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 */ 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 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 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 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 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 } 112 113 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 } 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 & (1<<24)) { 213 probe_spram("ISPRAM", 0x1c000000, 214 &ispram_load_tag, &ispram_store_tag); 215 } 216 if (config0 & (1<<23)) 217 probe_spram("DSPRAM", 0x1c100000, 218 &dspram_load_tag, &dspram_store_tag); 219 } 220 } 221