1/* 2 * User memory copy functions for kernel 3 * 4 * Copyright (c) 2010-2011, The Linux Foundation. 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 541009: 552009: 564009: 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 648089: 65 { 66 memd(dst) = d_dbuf 67 r2 += sub(src_sav,src) 68 } 69 { 70 r0 = r2 71 jumpr r31 72 } 73 .falign 744089: 75 { 76 memw(dst) = w_dbuf 77 r2 += sub(src_sav,src) 78 } 79 { 80 r0 = r2 81 jumpr r31 82 } 83 .falign 842089: 85 { 86 memh(dst) = w_dbuf 87 r2 += sub(src_sav,src) 88 } 89 { 90 r0 = r2 91 jumpr r31 92 } 93 .falign 941089: 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 115