1 #include <linux/bitops.h> 2 #include <linux/delay.h> 3 #include <linux/pci.h> 4 #include <asm/dma.h> 5 #include <linux/io.h> 6 #include <asm/processor-cyrix.h> 7 #include <asm/processor-flags.h> 8 #include <linux/timer.h> 9 #include <asm/pci-direct.h> 10 #include <asm/tsc.h> 11 #include <asm/cpufeature.h> 12 13 #include "cpu.h" 14 15 /* 16 * Read NSC/Cyrix DEVID registers (DIR) to get more detailed info. about the CPU 17 */ 18 static void __do_cyrix_devid(unsigned char *dir0, unsigned char *dir1) 19 { 20 unsigned char ccr2, ccr3; 21 22 /* we test for DEVID by checking whether CCR3 is writable */ 23 ccr3 = getCx86(CX86_CCR3); 24 setCx86(CX86_CCR3, ccr3 ^ 0x80); 25 getCx86(0xc0); /* dummy to change bus */ 26 27 if (getCx86(CX86_CCR3) == ccr3) { /* no DEVID regs. */ 28 ccr2 = getCx86(CX86_CCR2); 29 setCx86(CX86_CCR2, ccr2 ^ 0x04); 30 getCx86(0xc0); /* dummy */ 31 32 if (getCx86(CX86_CCR2) == ccr2) /* old Cx486SLC/DLC */ 33 *dir0 = 0xfd; 34 else { /* Cx486S A step */ 35 setCx86(CX86_CCR2, ccr2); 36 *dir0 = 0xfe; 37 } 38 } else { 39 setCx86(CX86_CCR3, ccr3); /* restore CCR3 */ 40 41 /* read DIR0 and DIR1 CPU registers */ 42 *dir0 = getCx86(CX86_DIR0); 43 *dir1 = getCx86(CX86_DIR1); 44 } 45 } 46 47 static void do_cyrix_devid(unsigned char *dir0, unsigned char *dir1) 48 { 49 unsigned long flags; 50 51 local_irq_save(flags); 52 __do_cyrix_devid(dir0, dir1); 53 local_irq_restore(flags); 54 } 55 /* 56 * Cx86_dir0_msb is a HACK needed by check_cx686_cpuid/slop in bugs.h in 57 * order to identify the Cyrix CPU model after we're out of setup.c 58 * 59 * Actually since bugs.h doesn't even reference this perhaps someone should 60 * fix the documentation ??? 61 */ 62 static unsigned char Cx86_dir0_msb = 0; 63 64 static const char Cx86_model[][9] = { 65 "Cx486", "Cx486", "5x86 ", "6x86", "MediaGX ", "6x86MX ", 66 "M II ", "Unknown" 67 }; 68 static const char Cx486_name[][5] = { 69 "SLC", "DLC", "SLC2", "DLC2", "SRx", "DRx", 70 "SRx2", "DRx2" 71 }; 72 static const char Cx486S_name[][4] = { 73 "S", "S2", "Se", "S2e" 74 }; 75 static const char Cx486D_name[][4] = { 76 "DX", "DX2", "?", "?", "?", "DX4" 77 }; 78 static char Cx86_cb[] = "?.5x Core/Bus Clock"; 79 static const char cyrix_model_mult1[] = "12??43"; 80 static const char cyrix_model_mult2[] = "12233445"; 81 82 /* 83 * Reset the slow-loop (SLOP) bit on the 686(L) which is set by some old 84 * BIOSes for compatibility with DOS games. This makes the udelay loop 85 * work correctly, and improves performance. 86 * 87 * FIXME: our newer udelay uses the tsc. We don't need to frob with SLOP 88 */ 89 90 static void check_cx686_slop(struct cpuinfo_x86 *c) 91 { 92 unsigned long flags; 93 94 if (Cx86_dir0_msb == 3) { 95 unsigned char ccr3, ccr5; 96 97 local_irq_save(flags); 98 ccr3 = getCx86(CX86_CCR3); 99 setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ 100 ccr5 = getCx86(CX86_CCR5); 101 if (ccr5 & 2) 102 setCx86(CX86_CCR5, ccr5 & 0xfd); /* reset SLOP */ 103 setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ 104 local_irq_restore(flags); 105 106 if (ccr5 & 2) { /* possible wrong calibration done */ 107 pr_info("Recalibrating delay loop with SLOP bit reset\n"); 108 calibrate_delay(); 109 c->loops_per_jiffy = loops_per_jiffy; 110 } 111 } 112 } 113 114 115 static void set_cx86_reorder(void) 116 { 117 u8 ccr3; 118 119 pr_info("Enable Memory access reorder on Cyrix/NSC processor.