1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* memmove.S: Simple memmove implementation. 3 * 4 * Copyright (C) 1997, 2004 David S. Miller (davem@redhat.com) 5 * Copyright (C) 1996, 1997, 1998, 1999 Jakub Jelinek (jj@ultra.linux.cz) 6 */ 7 8 #include <linux/export.h> 9 #include <linux/linkage.h> 10 11 .text 12 ENTRY(memmove) /* o0=dst o1=src o2=len */ 13 brz,pn %o2, 99f 14 mov %o0, %g1 15 16 cmp %o0, %o1 17 bleu,pt %xcc, 2f 18 add %o1, %o2, %g7 19 cmp %g7, %o0 20 bleu,pt %xcc, memcpy 21 add %o0, %o2, %o5 22 sub %g7, 1, %o1 23 24 sub %o5, 1, %o0 25 1: ldub [%o1], %g7 26 subcc %o2, 1, %o2 27 sub %o1, 1, %o1 28 stb %g7, [%o0] 29 bne,pt %icc, 1b 30 sub %o0, 1, %o0 31 99: 32 retl 33 mov %g1, %o0 34 35 /* We can't just call memcpy for these memmove cases. On some 36 * chips the memcpy uses cache initializing stores and when dst 37 * and src are close enough, those can clobber the source data 38 * before we've loaded it in. 39 */ 40 2: or %o0, %o1, %g7 41 or %o2, %g7, %g7 42 andcc %g7, 0x7, %g0 43 bne,pn %xcc, 4f 44 nop 45 46 3: ldx [%o1], %g7 47 add %o1, 8, %o1 48 subcc %o2, 8, %o2 49 add %o0, 8, %o0 50 bne,pt %icc, 3b 51 stx %g7, [%o0 - 0x8] 52 ba,a,pt %xcc, 99b 53 54 4: ldub [%o1], %g7 55 add %o1, 1, %o1 56 subcc %o2, 1, %o2 57 add %o0, 1, %o0 58 bne,pt %icc, 4b 59 stb %g7, [%o0 - 0x1] 60 ba,a,pt %xcc, 99b 61 ENDPROC(memmove) 62 EXPORT_SYMBOL(memmove)
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