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1/*
2 * arch/xtensa/lib/strncpy_user.S
3 *
4 * This file is subject to the terms and conditions of the GNU General
5 * Public License. See the file "COPYING" in the main directory of
6 * this archive for more details.
7 *
8 * Returns: -EFAULT if exception before terminator, N if the entire
9 * buffer filled, else strlen.
10 *
11 * Copyright (C) 2002 Tensilica Inc.
12 */
13
14#include <linux/errno.h>
15#include <linux/linkage.h>
16#include <asm/asmmacro.h>
17#include <asm/core.h>
18
19/*
20 * char *__strncpy_user(char *dst, const char *src, size_t len)
21 */
22
23#ifdef __XTENSA_EB__
24# define MASK0 0xff000000
25# define MASK1 0x00ff0000
26# define MASK2 0x0000ff00
27# define MASK3 0x000000ff
28#else
29# define MASK0 0x000000ff
30# define MASK1 0x0000ff00
31# define MASK2 0x00ff0000
32# define MASK3 0xff000000
33#endif
34
35# Register use
36# a0/ return address
37# a1/ stack pointer
38# a2/ return value
39# a3/ src
40# a4/ len
41# a5/ mask0
42# a6/ mask1
43# a7/ mask2
44# a8/ mask3
45# a9/ tmp
46# a10/ tmp
47# a11/ dst
48# a12/ tmp
49
50.text
51ENTRY(__strncpy_user)
52
53 abi_entry_default
54 # a2/ dst, a3/ src, a4/ len
55 mov a11, a2 # leave dst in return value register
56 beqz a4, .Lret # if len is zero
57 movi a5, MASK0 # mask for byte 0
58 movi a6, MASK1 # mask for byte 1
59 movi a7, MASK2 # mask for byte 2
60 movi a8, MASK3 # mask for byte 3
61 bbsi.l a3, 0, .Lsrc1mod2 # if only 8-bit aligned
62 bbsi.l a3, 1, .Lsrc2mod4 # if only 16-bit aligned
63.Lsrcaligned: # return here when src is word-aligned
64 srli a12, a4, 2 # number of loop iterations with 4B per loop
65 movi a9, 3
66 bnone a11, a9, .Laligned
67 j .Ldstunaligned
68
69.Lsrc1mod2: # src address is odd
70EX(11f) l8ui a9, a3, 0 # get byte 0
71 addi a3, a3, 1 # advance src pointer
72EX(10f) s8i a9, a11, 0 # store byte 0
73 beqz a9, .Lret # if byte 0 is zero
74 addi a11, a11, 1 # advance dst pointer
75 addi a4, a4, -1 # decrement len
76 beqz a4, .Lret # if len is zero
77 bbci.l a3, 1, .Lsrcaligned # if src is now word-aligned
78
79.Lsrc2mod4: # src address is 2 mod 4
80EX(11f) l8ui a9, a3, 0 # get byte 0
81 /* 1-cycle interlock */
82EX(10f) s8i a9, a11, 0 # store byte 0
83 beqz a9, .Lret # if byte 0 is zero
84 addi a11, a11, 1 # advance dst pointer
85 addi a4, a4, -1 # decrement len
86 beqz a4, .Lret # if len is zero
87EX(11f) l8ui a9, a3, 1 # get byte 0
88 addi a3, a3, 2 # advance src pointer
89EX(10f) s8i a9, a11, 0 # store byte 0
90 beqz a9, .Lret # if byte 0 is zero
91 addi a11, a11, 1 # advance dst pointer
92 addi a4, a4, -1 # decrement len
93 bnez a4, .Lsrcaligned # if len is nonzero
94.Lret:
95 sub a2, a11, a2 # compute strlen
96 abi_ret_default
97
98/*
99 * dst is word-aligned, src is word-aligned
100 */
101 .align 4 # 1 mod 4 alignment for LOOPNEZ
102 .byte 0 # (0 mod 4 alignment for LBEG)
103.Laligned:
104#if XCHAL_HAVE_LOOPS
105 loopnez a12, .Loop1done
106#else
107 beqz a12, .Loop1done
108 slli a12, a12, 2
109 add a12, a12, a11 # a12 = end of last 4B chunck
110#endif
111.Loop1:
