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7567746e RK |
1 | /* |
2 | * User memory copying routines for the Hexagon Kernel | |
3 | * | |
e1858b2a | 4 | * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. |
7567746e RK |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 and | |
8 | * only version 2 as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
18 | * 02110-1301, USA. | |
19 | */ | |
20 | ||
21 | /* The right way to do this involves valignb | |
22 | * The easy way to do this is only speed up src/dest similar alignment. | |
23 | */ | |
24 | ||
25 | /* | |
26 | * Copy to/from user are the same, except that for packets with a load and | |
27 | * a store, I don't know how to tell which kind of exception we got. | |
28 | * Therefore, we duplicate the function, and handle faulting addresses | |
29 | * differently for each function | |
30 | */ | |
31 | ||
32 | /* | |
33 | * copy to user: stores can fault | |
34 | */ | |
35 | #define src_sav r13 | |
36 | #define dst_sav r12 | |
37 | #define src_dst_sav r13:12 | |
38 | #define d_dbuf r15:14 | |
39 | #define w_dbuf r15 | |
40 | ||
41 | #define dst r0 | |
42 | #define src r1 | |
43 | #define bytes r2 | |
44 | #define loopcount r5 | |
45 | ||
46 | #define FUNCNAME __copy_to_user_hexagon | |
47 | #include "copy_user_template.S" | |
48 | ||
49 | /* STORE FAULTS from COPY_TO_USER */ | |
50 | .falign | |
51 | 1109: | |
52 | 2109: | |
53 | 4109: | |
54 | /* Alignment loop. r2 has been updated. Return it. */ | |
55 | { | |
56 | r0 = r2 | |
57 | jumpr r31 | |
58 | } | |
59 | /* Normal copy loops. Use dst-dst_sav to compute distance */ | |
60 | /* dst holds best write, no need to unwind any loops */ | |
61 | /* X - (A - B) == X + B - A */ | |
62 | .falign | |
63 | 8189: | |
64 | 8199: | |
65 | 4189: | |
66 | 4199: | |
67 | 2189: | |
68 | 2199: | |
69 | 1189: | |
70 | 1199: | |
71 | { | |
72 | r2 += sub(dst_sav,dst) | |
73 | } | |
74 | { | |
75 | r0 = r2 | |
76 | jumpr r31 | |
77 | } | |
78 | ||
79 | /* COPY TO USER: only stores can fail */ | |
80 | .section __ex_table,"a" | |
81 | .long 1100b,1109b | |
82 | .long 2100b,2109b | |
83 | .long 4100b,4109b | |
84 | .long 8180b,8189b | |
85 | .long 8190b,8199b | |
86 | .long 4180b,4189b | |
87 | .long 4190b,4199b | |
88 | .long 2180b,2189b | |
89 | .long 2190b,2199b | |
90 | .long 1180b,1189b | |
91 | .long 1190b,1199b | |
92 | .previous |