kernel.git/arch/s390/kernel/early.c, branch linux-6.10.y

s390/fpu: move, rename, and merge header files

2024-02-16T13:30:14Z

Move, rename, and merge the fpu and vx header files. This way fpu header files have a consistent naming scheme (fpu*.h). Also get rid of the fpu subdirectory and move header files to asm directory, so that all fpu and vx header files can be found at the same location. Merge internal.h header file into other header files, since the internal helpers are used at many locations. so those helper functions are really not internal. Signed-off-by: Heiko Carstens

s390/acrs: cleanup access register handling

2024-02-12T14:03:33Z

save_access_regs() and restore_access_regs() are only available by including switch_to.h. This is done by a couple of C files, which have nothing to do with switch_to(), but only need these functions. Move both functions to a new header file and improve the implementation: - Get rid of typedef - Add memory access instrumentation support - Use long displacement instructions lamy/stamy instead of lam/stam - all current users end up with better code because of this Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/fpu: get rid of MACHINE_HAS_VX

2023-12-11T13:33:07Z

Get rid of MACHINE_HAS_VX and replace it with cpu_has_vx() which is a short readable wrapper for "test_facility(129)". Facility bit 129 is set if the vector facility is present. test_facility() returns also true for all bits which are set in the architecture level set of the cpu that the kernel is compiled for. This means that test_facility(129) is a compile time constant which returns true for z13 and later, since the vector facility bit is part of the z13 kernel ALS. In result the compiled code will have less runtime checks, and less code. Reviewed-by: Hendrik Brueckner Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/fpu: remove "novx" option

2023-12-11T13:33:06Z

Remove the "novx" kernel command line option: the vector code runs without any problems since many years. Reviewed-by: Hendrik Brueckner Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/cmma: move parsing of cmma kernel parameter to early boot code

2023-11-05T21:34:57Z

The "cmma=" kernel command line parameter needs to be parsed early for upcoming changes. Therefore move the parsing code. Note that EX_TABLE handling of cmma_test_essa() needs to be open-coded, since the early boot code doesn't have infrastructure for handling expected exceptions. Reviewed-by: Claudio Imbrenda Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: use control register bit defines

2023-09-19T11:26:57Z

Use control register bit defines instead of plain numbers where possible. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/early: use system_ctl_set_bit() instead of local_ctl_set_bit()

2023-09-19T11:26:57Z

Use system_ctl_set_bit() instead of local_ctl_set_bit() to reflect that the control register changes are supposed to be global. This change is just for documentation purposes, since it still results only in local control register contents being changed. Signed-off-by: Heiko Carstens Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390/ctlreg: add local and system prefix to some functions

2023-09-19T11:26:56Z

Add local and system prefix to some functions to clarify they change control register contents on either the local CPU or the on all CPUs. This results in the following API: Two defines which load and save multiple control registers. The defines correlate with the following C prototypes: void __local_ctl_load(unsigned long *, unsigned int cr_low, unsigned int cr_high); void __local_ctl_store(unsigned long *, unsigned int cr_low, unsigned int cr_high); Two functions which locally set or clear one bit for a specified control register: void local_ctl_set_bit(unsigned int cr, unsigned int bit); void local_ctl_clear_bit(unsigned int cr, unsigned int bit); Two functions which set or clear one bit for a specified control register on all CPUs: void system_ctl_set_bit(unsigned int cr, unsigned int bit); void system_ctl_clear_bit(unsigend int cr, unsigned int bit); Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/smp,mcck: fix early IPI handling

2023-09-19T11:26:55Z

Both the external call as well as the emergency signal submask bits in control register 0 are set before any interrupt handler is registered. Change the order and first register the interrupt handler and only then enable the interrupts by setting the corresponding bits in control register 0. This prevents that the second part of the machine check handler for early machine check handling is not executed: the machine check handler sends an IPI to the CPU it runs on. If the corresponding interrupts are enabled, but no interrupt handler is present, the interrupt is ignored. Reviewed-by: Sven Schnelle Acked-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mm: simplify kernel mapping setup

2023-08-30T09:03:27Z

The kernel mapping is setup in two stages: in the decompressor map all pages with RWX permissions, and within the kernel change all mappings to their final permissions, where most of the mappings are changed from RWX to RWNX. Change this and map all pages RWNX from the beginning, however without enabling noexec via control register modification. This means that effectively all pages are used with RWX permissions like before. When the final permissions have been applied to the kernel mapping enable noexec via control register modification. This allows to remove quite a bit of non-obvious code. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens