| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Returns 0 if exception before NUL or reaching the supplied limit (N), |
| * a value greater than N if the string is longer than the limit, else |
| * strlen. |
| * |
| * Inputs: |
| * in0: address of buffer |
| * in1: string length limit N |
| * Outputs: |
| * r8: 0 in case of fault, strlen(buffer)+1 otherwise |
| * |
| * Copyright (C) 1999, 2001 David Mosberger-Tang <davidm@hpl.hp.com> |
| */ |
| |
| #include <asm/asmmacro.h> |
| #include <asm/export.h> |
| |
| GLOBAL_ENTRY(__strnlen_user) |
| .prologue |
| alloc r2=ar.pfs,2,0,0,0 |
| .save ar.lc, r16 |
| mov r16=ar.lc // preserve ar.lc |
| |
| .body |
| |
| add r3=-1,in1 |
| ;; |
| mov ar.lc=r3 |
| mov r9=0 |
| ;; |
| // XXX braindead strlen loop---this needs to be optimized |
| .Loop1: |
| EXCLR(.Lexit, ld1 r8=[in0],1) |
| add r9=1,r9 |
| ;; |
| cmp.eq p6,p0=r8,r0 |
| (p6) br.cond.dpnt .Lexit |
| br.cloop.dptk.few .Loop1 |
| |
| add r9=1,in1 // NUL not found---return N+1 |
| ;; |
| .Lexit: |
| mov r8=r9 |
| mov ar.lc=r16 // restore ar.lc |
| br.ret.sptk.many rp |
| END(__strnlen_user) |
| EXPORT_SYMBOL(__strnlen_user) |