\n"); 120 ccr3 = getCx86(CX86_CCR3); 121 setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ 122 123 /* Load/Store Serialize to mem access disable (=reorder it) */ 124 setCx86_old(CX86_PCR0, getCx86_old(CX86_PCR0) & ~0x80); 125 /* set load/store serialize from 1GB to 4GB */ 126 ccr3 |= 0xe0; 127 setCx86(CX86_CCR3, ccr3); 128 } 129 130 static void set_cx86_memwb(void) 131 { 132 pr_info("Enable Memory-Write-back mode on Cyrix/NSC processor.\n"); 133 134 /* CCR2 bit 2: unlock NW bit */ 135 setCx86_old(CX86_CCR2, getCx86_old(CX86_CCR2) & ~0x04); 136 /* set 'Not Write-through' */ 137 write_cr0(read_cr0() | X86_CR0_NW); 138 /* CCR2 bit 2: lock NW bit and set WT1 */ 139 setCx86_old(CX86_CCR2, getCx86_old(CX86_CCR2) | 0x14); 140 } 141 142 /* 143 * Configure later MediaGX and/or Geode processor. 144 */ 145 146 static void geode_configure(void) 147 { 148 unsigned long flags; 149 u8 ccr3; 150 local_irq_save(flags); 151 152 /* Suspend on halt power saving and enable #SUSP pin */ 153 setCx86_old(CX86_CCR2, getCx86_old(CX86_CCR2) | 0x88); 154 155 ccr3 = getCx86(CX86_CCR3); 156 setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ 157 158 159 /* FPU fast, DTE cache, Mem bypass */ 160 setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x38); 161 setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ 162 163 set_cx86_memwb(); 164 set_cx86_reorder(); 165 166 local_irq_restore(flags); 167 } 168 169 static void early_init_cyrix(struct cpuinfo_x86 *c) 170 { 171 unsigned char dir0, dir0_msn, dir1 = 0; 172 173 __do_cyrix_devid(&dir0, &dir1); 174 dir0_msn = dir0 >> 4; /* identifies CPU "family" */ 175 176 switch (dir0_msn) { 177 case 3: /* 6x86/6x86L */ 178 /* Emulate MTRRs using Cyrix's ARRs. */ 179 set_cpu_cap(c, X86_FEATURE_CYRIX_ARR); 180 break; 181 case 5: /* 6x86MX/M II */ 182 /* Emulate MTRRs using Cyrix's ARRs. */ 183 set_cpu_cap(c, X86_FEATURE_CYRIX_ARR); 184 break; 185 } 186 } 187 188 static void init_cyrix(struct cpuinfo_x86 *c) 189 { 190 unsigned char dir0, dir0_msn, dir0_lsn, dir1 = 0; 191 char *buf = c->x86_model_id; 192 const char *p = NULL; 193 194 /* 195 * Bit 31 in normal CPUID used for nonstandard 3DNow ID; 196 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway 197 */ 198 clear_cpu_cap(c, 0*32+31); 199 200 /* Cyrix used bit 24 in extended (AMD) CPUID for Cyrix MMX extensions */ 201 if (test_cpu_cap(c, 1*32+24)) { 202 clear_cpu_cap(c, 1*32+24); 203 set_cpu_cap(c, X86_FEATURE_CXMMX); 204 } 205 206 do_cyrix_devid(&dir0, &dir1); 207 208 check_cx686_slop(c); 209 210 Cx86_dir0_msb = dir0_msn = dir0 >> 4; /* identifies CPU "family" */ 211 dir0_lsn = dir0 & 0xf; /* model or clock multiplier */ 212 213 /* common case step number/rev -- exceptions handled below */ 214 c->x86_model = (dir1 >> 4) + 1; 215 c->x86_mask = dir1 & 0xf; 216 217 /* Now cook; the original recipe is by Channing Corn, from Cyrix. 