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[S390] zcore: CPU registers are not saved under LPAR

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To save the registers for all CPUs a sigp "store status" is done that
stores the registers to address absolute zero. To access storage at
absolute zero, normally the address of the prefix register of the
accessing CPU has to be used. This does not work when large pages are
active (currently only under LPAR). In order to fix that problem,
instead of memcpy memcpy_real is used, which switches to real mode
where prefixing works.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Michael Holzheu
2010-03-24 11:49:50 +01:00
committed by Martin Schwidefsky
parent ae6be51ed0
commit 92fe31329c
4 changed files with 32 additions and 32 deletions
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26
arch/s390/mm/maccess.c
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@@ -59,3 +59,29 @@ long probe_kernel_write(void *dst, void *src, size_t size)
}
return copied < 0 ? -EFAULT : 0;
}
int memcpy_real(void *dest, void *src, size_t count)
{
register unsigned long _dest asm("2") = (unsigned long) dest;
register unsigned long _len1 asm("3") = (unsigned long) count;
register unsigned long _src asm("4") = (unsigned long) src;
register unsigned long _len2 asm("5") = (unsigned long) count;
unsigned long flags;
int rc = -EFAULT;
if (!count)
return 0;
flags = __raw_local_irq_stnsm(0xf8UL);
asm volatile (
"0: mvcle %1,%2,0x0\n"
"1: jo 0b\n"
" lhi %0,0x0\n"
"2:\n"
EX_TABLE(1b,2b)
: "+d" (rc), "+d" (_dest), "+d" (_src), "+d" (_len1),
"+d" (_len2), "=m" (*((long *) dest))
: "m" (*((long *) src))
: "cc", "memory");
__raw_local_irq_ssm(flags);
return rc;
}