1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/sched.h> 4 #include <linux/sched/clock.h> 5 6 #include <asm/cpu.h> 7 #include <asm/cpufeature.h> 8 #include <asm/e820/api.h> 9 #include <asm/mtrr.h> 10 #include <asm/msr.h> 11 12 #include "cpu.h" 13 14 #define ACE_PRESENT (1 << 6) 15 #define ACE_ENABLED (1 << 7) 16 #define ACE_FCR (1 << 28) /* MSR_VIA_FCR */ 17 18 #define RNG_PRESENT (1 << 2) 19 #define RNG_ENABLED (1 << 3) 20 #define RNG_ENABLE (1 << 6) /* MSR_VIA_RNG */ 21 22 static void init_c3(struct cpuinfo_x86 *c) 23 { 24 u32 lo, hi; 25 26 /* Test for Centaur Extended Feature Flags presence */ 27 if (cpuid_eax(0xC0000000) >= 0xC0000001) { 28 u32 tmp = cpuid_edx(0xC0000001); 29 30 /* enable ACE unit, if present and disabled */ 31 if ((tmp & (ACE_PRESENT | ACE_ENABLED)) == ACE_PRESENT) { 32 rdmsr(MSR_VIA_FCR, lo, hi); 33 lo |= ACE_FCR; /* enable ACE unit */ 34 wrmsr(MSR_VIA_FCR, lo, hi); 35 pr_info("CPU: Enabled ACE h/w crypto\n"); 36 } 37 38 /* enable RNG unit, if present and disabled */ 39 if ((tmp & (RNG_PRESENT | RNG_ENABLED)) == RNG_PRESENT) { 40 rdmsr(MSR_VIA_RNG, lo, hi); 41 lo |= RNG_ENABLE; /* enable RNG unit */ 42 wrmsr(MSR_VIA_RNG, lo, hi); 43 pr_info("CPU: Enabled h/w RNG\n"); 44 } 45 46 /* store Centaur Extended Feature Flags as 47 * word 5 of the CPU capability bit array 48 */ 49 c->x86_capability[CPUID_C000_0001_EDX] = cpuid_edx(0xC0000001); 50 } 51 #ifdef CONFIG_X86_32 52 /* Cyrix III family needs CX8 & PGE explicitly enabled. */ 53 if (c->x86_model >= 6 && c->x86_model <= 13) { 54 rdmsr(MSR_VIA_FCR, lo, hi); 55 lo |= (1<<1 | 1<<7); 56 wrmsr(MSR_VIA_FCR, lo, hi); 57 set_cpu_cap(c, X86_FEATURE_CX8); 58 } 59 60 /* Before Nehemiah, the C3's had 3dNOW! */ 61 if (c->x86_model >= 6 && c->x86_model < 9) 62 set_cpu_cap(c, X86_FEATURE_3DNOW); 63 #endif 64 if (c->x86 == 0x6 && c->x86_model >= 0xf) { 65 c->x86_cache_alignment = c->x86_clflush_size * 2; 66 set_cpu_cap(c, X86_FEATURE_REP_GOOD); 67 } 68 69 if (c->x86 >= 7) 70 set_cpu_cap(c, X86_FEATURE_REP_GOOD); 71 } 72 73 enum { 74 ECX8 = 1<<1, 75 EIERRINT = 1<<2, 76 DPM = 1<<3, 77 DMCE = 1<<4, 78 DSTPCLK = 1<<5, 79 ELINEAR = 1<<6, 80 DSMC = 1<<7, 81 DTLOCK = 1<<8, 82 EDCTLB = 1<<8, 83 EMMX = 1<<9, 84 DPDC = 1<<11, 85 EBRPRED = 1<<12, 86 DIC = 1<<13, 87 DDC = 1<<14, 88 DNA = 1<<15, 89 ERETSTK = 1<<16, 90 E2MMX = 1<<19, 91 EAMD3D = 1<<20, 92 }; 93 94 static void early_init_centaur(struct cpuinfo_x86 *c) 95 { 96 #ifdef CONFIG_X86_32 97 /* Emulate MTRRs using Centaur's MCR. */ 98 if (c->x86 == 5) 99 set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR); 100 #endif 101 if ((c->x86 == 6 && c->x86_model >= 0xf) || 102 (c->x86 >= 7)) 103 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); 104 105 #ifdef CONFIG_X86_64 106 set_cpu_cap(c, X86_FEATURE_SYSENTER32); 107 #endif 108 if (c->x86_power & (1 << 8)) { 109 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); 110 set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); 111 } 112 } 113 114 static void init_centaur(struct cpuinfo_x86 *c) 115 { 116 #ifdef CONFIG_X86_32 117 char *name; 118 u32 fcr_set = 0; 119 u32 fcr_clr = 0; 120 u32 lo, hi, newlo; 121 u32 aa, bb, cc, dd; 122 123 /* 124 * Bit 31 in normal CPUID used for nonstandard 3DNow ID; 125 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway 