ARC: Remove redundant PCI_IOBASE declaration

ARC's asm/io.h includes the asm-generic/io.h which already defines the
PCI_IOBASE variable in exactly the same way, so it can be dropped from
the architecture specific header.

Signed-off-by: Thierry Reding <treding@nvidia.com>
ARM: ebsa110: Properly override I/O accessors

In order to override accessors properly they must be #define'd so that
subsequent generic headers (the one for ARM and finally the architecture
independent one) can properly detect it.

Signed-off-by: Thierry Reding <treding@nvidia.com>
ARM: ixp4xx: Properly override I/O accessors

In order to override accessors properly they must be #define'd so that
subsequent generic headers (the one for ARM and finally the architecture
independent one) can properly detect it.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Change xlate_dev_{kmem,mem}_ptr() prototypes

xlate_dev_mem_ptr() is used to convert a physical address to an uncached
kernel virtual address mapping, so make it use phys_addr_t as type for
the physical address and return void * for the kernel virtual address.

xlate_dev_kmem_ptr() converts a cached kernel virtual address mapping to
an uncached kernel virtual address mapping, so make it use void * for
both the input parameter and return value.

Signed-off-by: Thierry Reding <treding@nvidia.com>
/dev/mem: Use more consistent data types

The xlate_dev_{kmem,mem}_ptr() functions take either a physical address
or a kernel virtual address, so data types should be phys_addr_t and
void *. They both return a kernel virtual address which is only ever
used in calls to copy_{from,to}_user(), so make variables that store it
void * rather than char * for consistency.

Also only define a weak unxlate_dev_mem_ptr() function if architectures
haven't overridden them in the asm/io.h header file.

Signed-off-by: Thierry Reding <treding@nvidia.com>
asm-generic/io.h: Reconcile I/O accessor overrides

Overriding I/O accessors and helpers is currently very inconsistent.
This commit introduces a homogeneous way to override functions by
checking for the existence of a macro with the same of the function.
Architectures can provide their own implementations and communicate this
to the generic header by defining the appropriate macro. Doing this will
also help prevent the implementations from being subsequently
overridden.

While at it, also turn a lot of macros into static inline functions for
better type checking and to provide a canonical signature for overriding
architectures to copy. Also reorder functions by logical groups.

Signed-off-by: Thierry Reding <treding@nvidia.com>
asm-generic/io.h: Implement generic {read,write}s*()

Currently driver writers need to use io{read,write}{8,16,32}_rep() when
accessing FIFO registers portably. This is bad for two reasons: it is
inconsistent with how other registers are accessed using the standard
{read,write}{b,w,l}() functions, which can lead to confusion. On some
architectures the io{read,write}*() functions also need to perform some
extra checks to determine whether an address is memory-mapped or refers
to I/O space. Drivers which can be expected to never use I/O can safely
use the {read,write}s{b,w,l,q}(), just like they use their non-string
variants and there's no need for these extra checks.

This patch implements generic versions of readsb(), readsw(), readsl(),
readsq(), writesb(), writesw(), writesl() and writesq(). Variants of
these string functions for I/O accesses (ins*() and outs*() as well as
ioread*_rep() and iowrite*_rep()) are now implemented in terms of the
new functions.

Going forward, {read,write}{,s}{b,w,l,q}() should be used consistently
by drivers for devices that will only ever be memory-mapped and hence
don't need to access I/O space, whereas io{read,write}{8,16,32}_rep()
should be used by drivers for devices that can be either memory-mapped
or I/O-mapped.

Signed-off-by: Thierry Reding <treding@nvidia.com>
ARM: Use include/asm-generic/io.h

Include the generic I/O header file so that duplicate implementations
can be removed. This will also help to establish consistency across more
architectures regarding which accessors they support.

Signed-off-by: Thierry Reding <treding@nvidia.com>
arm64: Use include/asm-generic/io.h

Include the generic I/O header file so that duplicate implementations
can be removed. This will also help to establish consistency across more
architectures regarding which accessors they support.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>