218 * We do the same thing for each generation: we work out 219 * the model, multiplier and stepping. Black magic included, 220 * to make the silicon step/rev numbers match the printed ones. 221 */ 222 223 switch (dir0_msn) { 224 unsigned char tmp; 225 226 case 0: /* Cx486SLC/DLC/SRx/DRx */ 227 p = Cx486_name[dir0_lsn & 7]; 228 break; 229 230 case 1: /* Cx486S/DX/DX2/DX4 */ 231 p = (dir0_lsn & 8) ? Cx486D_name[dir0_lsn & 5] 232 : Cx486S_name[dir0_lsn & 3]; 233 break; 234 235 case 2: /* 5x86 */ 236 Cx86_cb[2] = cyrix_model_mult1[dir0_lsn & 5]; 237 p = Cx86_cb+2; 238 break; 239 240 case 3: /* 6x86/6x86L */ 241 Cx86_cb[1] = ' '; 242 Cx86_cb[2] = cyrix_model_mult1[dir0_lsn & 5]; 243 if (dir1 > 0x21) { /* 686L */ 244 Cx86_cb[0] = 'L'; 245 p = Cx86_cb; 246 (c->x86_model)++; 247 } else /* 686 */ 248 p = Cx86_cb+1; 249 /* Emulate MTRRs using Cyrix's ARRs. */ 250 set_cpu_cap(c, X86_FEATURE_CYRIX_ARR); 251 /* 6x86's contain this bug */ 252 set_cpu_bug(c, X86_BUG_COMA); 253 break; 254 255 case 4: /* MediaGX/GXm or Geode GXM/GXLV/GX1 */ 256 #ifdef CONFIG_PCI 257 { 258 u32 vendor, device; 259 /* 260 * It isn't really a PCI quirk directly, but the cure is the 261 * same. The MediaGX has deep magic SMM stuff that handles the 262 * SB emulation. It throws away the fifo on disable_dma() which 263 * is wrong and ruins the audio. 264 * 265 * Bug2: VSA1 has a wrap bug so that using maximum sized DMA 266 * causes bad things. According to NatSemi VSA2 has another 267 * bug to do with 'hlt'. I've not seen any boards using VSA2 268 * and X doesn't seem to support it either so who cares 8). 269 * VSA1 we work around however. 270 */ 271 272 pr_info("Working around Cyrix MediaGX virtual DMA bugs.\n"); 273 isa_dma_bridge_buggy = 2; 274 275 /* We do this before the PCI layer is running. However we 276 are safe here as we know the bridge must be a Cyrix 277 companion and must be present */ 278 vendor = read_pci_config_16(0, 0, 0x12, PCI_VENDOR_ID); 279 device = read_pci_config_16(0, 0, 0x12, PCI_DEVICE_ID); 280 281 /* 282 * The 5510/5520 companion chips have a funky PIT. 283 */ 284 if (vendor == PCI_VENDOR_ID_CYRIX && 285 (device == PCI_DEVICE_ID_CYRIX_5510 || 286 device == PCI_DEVICE_ID_CYRIX_5520)) 287 mark_tsc_unstable("cyrix 5510/5520 detected"); 288 } 289 #endif 290 c->x86_cache_size = 16; /* Yep 16K integrated cache thats it */ 291 292 /* GXm supports extended cpuid levels 'ala' AMD */ 293 if (c->cpuid_level == 2) { 294 /* Enable cxMMX extensions (GX1 Datasheet 54) */ 295 setCx86_old(CX86_CCR7, getCx86_old(CX86_CCR7) | 1); 296 297 /* 298 * GXm : 0x30 ... 0x5f GXm datasheet 51 299 * GXlv: 0x6x GXlv datasheet 54 300 * ? : 0x7x 301 * GX1 : 0x8x GX1 datasheet 56 302 */ 303 if ((0x30 <= dir1 && dir1 <= 0x6f) || 304 (0x80 <= dir1 && dir1 <= 0x8f)) 305 geode_configure(); 306 return; 307 } else { /* MediaGX */ 308 Cx86_cb[2] = (dir0_lsn & 1) ? '3' : '4'; 309 p = Cx86_cb+2; 310 c->x86_model = (dir1 & 0x20) ? 1 : 2; 311 } 312 break; 313 314 case 5: /* 6x86MX/M II */ 315 if (dir1 > 7) { 316 dir0_msn++; /* M II */ 317 /* Enable MMX extensions (App note 108) */ 318 setCx86_old(CX86_CCR7, getCx86_old(CX86_CCR7)|1); 319 } else { 320 /* A 6x86MX - it has the bug. */ 321 set_cpu_bug(c, X86_BUG_COMA); 322 } 323 tmp = (!(dir0_lsn & 7) || dir0_lsn & 1) ? 