1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * MIPS SPRAM support
4 *
5 * Copyright (C) 2007, 2008 MIPS Technologies, Inc.
6 */
7 #include <linux/kernel.h>
8 #include <linux/ptrace.h>
9 #include <linux/stddef.h>
10
11 #include <asm/fpu.h>
12 #include <asm/mipsregs.h>
13 #include <asm/r4kcache.h>
14 #include <asm/hazards.h>
15
16 /*
17 * These definitions are correct for the 24K/34K/74K SPRAM sample
18 * implementation. The 4KS interpreted the tags differently...
19 */
20 #define SPRAM_TAG0_ENABLE 0x00000080
21 #define SPRAM_TAG0_PA_MASK 0xfffff000
22 #define SPRAM_TAG1_SIZE_MASK 0xfffff000
23
24 #define SPRAM_TAG_STRIDE 8
25
26 #define ERRCTL_SPRAM (1 << 28)
27
28 /* errctl access */
29 #define read_c0_errctl(x) read_c0_ecc(x)
30 #define write_c0_errctl(x) write_c0_ecc(x)
31
32 /*
33 * Different semantics to the set_c0_* function built by __BUILD_SET_C0
34 */
bis_c0_errctl(unsigned int set)35 static unsigned int bis_c0_errctl(unsigned int set)
36 {
37 unsigned int res;
38 res = read_c0_errctl();
39 write_c0_errctl(res | set);
40 return res;
41 }
42
ispram_store_tag(unsigned int offset,unsigned int data)43 static void ispram_store_tag(unsigned int offset, unsigned int data)
44 {
45 unsigned int errctl;
46
47 /* enable SPRAM tag access */
48 errctl = bis_c0_errctl(ERRCTL_SPRAM);
49 ehb();
50
51 write_c0_taglo(data);
52 ehb();
53
54 cache_op(Index_Store_Tag_I, CKSEG0|offset);
55 ehb();
56
57 write_c0_errctl(errctl);
58 ehb();
59 }
60
61
ispram_load_tag(unsigned int offset)62 static unsigned int ispram_load_tag(unsigned int offset)
63 {
64 unsigned int data;
65 unsigned int errctl;
66
67 /* enable SPRAM tag access */
68 errctl = bis_c0_errctl(ERRCTL_SPRAM);
69 ehb();
70 cache_op(Index_Load_Tag_I, CKSEG0 | offset);
71 ehb();
72 data = read_c0_taglo();
73 ehb();
74 write_c0_errctl(errctl);
75 ehb();
76
77 return data;
78 }
79
dspram_store_tag(unsigned int offset,unsigned int data)80 static void dspram_store_tag(unsigned int offset, unsigned int data)
81 {
82 unsigned int errctl;
83
84 /* enable SPRAM tag access */
85 errctl = bis_c0_errctl(ERRCTL_SPRAM);
86 ehb();
87 write_c0_dtaglo(data);
88 ehb();
89 cache_op(Index_Store_Tag_D, CKSEG0 | offset);
90 ehb();
91 write_c0_errctl(errctl);
92 ehb();
93 }
94
95
dspram_load_tag(unsigned int offset)96 static unsigned int dspram_load_tag(unsigned int offset)
97 {
98 unsigned int data;
99 unsigned int errctl;
100
101 errctl = bis_c0_errctl(ERRCTL_SPRAM);
102 ehb();
103 cache_op(Index_Load_Tag_D, CKSEG0 | offset);
104 ehb();
105 data = read_c0_dtaglo();
106 ehb();
107 write_c0_errctl(errctl);
108 ehb();
109
110 return data;
111 }
112
probe_spram(char * type,unsigned int base,unsigned int (* read)(unsigned int),void (* write)(unsigned int,unsigned int))113 static void probe_spram(char *type,
114 unsigned int base,
115 unsigned int (*read)(unsigned int),
116 void (*write)(unsigned int, unsigned int))
117 {
118 unsigned int firstsize = 0, lastsize = 0;
119 unsigned int firstpa = 0, lastpa = 0, pa = 0;
120 unsigned int offset = 0;
121 unsigned int size, tag0, tag1;
122 unsigned int enabled;
123 int i;
124
125 /*
126 * The limit is arbitrary but avoids the loop running away if
127 * the SPRAM tags are implemented differently
128 */
129
130 for (i = 0; i < 8; i++) {
131 tag0 = read(offset);
132 tag1 = read(offset+SPRAM_TAG_STRIDE);
133 pr_debug("DBG %s%d: tag0=%08x tag1=%08x\n",
134 type, i, tag0, tag1);
135
136 size = tag1 & SPRAM_TAG1_SIZE_MASK;
137
138 if (size == 0)
139 break;
140
141 if (i != 0) {
142 /* tags may repeat... */
143 if ((pa == firstpa && size == firstsize) ||
144 (pa == lastpa && size == lastsize))
145 break;
146 }
147
148 /* Align base with size */
149 base = (base + size - 1) & ~(size-1);
150
151 /* reprogram the base address base address and enable */
152 tag0 = (base & SPRAM_TAG0_PA_MASK) | SPRAM_TAG0_ENABLE;
153 write(offset, tag0);
154
155 base += size;
156
157 /* reread the tag */
158 tag0 = read(offset);
159 pa = tag0 & SPRAM_TAG0_PA_MASK;
160 enabled = tag0 & SPRAM_TAG0_ENABLE;
161
162 if (i == 0) {
163 firstpa = pa;
164 firstsize = size;
165 }
166
167 lastpa = pa;
168 lastsize = size;
169
170 if (strcmp(type, "DSPRAM") == 0) {
171 unsigned int *vp = (unsigned int *)(CKSEG1 | pa);
172 unsigned int v;
173 #define TDAT 0x5a5aa5a5
174 vp[0] = TDAT;
175 vp[1] = ~TDAT;
176
177 mb();
178
179 v = vp[0];
180 if (v != TDAT)
181 printk(KERN_ERR "vp=%p wrote=%08x got=%08x\n",
182 vp, TDAT, v);
183 v = vp[1];
184 if (v != ~TDAT)
185 printk(KERN_ERR "vp=%p wrote=%08x got=%08x\n",
186 vp+1, ~TDAT, v);
187 }
188
189 pr_info("%s%d: PA=%08x,Size=%08x%s\n",
190 type, i, pa, size, enabled ? ",enabled" : "");
191 offset += 2 * SPRAM_TAG_STRIDE;
192 }
193 }
spram_config(void)194 void spram_config(void)
195 {
196 unsigned int config0;
197
198 switch (current_cpu_type()) {
199 case CPU_24K:
200 case CPU_34K:
201 case CPU_74K:
202 case CPU_1004K:
203 case CPU_1074K:
204 case CPU_INTERAPTIV:
205 case CPU_PROAPTIV:
206 case CPU_P5600:
207 case CPU_QEMU_GENERIC:
208 case CPU_I6400:
209 case CPU_P6600:
210 config0 = read_c0_config();
211 /* FIXME: addresses are Malta specific */
212 if (config0 & MIPS_CONF_ISP) {
213 probe_spram("ISPRAM", 0x1c000000,
214 &ispram_load_tag, &ispram_store_tag);
215 }
216 if (config0 & MIPS_CONF_DSP)
217 probe_spram("DSPRAM", 0x1c100000,
218 &dspram_load_tag, &dspram_store_tag);
219 }
220 }
221
