1/*
2 * String handling functions for PowerPC.
3 *
4 * Copyright (C) 1996 Paul Mackerras.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#include <asm/processor.h>
12#include <asm/errno.h>
13#include <asm/ppc_asm.h>
14
15	.section __ex_table,"a"
16	PPC_LONG_ALIGN
17	.text
18
19_GLOBAL(strcpy)
20	addi	r5,r3,-1
21	addi	r4,r4,-1
221:	lbzu	r0,1(r4)
23	cmpwi	0,r0,0
24	stbu	r0,1(r5)
25	bne	1b
26	blr
27
28/* This clears out any unused part of the destination buffer,
29   just as the libc version does.  -- paulus */
30_GLOBAL(strncpy)
31	PPC_LCMPI 0,r5,0
32	beqlr
33	mtctr	r5
34	addi	r6,r3,-1
35	addi	r4,r4,-1
361:	lbzu	r0,1(r4)
37	cmpwi	0,r0,0
38	stbu	r0,1(r6)
39	bdnzf	2,1b		/* dec ctr, branch if ctr != 0 && !cr0.eq */
40	bnelr			/* if we didn't hit a null char, we're done */
41	mfctr	r5
42	PPC_LCMPI 0,r5,0	/* any space left in destination buffer? */
43	beqlr			/* we know r0 == 0 here */
442:	stbu	r0,1(r6)	/* clear it out if so */
45	bdnz	2b
46	blr
47
48_GLOBAL(strcat)
49	addi	r5,r3,-1
50	addi	r4,r4,-1
511:	lbzu	r0,1(r5)
52	cmpwi	0,r0,0
53	bne	1b
54	addi	r5,r5,-1
551:	lbzu	r0,1(r4)
56	cmpwi	0,r0,0
57	stbu	r0,1(r5)
58	bne	1b
59	blr
60
61_GLOBAL(strcmp)
62	addi	r5,r3,-1
63	addi	r4,r4,-1
641:	lbzu	r3,1(r5)
65	cmpwi	1,r3,0
66	lbzu	r0,1(r4)
67	subf.	r3,r0,r3
68	beqlr	1
69	beq	1b
70	blr
71
72_GLOBAL(strncmp)
73	PPC_LCMPI 0,r5,0
74	beq-	2f
75	mtctr	r5
76	addi	r5,r3,-1
77	addi	r4,r4,-1
781:	lbzu	r3,1(r5)
79	cmpwi	1,r3,0
80	lbzu	r0,1(r4)
81	subf.	r3,r0,r3
82	beqlr	1
83	bdnzt	eq,1b
84	blr
852:	li	r3,0
86	blr
87
88_GLOBAL(strlen)
89	addi	r4,r3,-1
901:	lbzu	r0,1(r4)
91	cmpwi	0,r0,0
92	bne	1b
93	subf	r3,r3,r4
94	blr
95
96_GLOBAL(memcmp)
97	PPC_LCMPI 0,r5,0
98	beq-	2f
99	mtctr	r5
100	addi	r6,r3,-1
101	addi	r4,r4,-1
1021:	lbzu	r3,1(r6)
103	lbzu	r0,1(r4)
104	subf.	r3,r0,r3
105	bdnzt	2,1b
106	blr
1072:	li	r3,0
108	blr
109
110_GLOBAL(memchr)
111	PPC_LCMPI 0,r5,0
112	beq-	2f
113	mtctr	r5
114	addi	r3,r3,-1
1151:	lbzu	r0,1(r3)
116	cmpw	0,r0,r4
117	bdnzf	2,1b
118	beqlr
1192:	li	r3,0
120	blr
121
122_GLOBAL(__clear_user)
123	addi	r6,r3,-4
124	li	r3,0
125	li	r5,0
126	cmplwi	0,r4,4
127	blt	7f
128	/* clear a single word */
12911:	stwu	r5,4(r6)
130	beqlr
131	/* clear word sized chunks */
132	andi.	r0,r6,3
133	add	r4,r0,r4
134	subf	r6,r0,r6
135	srwi	r0,r4,2
136	andi.	r4,r4,3
137	mtctr	r0
138	bdz	7f
1391:	stwu	r5,4(r6)
140	bdnz	1b
141	/* clear byte sized chunks */
1427:	cmpwi	0,r4,0
143	beqlr
144	mtctr	r4
145	addi	r6,r6,3
1468:	stbu	r5,1(r6)
147	bdnz	8b
148	blr
14990:	mr	r3,r4
150	blr
15191:	mfctr	r3
152	slwi	r3,r3,2
153	add	r3,r3,r4
154	blr
15592:	mfctr	r3
156	blr
157
158	.section __ex_table,"a"
159	PPC_LONG	11b,90b
160	PPC_LONG	1b,91b
161	PPC_LONG	8b,92b
162	.text
163
164_GLOBAL(__strncpy_from_user)
165	addi	r6,r3,-1
166	addi	r4,r4,-1
167	cmpwi	0,r5,0
168	beq	2f
169	mtctr	r5
1701:	lbzu	r0,1(r4)
171	cmpwi	0,r0,0
172	stbu	r0,1(r6)
173	bdnzf	2,1b		/* dec ctr, branch if ctr != 0 && !cr0.eq */
174	beq	3f
1752:	addi	r6,r6,1
1763:	subf	r3,r3,r6
177	blr
17899:	li	r3,-EFAULT
179	blr
180
181	.section __ex_table,"a"
182	PPC_LONG	1b,99b
183	.text
184
185/* r3 = str, r4 = len (> 0), r5 = top (highest addr) */
186_GLOBAL(__strnlen_user)
187	addi	r7,r3,-1
188	subf	r6,r7,r5	/* top+1 - str */
189	cmplw	0,r4,r6
190	bge	0f
191	mr	r6,r4
1920:	mtctr	r6		/* ctr = min(len, top - str) */
1931:	lbzu	r0,1(r7)	/* get next byte */
194	cmpwi	0,r0,0
195	bdnzf	2,1b		/* loop if --ctr != 0 && byte != 0 */
196	addi	r7,r7,1
197	subf	r3,r3,r7	/* number of bytes we have looked at */
198	beqlr			/* return if we found a 0 byte */
199	cmpw	0,r3,r4		/* did we look at all len bytes? */
200	blt	99f		/* if not, must have hit top */
201	addi	r3,r4,1		/* return len + 1 to indicate no null found */
202	blr
20399:	li	r3,0		/* bad address, return 0 */
204	blr
205
206	.section __ex_table,"a"
207	PPC_LONG	1b,99b
208