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 <lgr_info_get>: 11325c: eb 9f f0 60 00 24 stmg %r9,%r15,96(%r15) 113262: c0 d0 00 29 0e 47 larl %r13,634ef0 <servi..> 113268: a7 f1 3f c0 tml %r15,16320 11326c: b9 04 00 ef lgr %r14,%r15 113270: a7 84 00 01 je 113272 <lgr_info_g..> 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 <add_e..> 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 <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Another round of cleanup for entry[64].S, in particular the program check handler looks more reasonable now. The code size for the 31 bit kernel has been reduced by 616 byte and by 528 byte for the 64 bit version. Even better the code is a bit faster as well. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This patch provides the architecture specific part of the s390 kdump support. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The alignment is missing for various global symbols in s390 assembly code. With a recent gcc and an instruction like stgrl this can lead to a specification exception if the instruction uses such a mis-aligned address. Specify the alignment explicitely and while add it define __ALIGN for s390 and use the ENTRY define to save some lines of code. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The latest binutils won't accept the stfl instruction with march=g5 which is the correct behaviour. Unfortunately head.S is assembled with -march=g5 even if the target cpu is z900 or later. To get 31-bit kernels compiled again the easiest fix is to use the .insn notation for the stfl instruction in head.S. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add a kernel config option for the IBM zEnterprise 196. This will produce faster code on newer compilers using the -march=z196 option. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Change default load address of the initrd in case of IPL from reader. The new load address is directly behind the kernel image. This way we can see immediatly if there are any problems with the code which tries to rescue the initrd in case the bootmem bitmap would overlap with the initrd. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Remove cpu_id from lowcore and replace addr_t with __u64. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix two bugs with the kernel image compression: 1) reset the bss section of the compressed vmlinux 2) clear the high half of the registers for 64 bit early enough for the decompression step Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add the "bzImage" compile target and the necessary code to generate compressed kernel images. The old style uncompressed "image" target is preserved, a simple make will build them both. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>