kernel.git/arch/s390/kernel/early.c, branch linux-5.18.y

s390/extable: add and use fixup_exception helper function

2022-03-07T23:33:00Z

Add and use fixup_exception helper function in order to remove the duplicated exception handler fixup code at several places. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/base: pass pt_regs to early program check handler

2022-03-07T23:33:00Z

Pass pt_regs to early program check handler like it is done for every other interrupt and exception handler. Also the passed pt_regs can be changed by the called function and the changes register contents and psw contents will be taken into account when returning. In addition the return psw will not be copied to the program check old psw in lowcore, but to the usual return psw location, like it is also done by the regular program check handler. This allows also to get rid of the code that disabled lowcore protection when changing the return address. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/extable: move EX_TABLE define to asm-extable.h

2022-03-07T23:33:00Z

Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h which is a lot less generic than the current linkage.h. Also make sure that all files which contain EX_TABLE usages actually include the new header file. This should make sure that the files always compile and there won't be any random compile breakage due to other header file dependencies. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/extable: sort amode31 extable early

2022-03-07T23:33:00Z

The early program check handler is active before the amode31 extable is sorted. Therefore in case a program check happens early within the amode31 code the extable entry might not be found. Fix this by sorting the amode31 extable early. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

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/sclp: sort out physical vs virtual pointers usage

2021-10-26T13:21:28Z

Provide physical addresses whenever the hardware interface expects it or a 32-bit value used for tracking. Variable sclp_early_sccb gets initialized in the decompressor and points to an address in physcal memory. Yet, it is used as virtual memory pointer and therefore should be converted. Note, the other two __bootdata variables sclp_info_sccb and sclp_info_sccb_valid contain plain data, but no pointers and do need any special care. Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390: make PCI mio support a machine flag

2021-07-27T07:39:19Z

Kernel support for the newer PCI mio instructions can be toggled off with the pci=nomio command line option which needs to integrate with common code PCI option parsing. However this option then toggles static branches which can't be toggled yet in an early_param() call. Thus commit 9964f396f1d0 ("s390: fix setting of mio addressing control") moved toggling the static branches to the PCI init routine. With this setup however we can't check for mio support outside the PCI code during early boot, i.e. before switching the static branches, which we need to be able to export this as an ELF HWCAP. Improve on this by turning mio availability into a machine flag that gets initially set based on CONFIG_PCI and the facility bit and gets toggled off if pci=nomio is found during PCI option parsing allowing simple access to this machine flag after early init. Reviewed-by: Heiko Carstens Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens

s390/boot: replace magic string check with a bootdata flag

2021-07-05T10:44:23Z

The magic string "S390EP" at offset 0x10008 indicated to the decompressed kernel that it was booted by the decompressor. Introduce a new bootdata flag instead which conveys the same information in an explicit and a cleaner way. But keep the magic string because it is a kernel ABI. Signed-off-by: Alexander Egorenkov Reviewed-by: Vasily Gorbik Signed-off-by: Vasily Gorbik

s390/facilities: move stfl information from lowcore to global data

2021-06-07T15:06:58Z

With gcc-11, there are a lot of warnings because the facility functions are accessing lowcore through a null pointer. Fix this by moving the facility arrays away from lowcore. Signed-off-by: Sven Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik