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/arch/parisc/lib/lusercopy.S

https://bitbucket.org/evzijst/gittest
Assembly | 193 lines | 167 code | 26 blank | 0 comment | 11 complexity | 7753e309b587fda5fb08ba247009a6ff MD5 | raw file
  1/*
  2 *    User Space Access Routines
  3 *
  4 *    Copyright (C) 2000-2002 Hewlett-Packard (John Marvin)
  5 *    Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
  6 *    Copyright (C) 2001 Matthieu Delahaye <delahaym at esiee.fr>
  7 *    Copyright (C) 2003 Randolph Chung <tausq with parisc-linux.org>
  8 *
  9 *
 10 *    This program is free software; you can redistribute it and/or modify
 11 *    it under the terms of the GNU General Public License as published by
 12 *    the Free Software Foundation; either version 2, or (at your option)
 13 *    any later version.
 14 *
 15 *    This program is distributed in the hope that it will be useful,
 16 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 17 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 18 *    GNU General Public License for more details.
 19 *
 20 *    You should have received a copy of the GNU General Public License
 21 *    along with this program; if not, write to the Free Software
 22 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 23 */
 24
 25/*
 26 * These routines still have plenty of room for optimization
 27 * (word & doubleword load/store, dual issue, store hints, etc.).
 28 */
 29
 30/*
 31 * The following routines assume that space register 3 (sr3) contains
 32 * the space id associated with the current users address space.
 33 */
 34
 35
 36	.text
 37	
 38#include <asm/assembly.h>
 39#include <asm/errno.h>
 40
 41	/*
 42	 * get_sr gets the appropriate space value into
 43	 * sr1 for kernel/user space access, depending
 44	 * on the flag stored in the task structure.
 45	 */
 46
 47	.macro  get_sr
 48	mfctl       %cr30,%r1
 49	ldw         TI_SEGMENT(%r1),%r22
 50	mfsp        %sr3,%r1
 51	or,<>       %r22,%r0,%r0
 52	copy        %r0,%r1
 53	mtsp        %r1,%sr1
 54	.endm
 55
 56	.macro fixup_branch lbl
 57	ldil	    L%\lbl, %r1
 58	ldo	    R%\lbl(%r1), %r1
 59	bv          %r0(%r1)
 60	.endm
 61
 62	/*
 63	 * long lstrncpy_from_user(char *dst, const char *src, long n)
 64	 *
 65	 * Returns -EFAULT if exception before terminator,
 66	 *         N if the entire buffer filled,
 67	 *         otherwise strlen (i.e. excludes zero byte)
 68	 */
 69
 70	.export lstrncpy_from_user,code
 71lstrncpy_from_user:
 72	.proc
 73	.callinfo NO_CALLS
 74	.entry
 75	comib,=     0,%r24,$lsfu_done
 76	copy        %r24,%r23
 77	get_sr
 781:      ldbs,ma     1(%sr1,%r25),%r1
 79$lsfu_loop:
 80	stbs,ma     %r1,1(%r26)
 81	comib,=,n   0,%r1,$lsfu_done
 82	addib,<>,n  -1,%r24,$lsfu_loop
 832:      ldbs,ma     1(%sr1,%r25),%r1
 84$lsfu_done:
 85	sub         %r23,%r24,%r28
 86$lsfu_exit:
 87	bv          %r0(%r2)
 88	nop
 89	.exit
 90
 91	.section .fixup,"ax"
 923:      fixup_branch $lsfu_exit
 93	ldi         -EFAULT,%r28
 94	.previous
 95
 96	.section __ex_table,"aw"
 97#ifdef __LP64__
 98	.dword      1b,3b
 99	.dword      2b,3b
100#else
101	.word       1b,3b
102	.word       2b,3b
103#endif
104	.previous
105
106	.procend
107
108	/*
109	 * unsigned long lclear_user(void *to, unsigned long n)
110	 *
111	 * Returns 0 for success.
112	 * otherwise, returns number of bytes not transferred.
113	 */
114
115	.export lclear_user,code
116lclear_user:
117	.proc
118	.callinfo NO_CALLS
119	.entry
120	comib,=,n   0,%r25,$lclu_done
121	get_sr
122$lclu_loop:
123	addib,<>    -1,%r25,$lclu_loop
1241:      stbs,ma     %r0,1(%sr1,%r26)
125
126$lclu_done:
127	bv          %r0(%r2)
128	copy        %r25,%r28
129	.exit
130
131	.section .fixup,"ax"
1322:      fixup_branch $lclu_done
133	ldo        1(%r25),%r25
134	.previous
135
136	.section __ex_table,"aw"
137#ifdef __LP64__
138	.dword      1b,2b
139#else
140	.word       1b,2b
141#endif
142	.previous
143
144	.procend
145
146	/*
147	 * long lstrnlen_user(char *s, long n)
148	 *
149	 * Returns 0 if exception before zero byte or reaching N,
150	 *         N+1 if N would be exceeded,
151	 *         else strlen + 1 (i.e. includes zero byte).
152	 */
153
154	.export lstrnlen_user,code
155lstrnlen_user:
156	.proc
157	.callinfo NO_CALLS
158	.entry
159	comib,=     0,%r25,$lslen_nzero
160	copy	    %r26,%r24
161	get_sr
1621:      ldbs,ma     1(%sr1,%r26),%r1
163$lslen_loop:
164	comib,=,n   0,%r1,$lslen_done
165	addib,<>    -1,%r25,$lslen_loop
1662:      ldbs,ma     1(%sr1,%r26),%r1
167$lslen_done:
168	bv          %r0(%r2)
169	sub	    %r26,%r24,%r28
170	.exit
171
172$lslen_nzero:
173	b           $lslen_done
174	ldo         1(%r26),%r26 /* special case for N == 0 */
175
176	.section .fixup,"ax"
1773:      fixup_branch $lslen_done
178	copy        %r24,%r26    /* reset r26 so 0 is returned on fault */
179	.previous
180
181	.section __ex_table,"aw"
182#ifdef __LP64__
183	.dword      1b,3b
184	.dword      2b,3b
185#else
186	.word       1b,3b
187	.word       2b,3b
188#endif
189	.previous
190
191	.procend
192
193	.end