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wdenkc74078f2001-10-21 10:56:49 +00001/*
2 * (C) Copyright 2001
3 * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com
4 *
5 * See file CREDITS for list of people who contributed to this
6 * project.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21 * MA 02111-1307 USA
22 */
23#include <config.h>
24
Jon Loeliger3a1ed1e2007-07-09 18:57:22 -050025#if defined(CONFIG_4xx) && defined(CONFIG_CMD_SETGETDCR)
wdenkc74078f2001-10-21 10:56:49 +000026
27#include <ppc4xx.h>
28
29#define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */
30
31#include <ppc_asm.tmpl>
32#include <ppc_defs.h>
33
34#include <asm/cache.h>
35#include <asm/mmu.h>
36
37#define _ASMLANGUAGE
38
39/*****************************************************************************
40 *
41 * XXX - DANGER
42 * These routines make use of self modifying code. DO NOT CALL THEM
43 * UNTIL THEY ARE RELOCATED TO RAM. Additionally, I do not
44 * recommend them for use in anything other than an interactive
45 * debugging environment. This is mainly due to performance reasons.
46 *
47 ****************************************************************************/
48
49/*
50 * static void _create_MFDCR(unsigned short dcrn)
51 *
52 * Builds a 'mfdcr' instruction for get_dcr
53 * function.
54 */
55 .section ".text"
56 .align 2
57 .type _create_MFDCR,@function
58_create_MFDCR:
59 /*
60 * Build up a 'mfdcr' instruction formatted as follows:
61 *
62 * OPCD | RT | DCRF | XO | CR |
63 * ---------------|--------------|--------------|----|
64 * 0 5 | 6 10 | 11 20 | 21 30 | 31 |
65 * | | DCRN | | |
66 * 31 | %r3 | (5..9|0..4) | 323 | 0 |
67 *
68 * Where:
69 * OPCD = opcode - 31
70 * RT = destination register - %r3 return register
71 * DCRF = DCRN # with upper and lower halves swapped
72 * XO = extended opcode - 323
73 * CR = CR[CR0] NOT undefined - 0
74 */
75 rlwinm r0, r3, 27, 27, 31 /* OPCD = 31 */
76 rlwinm r3, r3, 5, 22, 26
77 or r3, r3, r0
78 slwi r3, r3, 10
79 oris r3, r3, 0x3e30 /* RT = %r3 */
80 ori r3, r3, 323 /* XO = 323 */
81 slwi r3, r3, 1 /* CR = 0 */
82
83 mflr r4
84 stw r3, 0(r4) /* Store instr in get_dcr() */
85 dcbst r0, r4 /* Make sure val is written out */
86 sync /* Wait for write to complete */
87 icbi r0, r4 /* Make sure old instr is dumped */
88 isync /* Wait for icbi to complete */
89
90 blr
91.Lfe1: .size _create_MFDCR,.Lfe1-_create_MFDCR
92/* end _create_MFDCR() */
93
94/*
95 * static void _create_MTDCR(unsigned short dcrn, unsigned long value)
96 *
97 * Builds a 'mtdcr' instruction for set_dcr
98 * function.
99 */
100 .section ".text"
101 .align 2
102 .type _create_MTDCR,@function
103_create_MTDCR:
104 /*
105 * Build up a 'mtdcr' instruction formatted as follows:
106 *
107 * OPCD | RS | DCRF | XO | CR |
108 * ---------------|--------------|--------------|----|
109 * 0 5 | 6 10 | 11 20 | 21 30 | 31 |
110 * | | DCRN | | |
111 * 31 | %r3 | (5..9|0..4) | 451 | 0 |
112 *
113 * Where:
114 * OPCD = opcode - 31
115 * RS = source register - %r4
116 * DCRF = dest. DCRN # with upper and lower halves swapped
117 * XO = extended opcode - 451
118 * CR = CR[CR0] NOT undefined - 0
119 */
120 rlwinm r0, r3, 27, 27, 31 /* OPCD = 31 */
121 rlwinm r3, r3, 5, 22, 26
122 or r3, r3, r0
123 slwi r3, r3, 10
124 oris r3, r3, 0x3e40 /* RS = %r4 */
125 ori r3, r3, 451 /* XO = 451 */
126 slwi r3, r3, 1 /* CR = 0 */
127
128 mflr r5
129 stw r3, 0(r5) /* Store instr in set_dcr() */
130 dcbst r0, r5 /* Make sure val is written out */
131 sync /* Wait for write to complete */
132 icbi r0, r5 /* Make sure old instr is dumped */
133 isync /* Wait for icbi to complete */
134
135 blr
136.Lfe2: .size _create_MTDCR,.Lfe2-_create_MTDCR
137/* end _create_MTDCR() */
138
139
140/*
141 * unsigned long get_dcr(unsigned short dcrn)
142 *
143 * Return a given DCR's value.
144 */
145 /* */
146 /* XXX - This is self modifying code, hence */
147 /* it is in the data section. */
148 /* */
149 .section ".data"
150 .align 2
151 .globl get_dcr
152 .type get_dcr,@function
153get_dcr:
154 mflr r0 /* Get link register */
155 stwu r1, -32(r1) /* Save back chain and move SP */
156 stw r0, +36(r1) /* Save link register */
157
158 bl _create_MFDCR /* Build following instruction */
159 /* XXX - we build this instuction up on the fly. */
160 .long 0 /* Get DCR's value */
161
162 lwz r0, +36(r1) /* Get saved link register */
163 mtlr r0 /* Restore link register */
164 addi r1, r1, +32 /* Remove frame from stack */
165 blr /* Return to calling function */
166.Lfe3: .size get_dcr,.Lfe3-get_dcr
167/* end get_dcr() */
168
169
170/*
171 * unsigned void set_dcr(unsigned short dcrn, unsigned long value)
172 *
173 * Return a given DCR's value.
174 */
175 /*
176 * XXX - This is self modifying code, hence
177 * it is in the data section.
178 */
179 .section ".data"
180 .align 2
181 .globl set_dcr
182 .type set_dcr,@function
183set_dcr:
184 mflr r0 /* Get link register */
185 stwu r1, -32(r1) /* Save back chain and move SP */
186 stw r0, +36(r1) /* Save link register */
187
188 bl _create_MTDCR /* Build following instruction */
189 /* XXX - we build this instuction up on the fly. */
190 .long 0 /* Set DCR's value */
191
192 lwz r0, +36(r1) /* Get saved link register */
193 mtlr r0 /* Restore link register */
194 addi r1, r1, +32 /* Remove frame from stack */
195 blr /* Return to calling function */
196.Lfe4: .size set_dcr,.Lfe4-set_dcr
197/* end set_dcr() */
Jon Loeliger068b60a2007-07-10 10:27:39 -0500198#endif