linux-stable.git/arch/s390/kernel/head.S, branch linux-4.4.y

s390: remove SALIPL loader

2015-11-16T11:51:11+00:00

There is no known user, therefore remove the code.

Acked-by: Rob Van Der Heij 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/head: fix error message on unsupported hardware

2015-11-09T08:10:47+00:00

startup calls the C function _sclp_print_early() if the machine we're
running on is not supported by the kernel. sclp.c is getting built
with -m64, so _sclp_print_early() expects the zSeries ELF ABI to be
used.

We previously called _sclp_print_early() using the S/390 ELF ABI, with
a stack frame size of 96 bytes and while being in 31-bit address
mode. This caused _sclp_wait_int() (called indirectly from
_sclp_print_early()) to jump to an undefined address. While
_sclp_wait_int() contained some code to deal with being called in
31-bit addressing mode, it didn't quite work. While fixing this is
possible, the code would still only work by chance and could break any
time.

Ensure compliance with the zSeries ELF ABI by switching to 64-bit
addressing mode early and using a minimum stack frame size of 160
bytes.

Signed-off-by: Sascha Silbe 
Acked-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/facilities: remove transactional-execution bits

2015-08-19T08:03:34+00:00

Remove the two facility bits

50 - constrained transactional-execution facility
74 - transactional-execution facility

from the required facilities if the kernel is built with -march=zEC12.

E.g. z/VM 6.3 doesn't virtualize the TX facility yet. Therefore a kernel
built with -march=zEC12 and ipl'ed on a zEC12 machine as a z/VM 6.3 guest
will emit a message about the missing facilities and stop working.

The kernel however doesn't make use of the TX facility, therefore remove
the two TX related facility bits and fix this unpleasant behavior.

Signed-off-by: Heiko Carstens 
Reviewed-by: David Hildenbrand 
Signed-off-by: Martin Schwidefsky

s390/sclp: convert early sclp console code to C

2015-07-29T07:11:39+00:00

The 31-bit assembler code for the early sclp console is error
prone as git commit fde24b54d976cc123506695c17db01438a11b673
"s390/sclp: clear upper register halves in _sclp_print_early"
has shown.

Convert the assembler code to C.

Signed-off-by: Martin Schwidefsky

s390: remove 31 bit support

2015-03-25T10:49:33+00:00

Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

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

s390: add z13 code generation support

2015-01-22T11:15:57+00:00

Allow to generate code that only runs on z13 machines.

Signed-off-by: Martin Schwidefsky

s390/head.s: use zero as address for stfl

2014-09-25T08:52:06+00:00

The architecture suggests to use address 0 as parameter for stfl,
to allow for future extensions. Using __LC_STFL_FAC_LIST (0x200)
shows which address is used, but might be not future proof.

Signed-off-by: Christian Borntraeger 
Signed-off-by: Martin Schwidefsky

s390: require mvcos facility, not tod clock steering facility

2014-07-16T08:48:09+00:00

Inlined uaccess functions require the mvcos facility (bit 27), not the tod
clock steering facility (bit 28) for z10 and newer machines.

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

s390/facilities: remove extract-cpu-time facility check

2014-05-28T08:38:50+00:00

Remove the check for the extract-cpu-time facility within early startup
code. Both kernel and user space work if the facility is not installed.

The vdso code has a run time check if the ectg is available. Besides that
there is no known user.

Reported-by: Christian Borntraeger 
Acked-by: Christian Borntraeger 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390: require mvcos facility for z10 and newer machines

2014-05-27T08:26:05+00:00

With inlined uaccess functions we always need the mvcos facility.
Checking at each inline place if mvcos is available would make the
inlining of get_user/put_user pointless.

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