kernel/linux.git/arch/s390/include/asm/setup.h, branch v6.1.174

s390: make command line configurable

2021-10-26T13:21:31+00:00

Allow to configure the command line to an arbitrary length, with a default of 4096 bytes. Also remove COMMAND_LINE_SIZE from include/uapi/asm/setup.h as this is dynamic now and doesn't tell anything about the command line size limitations of a new kernel that might be loaded. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: support command lines longer than 896 bytes

2021-10-26T13:21:31+00:00

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

2021-10-26T13:21:30+00:00

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

s390: make PCI mio support a machine flag

2021-07-27T07:39:19+00:00

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: move EP_OFFSET and EP_STRING to head.S

2021-07-27T07:39:16+00:00

Both macros are used only in decompressor's head.S, unnecessary to put them in a global header used in many places like setup.h is. Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/setup: generate asm offsets from struct parmarea

2021-07-27T07:39:16+00:00

To reduce duplication, replace error-prone and hard-coded parameter area offsets with auto-generated ones. Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/setup: drop _OFFSET macros

2021-07-27T07:39:16+00:00

The macros * IPL_DEVICE_OFFSET * INITRD_START_OFFSET * INITRD_SIZE_OFFSET * OLDMEM_BASE_OFFSET * OLDMEM_SIZE_OFFSET * KERNEL_VERSION_OFFSET * COMMAND_LINE_OFFSET are no longer necessary and used only to define another set of macros with the same names but w/o the suffix _OFFSET. Therefore, drop this unnecessary indirection. Drop the macro KERNEL_VERSION_OFFSET w/o renaming it to KERNEL_VERSION because it is used nowhere. Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/setup: remove unused symbolic constants for C code from setup.h

2021-07-27T07:39:16+00:00

These symbolic constants are used only by assembler code now: * COMMAND_LINE * IPL_DEVICE C code of the decompressed kernel should use boot data passed by the decompressor instead. Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/dump: introduce boot data 'oldmem_data'

2021-07-27T07:39:16+00:00

The new boot data struct shall replace global variables OLDMEM_BASE and OLDMEM_SIZE. It is initialized in the decompressor and passed to the decompressed kernel. In comparison to the old solution, this one doesn't access data at fixed physical addresses which will become important when the decompressor becomes relocatable. Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/boot: introduce boot data 'initrd_data'

2021-07-27T07:39:15+00:00

The new boot data struct shall replace global variables INITRD_START and INITRD_SIZE. It is initialized in the decompressor and passed to the decompressed kernel. In comparison to the old solution, this one doesn't access data at fixed physical addresses which will become important when the decompressor becomes relocatable. Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens