[mirror_ubuntu-artful-kernel.git] / arch / hexagon / mm / copy_from_user.S

/*
 * User memory copy functions for kernel
 *
 * Copyright (c) 2010-2011, The Linux Foundation. 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
Commit	Line	Data
7567746e RK	1	/*
	2	* User memory copy functions for kernel
	3	*
e1858b2a	4	* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
7567746e RK	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