kernel/arch/s390/boot/head.S, branch linux-6.2.y

s390/head: get rid of 31 bit leftovers

2022-05-18T11:31:07Z

Get rid of old 31 bit leftovers within ipl code: - convert everything to pc relative code - use 64 bit addressing mode as early as possible - use 64 bit arithmetics wherever possible This way the code doesn't look as odd as before anymore. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

s390/boot: workaround llvm IAS bug

2022-05-17T13:16:29Z

For at least the mvc and clc instructions llvm's integrated assembler can generate incorrect code. In particular this happens with decompressor boot code. The reason seems to be that relocations for the second displacement of each instruction are at incorrect locations (-/+: gas vs llvm IAS): mvc __LC_IO_NEW_PSW(16),.Lnewpsw results in 4: d2 0f 01 f0 00 00 mvc 496(16,%r0),0 - 8: R_390_12 .head.text+0x10 + 6: R_390_12 .head.text+0x10 and clc 0(3,%r4),.L_hdr results in 258: d5 02 40 00 00 00 clc 0(3,%r4),0 - 25c: R_390_12 .head.text+0x324 + 25a: R_390_12 .head.text+0x324 Workaround this by writing the code in a different way. Tested-by: Nathan Chancellor Tested-by: Nick Desaulniers Link: https://github.com/llvm/llvm-project/issues/55411 Link: https://lore.kernel.org/r/20220511120532.2228616-7-hca@linux.ibm.com Signed-off-by: Heiko Carstens

s390/boot: convert parmarea to C

2022-05-06T18:45:15Z

Convert parmarea to C, which makes it much easier to initialize it. No need to keep offsets in assembler code in sync with struct parmarea anymore. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/boot: convert initial lowcore to C

2022-05-06T18:45:15Z

Convert initial lowcore to C and use proper defines and structures to initialize it. This should make the z/VM ipl procedure a bit less magic. Acked-by: Peter Oberparleiter Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/head: initialize all new psws

2022-05-06T18:45:15Z

Initialize all new psws with disabled wait psws, except for the restart new psw. This way every unexpected exception, svc, machine check, or interrupt is handled properly. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/boot: change initial program check handler to disabled wait psw

2022-05-06T18:45:15Z

The program check handler of the kernel image points to startup_pgm_check_handler. However an early program check which happens while loading the kernel image will jump to potentially random code, since the code of the program check handler is not yet loaded; leading to a program check loop. Therefore initialize it to a disabled wait psw and let the startup code set the proper psw when everything is in memory. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/head: adjust iplstart entry point

2022-05-06T18:45:14Z

Move iplstart entry point to 0x200 again, instead of the middle of the ipl code. This way even the comment describing the ccw program is correct again. Acked-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390: remove invalid email address of Heiko Carstens

2022-02-06T22:31:29Z

Remove my old invalid email address which can be found in a couple of files. Instead of updating it, just remove my contact data completely from source files. We have git and other tools which allow to figure out who is responsible for what with recent contact data. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: support command lines longer than 896 bytes

2021-10-26T13:21:31Z

Currently s390 supports a fixed maximum command line length of 896 bytes. This isn't enough as some installers are trying to pass all configuration data via kernel command line, and even with zfcp alone it is easy to generate really long command lines. Therefore extend the command line to 4 kbytes. In the parm area where the command line is stored there is no indication of the maximum allowed length, so a new field which contains the maximum length is added. The parm area has always been initialized to zero, so with old kernels this field would read zero. This is important because tools like zipl could read this field. If it contains a number larger than zero zipl knows the maximum length that can be stored in the parm area, otherwise it must assume that it is booting a legacy kernel and only 896 bytes are available. The removing of trailing whitespace in head.S is also removed because code to do this is already present in setup_boot_command_line(). Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/kexec_file: move kernel image size check

2021-10-26T13:21:30Z

In preparation of adding support for command lines with variable sizes on s390, the check whether the new kernel image is at least HEAD_END bytes long isn't correct. Move the check to kexec_file_add_components() so we can get the size of the parm area and check the size there. The '.org HEAD_END' directive can now also be removed from head.S. This was used in the past to reserve space for the early sccb buffer, but with commit 9a5131b87cac1 ("s390/boot: move sclp early buffer from fixed address in asm to C") this is no longer required. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik