linux.git/arch/s390/include/asm/string.h, branch v4.13

s390/lib: add missing memory barriers to string inline assemblies

2016-12-14T15:33:41+00:00

We have a couple of inline assemblies like memchr() and strlen() that
read from memory, but tell the compiler only they need the addresses
of the strings they access.
This allows the compiler to omit the initialization of such strings
and therefore generate broken code. Add the missing memory barrier to
all string related inline assemblies to fix this potential issue. It
looks like the compiler currently does not generate broken code due to
these bugs.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390: provide memmove implementation

2016-12-12T11:11:32+00:00

Provide an s390 specific memmove implementation which is faster than
the generic implementation which copies byte-wise.

For non-destructive (as defined by the mvc instruction) memmove
operations the following table compares the old default implementation
versus the new s390 specific implementation:

size     old   new
   1     1ns   8ns
   2     2ns   8ns
   4     4ns   8ns
   8     7ns   8ns
  16    17ns   8ns
  32    35ns   8ns
  64    65ns   9ns
 128   146ns  10ns
 256   298ns  11ns
 512   537ns  11ns
1024  1193ns  19ns
2048  2405ns  36ns

So only for very small sizes the old implementation is faster. For
overlapping memmoves, where the mvc instruction can't be used, the new
implementation is as slow as the old one.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

lib/string.c: remove strnicmp()

2015-02-13T02:54:14+00:00

Now that all in-tree users of strnicmp have been converted to
strncasecmp, the wrapper can be removed.

Signed-off-by: Rasmus Villemoes 
Cc: David Howells 
Cc: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

s390/string: provide asm lib functions for memcpy and memcmp

2012-09-26T13:44:50+00:00

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 
Signed-off-by: Martin Schwidefsky

s390/comments: unify copyright messages and remove file names

2012-07-20T09:15:04+00:00

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

s390/headers: remove #ifdef KERNEL from not exported headers

2012-05-24T08:10:05+00:00

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] use compiler builtin versions of strlen/strcpy/strcat

2009-03-26T14:24:24+00:00

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 
Signed-off-by: Martin Schwidefsky

[S390] allow usage of string functions in linux/string.h

2009-03-26T14:24:23+00:00

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 
Signed-off-by: Martin Schwidefsky

[S390] move include/asm-s390 to arch/s390/include/asm

2008-08-01T18:42:05+00:00

Signed-off-by: Martin Schwidefsky