1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/sparc64/kernel/setup.c 4 * 5 * Copyright (C) 1995,1996 David S. Miller (davem@caip.rutgers.edu) 6 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 7 */ 8 9 #include <linux/errno.h> 10 #include <linux/sched.h> 11 #include <linux/kernel.h> 12 #include <linux/mm.h> 13 #include <linux/stddef.h> 14 #include <linux/unistd.h> 15 #include <linux/ptrace.h> 16 #include <asm/smp.h> 17 #include <linux/user.h> 18 #include <linux/delay.h> 19 #include <linux/fs.h> 20 #include <linux/seq_file.h> 21 #include <linux/syscalls.h> 22 #include <linux/kdev_t.h> 23 #include <linux/major.h> 24 #include <linux/string.h> 25 #include <linux/init.h> 26 #include <linux/inet.h> 27 #include <linux/console.h> 28 #include <linux/root_dev.h> 29 #include <linux/interrupt.h> 30 #include <linux/cpu.h> 31 #include <linux/initrd.h> 32 #include <linux/module.h> 33 #include <linux/start_kernel.h> 34 #include <linux/memblock.h> 35 #include <uapi/linux/mount.h> 36 37 #include <asm/io.h> 38 #include <asm/processor.h> 39 #include <asm/oplib.h> 40 #include <asm/page.h> 41 #include <asm/idprom.h> 42 #include <asm/head.h> 43 #include <asm/starfire.h> 44 #include <asm/mmu_context.h> 45 #include <asm/timer.h> 46 #include <asm/sections.h> 47 #include <asm/setup.h> 48 #include <asm/mmu.h> 49 #include <asm/ns87303.h> 50 #include <asm/btext.h> 51 #include <asm/elf.h> 52 #include <asm/mdesc.h> 53 #include <asm/cacheflush.h> 54 #include <asm/dma.h> 55 #include <asm/irq.h> 56 57 #ifdef CONFIG_IP_PNP 58 #include <net/ipconfig.h> 59 #endif 60 61 #include "entry.h" 62 #include "kernel.h" 63 64 /* Used to synchronize accesses to NatSemi SUPER I/O chip configure 65 * operations in asm/ns87303.h 66 */ 67 DEFINE_SPINLOCK(ns87303_lock); 68 EXPORT_SYMBOL(ns87303_lock); 69 70 static void 71 prom_console_write(struct console *con, const char *s, unsigned int n) 72 { 73 prom_write(s, n); 74 } 75 76 /* Exported for mm/init.c:paging_init. */ 77 unsigned long cmdline_memory_size = 0; 78 79 static struct console prom_early_console = { 80 .name = "earlyprom", 81 .write = prom_console_write, 82 .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME, 83 .index = -1, 84 }; 85 86 /* 87 * Process kernel command line switches that are specific to the 88 * SPARC or that require special low-level processing. 89 */ 90 static void __init process_switch(char c) 91 { 92 switch (c) { 93 case 'd': 94 case 's': 95 break; 96 case 'h': 97 prom_printf("boot_flags_init: Halt!\n"); 98 prom_halt(); 99 break; 100 case 'p': 101 prom_early_console.flags &= ~CON_BOOT; 102 break; 103 case 'P': 104 /* Force UltraSPARC-III P-Cache on. */ 105 if (tlb_type != cheetah) { 106 printk("BOOT: Ignoring P-Cache force option.\n"); 107 break; 108 } 109 cheetah_pcache_forced_on = 1; 110 add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); 111 cheetah_enable_pcache(); 112 break; 113 114 default: 115 printk("Unknown boot switch (-%c)\n", c); 116 break; 117 } 118 } 119 120 static void __init boot_flags_init(char *commands) 121 { 122 while (*commands) { 123 /* Move to the start of the next "argument". */ 124 while (*commands == ' ') 125 commands++; 126 127 /* Process any command switches, otherwise skip it. */ 128 if (*commands == '\0') 129 break; 130 if (*commands == '-') { 131 commands++; 132 while (*commands && *commands != ' ') 133 process_switch(*commands++); 134 continue; 135 } 136 if (!strncmp(commands, "mem=", 4)) 137 cmdline_memory_size = memparse(commands + 4, &commands); 138 139 while (*commands && *commands != ' ') 140 commands++; 141 } 142 } 143 144 extern unsigned short root_flags; 145 extern unsigned short root_dev; 146 extern unsigned short ram_flags; 147 #define RAMDISK_IMAGE_START_MASK 0x07FF 148 #define RAMDISK_PROMPT_FLAG 0x8000 149 #define RAMDISK_LOAD_FLAG 0x4000 150 151 extern int root_mountflags; 152 153 char reboot_command[COMMAND_LINE_SIZE]; 154 155 static void __init per_cpu_patch(void) 156 { 157 struct cpuid_patch_entry *p; 158 unsigned long ver; 159 int is_jbus; 160 161 if (tlb_type == spitfire && !this_is_starfire) 162 return; 163 164 is_jbus = 0; 165 if (tlb_type != hypervisor) { 166 __asm__ ("rdpr %%ver, %0" : "=r" (ver)); 167 is_jbus = ((ver >> 32UL) == __JALAPENO_ID || 168 (ver >> 32UL) == __SERRANO_ID); 169 } 170 171 p = &__cpuid_patch; 172 while (p < &__cpuid_patch_end) { 173 unsigned long addr = p->addr; 174 unsigned int *insns; 175 176 switch (tlb_type) { 177 case spitfire: 178 insns = &p->starfire[0]; 179 break; 180 case cheetah: 181 case cheetah_plus: 182 if (is_jbus) 183 insns = &p->cheetah_jbus[0]; 184 else 185 insns = &p->cheetah_safari[0]; 186 break; 187 case hypervisor: 188 insns = &p->sun4v[0]; 189 break; 190 default: 191 prom_printf("Unknown cpu type, halting.\n"); 192 prom_halt(); 193 } 194 195 *(unsigned int *) (addr + 0) = insns[0]; 196 wmb(); 197 __asm__ __volatile__("flush %0" : : "r" (addr + 0)); 198 199 *(unsigned int *) (addr + 4) = insns[1]; 200 wmb(); 201 __asm__ __volatile__("flush %0" : : "r" (addr + 4)); 202 203 *(unsigned int *) (addr + 8) = insns[2]; 204 wmb(); 205 __asm__ __volatile__("flush %0" : : "r" (addr + 8)); 206 207 *(unsigned int *) (addr + 12) = insns[3]; 208 wmb(); 209 __asm__ __volatile__("flush %0" : : "r" (addr + 12)); 210 211 p++; 212 } 213 } 214 215 void sun4v_patch_1insn_range(struct sun4v_1insn_patch_entry *start, 216 struct sun4v_1insn_patch_entry *end) 217 { 218 while (start < end) { 219 unsigned long addr = start->addr; 220 221 *(unsigned int *) (addr + 0) = start->insn; 222 wmb(); 223 __asm__ __volatile__("flush %0" : : "r" (addr + 0)); 224 225 start++; 226 } 227 } 228 229 void sun4v_patch_2insn_range(struct sun4v_2insn_patch_entry *start, 230 struct sun4v_2insn_patch_entry *end) 231 { 232 while (start < end) { 233 unsigned long addr = start->addr; 234 235 *(unsigned int *) (addr + 0) = start->insns[0]; 236 wmb(); 237 __asm__ __volatile__("flush %0" : : "r" (addr + 0)); 238 239 *(unsigned int *) (addr + 4) = start->insns[1]; 240 wmb(); 241 __asm__ __volatile__("flush %0" : : "r" (addr + 4)); 242 243 start++; 244 } 245 } 246 247 void sun_m7_patch_2insn_range(struct sun4v_2insn_patch_entry *start, 248 struct sun4v_2insn_patch_entry *end) 249 { 250 while (start < end) { 251 unsigned long addr = start->addr; 252 253 *(unsigned int *) (addr + 0) = start->insns[0]; 254 wmb(); 255 __asm__ __volatile__("flush %0" : : "r" (addr + 0)); 256 257 *(unsigned int *) (addr + 4) = start->insns[1]; 258 wmb(); 259 __asm__ __volatile__("flush %0" : : "r" (addr + 4)); 260 261 start++; 262 } 263 } 264 265 static void __init sun4v_patch(void) 266 { 267 extern void sun4v_hvapi_init(void); 268 269 if (tlb_type != hypervisor) 270 return; 271 272 sun4v_patch_1insn_range(&__sun4v_1insn_patch, 273 &__sun4v_1insn_patch_end); 274 275 sun4v_patch_2insn_range(&__sun4v_2insn_patch, 276 &__sun4v_2insn_patch_end); 277 278 switch (sun4v_chip_type) { 279 case SUN4V_CHIP_SPARC_M7: 280 case