1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Processor capabilities determination functions. 4 * 5 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited 6 */ 7 #include <linux/init.h> 8 #include <linux/kernel.h> 9 #include <linux/ptrace.h> 10 #include <linux/smp.h> 11 #include <linux/stddef.h> 12 #include <linux/export.h> 13 #include <linux/printk.h> 14 #include <linux/uaccess.h> 15 16 #include <asm/cpu-features.h> 17 #include <asm/elf.h> 18 #include <asm/fpu.h> 19 #include <asm/loongarch.h> 20 #include <asm/pgtable-bits.h> 21 #include <asm/setup.h> 22 23 /* Hardware capabilities */ 24 unsigned int elf_hwcap __read_mostly; 25 EXPORT_SYMBOL_GPL(elf_hwcap); 26 27 /* 28 * Determine the FCSR mask for FPU hardware. 29 */ 30 static inline void cpu_set_fpu_fcsr_mask(struct cpuinfo_loongarch *c) 31 { 32 unsigned long sr, mask, fcsr, fcsr0, fcsr1; 33 34 fcsr = c->fpu_csr0; 35 mask = FPU_CSR_ALL_X | FPU_CSR_ALL_E | FPU_CSR_ALL_S | FPU_CSR_RM; 36 37 sr = read_csr_euen(); 38 enable_fpu(); 39 40 fcsr0 = fcsr & mask; 41 write_fcsr(LOONGARCH_FCSR0, fcsr0); 42 fcsr0 = read_fcsr(LOONGARCH_FCSR0); 43 44 fcsr1 = fcsr | ~mask; 45 write_fcsr(LOONGARCH_FCSR0, fcsr1); 46 fcsr1 = read_fcsr(LOONGARCH_FCSR0); 47 48 write_fcsr(LOONGARCH_FCSR0, fcsr); 49 50 write_csr_euen(sr); 51 52 c->fpu_mask = ~(fcsr0 ^ fcsr1) & ~mask; 53 } 54 55 static inline void set_elf_platform(int cpu, const char *plat) 56 { 57 if (cpu == 0) 58 __elf_platform = plat; 59 } 60 61 /* MAP BASE */ 62 unsigned long vm_map_base; 63 EXPORT_SYMBOL(vm_map_base); 64 65 static void cpu_probe_addrbits(struct cpuinfo_loongarch *c) 66 { 67 #ifdef __NEED_ADDRBITS_PROBE 68 c->pabits = (read_cpucfg(LOONGARCH_CPUCFG1) & CPUCFG1_PABITS) >> 4; 69 c->vabits = (read_cpucfg(LOONGARCH_CPUCFG1) & CPUCFG1_VABITS) >> 12; 70 vm_map_base = 0UL - (1UL << c->vabits); 71 #endif 72 } 73 74 static void set_isa(struct cpuinfo_loongarch *c, unsigned int isa) 75 { 76 switch (isa) { 77 case LOONGARCH_CPU_ISA_LA64: 78 c->isa_level |= LOONGARCH_CPU_ISA_LA64; 79 fallthrough; 80 case LOONGARCH_CPU_ISA_LA32S: 81 c->isa_level |= LOONGARCH_CPU_ISA_LA32S; 82 fallthrough; 83 case LOONGARCH_CPU_ISA_LA32R: 84 c->isa_level |= LOONGARCH_CPU_ISA_LA32R; 85 break; 86 } 87 } 88 89 static void cpu_probe_common(struct cpuinfo_loongarch *c) 90 { 91 unsigned int config; 92 unsigned long asid_mask; 93 94 c->options = LOONGARCH_CPU_CPUCFG | LOONGARCH_CPU_CSR | LOONGARCH_CPU_VINT; 95 96 elf_hwcap = HWCAP_LOONGARCH_CPUCFG; 97 98 config = read_cpucfg(LOONGARCH_CPUCFG1); 99 100 switch (config & CPUCFG1_ISA) { 101 case 0: 102 set_isa(c, LOONGARCH_CPU_ISA_LA32R); 103 break; 104 case 1: 105 set_isa(c, LOONGARCH_CPU_ISA_LA32S); 106 break; 107 case 2: 108 set_isa(c, LOONGARCH_CPU_ISA_LA64); 109 break; 110 default: 111 pr_warn("Warning: unknown ISA level\n"); 112 } 113 114 if (config & CPUCFG1_PAGING) 115 c->options |= LOONGARCH_CPU_TLB; 116 if (config & CPUCFG1_IOCSR) 117 c->options |= LOONGARCH_CPU_IOCSR; 118 if (config & CPUCFG1_UAL) { 119 c->options |= LOONGARCH_CPU_UAL; 120 elf_hwcap |= HWCAP_LOONGARCH_UAL; 121 } 122 if (config & CPUCFG1_CRC32) { 123 c->options |= LOONGARCH_CPU_CRC32; 124 elf_hwcap |= HWCAP_LOONGARCH_CRC32; 125 } 126 127 config = read_cpucfg(LOONGARCH_CPUCFG2); 128 if (config & CPUCFG2_LAM) { 129 c->options |= LOONGARCH_CPU_LAM; 130 elf_hwcap |= HWCAP_LOONGARCH_LAM; 131 } 132 if (config & CPUCFG2_FP) { 133 c->options |= LOONGARCH_CPU_FPU; 134 elf_hwcap |= HWCAP_LOONGARCH_FPU; 135 } 136 #ifdef CONFIG_CPU_HAS_LSX 137 if (config & CPUCFG2_LSX) { 138 c->options |= LOONGARCH_CPU_LSX; 139 elf_hwcap |= HWCAP_LOONGARCH_LSX; 140 } 141 #endif 142 #ifdef CONFIG_CPU_HAS_LASX 143 if (config & CPUCFG2_LASX) { 144 c->options |= LOONGARCH_CPU_LASX; 145 elf_hwcap |= HWCAP_LOONGARCH_LASX; 146 } 147 #endif 148 if (config & CPUCFG2_COMPLEX) { 149 c->options |= LOONGARCH_CPU_COMPLEX; 150 elf_hwcap |= HWCAP_LOONGARCH_COMPLEX; 151 } 152 if (config & CPUCFG2_CRYPTO) { 153 c->options |= LOONGARCH_CPU_CRYPTO; 154 elf_hwcap |= HWCAP_LOONGARCH_CRYPTO; 155 } 156 if (config & CPUCFG2_PTW) { 157 c->options |= LOONGARCH_CPU_PTW; 158 elf_hwcap |= HWCAP_LOONGARCH_PTW; 159 } 160 if (config & CPUCFG2_LSPW) { 161 c->options |= LOONGARCH_CPU_LSPW; 162 elf_hwcap |= HWCAP_LOONGARCH_LSPW; 163 } 164 if (config & CPUCFG2_LVZP) { 165 c->options |= LOONGARCH_CPU_LVZ; 166 elf_hwcap |= HWCAP_LOONGARCH_LVZ; 167 } 168 #ifdef CONFIG_CPU_HAS_LBT 169 if (config & CPUCFG2_X86BT) { 170 c->options |= LOONGARCH_CPU_LBT_X86; 171 elf_hwcap |= HWCAP_LOONGARCH_LBT_X86; 172 } 173 if (config & CPUCFG2_ARMBT) { 174 c->options |= LOONGARCH_CPU_LBT_ARM; 175 elf_hwcap |= HWCAP_LOONGARCH_LBT_ARM; 176 } 177 if (config & CPUCFG2_MIPSBT) { 178 c->options |= LOONGARCH_CPU_LBT_MIPS; 179 elf_hwcap |= HWCAP_LOONGARCH_LBT_MIPS; 180 } 181 #endif 182 183 config = read_cpucfg(LOONGARCH_CPUCFG6); 184 if (config & CPUCFG6_PMP) 185 c->options |= LOONGARCH_CPU_PMP; 186 187 config = csr_read32(LOONGARCH_CSR_ASID); 188 config = (config & CSR_ASID_BIT) >> CSR_ASID_BIT_SHIFT; 189 asid_mask = GENMASK(config - 1, 0); 190 set_cpu_asid_mask(c, asid_mask); 191 192 config = read_csr_prcfg1(); 193 c->ksave_mask = GENMASK((config & CSR_CONF1_KSNUM) - 1, 0); 194 c->ksave_mask &= ~(EXC_KSAVE_MASK | PERCPU_KSAVE_MASK | KVM_KSAVE_MASK); 195 196 config = read_csr_prcfg3(); 197 switch (config & CSR_CONF3_TLBTYPE) { 198 case 0: 199 c->tlbsizemtlb = 0; 200 c->tlbsizestlbsets = 0; 201 c->tlbsizestlbways = 0; 202 c->tlbsize = 0; 203 break; 204 case 1: 205 c->tlbsizemtlb = ((config & CSR_CONF3_MTLBSIZE) >> CSR_CONF3_MTLBSIZE_SHIFT) + 1; 206 c->tlbsizestlbsets = 0; 207 c->tlbsizestlbways = 0; 208 c->tlbsize = c->tlbsizemtlb + c->tlbsizestlbsets * c->tlbsizestlbways; 209 break; 210 case 2: 211 c->tlbsizemtlb = ((config & CSR_CONF3_MTLBSIZE) >> CSR_CONF3_MTLBSIZE_SHIFT) + 1; 212 c->tlbsizestlbsets = 1 << ((config & CSR_CONF3_STLBIDX) >> CSR_CONF3_STLBIDX_SHIFT); 213 c->tlbsizestlbways = ((config & CSR_CONF3_STLBWAYS) >> CSR_CONF3_STLBWAYS_SHIFT) + 1; 214 c->tlbsize = c->tlbsizemtlb + c->tlbsizestlbsets * c->tlbsizestlbways; 215 break; 216 default: 217 pr_warn("Warning: unknown TLB type\n"); 218 } 219 220 if (get_num_brps() + get_num_wrps()) 221 c->options |= LOONGARCH_CPU_WATCH; 222 } 223 224 #define MAX_NAME_LEN 32 225 #define VENDOR_OFFSET 0 226 #define CPUNAME_OFFSET 9 227 228 static char cpu_full_name[MAX_NAME_LEN] = " - "; 229 230 static inline void cpu_probe_loongson(struct cpuinfo_loongarch *c, unsigned int cpu) 231 { 232 uint32_t config; 233 uint64_t *vendor = (void *)(&cpu_full_name[VENDOR_OFFSET]); 234 uint64_t *cpuname = (void *)(&cpu_full_name[CPUNAME_OFFSET]); 235 const char *core_name = "Unknown"; 236 237 switch (BIT(fls(c->isa_level) - 1)) { 238 case LOONGARCH_CPU_ISA_LA32R: 239 case LOONGARCH_CPU_ISA_LA32S: 240 c->cputype = CPU_LOONGSON32; 241 __cpu_family[cpu] = "Loongson-32bit"; 242 break; 243 case LOONGARCH_CPU_ISA_LA64: 244 c->cputype = CPU_LOONGSON64; 245 __cpu_family[cpu] = "Loongson-64bit"; 246 break; 247 } 248 249 switch (c->processor_id & PRID_SERIES_MASK) { 250 case PRID_SERIES_LA132: 251 core_name = "LA132"; 252 break; 253 case PRID_SERIES_LA264: 254 core_name = "LA264"; 255 break; 256 case PRID_SERIES_LA364: 257 core_name = "LA364"; 258 break; 259 case PRID_SERIES_LA464: 260 core_name = "LA464"; 261 break; 262 case PRID_SERIES_LA664: 263 core_name = "LA664"; 264 break; 265 } 266 267 pr_info("%s Processor probed (%s Core)\n", __cpu_family[cpu], core_name); 268 269 if (!cpu_has_iocsr) 270 return; 271 272 if (!__cpu_full_name[cpu]) 273 __cpu_full_name[cpu] = cpu_full_name; 274 275 *vendor = iocsr_read64(LOONGARCH_IOCSR_VENDOR); 276 *cpuname = iocsr_read64(LOONGARCH_IOCSR_CPUNAME); 277 278 config = iocsr_read32(LOONGARCH_IOCSR_FEATURES); 279 if (config & IOCSRF_CSRIPI) 280 c->options |= LOONGARCH_CPU_CSRIPI; 281 if (config & IOCSRF_EXTIOI) 282 c->options |= LOONGARCH_CPU_EXTIOI; 283 if (config & IOCSRF_FREQSCALE) 284 c->options |= LOONGARCH_CPU_SCALEFREQ; 285 if (config & IOCSRF_FLATMODE) 286 c->options |= LOONGARCH_CPU_FLATMODE; 287 if (config & IOCSRF_EIODECODE) 288 c->options |= LOONGARCH_CPU_EIODECODE; 289 if (config & IOCSRF_AVEC) 290 c->options |= LOONGARCH_CPU_AVECINT; 291 if (config & IOCSRF_VM) 292 c->options |= LOONGARCH_CPU_HYPERVISOR; 293 } 294 295 #ifdef CONFIG_64BIT 296 /* For use by uaccess.h */ 297 u64 __ua_limit; 298 EXPORT_SYMBOL(__ua_limit); 299 #endif 300 301 const char *__cpu_family[NR_CPUS]; 302 const char *__cpu_full_name[NR_CPUS]; 303 const char *__elf_platform; 304 305 static void cpu_report(void) 306 { 307 struct cpuinfo_loongarch *c = ¤t_cpu_data; 308 309 pr_info("CPU%d revision is: %08x (%s)\n", 310 smp_processor_id(), c->processor_id, cpu_family_string()); 311 if (c->options & LOONGARCH_CPU_FPU) 312 pr_info("FPU%d revision is: %08x\n", smp_processor_id(), c->fpu_vers); 313 } 314 315 void cpu_probe(void) 316 { 317 unsigned int cpu = smp_processor_id(); 318 struct cpuinfo_loongarch *c = ¤t_cpu_data; 319 320 /* 321 * Set a default ELF platform, cpu probe may later 322 * overwrite it with a more precise value 323 */ 324 set_elf_platform(cpu, "loongarch"); 325 326 c->cputype = CPU_UNKNOWN; 327 c->processor_id = read_cpucfg(LOONGARCH_CPUCFG0); 328 c->fpu_vers = (read_cpucfg(LOONGARCH_CPUCFG2) & CPUCFG2_FPVERS) >> 3; 329 330 c->fpu_csr0 = FPU_CSR_RN; 331 c->fpu_mask = FPU_CSR_RSVD; 332 333 cpu_probe_common(c); 334 335 per_cpu_trap_init(cpu); 336 337 switch (c->processor_id & PRID_COMP_MASK) { 338 case PRID_COMP_LOONGSON: 339 cpu_probe_loongson(c, cpu); 340 break; 341 } 342 343 BUG_ON(!__cpu_family[cpu]); 344 BUG_ON(c->cputype == CPU_UNKNOWN); 345 346 cpu_probe_addrbits(c); 347 348 #ifdef CONFIG_64BIT 349 if (cpu == 0) 350 __ua_limit = ~((1ull << cpu_vabits) - 1); 351 #endif 352 353 cpu_report(); 354 } 355