Re: [PATCH 01/11] ARM: disable virt_to_bus/virt_to_bus almost everywhere

[James Hogan <james.hogan@imgtec.com>]

On 20/02/13 16:00, Arnd Bergmann wrote:
> On Wednesday 20 February 2013, James Hogan wrote:
>> There's a patch in linux-next by Stephen Rothwell "Centralise
>> CONFIG_ARCH_NO_VIRT_TO_BUS" that removes this Kconfig symbol,
>> inverting/replacing it with "select HAVE_VIRT_TO_BUS" (including for
>> arch/arm) which will undo the effects of this.
> 
> Ah, thanks for pointing that out. At least my patch is harmless then
> although also useless. I'll leave it in for now so I don't have to
> rebase all the other bug fixes that are queued for 3.9, but I'm making
> a note that I'll have to replace this with a proper one. I also
> don't think that anything breaks if we apply both patches for a while,
> it will just make my patch useless.

Agreed.

> I guess you'll have to do something similar for arch/metag, and Vineet
> will do it for arch/arc.

Yes, I have a little series of patches to fix this sort of harmless
thing in arch/metag, removing GENERIC_SIGALTSTACK, HAVE_IRQ_WORK,
ARCH_NO_VIRT_TO_BUS, and CONFIG_EXPERIMENTAL from defconfigs. I wasn't
sure how it's normally handled though, so I was just going to wait until
the other things go in before requesting a second pull.

> 
> Stephen's patch is currently in Andrew's tree, and I don't see an easy
> way to coordinate this. The patch we will need once both are merged
> is below.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

FWIW:
Acked-by: James Hogan <james.hogan@imgtec.com> (for arch/metag)

Cheers
James

> 
> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> index 4fef29f..5829b67 100644
> --- a/arch/arc/Kconfig
> +++ b/arch/arc/Kconfig
> @@ -76,9 +76,6 @@ config HAVE_LATENCYTOP_SUPPORT
>  config NO_DMA
>  	def_bool n
>  
> -config ARCH_NO_VIRT_TO_BUS
> -	def_bool y
> -
>  source "init/Kconfig"
>  source "kernel/Kconfig.freezer"
>  
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index dedf02b..7b35b39 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -49,7 +49,6 @@ config ARM
>  	select HAVE_REGS_AND_STACK_ACCESS_API
>  	select HAVE_SYSCALL_TRACEPOINTS
>  	select HAVE_UID16
> -	select HAVE_VIRT_TO_BUS
>  	select KTIME_SCALAR
>  	select PERF_USE_VMALLOC
>  	select RTC_LIB
> @@ -744,6 +743,7 @@ config ARCH_RPC
>  	select NEED_MACH_IO_H
>  	select NEED_MACH_MEMORY_H
>  	select NO_IOPORT
> +	select HAVE_VIRT_TO_BUS
>  	help
>  	  On the Acorn Risc-PC, Linux can support the internal IDE disk and
>  	  CD-ROM interface, serial and parallel port, and the floppy drive.
> @@ -880,6 +880,7 @@ config ARCH_SHARK
>  	select NEED_MACH_MEMORY_H
>  	select PCI
>  	select ZONE_DMA
> +	select HAVE_VIRT_TO_BUS
>  	help
>  	  Support for the StrongARM based Digital DNARD machine, also known
>  	  as "Shark" (<http://www.shark-linux.de/shark.html>).
> @@ -1462,10 +1463,6 @@ config ISA_DMA
>  	bool
>  	select ISA_DMA_API
>  
> -config ARCH_NO_VIRT_TO_BUS
> -	def_bool y
> -	depends on !ARCH_RPC && !ARCH_NETWINDER && !ARCH_SHARK
> -
>  # Select ISA DMA interface
>  config ISA_DMA_API
>  	bool
> diff --git a/arch/arm/mach-footbridge/Kconfig b/arch/arm/mach-footbridge/Kconfig
> index abda5a1..42bf587 100644
> --- a/arch/arm/mach-footbridge/Kconfig
> +++ b/arch/arm/mach-footbridge/Kconfig
> @@ -67,6 +67,7 @@ config ARCH_NETWINDER
>  	select ISA
>  	select ISA_DMA
>  	select PCI
> +	select HAVE_VIRT_TO_BUS
>  	help
>  	  Say Y here if you intend to run this kernel on the Rebel.COM
>  	  NetWinder.  Information about this machine can be found at:
> diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
> index 30adc78..03e216e 100644
> --- a/arch/metag/Kconfig
> +++ b/arch/metag/Kconfig
> @@ -35,9 +35,6 @@ config METAG
>  	select OF_EARLY_FLATTREE
>  	select SPARSE_IRQ
>  
> -config ARCH_NO_VIRT_TO_BUS
> -	def_bool y
> -
>  config STACKTRACE_SUPPORT
>  	def_bool y
>  
>