Re: [PATCH] openrisc: io: Define iounmap argument as volatile

[Guenter Roeck <linux@roeck-us.net>]

On Fri, Jul 29, 2022 at 08:07:25PM +0900, Stafford Horne wrote:
> When OpenRISC enables PCI it allows for more drivers to be compiled
> resulting in exposing the following with -Werror.
> 
>     drivers/video/fbdev/riva/fbdev.c: In function 'rivafb_probe':
>     drivers/video/fbdev/riva/fbdev.c:2062:42: error:
> 	    passing argument 1 of 'iounmap' discards 'volatile' qualifier from pointer target type
> 
>     drivers/video/fbdev/nvidia/nvidia.c: In function 'nvidiafb_probe':
>     drivers/video/fbdev/nvidia/nvidia.c:1414:20: error:
> 	    passing argument 1 of 'iounmap' discards 'volatile' qualifier from pointer target type
> 
>     drivers/scsi/aic7xxx/aic7xxx_osm.c: In function 'ahc_platform_free':
>     drivers/scsi/aic7xxx/aic7xxx_osm.c:1231:41: error:
> 	    passing argument 1 of 'iounmap' discards 'volatile' qualifier from pointer target type
> 
> Most architectures define the iounmap argument to be volatile.  To fix this
> issue we do the same for OpenRISC.  This patch must go before PCI is enabled on
> OpenRISC to avoid any compile failures.
> 
> Link: https://lore.kernel.org/lkml/20220729033728.GA2195022@roeck-us.net/
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Stafford Horne <shorne@gmail.com>

Tested-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  arch/openrisc/include/asm/io.h | 2 +-
>  arch/openrisc/mm/ioremap.c     | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/openrisc/include/asm/io.h b/arch/openrisc/include/asm/io.h
> index 625ac6ad1205..ee6043a03173 100644
> --- a/arch/openrisc/include/asm/io.h
> +++ b/arch/openrisc/include/asm/io.h
> @@ -31,7 +31,7 @@
>  void __iomem *ioremap(phys_addr_t offset, unsigned long size);
>  
>  #define iounmap iounmap
> -extern void iounmap(void __iomem *addr);
> +extern void iounmap(volatile void __iomem *addr);
>  
>  #include <asm-generic/io.h>
>  
> diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
> index daae13a76743..8ec0dafecf25 100644
> --- a/arch/openrisc/mm/ioremap.c
> +++ b/arch/openrisc/mm/ioremap.c
> @@ -77,7 +77,7 @@ void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
>  }
>  EXPORT_SYMBOL(ioremap);
>  
> -void iounmap(void __iomem *addr)
> +void iounmap(volatile void __iomem *addr)
>  {
>  	/* If the page is from the fixmap pool then we just clear out
>  	 * the fixmap mapping.
> -- 
> 2.37.1
>