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