BMC/Intel-BMC/linux.git/arch/s390/kernel/head.S, branch dev-4.3

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

s390/bitops: optimize set_bit() for constant values

2013-10-24T15:16:53+00:00

Since zEC12 we have the interlocked-access facility 2 which allows to use the instructions ni/oi/xi to update a single byte in storage with compare-and-swap semantics. So change set_bit(), clear_bit() and change_bit() to generate such code instead of a compare-and-swap loop (or using the load-and-* instruction family), if possible. This reduces the text segment by yet another 8KB (defconfig). Alternatively the long displacement variants niy/oiy/xiy could have been used, but the extended displacement field is usually not needed and therefore would only increase the size of the text segment again. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390: add zEC12 code generation support

2012-11-23T10:14:31+00:00

Allow to generate code that only runs on zEC12 machines. Also add a check which prevents the kernel to run on machines which do not have any of the following new facilities installed: - (48) decimal-floating-point zoned-conversion - (49) execution-hint - (49) load-and-trap - (49) miscellaneous-instruction-extensions - (49) processor-assist - (50) constrained transactional-execution - (73) transactional-execution 48, 49, 50 and 73 are the bit numbers of the facility indications for each of the required facilities. Note that we assume that user-space gets compiled with the same compiler options, therefore we also test for a dfp facility even if the kernel doesn't make use of it. Signed-off-by: Heiko Carstens