| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * String handling functions. |
| * |
| * Copyright IBM Corp. 2012 |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/export.h> |
| #include <asm/nospec-insn.h> |
| |
| GEN_BR_THUNK %r14 |
| |
| /* |
| * void *memmove(void *dest, const void *src, size_t n) |
| */ |
| ENTRY(memmove) |
| ltgr %r4,%r4 |
| lgr %r1,%r2 |
| jz .Lmemmove_exit |
| aghi %r4,-1 |
| clgr %r2,%r3 |
| jnh .Lmemmove_forward |
| la %r5,1(%r4,%r3) |
| clgr %r2,%r5 |
| jl .Lmemmove_reverse |
| .Lmemmove_forward: |
| srlg %r0,%r4,8 |
| ltgr %r0,%r0 |
| jz .Lmemmove_forward_remainder |
| .Lmemmove_forward_loop: |
| mvc 0(256,%r1),0(%r3) |
| la %r1,256(%r1) |
| la %r3,256(%r3) |
| brctg %r0,.Lmemmove_forward_loop |
| .Lmemmove_forward_remainder: |
| larl %r5,.Lmemmove_mvc |
| ex %r4,0(%r5) |
| .Lmemmove_exit: |
| BR_EX %r14 |
| .Lmemmove_reverse: |
| ic %r0,0(%r4,%r3) |
| stc %r0,0(%r4,%r1) |
| brctg %r4,.Lmemmove_reverse |
| ic %r0,0(%r4,%r3) |
| stc %r0,0(%r4,%r1) |
| BR_EX %r14 |
| .Lmemmove_mvc: |
| mvc 0(1,%r1),0(%r3) |
| EXPORT_SYMBOL(memmove) |
| |
| /* |
| * 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) |
| ltgr %r4,%r4 |
| jz .Lmemset_exit |
| ltgr %r3,%r3 |
| jnz .Lmemset_fill |
| aghi %r4,-1 |
| srlg %r3,%r4,8 |
| ltgr %r3,%r3 |
| lgr %r1,%r2 |
| jz .Lmemset_clear_remainder |
| .Lmemset_clear_loop: |
| xc 0(256,%r1),0(%r1) |
| la %r1,256(%r1) |
| brctg %r3,.Lmemset_clear_loop |
| .Lmemset_clear_remainder: |
| larl %r3,.Lmemset_xc |
| ex %r4,0(%r3) |
| .Lmemset_exit: |
| BR_EX %r14 |
| .Lmemset_fill: |
| stc %r3,0(%r2) |
| cghi %r4,1 |
| lgr %r1,%r2 |
| je .Lmemset_fill_exit |
| aghi %r4,-2 |
| srlg %r3,%r4,8 |
| ltgr %r3,%r3 |
| jz .Lmemset_fill_remainder |
| .Lmemset_fill_loop: |
| mvc 1(256,%r1),0(%r1) |
| la %r1,256(%r1) |
| brctg %r3,.Lmemset_fill_loop |
| .Lmemset_fill_remainder: |
| larl %r3,.Lmemset_mvc |
| ex %r4,0(%r3) |
| .Lmemset_fill_exit: |
| BR_EX %r14 |
| .Lmemset_xc: |
| xc 0(1,%r1),0(%r1) |
| .Lmemset_mvc: |
| mvc 1(1,%r1),0(%r1) |
| EXPORT_SYMBOL(memset) |
| |
| /* |
| * memcpy implementation |
| * |
| * void *memcpy(void *dest, const void *src, size_t n) |
| */ |
| ENTRY(memcpy) |
| ltgr %r4,%r4 |
| jz .Lmemcpy_exit |
| aghi %r4,-1 |
| srlg %r5,%r4,8 |
| ltgr %r5,%r5 |
| lgr %r1,%r2 |
| jnz .Lmemcpy_loop |
| .Lmemcpy_remainder: |
| larl %r5,.Lmemcpy_mvc |
| ex %r4,0(%r5) |
| .Lmemcpy_exit: |
| BR_EX %r14 |
| .Lmemcpy_loop: |
| mvc 0(256,%r1),0(%r3) |
| la %r1,256(%r1) |
| la %r3,256(%r3) |
| brctg %r5,.Lmemcpy_loop |
| j .Lmemcpy_remainder |
| .Lmemcpy_mvc: |
| mvc 0(1,%r1),0(%r3) |
| EXPORT_SYMBOL(memcpy) |