1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
/*
* (C) Copyright 2001
* Erik Theisen, Wave 7 Optics, etheisen@mindspring.com
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <config.h>
#if defined(CONFIG_4xx) && defined(CONFIG_CMD_SETGETDCR)
#include <ppc4xx.h>
#define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */
#include <ppc_asm.tmpl>
#include <ppc_defs.h>
#include <asm/cache.h>
#include <asm/mmu.h>
#define _ASMLANGUAGE
/*****************************************************************************
*
* XXX - DANGER
* These routines make use of self modifying code. DO NOT CALL THEM
* UNTIL THEY ARE RELOCATED TO RAM. Additionally, I do not
* recommend them for use in anything other than an interactive
* debugging environment. This is mainly due to performance reasons.
*
****************************************************************************/
/*
* static void _create_MFDCR(unsigned short dcrn)
*
* Builds a 'mfdcr' instruction for get_dcr
* function.
*/
.section ".text"
.align 2
.type _create_MFDCR,@function
_create_MFDCR:
/*
* Build up a 'mfdcr' instruction formatted as follows:
*
* OPCD | RT | DCRF | XO | CR |
* ---------------|--------------|--------------|----|
* 0 5 | 6 10 | 11 20 | 21 30 | 31 |
* | | DCRN | | |
* 31 | %r3 | (5..9|0..4) | 323 | 0 |
*
* Where:
* OPCD = opcode - 31
* RT = destination register - %r3 return register
* DCRF = DCRN # with upper and lower halves swapped
* XO = extended opcode - 323
* CR = CR[CR0] NOT undefined - 0
*/
rlwinm r0, r3, 27, 27, 31 /* OPCD = 31 */
rlwinm r3, r3, 5, 22, 26
or r3, r3, r0
slwi r3, r3, 10
oris r3, r3, 0x3e30 /* RT = %r3 */
ori r3, r3, 323 /* XO = 323 */
slwi r3, r3, 1 /* CR = 0 */
mflr r4
stw r3, 0(r4) /* Store instr in get_dcr() */
dcbst r0, r4 /* Make sure val is written out */
sync /* Wait for write to complete */
icbi r0, r4 /* Make sure old instr is dumped */
isync /* Wait for icbi to complete */
blr
.Lfe1: .size _create_MFDCR,.Lfe1-_create_MFDCR
/* end _create_MFDCR() */
/*
* static void _create_MTDCR(unsigned short dcrn, unsigned long value)
*
* Builds a 'mtdcr' instruction for set_dcr
* function.
*/
.section ".text"
.align 2
.type _create_MTDCR,@function
_create_MTDCR:
/*
* Build up a 'mtdcr' instruction formatted as follows:
*
* OPCD | RS | DCRF | XO | CR |
* ---------------|--------------|--------------|----|
* 0 5 | 6 10 | 11 20 | 21 30 | 31 |
* | | DCRN | | |
* 31 | %r3 | (5..9|0..4) | 451 | 0 |
*
* Where:
* OPCD = opcode - 31
* RS = source register - %r4
* DCRF = dest. DCRN # with upper and lower halves swapped
* XO = extended opcode - 451
* CR = CR[CR0] NOT undefined - 0
*/
rlwinm r0, r3, 27, 27, 31 /* OPCD = 31 */
rlwinm r3, r3, 5, 22, 26
or r3, r3, r0
slwi r3, r3, 10
oris r3, r3, 0x3e40 /* RS = %r4 */
ori r3, r3, 451 /* XO = 451 */
slwi r3, r3, 1 /* CR = 0 */
mflr r5
stw r3, 0(r5) /* Store instr in set_dcr() */
dcbst r0, r5 /* Make sure val is written out */
sync /* Wait for write to complete */
icbi r0, r5 /* Make sure old instr is dumped */
isync /* Wait for icbi to complete */
blr
.Lfe2: .size _create_MTDCR,.Lfe2-_create_MTDCR
/* end _create_MTDCR() */
/*
* unsigned long get_dcr(unsigned short dcrn)
*
* Return a given DCR's value.
*/
/* */
/* XXX - This is self modifying code, hence */
/* it is in the data section. */
/* */
.section ".data"
.align 2
.globl get_dcr
.type get_dcr,@function
get_dcr:
mflr r0 /* Get link register */
stwu r1, -32(r1) /* Save back chain and move SP */
stw r0, +36(r1) /* Save link register */
bl _create_MFDCR /* Build following instruction */
/* XXX - we build this instuction up on the fly. */
.long 0 /* Get DCR's value */
lwz r0, +36(r1) /* Get saved link register */
mtlr r0 /* Restore link register */
addi r1, r1, +32 /* Remove frame from stack */
blr /* Return to calling function */
.Lfe3: .size get_dcr,.Lfe3-get_dcr
/* end get_dcr() */
/*
* unsigned void set_dcr(unsigned short dcrn, unsigned long value)
*
* Return a given DCR's value.
*/
/*
* XXX - This is self modifying code, hence
* it is in the data section.
*/
.section ".data"
.align 2
.globl set_dcr
.type set_dcr,@function
set_dcr:
mflr r0 /* Get link register */
stwu r1, -32(r1) /* Save back chain and move SP */
stw r0, +36(r1) /* Save link register */
bl _create_MTDCR /* Build following instruction */
/* XXX - we build this instuction up on the fly. */
.long 0 /* Set DCR's value */
lwz r0, +36(r1) /* Get saved link register */
mtlr r0 /* Restore link register */
addi r1, r1, +32 /* Remove frame from stack */
blr /* Return to calling function */
.Lfe4: .size set_dcr,.Lfe4-set_dcr
/* end set_dcr() */
#endif
|
