When compiling a MMU kernel with CPU_HAS_ADDRESS_SPACES=n (e.g. "MMU=y
allnoconfig": "echo CONFIG_MMU=y > allno.config && make KCONFIG_ALLCONFIG=1
allnoconfig"), we use plain "move" instead of "moves", and I got:

  CC      arch/m68k/lib/uaccess.o
{standard input}: Assembler messages:
{standard input}:47: Error: operands mismatch -- statement `move.b %a0,(%a1)' ignored

This happens because plain "move" doesn't support byte transfers between
memory and address registers, while "moves" does.

Fix the asm constraints for __generic_copy_from_user(),
__generic_copy_to_user(), and __clear_user() to only use data registers
when accessing userspace.

Also, relax the asm constraints for 16-bit userspace accesses in
__put_user() and __get_user(), as both "move" and "moves" do support
such transfers between memory and address registers.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gcc may replace calls to standard string functions by open code and/or
calls to other standard string functions. If the replacement function is
not available out-of-line, link errors will happen.

To avoid this, the out-of-line versions were provided by
arch/m68k/lib/string.c, but they were usually not linked in anymore as
typically none of its symbols are referenced by built-in code.
However, if any module would need them, they would not be available.

Hence remove the inline strcpy() and strcat() implementations, remove
arch/m68k/lib/string.c, and let the generic string library code handle it.

Impact on a typical kernel build seems minimal or nonexistent:

-      .text : 0x00001000 - 0x002aac74   (2728 KiB)
-      .data : 0x002ada48 - 0x00392148   ( 914 KiB)
+      .text : 0x00001000 - 0x002aacf4   (2728 KiB)
+      .data : 0x002adac8 - 0x00392148   ( 914 KiB)

See also commit e00c73ee05dc38ecaccced55d4f5fc58b0b769f7 ("m68k: Remove
inline strlen() implementation").

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

GCC can replace a strncat() call with constant second argument into a
strlen + store, which results in a link error:

ERROR: "strlen" [net/ipv4/ip_tunnel.ko] undefined!

The inline function is a simple for loop in C. Other architectures
either use an asm optimized variant, or use the generic function from
lib/string.c.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

When compiling for original 68000 or ColdFire targets you will get the
following warning when compiling arch/m68k/lib/memcpy.c:

  CC      arch/m68k/lib/memcpy.o
arch/m68k/lib/memcpy.c: In function ‘__builtin_memcpy’:
arch/m68k/lib/memcpy.c:13:15: warning: unused variable ‘temp1’

This is easily fixed by moving the definition of temp1 into the code block
where it is used.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>

instead of open coding CONFIG_M68000 || CONFIG_COLDFIRE

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Greg Ungerer<gerg@uclinux.org>

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>

Modify the user space access functions to support the ColdFire V4e cores
running with MMU enabled.

The ColdFire processors do not support the "moves" instruction used by
the traditional 680x0 processors for moving data into and out of another
address space. They only support the notion of a single address space,
and you use the usual "move" instruction to access that.

Create a new config symbol (CONFIG_CPU_HAS_ADDRESS_SPACES) to mark the
CPU types that support separate address spaces, and thus also support
the sfc/dfc registers and the "moves" instruction that go along with that.

The code is almost identical for user space access, so lets just use a
define to choose either the "move" or "moves" in the assembler code.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Matt Waddel <mwaddel@yahoo.com>
Acked-by: Kurt Mahan <kmahan@xmission.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

The traditional 68000 processors and the newer reduced instruction set
ColdFire processors do not support the 32*32->64 multiply or the 64/32->32
divide instructions. This is not a difference based on the presence of
a hardware MMU or not.

Create a new config symbol to mark that a CPU type doesn't support the
longer multiply/divide instructions. Use this then as a basis for using
the fast 64bit based divide (in div64.h) and for linking in the extra
libgcc functions that may be required (mulsi3, divsi3, etc).

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

We have two implementations of the IP checksuming code for the m68k arch.
One uses the more advanced instructions available in 68020 and above
processors, the other uses the simpler instructions available on the
original 68000 processors and the modern ColdFire processors.

This simpler code is pretty much the same as the generic lib implementation
of the IP csum functions. So lets just switch over to using that. That
means we can completely remove the checksum_no.c file, and only have the
local fast code used for the more complex 68k CPU family members.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>

The original 68000 processors cannot copy 16bit or larger quantities from
odd addresses. All newer members of the 68k family (including ColdFire)
can do this.

In the current memcpy implementation after trying to align the destination
address to a 16bit boundary if we end up with an odd source address we go
off and try to copy multi-byte quantities from it. This will trap on the
68000.

The only solution if we end with an odd source address is to byte wise
copy the whole memcpy region. We only need to do this if we are supporting
original 68000 processors.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>