SUN4V_CHIP_SPARC_M8: 281 case SUN4V_CHIP_SPARC_SN: 282 sun4v_patch_1insn_range(&__sun_m7_1insn_patch, 283 &__sun_m7_1insn_patch_end); 284 sun_m7_patch_2insn_range(&__sun_m7_2insn_patch, 285 &__sun_m7_2insn_patch_end); 286 break; 287 default: 288 break; 289 } 290 291 if (sun4v_chip_type != SUN4V_CHIP_NIAGARA1) { 292 sun4v_patch_1insn_range(&__fast_win_ctrl_1insn_patch, 293 &__fast_win_ctrl_1insn_patch_end); 294 } 295 296 sun4v_hvapi_init(); 297 } 298 299 static void __init popc_patch(void) 300 { 301 struct popc_3insn_patch_entry *p3; 302 struct popc_6insn_patch_entry *p6; 303 304 p3 = &__popc_3insn_patch; 305 while (p3 < &__popc_3insn_patch_end) { 306 unsigned long i, addr = p3->addr; 307 308 for (i = 0; i < 3; i++) { 309 *(unsigned int *) (addr + (i * 4)) = p3->insns[i]; 310 wmb(); 311 __asm__ __volatile__("flush %0" 312 : : "r" (addr + (i * 4))); 313 } 314 315 p3++; 316 } 317 318 p6 = &__popc_6insn_patch; 319 while (p6 < &__popc_6insn_patch_end) { 320 unsigned long i, addr = p6->addr; 321 322 for (i = 0; i < 6; i++) { 323 *(unsigned int *) (addr + (i * 4)) = p6->insns[i]; 324 wmb(); 325 __asm__ __volatile__("flush %0" 326 : : "r" (addr + (i * 4))); 327 } 328 329 p6++; 330 } 331 } 332 333 static void __init pause_patch(void) 334 { 335 struct pause_patch_entry *p; 336 337 p = &__pause_3insn_patch; 338 while (p < &__pause_3insn_patch_end) { 339 unsigned long i, addr = p->addr; 340 341 for (i = 0; i < 3; i++) { 342 *(unsigned int *) (addr + (i * 4)) = p->insns[i]; 343 wmb(); 344 __asm__ __volatile__("flush %0" 345 : : "r" (addr + (i * 4))); 346 } 347 348 p++; 349 } 350 } 351 352 void __init start_early_boot(void) 353 { 354 int cpu; 355 356 check_if_starfire(); 357 per_cpu_patch(); 358 sun4v_patch(); 359 smp_init_cpu_poke(); 360 361 cpu = hard_smp_processor_id(); 362 if (cpu >= NR_CPUS) { 363 prom_printf("Serious problem, boot cpu id (%d) >= NR_CPUS (%d)\n", 364 cpu, NR_CPUS); 365 prom_halt(); 366 } 367 current_thread_info()->cpu = cpu; 368 369 time_init_early(); 370 prom_init_report(); 371 start_kernel(); 372 } 373 374 /* On Ultra, we support all of the v8 capabilities. */ 375 unsigned long sparc64_elf_hwcap = (HWCAP_SPARC_FLUSH | HWCAP_SPARC_STBAR | 376 HWCAP_SPARC_SWAP | HWCAP_SPARC_MULDIV | 377 HWCAP_SPARC_V9); 378 EXPORT_SYMBOL(sparc64_elf_hwcap); 379 380 static const char *hwcaps[] = { 381 "flush", "stbar", "swap", "muldiv", "v9", 382 "ultra3", "blkinit", "n2", 383 384 /* These strings are as they appear in the machine description 385 * 'hwcap-list' property for cpu nodes. 386 */ 387 "mul32", "div32", "fsmuld", "v8plus", "popc", "vis", "vis2", 388 "ASIBlkInit", "fmaf", "vis3", "hpc", "random", "trans", "fjfmau", 389 "ima", "cspare", "pause", "cbcond", NULL /*reserved for crypto */, 390 "adp", 391 }; 392 393 static const char *crypto_hwcaps[] = { 394 "aes", "des", "kasumi", "camellia", "md5", "sha1", "sha256", 395 "sha512", "mpmul", "montmul", "montsqr", "crc32c", 396 }; 397 398 void cpucap_info(struct seq_file *m) 399 { 400 unsigned long caps = sparc64_elf_hwcap; 401 int i, printed = 0; 402 403 seq_puts(m, "cpucaps\t\t: "); 404 for (i = 0; i < ARRAY_SIZE(hwcaps); i++) { 405 unsigned long bit = 1UL << i; 406 if (hwcaps[i] && (caps & bit)) { 407 seq_printf(m, "%s%s", 408 printed ? "," : "", hwcaps[i]); 409 printed++; 410 } 411 } 412 if (caps & HWCAP_SPARC_CRYPTO) { 413 unsigned long cfr; 414 415 __asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr)); 416 for (i = 0; i < ARRAY_SIZE(crypto_hwcaps); i++) { 