[S390] kernel: Use local_irq_save() for memcpy_real()

Currently in the memcpy_real() function interrupts are disabled with
__arch_local_irq_stnsm(). In order to notify lockdep that interrupts
are disabled, with this patch local_irq_save() is used instead. The
function __arch_local_irq_stnsm() is still used for switching to
real mode.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 18 insertions, 9 deletions

diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 7bb15fcca75e..e1335dc2b1b7 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -61,21 +61,14 @@ long probe_kernel_write(void *dst, const void *src, size_t size)
         return copied < 0 ? -EFAULT : 0;
 }
 
-/*
- * Copy memory in real mode (kernel to kernel)
- */
-int memcpy_real(void *dest, void *src, size_t count)
+static 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 = __arch_local_irq_stnsm(0xf8UL);
         asm volatile (
                 "0:     mvcle   %1,%2,0x0\n"
                 "1:     jo      0b\n"
@@ -86,7 +79,23 @@ int memcpy_real(void *dest, void *src, size_t count)
                   "+d" (_len2), "=m" (*((long *) dest))
                 : "m" (*((long *) src))
                 : "cc", "memory");
-        arch_local_irq_restore(flags);
+        return rc;
+}
+
+/*
+ * Copy memory in real mode (kernel to kernel)
+ */
+int memcpy_real(void *dest, void *src, size_t count)
+{
+        unsigned long flags;
+        int rc;
+
+        if (!count)
+                return 0;
+        local_irq_save(flags);
+        __arch_local_irq_stnsm(0xfbUL);
+        rc = __memcpy_real(dest, src, count);
+        local_irq_restore(flags);
         return rc;
 }