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

[Arnd Bergmann <arnd@arndb.de>]

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.

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

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>

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