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

[Helge Deller <deller@gmx.de>]

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