[S390] boot from NSS support

Add support to boot from a named saved segment (NSS).

Signed-off-by: Hongjie Yang <hongjie@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 7 insertions, 23 deletions

diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index e940e802cb40..030a1c95f47c 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -58,18 +58,11 @@ startup_continue:
         stg     %r15,__LC_KERNEL_STACK  # set end of kernel stack
         aghi    %r15,-160
         xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
-
-        brasl   %r14,ipl_save_parameters
 #
-# clear bss memory
+# Save ipl parameters, clear bss memory, initialize storage key for kernel pages,
+# and create a kernel NSS if the SAVESYS= parm is defined
 #
-        larl    %r2,__bss_start         # start of bss segment
-        larl    %r3,_end                # end of bss segment
-        sgr     %r3,%r2                 # length of bss
-        sgr     %r4,%r4                 #
-        sgr     %r5,%r5                 # set src,length and pad to zero
-        mvcle   %r2,%r4,0               # clear mem
-        jo      .-4                     # branch back, if not finish
+        brasl   %r14,startup_init
                                         # set program check new psw mask
         mvc     __LC_PGM_NEW_PSW(8),.Lpcmsk-.LPG1(%r13)
         larl    %r1,.Lslowmemdetect     # set program check address
@@ -78,6 +71,10 @@ startup_continue:
         diag    %r0,%r1,0x260           # get memory size of virtual machine
         cgr     %r0,%r1                 # different? -> old detection routine
         jne     .Lslowmemdetect
+        larl    %r3,ipl_flags
+        llgt    %r3,0(%r3)
+        chi     %r3,4                   # ipled from an kernel NSS
+        je      .Lslowmemdetect
         aghi    %r1,1                   # size is one more than end
         larl    %r2,memory_chunk
         stg     %r1,8(%r2)              # store size of chunk
@@ -226,19 +223,6 @@ startup_continue:
 
         larl    %r12,machine_flags
 #
-# find out if we are running under VM
-#
-        stidp   __LC_CPUID              # store cpuid
-        tm      __LC_CPUID,0xff         # running under VM ?
-        bno     0f-.LPG1(%r13)
-        oi      7(%r12),1               # set VM flag
-0:      lh      %r0,__LC_CPUID+4        # get cpu version
-        chi     %r0,0x7490              # running on a P/390 ?
-        bne     1f-.LPG1(%r13)
-        oi      7(%r12),4               # set P/390 flag
-1:
-
-#
 # find out if we have the MVPG instruction
 #
         la      %r1,0f-.LPG1(%r13)      # set program check address