arch/*/: remove CONFIG_VIRT_TO_BUS

All architecture-independent users of virt_to_bus() and bus_to_virt()
have been fixed to use the dma mapping interfaces or have been
removed now.  This means the definitions on most architectures, and the
CONFIG_VIRT_TO_BUS symbol are now obsolete and can be removed.

The only exceptions to this are a few network and scsi drivers for m68k
Amiga and VME machines and ppc32 Macintosh. These drivers work correctly
with the old interfaces and are probably not worth changing.

On alpha and parisc, virt_to_bus() were still used in asm/floppy.h.
alpha can use isa_virt_to_bus() like x86 does, and parisc can just
open-code the virt_to_phys() here, as this is architecture specific
code.

I tried updating the bus-virt-phys-mapping.rst documentation, which
started as an email from Linus to explain some details of the Linux-2.0
driver interfaces. The bits about virt_to_bus() were declared obsolete
backin 2000, and the rest is not all that relevant any more, so in the
end I just decided to remove the file completely.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 0 insertions, 14 deletions

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 9c5114335a2d..7197e0642757 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1142,20 +1142,6 @@ static inline void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
 }
 #endif
 
-#ifdef CONFIG_VIRT_TO_BUS
-#ifndef virt_to_bus
-static inline unsigned long virt_to_bus(void *address)
-{
-	return (unsigned long)address;
-}
-
-static inline void *bus_to_virt(unsigned long address)
-{
-	return (void *)address;
-}
-#endif
-#endif
-
 #ifndef memset_io
 #define memset_io memset_io
 /**