/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) Paul Mackerras 1997.
 *
 * NOTE: this code runs in 32 bit mode and is packaged as ELF32.
 */

#include "ppc_asm.h"

        .text
        .globl  strcpy
strcpy:
        addi    r5,r3,-1
        addi    r4,r4,-1
1:      lbzu    r0,1(r4)
        cmpwi   0,r0,0
        stbu    r0,1(r5)
        bne     1b
        blr

        .globl  strncpy
strncpy:
        cmpwi   0,r5,0
        beqlr
        mtctr   r5
        addi    r6,r3,-1
        addi    r4,r4,-1
1:      lbzu    r0,1(r4)
        cmpwi   0,r0,0
        stbu    r0,1(r6)
        bdnzf   2,1b            /* dec ctr, branch if ctr != 0 && !cr0.eq */
        blr

        .globl  strcat
strcat:
        addi    r5,r3,-1
        addi    r4,r4,-1
1:      lbzu    r0,1(r5)
        cmpwi   0,r0,0
        bne     1b
        addi    r5,r5,-1
1:      lbzu    r0,1(r4)
        cmpwi   0,r0,0
        stbu    r0,1(r5)
        bne     1b
        blr

        .globl  strchr
strchr:
        addi    r3,r3,-1
1:      lbzu    r0,1(r3)
        cmpw    0,r0,r4
        beqlr
        cmpwi   0,r0,0
        bne     1b
        li      r3,0
        blr

        .globl  strcmp
strcmp:
        addi    r5,r3,-1
        addi    r4,r4,-1
1:      lbzu    r3,1(r5)
        cmpwi   1,r3,0
        lbzu    r0,1(r4)
        subf.   r3,r0,r3
        beqlr   1
        beq     1b
        blr

        .globl  strncmp
strncmp:
        mtctr   r5
        addi    r5,r3,-1
        addi    r4,r4,-1
1:      lbzu    r3,1(r5)
        cmpwi   1,r3,0
        lbzu    r0,1(r4)
        subf.   r3,r0,r3
        beqlr   1
        bdnzt   eq,1b
        blr

        .globl  strlen
strlen:
        addi    r4,r3,-1
1:      lbzu    r0,1(r4)
        cmpwi   0,r0,0
        bne     1b
        subf    r3,r3,r4
        blr

        .globl  memset
memset:
        rlwimi  r4,r4,8,16,23
        rlwimi  r4,r4,16,0,15
        addi    r6,r3,-4
        cmplwi  0,r5,4
        blt     7f
        stwu    r4,4(r6)
        beqlr
        andi.   r0,r6,3
        add     r5,r0,r5
        subf    r6,r0,r6
        rlwinm  r0,r5,32-2,2,31
        mtctr   r0
        bdz     6f
1:      stwu    r4,4(r6)
        bdnz    1b
6:      andi.   r5,r5,3
7:      cmpwi   0,r5,0
        beqlr
        mtctr   r5
        addi    r6,r6,3
8:      stbu    r4,1(r6)
        bdnz    8b
        blr

        .globl  memmove
memmove:
        cmplw   0,r3,r4
        bgt     backwards_memcpy
        /* fall through */

        .globl  memcpy
memcpy:
        rlwinm. r7,r5,32-3,3,31         /* r7 = r5 >> 3 */
        addi    r6,r3,-4
        addi    r4,r4,-4
        beq     3f                      /* if less than 8 bytes to do */
        andi.   r0,r6,3                 /* get dest word aligned */
        mtctr   r7
        bne     5f
        andi.   r0,r4,3                 /* check src word aligned too */
        bne     3f
1:      lwz     r7,4(r4)
        lwzu    r8,8(r4)
        stw     r7,4(r6)
        stwu    r8,8(r6)
        bdnz    1b
        andi.   r5,r5,7
2:      cmplwi  0,r5,4
        blt     3f
        lwzu    r0,4(r4)
        addi    r5,r5,-4
        stwu    r0,4(r6)
3:      cmpwi   0,r5,0
        beqlr
        mtctr   r5
        addi    r4,r4,3
        addi    r6,r6,3
4:      lbzu    r0,1(r4)
        stbu    r0,1(r6)
        bdnz    4b
        blr
5:      subfic  r0,r0,4
        cmpw    cr1,r0,r5
        add     r7,r0,r4
        andi.   r7,r7,3                 /* will source be word-aligned too? */
        ble     cr1,3b
        bne     3b                      /* do byte-by-byte if not */
        mtctr   r0
6:      lbz     r7,4(r4)
        addi    r4,r4,1
        stb     r7,4(r6)
        addi    r6,r6,1
        bdnz    6b
        subf    r5,r0,r5
        rlwinm. r7,r5,32-3,3,31
        beq     2b
        mtctr   r7
        b       1b

        .globl  backwards_memcpy
backwards_memcpy:
        rlwinm. r7,r5,32-3,3,31         /* r7 = r5 >> 3 */
        add     r6,r3,r5
        add     r4,r4,r5
        beq     3f
        andi.   r0,r6,3
        mtctr   r7
        bne     5f
        andi.   r0,r4,3
        bne     3f
1:      lwz     r7,-4(r4)
        lwzu    r8,-8(r4)
        stw     r7,-4(r6)
        stwu    r8,-8(r6)
        bdnz    1b
        andi.   r5,r5,7
2:      cmplwi  0,r5,4
        blt     3f
        lwzu    r0,-4(r4)
        subi    r5,r5,4
        stwu    r0,-4(r6)
3:      cmpwi   0,r5,0
        beqlr
        mtctr   r5
4:      lbzu    r0,-1(r4)
        stbu    r0,-1(r6)
        bdnz    4b
        blr
5:      cmpw    cr1,r0,r5
        subf    r7,r0,r4
        andi.   r7,r7,3
        ble     cr1,3b
        bne     3b
        mtctr   r0
6:      lbzu    r7,-1(r4)
        stbu    r7,-1(r6)
        bdnz    6b
        subf    r5,r0,r5
        rlwinm. r7,r5,32-3,3,31
        beq     2b
        mtctr   r7
        b       1b

        .globl  memchr
memchr:
        cmpwi   0,r5,0
        blelr
        mtctr   r5
        addi    r3,r3,-1
1:      lbzu    r0,1(r3)
        cmpw    r0,r4
        beqlr
        bdnz    1b
        li      r3,0
        blr

        .globl  memcmp
memcmp:
        cmpwi   0,r5,0
        ble     2f
        mtctr   r5
        addi    r6,r3,-1
        addi    r4,r4,-1
1:      lbzu    r3,1(r6)
        lbzu    r0,1(r4)
        subf.   r3,r0,r3
        bdnzt   2,1b
        blr
2:      li      r3,0
        blr


/*
 * Flush the dcache and invalidate the icache for a range of addresses.
 *
 * flush_cache(addr, len)
 */
        .global flush_cache
flush_cache:
        addi    4,4,0x1f        /* len = (len + 0x1f) / 0x20 */
        rlwinm. 4,4,27,5,31
        mtctr   4
        beqlr
1:      dcbf    0,3
        icbi    0,3
        addi    3,3,0x20
        bdnz    1b
        sync
        isync
        blr