• Heiko Carstens's avatar
    s390/smp: make absolute lowcore / cpu restart parameter accesses more robust · fbe76568
    Heiko Carstens authored
    Setting the cpu restart parameters is done in three different fashions:
    - directly setting the four parameters individually
    - copying the four parameters with memcpy (using 4 * sizeof(long))
    - copying the four parameters using a private structure
    
    In addition code in entry*.S relies on a certain order of the restart
    members of struct _lowcore.
    
    Make all of this more robust to future changes by adding a
    mem_absolute_assign(dest, val) define, which assigns val to dest
    using absolute addressing mode. Also the load multiple instructions
    in entry*.S have been split into separate load instruction so the
    order of the struct _lowcore members doesn't matter anymore.
    
    In addition move the prototypes of memcpy_real/absolute from uaccess.h
    to processor.h. These memcpy* variants are not related to uaccess at all.
    string.h doesn't seem to match as well, so lets use processor.h.
    
    Also replace the eight byte array in struct _lowcore which represents a
    misaliged u64 with a u64. The compiler will always create code that
    handles the misaligned u64 correctly.
    Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    fbe76568
os_info.c 3.87 KB