Our memcpy and memcmp variants were implemented by calling the corresponding
gcc builtin variants.
However gcc is free to replace a call to __builtin_memcmp with a call to memcmp
which, when called, will result in an endless recursion within memcmp.
So let's provide asm variants and also fix the variants that are used for
uncompressing the kernel image.
In addition remove all other occurences of builtin function calls.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Use builtin variants if gcc 4 or newer is used to compile the kernel.
Generates better code than the asm variants.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

In introducing a trivial "strstarts()" function in linux/string.h, we
hit the following error on s390:

In file included from include/linux/bitmap.h:8,
                 from include/linux/cpumask.h:142,
                 from include/linux/smp.h:12,
                 from /home/rusty/devel/kernel/patches/linux-2.6/arch/s390/include/asm/spinlock.h:14,
                 from include/linux/spinlock.h:88,
                 from include/linux/seqlock.h:29,
                 from include/linux/time.h:8,
                 from include/linux/stat.h:60,
                 from include/linux/module.h:10,
                 from arch/s390/lib/string.c:13:
include/linux/string.h: In function 'strstarts':
include/linux/string.h:124: error: implicit declaration of function 'strlen'
include/linux/string.h:124: warning: incompatible implicit declaration of built-in function 'strlen'

Because when including asm/string.h from arch/s390/lib/string.c we
don't declare the string ops we are about to define, and
linux/string.h barfs.

The fix is to declare them in this IN_ARCH_STRING_C case, but in
general I wonder if there's a neater fix.

Reported-by: linux-next
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>