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-rw-r--r--arch/s390/lib/mem32.S92
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/s390/lib/mem32.S b/arch/s390/lib/mem32.S
new file mode 100644
index 000000000000..14ca9244b615
--- /dev/null
+++ b/arch/s390/lib/mem32.S
@@ -0,0 +1,92 @@
+/*
+ * String handling functions.
+ *
+ * Copyright IBM Corp. 2012
+ */
+
+#include <linux/linkage.h>
+
+/*
+ * memset implementation
+ *
+ * This code corresponds to the C construct below. We do distinguish
+ * between clearing (c == 0) and setting a memory array (c != 0) simply
+ * because nearly all memset invocations in the kernel clear memory and
+ * the xc instruction is preferred in such cases.
+ *
+ * void *memset(void *s, int c, size_t n)
+ * {
+ * if (likely(c == 0))
+ * return __builtin_memset(s, 0, n);
+ * return __builtin_memset(s, c, n);
+ * }
+ */
+ENTRY(memset)
+ basr %r5,%r0
+.Lmemset_base:
+ ltr %r4,%r4
+ bzr %r14
+ ltr %r3,%r3
+ jnz .Lmemset_fill
+ ahi %r4,-1
+ lr %r3,%r4
+ srl %r3,8
+ ltr %r3,%r3
+ lr %r1,%r2
+ je .Lmemset_clear_rest
+.Lmemset_clear_loop:
+ xc 0(256,%r1),0(%r1)
+ la %r1,256(%r1)
+ brct %r3,.Lmemset_clear_loop
+.Lmemset_clear_rest:
+ ex %r4,.Lmemset_xc-.Lmemset_base(%r5)
+ br %r14
+.Lmemset_fill:
+ stc %r3,0(%r2)
+ chi %r4,1
+ lr %r1,%r2
+ ber %r14
+ ahi %r4,-2
+ lr %r3,%r4
+ srl %r3,8
+ ltr %r3,%r3
+ je .Lmemset_fill_rest
+.Lmemset_fill_loop:
+ mvc 1(256,%r1),0(%r1)
+ la %r1,256(%r1)
+ brct %r3,.Lmemset_fill_loop
+.Lmemset_fill_rest:
+ ex %r4,.Lmemset_mvc-.Lmemset_base(%r5)
+ br %r14
+.Lmemset_xc:
+ xc 0(1,%r1),0(%r1)
+.Lmemset_mvc:
+ mvc 1(1,%r1),0(%r1)
+
+/*
+ * memcpy implementation
+ *
+ * void *memcpy(void *dest, const void *src, size_t n)
+ */
+ENTRY(memcpy)
+ basr %r5,%r0
+.Lmemcpy_base:
+ ltr %r4,%r4
+ bzr %r14
+ ahi %r4,-1
+ lr %r0,%r4
+ srl %r0,8
+ ltr %r0,%r0
+ lr %r1,%r2
+ jnz .Lmemcpy_loop
+.Lmemcpy_rest:
+ ex %r4,.Lmemcpy_mvc-.Lmemcpy_base(%r5)
+ br %r14
+.Lmemcpy_loop:
+ mvc 0(256,%r1),0(%r3)
+ la %r1,256(%r1)
+ la %r3,256(%r3)
+ brct %r0,.Lmemcpy_loop
+ j .Lmemcpy_rest
+.Lmemcpy_mvc:
+ mvc 0(1,%r1),0(%r3)
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