kernel.git/arch/s390/kernel/head.S, branch linux-3.18.y

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

2014-09-25T08:52:06Z

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

2014-07-16T08:48:09Z

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

2014-05-28T08:38:50Z

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

2014-05-27T08:26:05Z

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

2013-10-24T15:16:53Z

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

2012-11-23T10:14:31Z

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

s390: add support to start the kernel in 64 bit mode.

2012-10-09T12:16:58Z

Do the switch to z/Architecture (alias 64 bit) mode early in head.S. If the machine is already running in 64 bit mode the sigp turns into a nop. With this change it doesn't matter in which mode the kernel is started. Reviewd-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

s390/comments: unify copyright messages and remove file names

2012-07-20T09:15:04Z

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/ipl: remove builtin tape ipl code

2012-05-16T12:42:40Z

Remove the builtin tape ipl code. If somebody really wants to create a tape which can be ipl'ed from, then this can be achieved by using zipl. zipl can write an ipl record to a tape device and aftwards the kernel image must be written to tape. The steps are described in the "Linux on System z - Device Drivers, Features, and Commands" book (SC33-8411). Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky

[S390] Fix stfle() lowcore protection problem

2012-04-11T12:28:26Z

The stfle() function writes into lowcore memory when stfl_fac_list is initialized with "S390_lowcore.stfl_fac_list = 0". For older compilers this triggers a lowcore exception. With newer compilers and "-OXX" compile option the bug does not show up because the "S390_lowcore.stfl_fac_list" initialization is removed by the compiler. The reason for thatis the incorrect "=m" (S390_lowcore.stfl_fac_list) constraint in the stfl inline assembly. The following shows the disassembly of the stfle() optimized code that is inlined in the lgr_info_get() function: 000000000011325c : 11325c: eb 9f f0 60 00 24 stmg %r9,%r15,96(%r15) 113262: c0 d0 00 29 0e 47 larl %r13,634ef0 113268: a7 f1 3f c0 tml %r15,16320 11326c: b9 04 00 ef lgr %r14,%r15 113270: a7 84 00 01 je 113272 113274: a7 fb ff c0 aghi %r15,-64 113278: b9 04 00 c2 lgr %r12,%r2 11327c: a7 29 00 01 lghi %r2,1 113280: e3 e0 f0 98 00 24 stg %r14,152(%r15) 113286: d7 97 c0 00 c0 00 xc 0(152,%r12),0(%r12) 11328c: c0 e5 00 28 db 4c brasl %r14,62e924 113292: b2 b1 00 00 stfl 0 To fix the problem we now clear the S390_lowcore.stfl_fac_list at startup in "head.S" for all machine types before lowcore protection is enabled. In addition to that the "=m" constraint is replaced by "+m". Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky