1 /* SPDX-License-Identifier: GPL-2.0 */
3 * String handling functions.
5 * Copyright IBM Corp. 2012
8 #include <linux/linkage.h>
9 #include <asm/export.h>
10 #include <asm/nospec-insn.h>
15 * void *memmove(void *dest, const void *src, size_t n)
30 jz .Lmemmove_forward_remainder
31 .Lmemmove_forward_loop:
35 brctg %r0,.Lmemmove_forward_loop
36 .Lmemmove_forward_remainder:
37 larl %r5,.Lmemmove_mvc
44 brctg %r4,.Lmemmove_reverse
50 EXPORT_SYMBOL(memmove)
53 * memset implementation
55 * This code corresponds to the C construct below. We do distinguish
56 * between clearing (c == 0) and setting a memory array (c != 0) simply
57 * because nearly all memset invocations in the kernel clear memory and
58 * the xc instruction is preferred in such cases.
60 * void *memset(void *s, int c, size_t n)
63 * return __builtin_memset(s, 0, n);
64 * return __builtin_memset(s, c, n);
76 jz .Lmemset_clear_remainder
80 brctg %r3,.Lmemset_clear_loop
81 .Lmemset_clear_remainder:
93 jz .Lmemset_fill_remainder
98 brctg %r5,.Lmemset_fill_loop
99 .Lmemset_fill_remainder:
101 larl %r5,.Lmemset_mvc
111 EXPORT_SYMBOL(memset)
114 * memcpy implementation
116 * void *memcpy(void *dest, const void *src, size_t n)
127 larl %r5,.Lmemcpy_mvc
132 mvc 0(256,%r1),0(%r3)
135 brctg %r5,.Lmemcpy_loop
139 EXPORT_SYMBOL(memcpy)
144 * void *__memset16(uint16_t *s, uint16_t v, size_t count)
145 * void *__memset32(uint32_t *s, uint32_t v, size_t count)
146 * void *__memset64(uint64_t *s, uint64_t v, size_t count)
148 .macro __MEMSET bits,bytes,insn
151 jz .L__memset_exit\bits
153 je .L__memset_store\bits
158 jz .L__memset_remainder\bits
159 .L__memset_loop\bits:
161 mvc \bytes(256-\bytes,%r1),0(%r1)
163 brctg %r5,.L__memset_loop\bits
164 .L__memset_remainder\bits:
166 larl %r5,.L__memset_mvc\bits
169 .L__memset_store\bits:
171 .L__memset_exit\bits:
174 mvc \bytes(1,%r1),0(%r1)
178 EXPORT_SYMBOL(__memset16)
181 EXPORT_SYMBOL(__memset32)
184 EXPORT_SYMBOL(__memset64)