|  | /* | 
|  | * String handling functions for PowerPC. | 
|  | * | 
|  | * Copyright (C) 1996 Paul Mackerras. | 
|  | * | 
|  | * This program is free software; you can redistribute it and/or | 
|  | * modify it under the terms of the GNU General Public License | 
|  | * as published by the Free Software Foundation; either version | 
|  | * 2 of the License, or (at your option) any later version. | 
|  | */ | 
|  | #include <asm/processor.h> | 
|  | #include <asm/errno.h> | 
|  | #include <asm/ppc_asm.h> | 
|  |  | 
|  | .section __ex_table,"a" | 
|  | PPC_LONG_ALIGN | 
|  | .text | 
|  |  | 
|  | _GLOBAL(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 | 
|  |  | 
|  | /* This clears out any unused part of the destination buffer, | 
|  | just as the libc version does.  -- paulus */ | 
|  | _GLOBAL(strncpy) | 
|  | PPC_LCMPI 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 */ | 
|  | bnelr			/* if we didn't hit a null char, we're done */ | 
|  | mfctr	r5 | 
|  | PPC_LCMPI 0,r5,0	/* any space left in destination buffer? */ | 
|  | beqlr			/* we know r0 == 0 here */ | 
|  | 2:	stbu	r0,1(r6)	/* clear it out if so */ | 
|  | bdnz	2b | 
|  | blr | 
|  |  | 
|  | _GLOBAL(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 | 
|  |  | 
|  | _GLOBAL(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 | 
|  |  | 
|  | _GLOBAL(strncmp) | 
|  | PPC_LCMPI 0,r5,0 | 
|  | beq-	2f | 
|  | 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 | 
|  | 2:	li	r3,0 | 
|  | blr | 
|  |  | 
|  | _GLOBAL(strlen) | 
|  | addi	r4,r3,-1 | 
|  | 1:	lbzu	r0,1(r4) | 
|  | cmpwi	0,r0,0 | 
|  | bne	1b | 
|  | subf	r3,r3,r4 | 
|  | blr | 
|  |  | 
|  | _GLOBAL(memcmp) | 
|  | PPC_LCMPI 0,r5,0 | 
|  | beq-	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 | 
|  |  | 
|  | _GLOBAL(memchr) | 
|  | PPC_LCMPI 0,r5,0 | 
|  | beq-	2f | 
|  | mtctr	r5 | 
|  | addi	r3,r3,-1 | 
|  | 1:	lbzu	r0,1(r3) | 
|  | cmpw	0,r0,r4 | 
|  | bdnzf	2,1b | 
|  | beqlr | 
|  | 2:	li	r3,0 | 
|  | blr | 
|  |  | 
|  | _GLOBAL(__clear_user) | 
|  | addi	r6,r3,-4 | 
|  | li	r3,0 | 
|  | li	r5,0 | 
|  | cmplwi	0,r4,4 | 
|  | blt	7f | 
|  | /* clear a single word */ | 
|  | 11:	stwu	r5,4(r6) | 
|  | beqlr | 
|  | /* clear word sized chunks */ | 
|  | andi.	r0,r6,3 | 
|  | add	r4,r0,r4 | 
|  | subf	r6,r0,r6 | 
|  | srwi	r0,r4,2 | 
|  | andi.	r4,r4,3 | 
|  | mtctr	r0 | 
|  | bdz	7f | 
|  | 1:	stwu	r5,4(r6) | 
|  | bdnz	1b | 
|  | /* clear byte sized chunks */ | 
|  | 7:	cmpwi	0,r4,0 | 
|  | beqlr | 
|  | mtctr	r4 | 
|  | addi	r6,r6,3 | 
|  | 8:	stbu	r5,1(r6) | 
|  | bdnz	8b | 
|  | blr | 
|  | 90:	mr	r3,r4 | 
|  | blr | 
|  | 91:	mfctr	r3 | 
|  | slwi	r3,r3,2 | 
|  | add	r3,r3,r4 | 
|  | blr | 
|  | 92:	mfctr	r3 | 
|  | blr | 
|  |  | 
|  | .section __ex_table,"a" | 
|  | PPC_LONG	11b,90b | 
|  | PPC_LONG	1b,91b | 
|  | PPC_LONG	8b,92b | 
|  | .text | 
|  |  | 
|  | _GLOBAL(__strncpy_from_user) | 
|  | addi	r6,r3,-1 | 
|  | addi	r4,r4,-1 | 
|  | cmpwi	0,r5,0 | 
|  | beq	2f | 
|  | mtctr	r5 | 
|  | 1:	lbzu	r0,1(r4) | 
|  | cmpwi	0,r0,0 | 
|  | stbu	r0,1(r6) | 
|  | bdnzf	2,1b		/* dec ctr, branch if ctr != 0 && !cr0.eq */ | 
|  | beq	3f | 
|  | 2:	addi	r6,r6,1 | 
|  | 3:	subf	r3,r3,r6 | 
|  | blr | 
|  | 99:	li	r3,-EFAULT | 
|  | blr | 
|  |  | 
|  | .section __ex_table,"a" | 
|  | PPC_LONG	1b,99b | 
|  | .text | 
|  |  | 
|  | /* r3 = str, r4 = len (> 0), r5 = top (highest addr) */ | 
|  | _GLOBAL(__strnlen_user) | 
|  | addi	r7,r3,-1 | 
|  | subf	r6,r7,r5	/* top+1 - str */ | 
|  | cmplw	0,r4,r6 | 
|  | bge	0f | 
|  | mr	r6,r4 | 
|  | 0:	mtctr	r6		/* ctr = min(len, top - str) */ | 
|  | 1:	lbzu	r0,1(r7)	/* get next byte */ | 
|  | cmpwi	0,r0,0 | 
|  | bdnzf	2,1b		/* loop if --ctr != 0 && byte != 0 */ | 
|  | addi	r7,r7,1 | 
|  | subf	r3,r3,r7	/* number of bytes we have looked at */ | 
|  | beqlr			/* return if we found a 0 byte */ | 
|  | cmpw	0,r3,r4		/* did we look at all len bytes? */ | 
|  | blt	99f		/* if not, must have hit top */ | 
|  | addi	r3,r4,1		/* return len + 1 to indicate no null found */ | 
|  | blr | 
|  | 99:	li	r3,0		/* bad address, return 0 */ | 
|  | blr | 
|  |  | 
|  | .section __ex_table,"a" | 
|  | PPC_LONG	1b,99b |