copy_to_user.S (1551B)
1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * User memory copying routines for the Hexagon Kernel 4 * 5 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. 6 */ 7 8/* The right way to do this involves valignb 9 * The easy way to do this is only speed up src/dest similar alignment. 10 */ 11 12/* 13 * Copy to/from user are the same, except that for packets with a load and 14 * a store, I don't know how to tell which kind of exception we got. 15 * Therefore, we duplicate the function, and handle faulting addresses 16 * differently for each function 17 */ 18 19/* 20 * copy to user: stores can fault 21 */ 22#define src_sav r13 23#define dst_sav r12 24#define src_dst_sav r13:12 25#define d_dbuf r15:14 26#define w_dbuf r15 27 28#define dst r0 29#define src r1 30#define bytes r2 31#define loopcount r5 32 33#define FUNCNAME raw_copy_to_user 34#include "copy_user_template.S" 35 36 /* STORE FAULTS from COPY_TO_USER */ 37 .falign 381109: 392109: 404109: 41 /* Alignment loop. r2 has been updated. Return it. */ 42 { 43 r0 = r2 44 jumpr r31 45 } 46 /* Normal copy loops. Use dst-dst_sav to compute distance */ 47 /* dst holds best write, no need to unwind any loops */ 48 /* X - (A - B) == X + B - A */ 49 .falign 508189: 518199: 524189: 534199: 542189: 552199: 561189: 571199: 58 { 59 r2 += sub(dst_sav,dst) 60 } 61 { 62 r0 = r2 63 jumpr r31 64 } 65 66 /* COPY TO USER: only stores can fail */ 67 .section __ex_table,"a" 68 .long 1100b,1109b 69 .long 2100b,2109b 70 .long 4100b,4109b 71 .long 8180b,8189b 72 .long 8190b,8199b 73 .long 4180b,4189b 74 .long 4190b,4199b 75 .long 2180b,2189b 76 .long 2190b,2199b 77 .long 1180b,1189b 78 .long 1190b,1199b 79 .previous