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-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 81756271dc44..a8c2af8c650f 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;
+}