| Richard Kuo | 7567746 | 2011-10-31 18:48:07 -0500 | [diff] [blame] | 1 | /* |
| 2 | * User memory copy functions for kernel |
| 3 | * |
| 4 | * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. |
| 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 | /* |
| 22 | * The right way to do this involves valignb |
| 23 | * The easy way to do this is only speed up src/dest similar alignment. |
| 24 | */ |
| 25 | |
| 26 | /* |
| 27 | * Copy to/from user are the same, except that for packets with a load and |
| 28 | * a store, I don't know how to tell which kind of exception we got. |
| 29 | * Therefore, we duplicate the function, and handle faulting addresses |
| 30 | * differently for each function |
| 31 | */ |
| 32 | |
| 33 | /* |
| 34 | * copy from user: loads can fault |
| 35 | */ |
| 36 | #define src_sav r13 |
| 37 | #define dst_sav r12 |
| 38 | #define src_dst_sav r13:12 |
| 39 | #define d_dbuf r15:14 |
| 40 | #define w_dbuf r15 |
| 41 | |
| 42 | #define dst r0 |
| 43 | #define src r1 |
| 44 | #define bytes r2 |
| 45 | #define loopcount r5 |
| 46 | |
| 47 | #define FUNCNAME __copy_from_user_hexagon |
| 48 | #include "copy_user_template.S" |
| 49 | |
| 50 | /* LOAD FAULTS from COPY_FROM_USER */ |
| 51 | |
| 52 | /* Alignment loop. r2 has been updated. Return it. */ |
| 53 | .falign |
| 54 | 1009: |
| 55 | 2009: |
| 56 | 4009: |
| 57 | { |
| 58 | r0 = r2 |
| 59 | jumpr r31 |
| 60 | } |
| 61 | /* Normal copy loops. Do epilog. Use src-src_sav to compute distance */ |
| 62 | /* X - (A - B) == X + B - A */ |
| 63 | .falign |
| 64 | 8089: |
| 65 | { |
| 66 | memd(dst) = d_dbuf |
| 67 | r2 += sub(src_sav,src) |
| 68 | } |
| 69 | { |
| 70 | r0 = r2 |
| 71 | jumpr r31 |
| 72 | } |
| 73 | .falign |
| 74 | 4089: |
| 75 | { |
| 76 | memw(dst) = w_dbuf |
| 77 | r2 += sub(src_sav,src) |
| 78 | } |
| 79 | { |
| 80 | r0 = r2 |
| 81 | jumpr r31 |
| 82 | } |
| 83 | .falign |
| 84 | 2089: |
| 85 | { |
| 86 | memh(dst) = w_dbuf |
| 87 | r2 += sub(src_sav,src) |
| 88 | } |
| 89 | { |
| 90 | r0 = r2 |
| 91 | jumpr r31 |
| 92 | } |
| 93 | .falign |
| 94 | 1089: |
| 95 | { |
| 96 | memb(dst) = w_dbuf |
| 97 | r2 += sub(src_sav,src) |
| 98 | } |
| 99 | { |
| 100 | r0 = r2 |
| 101 | jumpr r31 |
| 102 | } |
| 103 | |
| 104 | /* COPY FROM USER: only loads can fail */ |
| 105 | |
| 106 | .section __ex_table,"a" |
| 107 | .long 1000b,1009b |
| 108 | .long 2000b,2009b |
| 109 | .long 4000b,4009b |
| 110 | .long 8080b,8089b |
| 111 | .long 4080b,4089b |
| 112 | .long 2080b,2089b |
| 113 | .long 1080b,1089b |
| 114 | .previous |