From: Arnd Bergmann
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.
Signed-off-by: Arnd Bergmann
---
.../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
diff --git a/Documentation/core-api/bus-virt-phys-mapping.rst
b/Documentation/core-api/bus-virt-phys-mapping.rst
deleted file mode 100644
index c72b24a7d52c..
--- a/Documentation/core-api/bus-virt-phys-mapping.rst
+++ /dev/null
@@ -1,220 +0,0 @@
-==
-How to access I/O mapped memory from within device drivers
-==
-
-:Author: Linus
-
-.. warning::
-
- The virt_to_bus() and bus_to_virt() functions have been
- superseded by the functionality provided by the PCI DMA interface
- (see Documentation/core-api/dma-api-howto.rst). They continue
- to be documented below for historical purposes, but new code
- must not use them. --davidm 00/12/12
-
-::
-
- [ This is a mail message in response to a query on IO mapping, thus the
-strange format for a "document" ]
-
-The AHA-1542 is a bus-master device, and your patch makes the driver give the
-controller the physical address of the buffers, which is correct on x86
-(because all bus master devices see the physical memory mappings directly).
-
-However, on many setups, there are actually **three** different ways of looking
-at memory addresses, and in this case we actually want the third, the
-so-called "bus address".
-
-Essentially, the three ways of addressing memory are (this is "real memory",
-that is, normal RAM--see later about other details):
-
- - CPU untranslated. This is the "physical" address. Physical address
- 0 is what the CPU sees when it drives zeroes on the memory bus.
-
- - CPU translated address. This is the "virtual" address, and is
- completely internal to the CPU itself with the CPU doing the appropriate
- translations into "CPU untranslated".
-
- - bus address. This is the address of memory as seen by OTHER devices,
- not the CPU. Now, in theory there could be many different bus
- addresses, with each device seeing memory in some device-specific way, but
- happily most hardware designers aren't actually actively trying to make
- things any more complex than necessary, so you can assume that all
- external hardware sees the memory the same way.
-
-Now, on normal PCs the bus address is exactly the same as the