2 : 0; 324 Cx86_cb[tmp] = cyrix_model_mult2[dir0_lsn & 7]; 325 p = Cx86_cb+tmp; 326 if (((dir1 & 0x0f) > 4) || ((dir1 & 0xf0) == 0x20)) 327 (c->x86_model)++; 328 /* Emulate MTRRs using Cyrix's ARRs. */ 329 set_cpu_cap(c, X86_FEATURE_CYRIX_ARR); 330 break; 331 332 case 0xf: /* Cyrix 486 without DEVID registers */ 333 switch (dir0_lsn) { 334 case 0xd: /* either a 486SLC or DLC w/o DEVID */ 335 dir0_msn = 0; 336 p = Cx486_name[!!boot_cpu_has(X86_FEATURE_FPU)]; 337 break; 338 339 case 0xe: /* a 486S A step */ 340 dir0_msn = 0; 341 p = Cx486S_name[0]; 342 break; 343 } 344 break; 345 346 default: /* unknown (shouldn't happen, we know everyone ;-) */ 347 dir0_msn = 7; 348 break; 349 } 350 strcpy(buf, Cx86_model[dir0_msn & 7]); 351 if (p) 352 strcat(buf, p); 353 return; 354 } 355 356 /* 357 * Handle National Semiconductor branded processors 358 */ 359 static void init_nsc(struct cpuinfo_x86 *c) 360 { 361 /* 362 * There may be GX1 processors in the wild that are branded 363 * NSC and not Cyrix. 364 * 365 * This function only handles the GX processor, and kicks every 366 * thing else to the Cyrix init function above - that should 367 * cover any processors that might have been branded differently 368 * after NSC acquired Cyrix. 369 * 370 * If this breaks your GX1 horribly, please e-mail 371 * info-linux@ldcmail.amd.com to tell us. 372 */ 373 374 /* Handle the GX (Formally known as the GX2) */ 375 376 if (c->x86 == 5 && c->x86_model == 5) 377 cpu_detect_cache_sizes(c); 378 else 379 init_cyrix(c); 380 } 381 382 /* 383 * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected 384 * by the fact that they preserve the flags across the division of 5/2. 385 * PII and PPro exhibit this behavior too, but they have cpuid available. 386 */ 387 388 /* 389 * Perform the Cyrix 5/2 test. A Cyrix won't change 390 * the flags, while other 486 chips will. 391 */ 392 static inline int test_cyrix_52div(void) 393 { 394 unsigned int test; 395 396 __asm__ __volatile__( 397 "sahf\n\t" /* clear flags (%eax = 0x0005) */ 398 "div %b2\n\t" /* divide 5 by 2 */ 399 "lahf" /* store flags into %ah */ 400 : "=a" (test) 401 : "0" (5), "q" (2) 402 : "cc"); 403 404 /* AH is 0x02 on Cyrix after the divide.. */ 405 return (unsigned char) (test >> 8) == 0x02; 406 } 407 408 static void cyrix_identify(struct cpuinfo_x86 *c) 409 { 410 /* Detect Cyrix with disabled CPUID */ 411 if (c->x86 == 4 && test_cyrix_52div()) { 412 unsigned char dir0, dir1; 413 414 strcpy(c->x86_vendor_id, "CyrixInstead"); 415 c->x86_vendor = X86_VENDOR_CYRIX; 416 417 /* Actually enable cpuid on the older cyrix */ 418 419 /* Retrieve CPU revisions */ 420 421 do_cyrix_devid(&dir0, &dir1); 422 423 dir0 >>= 4; 424 425 /* Check it is an affected model */ 426 427 if (dir0 == 5 || dir0 == 3) { 428 unsigned char ccr3; 429 unsigned long flags; 430 pr_info("Enabling CPUID on Cyrix processor.\n"); 431 local_irq_save(flags); 432 ccr3 = getCx86(CX86_CCR3); 433 /* enable MAPEN */ 434 setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); 435 /* enable cpuid */ 436 setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x80); 437 /* disable MAPEN */ 438 setCx86(CX86_CCR3, ccr3); 439 local_irq_restore(flags); 440 } 441 } 442 } 443 444 static const struct cpu_dev cyrix_cpu_dev = { 445 .c_vendor = "Cyrix", 446 .c_ident = { "CyrixInstead" }, 447 .c_early_init = early_init_cyrix, 448 .c_init = init_cyrix, 449 .c_identify = cyrix_identify, 450 .c_x86_vendor = X86_VENDOR_CYRIX, 451 }; 452 453 cpu_dev_register(cyrix_cpu_dev); 454 455 static const struct cpu_dev nsc_cpu_dev = { 456 .c_vendor = "NSC", 457 .c_ident = { "Geode by NSC" }, 458 .c_init = init_nsc, 459 .c_x86_vendor = X86_VENDOR_NSC, 460 }; 461 462 cpu_dev_register(nsc_cpu_dev); 463