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Subject[patch 10/11] s390: memory detection > 32GB.
[patch 10/11] s390: memory detection > 32GB.

From: Heiko Carstens <heiko.carstens@de.ibm.com>

The kernel takes a very long time to boot if the memory size is bigger
then 32767 MB. The memory size is contained in a structure created by
an sclp call. The kernel accesses the field with a LH instrution which
performs a sign extension of a 16 bit word. In the case of a memory size
with bit 2^15 set this results in a very large value and the memory
detection just loops for a long time. In addition if more then 64 GB
are used on a 64 bit system the memory size is read from an incorrect
storage location.
Use zero-extention to read the 16 bit memory size and the correct offset
to read the 4 byte memory size on 64 bit.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diffstat:
arch/s390/kernel/head.S | 8 ++++----
arch/s390/kernel/head64.S | 6 +++---
2 files changed, 7 insertions(+), 7 deletions(-)

diff -urpN linux-2.6/arch/s390/kernel/head64.S linux-2.6-patched/arch/s390/kernel/head64.S
--- linux-2.6/arch/s390/kernel/head64.S 2005-03-02 08:37:54.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/head64.S 2005-06-01 19:43:21.000000000 +0200
@@ -518,9 +518,9 @@ startup:basr %r13,0
l %r2,.Lrcp2-.LPG1(%r13) # try with Read SCP
b .Lservicecall-.LPG1(%r13)
.Lprocsccb:
- lh %r1,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
- chi %r1,0x00
- jne .Lscnd
+ lghi %r1,0
+ icm %r1,3,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
+ jnz .Lscnd
lg %r1,.Lscpincr2-PARMAREA(%r4) # otherwise use this one
.Lscnd:
xr %r3,%r3 # same logic
diff -urpN linux-2.6/arch/s390/kernel/head.S linux-2.6-patched/arch/s390/kernel/head.S
--- linux-2.6/arch/s390/kernel/head.S 2005-03-02 08:37:51.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/head.S 2005-06-01 19:43:21.000000000 +0200
@@ -517,10 +517,10 @@ startup:basr %r13,0
l %r2, .Lrcp2-.LPG1(%r13) # try with Read SCP
b .Lservicecall-.LPG1(%r13)
.Lprocsccb:
- lh %r1,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
- chi %r1,0x00
- jne .Lscnd
- l %r1,.Lscpincr2-PARMAREA(%r4) # otherwise use this one
+ lhi %r1,0
+ icm %r1,3,.Lscpincr1-PARMAREA(%r4) # use this one if != 0
+ jnz .Lscnd
+ l %r1,.Lscpincr2-PARMAREA+4(%r4) # otherwise use this one
.Lscnd:
xr %r3,%r3 # same logic
ic %r3,.Lscpa1-PARMAREA(%r4)
-
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