• Gerald Schaefer's avatar
    s390/kernel: introduce .dma sections · a80313ff
    Gerald Schaefer authored
    With a relocatable kernel that could reside at any place in memory, code
    and data that has to stay below 2 GB needs special handling.
    
    This patch introduces .dma sections for such text, data and ex_table.
    The sections will be part of the decompressor kernel, so they will not
    be relocated and stay below 2 GB. Their location is passed over to the
    decompressed / relocated kernel via the .boot.preserved.data section.
    
    The duald and aste for control register setup also need to stay below
    2 GB, so move the setup code from arch/s390/kernel/head64.S to
    arch/s390/boot/head.S. The duct and linkage_stack could reside above
    2 GB, but their content has to be preserved for the decompresed kernel,
    so they are also moved into the .dma section.
    
    The start and end address of the .dma sections is added to vmcoreinfo,
    for crash support, to help debugging in case the kernel crashed there.
    Signed-off-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
    Reviewed-by: default avatarPhilipp Rudo <prudo@linux.ibm.com>
    Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    a80313ff
ipl.c 46.7 KB