB && PCI && GPIOLIB && I2C && HAS_IOPORT && (X86 || COMPILE_TEST)
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -1463,7 +1464,7 @@  endif
 
 config FB_NEOMAGIC
 	tristate "NeoMagic display support"
-	depends on FB && PCI
+	depends on FB && PCI && HAS_IOPORT
 	select FB_MODE_HELPERS
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
@@ -1493,7 +1494,7 @@  config FB_KYRO
 
 config FB_3DFX
 	tristate "3Dfx Banshee/Voodoo3/Voodoo5 display support"
-	depends on FB && PCI
+	depends on FB && PCI && HAS_IOPORT
 	select FB_CFB_IMAGEBLIT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
@@ -1543,7 +1544,7 @@  config FB_VOODOO1
 
 config FB_VT8623
 	tristate "VIA VT8623 support"
-	depends on FB && PCI
+	depends on FB && PCI && HAS_IOPORT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -1558,7 +1559,7 @@  config FB_VT8623
 
 config FB_TRIDENT
 	tristate "Trident/CyberXXX/CyberBlade support"
-	depends on FB && PCI
+	depends on FB && PCI && HAS_IOPORT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -1581,7 +1582,7 @@  config FB_TRIDENT
 
 config FB_ARK
 	tristate "ARK 2000PV support"
-	depends on FB && PCI
+	depends on FB && PCI && HAS_IOPORT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
@@ -2195,7 +2196,7 @@  config FB_SSD1307
 
 config FB_SM712
 	tristate "Silicon Motion SM712 framebuffer support"
-	depends on FB && PCI
+	depends on FB && PCI && HAS_IOPORT
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
diff --git a/include/video/vga.h b/include/video/vga.h
index 947c0abd04ef..f4b806b85c86 100644
--- a/include/video/vga.h
+++ b/include/video/vga.h
@@ -203,18 +203,26 @@  extern int restore_vga(struct vgastate *state);
 
 static inline unsigned char vga_io_r (unsigned short port)
 {
+#ifdef CONFIG_HAS_IOPORT
 	return inb_p(port);
+#else
+	return 0xff;
+#endif
 }
 
 static inline void vga_io_w (unsigned short port, unsigned char val)
 {
+#ifdef CONFIG_HAS_IOPORT
 	outb_p(val, port);
+#endif
 }
 
 static inline void vga_io_w_fast (unsigned short port, unsigned char reg,
 				  unsigned char val)
 {
+#ifdef CONFIG_HAS_IOPORT
 	outw(VGA_OUT16VAL (val, reg), port);
+#endif
 }
 
 static inline unsigned char vga_mm_r (void __iomem *regbase, unsigned short port)