112EX(11f) l32i a9, a3, 0 # get word from src
113 addi a3, a3, 4 # advance src pointer
114 bnone a9, a5, .Lz0 # if byte 0 is zero
115 bnone a9, a6, .Lz1 # if byte 1 is zero
116 bnone a9, a7, .Lz2 # if byte 2 is zero
117EX(10f) s32i a9, a11, 0 # store word to dst
118 bnone a9, a8, .Lz3 # if byte 3 is zero
119 addi a11, a11, 4 # advance dst pointer
120#if !XCHAL_HAVE_LOOPS
121 blt a11, a12, .Loop1
122#endif
123
124.Loop1done:
125 bbci.l a4, 1, .L100
126 # copy 2 bytes
127EX(11f) l16ui a9, a3, 0
128 addi a3, a3, 2 # advance src pointer
129#ifdef __XTENSA_EB__
130 bnone a9, a7, .Lz0 # if byte 2 is zero
131 bnone a9, a8, .Lz1 # if byte 3 is zero
132#else
133 bnone a9, a5, .Lz0 # if byte 0 is zero
134 bnone a9, a6, .Lz1 # if byte 1 is zero
135#endif
136EX(10f) s16i a9, a11, 0
137 addi a11, a11, 2 # advance dst pointer
138.L100:
139 bbci.l a4, 0, .Lret
140EX(11f) l8ui a9, a3, 0
141 /* slot */
142EX(10f) s8i a9, a11, 0
143 beqz a9, .Lret # if byte is zero
144 addi a11, a11, 1-3 # advance dst ptr 1, but also cancel
145 # the effect of adding 3 in .Lz3 code
146 /* fall thru to .Lz3 and "retw" */
147
148.Lz3: # byte 3 is zero
149 addi a11, a11, 3 # advance dst pointer
150 sub a2, a11, a2 # compute strlen
151 abi_ret_default
152.Lz0: # byte 0 is zero
153#ifdef __XTENSA_EB__
154 movi a9, 0
155#endif /* __XTENSA_EB__ */
156EX(10f) s8i a9, a11, 0
157 sub a2, a11, a2 # compute strlen
158 abi_ret_default
159.Lz1: # byte 1 is zero
160#ifdef __XTENSA_EB__
161 extui a9, a9, 16, 16
162#endif /* __XTENSA_EB__ */
163EX(10f) s16i a9, a11, 0
164 addi a11, a11, 1 # advance dst pointer
165 sub a2, a11, a2 # compute strlen
166 abi_ret_default
167.Lz2: # byte 2 is zero
168#ifdef __XTENSA_EB__
169 extui a9, a9, 16, 16
170#endif /* __XTENSA_EB__ */
171EX(10f) s16i a9, a11, 0
172 movi a9, 0
173EX(10f) s8i a9, a11, 2
174 addi a11, a11, 2 # advance dst pointer
175 sub a2, a11, a2 # compute strlen
176 abi_ret_default
177
178 .align 4 # 1 mod 4 alignment for LOOPNEZ
179 .byte 0 # (0 mod 4 alignment for LBEG)
180.Ldstunaligned:
181/*
182 * for now just use byte copy loop
183 */
184#if XCHAL_HAVE_LOOPS
185 loopnez a4, .Lunalignedend
186#else
187 beqz a4, .Lunalignedend
188 add a12, a11, a4 # a12 = ending address
189#endif /* XCHAL_HAVE_LOOPS */
190.Lnextbyte:
191EX(11f) l8ui a9, a3, 0
192 addi a3, a3, 1
193EX(10f) s8i a9, a11, 0
194 beqz a9, .Lunalignedend
195 addi a11, a11, 1
196#if !XCHAL_HAVE_LOOPS
197 blt a11, a12, .Lnextbyte
198#endif
199
200.Lunalignedend:
201 sub a2, a11, a2 # compute strlen
202 abi_ret_default
203
204ENDPROC(__strncpy_user)
205
206 .section .fixup, "ax"
207 .align 4
208
209 /* For now, just return -EFAULT. Future implementations might
210 * like to clear remaining kernel space, like the fixup
211 * implementation in memset(). Thus, we differentiate between
212 * load/store fixups. */
213
21410:
21511:
216 movi a2, -EFAULT
217 abi_ret_default
1/*
2 * arch/xtensa/lib/strncpy_user.S
3 *
4 * This file is subject to the terms and conditions of the GNU General
5 * Public License. See the file "COPYING" in the main directory of
6 * this archive for more details.