126 */ 127 clear_cpu_cap(c, 0*32+31); 128 #endif 129 early_init_centaur(c); 130 init_intel_cacheinfo(c); 131 detect_num_cpu_cores(c); 132 #ifdef CONFIG_X86_32 133 detect_ht(c); 134 #endif 135 136 if (c->cpuid_level > 9) { 137 unsigned int eax = cpuid_eax(10); 138 139 /* 140 * Check for version and the number of counters 141 * Version(eax[7:0]) can't be 0; 142 * Counters(eax[15:8]) should be greater than 1; 143 */ 144 if ((eax & 0xff) && (((eax >> 8) & 0xff) > 1)) 145 set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON); 146 } 147 148 #ifdef CONFIG_X86_32 149 if (c->x86 == 5) { 150 switch (c->x86_model) { 151 case 4: 152 name = "C6"; 153 fcr_set = ECX8|DSMC|EDCTLB|EMMX|ERETSTK; 154 fcr_clr = DPDC; 155 pr_notice("Disabling bugged TSC.\n"); 156 clear_cpu_cap(c, X86_FEATURE_TSC); 157 break; 158 case 8: 159 switch (c->x86_stepping) { 160 default: 161 name = "2"; 162 break; 163 case 7 ... 9: 164 name = "2A"; 165 break; 166 case 10 ... 15: 167 name = "2B"; 168 break; 169 } 170 fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK| 171 E2MMX|EAMD3D; 172 fcr_clr = DPDC; 173 break; 174 case 9: 175 name = "3"; 176 fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK| 177 E2MMX|EAMD3D; 178 fcr_clr = DPDC; 179 break; 180 default: 181 name = "??"; 182 } 183 184 rdmsr(MSR_IDT_FCR1, lo, hi); 185 newlo = (lo|fcr_set) & (~fcr_clr); 186 187 if (newlo != lo) { 188 pr_info("Centaur FCR was 0x%X now 0x%X\n", 189 lo, newlo); 190 wrmsr(MSR_IDT_FCR1, newlo, hi); 191 } else { 192 pr_info("Centaur FCR is 0x%X\n", lo); 193 } 194 /* Emulate MTRRs using Centaur's MCR. */ 195 set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR); 196 /* Report CX8 */ 197 set_cpu_cap(c, X86_FEATURE_CX8); 198 /* Set 3DNow! on Winchip 2 and above. */ 199 if (c->x86_model >= 8) 200 set_cpu_cap(c, X86_FEATURE_3DNOW); 201 /* See if we can find out some more. */ 202 if (cpuid_eax(0x80000000) >= 0x80000005) { 203 /* Yes, we can. */ 204 cpuid(0x80000005, &aa, &bb, &cc, &dd); 205 /* Add L1 data and code cache sizes. */ 206 c->x86_cache_size = (cc>>24)+(dd>>24); 207 } 208 sprintf(c->x86_model_id, "WinChip %s", name); 209 } 210 #endif 211 if (c->x86 == 6 || c->x86 >= 7) 212 init_c3(c); 213 #ifdef CONFIG_X86_64 214 set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC); 215 #endif 216 217 init_ia32_feat_ctl(c); 218 } 219 220 #ifdef CONFIG_X86_32 221 static unsigned int 222 centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size) 223 { 224 /* VIA C3 CPUs (670-68F) need further shifting. */ 225 if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8))) 226 size >>= 8; 227 228 /* 229 * There's also an erratum in Nehemiah stepping 1, which 230 * returns '65KB' instead of '64KB' 231 * - Note, it seems this may only be in engineering samples. 232 */ 233 if ((c->x86 == 6) && (c->x86_model == 9) && 234 (c->x86_stepping == 1) && (size == 65)) 235 size -= 1; 236 return size; 237 } 238 #endif 239 240 static const struct cpu_dev centaur_cpu_dev = { 241 .c_vendor = "Centaur", 242 .c_ident = { "CentaurHauls" }, 243 .c_early_init = early_init_centaur, 244 .c_init = init_centaur, 245 #ifdef CONFIG_X86_32 246 .legacy_cache_size = centaur_size_cache, 247 #endif 248 .c_x86_vendor = X86_VENDOR_CENTAUR, 249 }; 250 251 cpu_dev_register(centaur_cpu_dev); 252