Re: [PATCH v3 3/3] arch/*/: remove CONFIG_VIRT_TO_BUS

Helge Deller
2022-06-26T09:39:40Z

On 6/24/22 17:52, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> 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)
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for this cleanup!

You may add:
Acked-by: Helge Deller <deller@gmx.de> # parisc

Helge

> ---
> .../core-api/bus-virt-phys-mapping.rst | 220 ------------------
> Documentation/core-api/dma-api-howto.rst | 14 --
> Documentation/core-api/index.rst | 1 -
> .../translations/zh_CN/core-api/index.rst | 1 -
> arch/alpha/Kconfig | 1 -
> arch/alpha/include/asm/floppy.h | 2 +-
> arch/alpha/include/asm/io.h | 8 +-
> arch/ia64/Kconfig | 1 -
> arch/ia64/include/asm/io.h | 8 -
> arch/m68k/Kconfig | 1 -
> arch/m68k/include/asm/virtconvert.h | 4 +-
> arch/microblaze/Kconfig | 1 -
> arch/microblaze/include/asm/io.h | 2 -
> arch/mips/Kconfig | 1 -
> arch/mips/include/asm/io.h | 9 -
> arch/parisc/Kconfig | 1 -
> arch/parisc/include/asm/floppy.h | 4 +-
> arch/parisc/include/asm/io.h | 2 -
> arch/powerpc/Kconfig | 1 -
> arch/powerpc/include/asm/io.h | 2 -
> arch/riscv/include/asm/page.h | 1 -
> arch/x86/Kconfig | 1 -
> arch/x86/include/asm/io.h | 9 -
> arch/xtensa/Kconfig | 1 -
> arch/xtensa/include/asm/io.h | 3 -
> include/asm-generic/io.h | 14 --
> mm/Kconfig | 8 -
> 27 files changed, 10 insertions(+), 311 deletions(-)
> delete mode 100644 Documentation/core-api/bus-virt-phys-mapping.rst