7 *
8 * Returns: -EFAULT if exception before terminator, N if the entire
9 * buffer filled, else strlen.
10 *
11 * Copyright (C) 2002 Tensilica Inc.
12 */
13
14#include <linux/errno.h>
15#include <linux/linkage.h>
16#include <asm/asmmacro.h>
17#include <asm/core.h>
18
19/*
20 * char *__strncpy_user(char *dst, const char *src, size_t len)
21 */
22
23#ifdef __XTENSA_EB__
24# define MASK0 0xff000000
25# define MASK1 0x00ff0000
26# define MASK2 0x0000ff00
27# define MASK3 0x000000ff
28#else
29# define MASK0 0x000000ff
30# define MASK1 0x0000ff00
31# define MASK2 0x00ff0000
32# define MASK3 0xff000000
33#endif
34
35# Register use
36# a0/ return address
37# a1/ stack pointer
38# a2/ return value
39# a3/ src
40# a4/ len
41# a5/ mask0
42# a6/ mask1
43# a7/ mask2
44# a8/ mask3
45# a9/ tmp
46# a10/ tmp
47# a11/ dst
48
49.text
50ENTRY(__strncpy_user)
51
52 abi_entry_default
53 # a2/ dst, a3/ src, a4/ len
54 mov a11, a2 # leave dst in return value register
55 beqz a4, .Lret # if len is zero
56 movi a5, MASK0 # mask for byte 0
57 movi a6, MASK1 # mask for byte 1
58 movi a7, MASK2 # mask for byte 2
59 movi a8, MASK3 # mask for byte 3
60 bbsi.l a3, 0, .Lsrc1mod2 # if only 8-bit aligned
61 bbsi.l a3, 1, .Lsrc2mod4 # if only 16-bit aligned
62.Lsrcaligned: # return here when src is word-aligned
63 srli a10, a4, 2 # number of loop iterations with 4B per loop
64 movi a9, 3
65 bnone a11, a9, .Laligned
66 j .Ldstunaligned
67
68.Lsrc1mod2: # src address is odd
69EX(11f) l8ui a9, a3, 0 # get byte 0
70 addi a3, a3, 1 # advance src pointer
71EX(10f) s8i a9, a11, 0 # store byte 0
72 beqz a9, .Lret # if byte 0 is zero
73 addi a11, a11, 1 # advance dst pointer
74 addi a4, a4, -1 # decrement len
75 beqz a4, .Lret # if len is zero
76 bbci.l a3, 1, .Lsrcaligned # if src is now word-aligned
77
78.Lsrc2mod4: # src address is 2 mod 4
79EX(11f) l8ui a9, a3, 0 # get byte 0
80 /* 1-cycle interlock */
81EX(10f) s8i a9, a11, 0 # store byte 0
82 beqz a9, .Lret # if byte 0 is zero
83 addi a11, a11, 1 # advance dst pointer
84 addi a4, a4, -1 # decrement len
85 beqz a4, .Lret # if len is zero
86EX(11f) l8ui a9, a3, 1 # get byte 0
87 addi a3, a3, 2 # advance src pointer
88EX(10f) s8i a9, a11, 0 # store byte 0
89 beqz a9, .Lret # if byte 0 is zero
90 addi a11, a11, 1 # advance dst pointer
91 addi a4, a4, -1 # decrement len
92 bnez a4, .Lsrcaligned # if len is nonzero
93.Lret:
94 sub a2, a11, a2 # compute strlen
95 abi_ret_default
96
97/*
98 * dst is word-aligned, src is word-aligned
99 */
100 .align 4 # 1 mod 4 alignment for LOOPNEZ
101 .byte 0 # (0 mod 4 alignment for LBEG)
102.Laligned:
103#if XCHAL_HAVE_LOOPS
104 loopnez a10, .Loop1done
105#else
106 beqz a10, .Loop1done
107 slli a10, a10, 2
108 add a10, a10, a11 # a10 = end of last 4B chunck
109#endif
110.Loop1:
111EX(11f) l32i a9, a3, 0 # get word from src
