xref: /openbmc/u-boot/arch/arm/lib/cache-cp15.c (revision 15855700)
1 /*
2  * (C) Copyright 2002
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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 
24 #include <common.h>
25 #include <asm/system.h>
26 
27 #if !(defined(CONFIG_SYS_NO_ICACHE) && defined(CONFIG_SYS_NO_DCACHE))
28 static void cp_delay (void)
29 {
30 	volatile int i;
31 
32 	/* copro seems to need some delay between reading and writing */
33 	for (i = 0; i < 100; i++)
34 		nop();
35 }
36 
37 /* cache_bit must be either CR_I or CR_C */
38 static void cache_enable(uint32_t cache_bit)
39 {
40 	uint32_t reg;
41 
42 	reg = get_cr();	/* get control reg. */
43 	cp_delay();
44 	set_cr(reg | cache_bit);
45 }
46 
47 /* cache_bit must be either CR_I or CR_C */
48 static void cache_disable(uint32_t cache_bit)
49 {
50 	uint32_t reg;
51 
52 	reg = get_cr();
53 	cp_delay();
54 	set_cr(reg & ~cache_bit);
55 }
56 #endif
57 
58 #ifdef CONFIG_SYS_NO_ICACHE
59 void icache_enable (void)
60 {
61 	return;
62 }
63 
64 void icache_disable (void)
65 {
66 	return;
67 }
68 
69 int icache_status (void)
70 {
71 	return 0;					/* always off */
72 }
73 #else
74 void icache_enable(void)
75 {
76 	cache_enable(CR_I);
77 }
78 
79 void icache_disable(void)
80 {
81 	cache_disable(CR_I);
82 }
83 
84 int icache_status(void)
85 {
86 	return (get_cr() & CR_I) != 0;
87 }
88 #endif
89 
90 #ifdef CONFIG_SYS_NO_DCACHE
91 void dcache_enable (void)
92 {
93 	return;
94 }
95 
96 void dcache_disable (void)
97 {
98 	return;
99 }
100 
101 int dcache_status (void)
102 {
103 	return 0;					/* always off */
104 }
105 #else
106 void dcache_enable(void)
107 {
108 	cache_enable(CR_C);
109 }
110 
111 void dcache_disable(void)
112 {
113 	cache_disable(CR_C);
114 }
115 
116 int dcache_status(void)
117 {
118 	return (get_cr() & CR_C) != 0;
119 }
120 #endif
121