1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * User memory copy functions for kernel |
4 | * |
5 | * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. |
6 | */ |
7 | |
8 | /* |
9 | * The right way to do this involves valignb |
10 | * The easy way to do this is only speed up src/dest similar alignment. |
11 | */ |
12 | |
13 | /* |
14 | * Copy to/from user are the same, except that for packets with a load and |
15 | * a store, I don't know how to tell which kind of exception we got. |
16 | * Therefore, we duplicate the function, and handle faulting addresses |
17 | * differently for each function |
18 | */ |
19 | |
20 | /* |
21 | * copy from user: loads can fault |
22 | */ |
23 | #define src_sav r13 |
24 | #define dst_sav r12 |
25 | #define src_dst_sav r13:12 |
26 | #define d_dbuf r15:14 |
27 | #define w_dbuf r15 |
28 | |
29 | #define dst r0 |
30 | #define src r1 |
31 | #define bytes r2 |
32 | #define loopcount r5 |
33 | |
34 | #define FUNCNAME raw_copy_from_user |
35 | #include "copy_user_template.S" |
36 | |
37 | /* LOAD FAULTS from COPY_FROM_USER */ |
38 | |
39 | /* Alignment loop. r2 has been updated. Return it. */ |
40 | .falign |
41 | 1009: |
42 | 2009: |
43 | 4009: |
44 | { |
45 | r0 = r2 |
46 | jumpr r31 |
47 | } |
48 | /* Normal copy loops. Do epilog. Use src-src_sav to compute distance */ |
49 | /* X - (A - B) == X + B - A */ |
50 | .falign |
51 | 8089: |
52 | { |
53 | memd(dst) = d_dbuf |
54 | r2 += sub(src_sav,src) |
55 | } |
56 | { |
57 | r0 = r2 |
58 | jumpr r31 |
59 | } |
60 | .falign |
61 | 4089: |
62 | { |
63 | memw(dst) = w_dbuf |
64 | r2 += sub(src_sav,src) |
65 | } |
66 | { |
67 | r0 = r2 |
68 | jumpr r31 |
69 | } |
70 | .falign |
71 | 2089: |
72 | { |
73 | memh(dst) = w_dbuf |
74 | r2 += sub(src_sav,src) |
75 | } |
76 | { |
77 | r0 = r2 |
78 | jumpr r31 |
79 | } |
80 | .falign |
81 | 1089: |
82 | { |
83 | memb(dst) = w_dbuf |
84 | r2 += sub(src_sav,src) |
85 | } |
86 | { |
87 | r0 = r2 |
88 | jumpr r31 |
89 | } |
90 | |
91 | /* COPY FROM USER: only loads can fail */ |
92 | |
93 | .section __ex_table,"a" |
94 | .long 1000b,1009b |
95 | .long 2000b,2009b |
96 | .long 4000b,4009b |
97 | .long 8080b,8089b |
98 | .long 4080b,4089b |
99 | .long 2080b,2089b |
100 | .long 1080b,1089b |
101 | .previous |
102 | |