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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2010-03-24 11:49:50 +0100
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2010-03-24 11:49:53 +0100
commit92fe31329cb3a2b02f1c7616965872d6a34bcf08 (patch)
tree678d046b5864d302e424a2377cf1974b95b1d1f8 /arch/s390/mm
parentae6be51ed01d6c4aaf249a207b4434bc7785853b (diff)
downloadlinux-linaro-android-92fe31329cb3a2b02f1c7616965872d6a34bcf08.tar.gz
[S390] zcore: CPU registers are not saved under LPAR
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>
Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/maccess.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 81756271dc4..a8c2af8c650 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -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;
+}