112 addi a3, a3, 4 # advance src pointer
113 bnone a9, a5, .Lz0 # if byte 0 is zero
114 bnone a9, a6, .Lz1 # if byte 1 is zero
115 bnone a9, a7, .Lz2 # if byte 2 is zero
116EX(10f) s32i a9, a11, 0 # store word to dst
117 bnone a9, a8, .Lz3 # if byte 3 is zero
118 addi a11, a11, 4 # advance dst pointer
119#if !XCHAL_HAVE_LOOPS
120 blt a11, a10, .Loop1
121#endif
122
123.Loop1done:
124 bbci.l a4, 1, .L100
125 # copy 2 bytes
126EX(11f) l16ui a9, a3, 0
127 addi a3, a3, 2 # advance src pointer
128#ifdef __XTENSA_EB__
129 bnone a9, a7, .Lz0 # if byte 2 is zero
130 bnone a9, a8, .Lz1 # if byte 3 is zero
131#else
132 bnone a9, a5, .Lz0 # if byte 0 is zero
133 bnone a9, a6, .Lz1 # if byte 1 is zero
134#endif
135EX(10f) s16i a9, a11, 0
136 addi a11, a11, 2 # advance dst pointer
137.L100:
138 bbci.l a4, 0, .Lret
139EX(11f) l8ui a9, a3, 0
140 /* slot */
141EX(10f) s8i a9, a11, 0
142 beqz a9, .Lret # if byte is zero
143 addi a11, a11, 1-3 # advance dst ptr 1, but also cancel
144 # the effect of adding 3 in .Lz3 code
145 /* fall thru to .Lz3 and "retw" */
146
147.Lz3: # byte 3 is zero
148 addi a11, a11, 3 # advance dst pointer
149 sub a2, a11, a2 # compute strlen
150 abi_ret_default
151.Lz0: # byte 0 is zero
152#ifdef __XTENSA_EB__
153 movi a9, 0
154#endif /* __XTENSA_EB__ */
155EX(10f) s8i a9, a11, 0
156 sub a2, a11, a2 # compute strlen
157 abi_ret_default
158.Lz1: # byte 1 is zero
159#ifdef __XTENSA_EB__
160 extui a9, a9, 16, 16
161#endif /* __XTENSA_EB__ */
162EX(10f) s16i a9, a11, 0
163 addi a11, a11, 1 # advance dst pointer
164 sub a2, a11, a2 # compute strlen
165 abi_ret_default
166.Lz2: # byte 2 is zero
167#ifdef __XTENSA_EB__
168 extui a9, a9, 16, 16
169#endif /* __XTENSA_EB__ */
170EX(10f) s16i a9, a11, 0
171 movi a9, 0
172EX(10f) s8i a9, a11, 2
173 addi a11, a11, 2 # advance dst pointer
174 sub a2, a11, a2 # compute strlen
175 abi_ret_default
176
177 .align 4 # 1 mod 4 alignment for LOOPNEZ
178 .byte 0 # (0 mod 4 alignment for LBEG)
179.Ldstunaligned:
180/*
181 * for now just use byte copy loop
182 */
183#if XCHAL_HAVE_LOOPS
184 loopnez a4, .Lunalignedend
185#else
186 beqz a4, .Lunalignedend
187 add a10, a11, a4 # a10 = ending address
188#endif /* XCHAL_HAVE_LOOPS */
189.Lnextbyte:
190EX(11f) l8ui a9, a3, 0
191 addi a3, a3, 1
192EX(10f) s8i a9, a11, 0
193 beqz a9, .Lunalignedend
194 addi a11, a11, 1
195#if !XCHAL_HAVE_LOOPS
196 blt a11, a10, .Lnextbyte
197#endif
198
199.Lunalignedend:
200 sub a2, a11, a2 # compute strlen
201 abi_ret_default
202
203ENDPROC(__strncpy_user)
204
205 .section .fixup, "ax"
206 .align 4
207
208 /* For now, just return -EFAULT. Future implementations might
209 * like to clear remaining kernel space, like the fixup
210 * implementation in memset(). Thus, we differentiate between
211 * load/store fixups. */
212
21310:
21411:
215 movi a2, -EFAULT
216 abi_ret_default