s390/kdump: add support for vector extension
With this patch for kdump the s390 vector registers are stored into the prepared save areas in the old kernel and into the REGSET_VX_LOW and REGSET_VX_HIGH ELF notes for /proc/vmcore in the new kernel. The NT_S390_VXRS_LOW note contains the lower halves of the first 16 vector registers 0-15. The higher halves are stored in the floating point register ELF note. The NT_S390_VXRS_HIGH contains the full vector registers 16-31. The kernel provides a save area for storing vector register in case of machine checks. A pointer to this save are is stored in the CPU lowcore at offset 0x11b0. This save area is also used to save the registers for kdump. In case of a dumped crashed kdump those areas are used to extract the registers of the production system. The vector registers for remote CPUs are stored using the "store additional status at address" SIGP. For the dump CPU the vector registers are stored with the VSTM instruction. With this patch also zfcpdump stores the vector registers. Reviewed-by:Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: