mirror of https://gitee.com/openkylin/linux.git
115 lines
2.3 KiB
ArmAsm
115 lines
2.3 KiB
ArmAsm
/*
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* User memory copy functions for kernel
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*
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* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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/*
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* The right way to do this involves valignb
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* The easy way to do this is only speed up src/dest similar alignment.
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*/
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/*
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* Copy to/from user are the same, except that for packets with a load and
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* a store, I don't know how to tell which kind of exception we got.
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* Therefore, we duplicate the function, and handle faulting addresses
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* differently for each function
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*/
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/*
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* copy from user: loads can fault
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*/
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#define src_sav r13
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#define dst_sav r12
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#define src_dst_sav r13:12
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#define d_dbuf r15:14
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#define w_dbuf r15
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#define dst r0
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#define src r1
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#define bytes r2
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#define loopcount r5
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#define FUNCNAME raw_copy_from_user
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#include "copy_user_template.S"
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/* LOAD FAULTS from COPY_FROM_USER */
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/* Alignment loop. r2 has been updated. Return it. */
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.falign
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1009:
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2009:
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4009:
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{
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r0 = r2
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jumpr r31
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}
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/* Normal copy loops. Do epilog. Use src-src_sav to compute distance */
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/* X - (A - B) == X + B - A */
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.falign
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8089:
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{
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memd(dst) = d_dbuf
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r2 += sub(src_sav,src)
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}
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{
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r0 = r2
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jumpr r31
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}
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.falign
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4089:
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{
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memw(dst) = w_dbuf
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r2 += sub(src_sav,src)
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}
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{
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r0 = r2
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jumpr r31
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}
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.falign
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2089:
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{
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memh(dst) = w_dbuf
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r2 += sub(src_sav,src)
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}
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{
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r0 = r2
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jumpr r31
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}
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.falign
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1089:
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{
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memb(dst) = w_dbuf
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r2 += sub(src_sav,src)
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}
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{
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r0 = r2
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jumpr r31
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}
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/* COPY FROM USER: only loads can fail */
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.section __ex_table,"a"
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.long 1000b,1009b
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.long 2000b,2009b
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.long 4000b,4009b
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.long 8080b,8089b
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.long 4080b,4089b
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.long 2080b,2089b
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.long 1080b,1089b
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.previous
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