417 unsigned long bit = 1UL << i; 418 if (cfr & bit) { 419 seq_printf(m, "%s%s", 420 printed ? "," : "", crypto_hwcaps[i]); 421 printed++; 422 } 423 } 424 } 425 seq_putc(m, '\n'); 426 } 427 428 static void __init report_one_hwcap(int *printed, const char *name) 429 { 430 if ((*printed) == 0) 431 printk(KERN_INFO "CPU CAPS: ["); 432 printk(KERN_CONT "%s%s", 433 (*printed) ? "," : "", name); 434 if (++(*printed) == 8) { 435 printk(KERN_CONT "]\n"); 436 *printed = 0; 437 } 438 } 439 440 static void __init report_crypto_hwcaps(int *printed) 441 { 442 unsigned long cfr; 443 int i; 444 445 __asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr)); 446 447 for (i = 0; i < ARRAY_SIZE(crypto_hwcaps); i++) { 448 unsigned long bit = 1UL << i; 449 if (cfr & bit) 450 report_one_hwcap(printed, crypto_hwcaps[i]); 451 } 452 } 453 454 static void __init report_hwcaps(unsigned long caps) 455 { 456 int i, printed = 0; 457 458 for (i = 0; i < ARRAY_SIZE(hwcaps); i++) { 459 unsigned long bit = 1UL << i; 460 if (hwcaps[i] && (caps & bit)) 461 report_one_hwcap(&printed, hwcaps[i]); 462 } 463 if (caps & HWCAP_SPARC_CRYPTO) 464 report_crypto_hwcaps(&printed); 465 if (printed != 0) 466 printk(KERN_CONT "]\n"); 467 } 468 469 static unsigned long __init mdesc_cpu_hwcap_list(void) 470 { 471 struct mdesc_handle *hp; 472 unsigned long caps = 0; 473 const char *prop; 474 int len; 475 u64 pn; 476 477 hp = mdesc_grab(); 478 if (!hp) 479 return 0; 480 481 pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "cpu"); 482 if (pn == MDESC_NODE_NULL) 483 goto out; 484 485 prop = mdesc_get_property(hp, pn, "hwcap-list", &len); 486 if (!prop) 487 goto out; 488 489 while (len) { 490 int i, plen; 491 492 for (i = 0; i < ARRAY_SIZE(hwcaps); i++) { 493 unsigned long bit = 1UL << i; 494 495 if (hwcaps[i] && !strcmp(prop, hwcaps[i])) { 496 caps |= bit; 497 break; 498 } 499 } 500 for (i = 0; i < ARRAY_SIZE(crypto_hwcaps); i++) { 501 if (!strcmp(prop, crypto_hwcaps[i])) 502 caps |= HWCAP_SPARC_CRYPTO; 503 } 504 505 plen = strlen(prop) + 1; 506 prop += plen; 507 len -= plen; 508 } 509 510 out: 511 mdesc_release(hp); 512 return caps; 513 } 514 515 /* This yields a mask that user programs can use to figure out what 516 * instruction set this cpu supports. 517 */ 518 static void __init init_sparc64_elf_hwcap(void) 519 { 520 unsigned long cap = sparc64_elf_hwcap; 521 unsigned long mdesc_caps; 522 523 if (tlb_type == cheetah || tlb_type == cheetah_plus) 524 cap |= HWCAP_SPARC_ULTRA3; 525 else if (tlb_type == hypervisor) { 526 if (sun4v_chip_type == SUN4V_CHIP_NIAGARA1 || 527 sun4v_chip_type == SUN4V_CHIP_NIAGARA2 || 528 sun4v_chip_type == SUN4V_CHIP_NIAGARA3 || 529 sun4v_chip_type == SUN4V_CHIP_NIAGARA4 || 530 sun4v_chip_type == SUN4V_CHIP_NIAGARA5 || 531 sun4v_chip_type == SUN4V_CHIP_SPARC_M6 || 532 sun4v_chip_type == SUN4V_CHIP_SPARC_M7 || 533 sun4v_chip_type == SUN4V_CHIP_SPARC_M8 || 534 sun4v_chip_type == SUN4V_CHIP_SPARC_SN || 535 sun4v_chip_type == SUN4V_CHIP_SPARC64X) 536 cap |= HWCAP_SPARC_BLKINIT; 537 if (sun4v_chip_type == SUN4V_CHIP_NIAGARA2 || 538 sun4v_chip_type == SUN4V_CHIP_NIAGARA3 || 539 sun4v_chip_type == SUN4V_CHIP_NIAGARA4 || 540 sun4v_chip_type == SUN4V_CHIP_NIAGARA5 || 541 sun4v_chip_type == SUN4V_CHIP_SPARC_M6 || 542 sun4v_chip_type == SUN4V_CHIP_SPARC_M7 || 543 sun4v_chip_type == SUN4V_CHIP_SPARC_M8 || 544 sun4v_chip_type == SUN4V_CHIP_SPARC_SN || 545 sun4v_chip_type == SUN4V_CHIP_SPARC64X) 546 cap |= HWCAP_SPARC_N2; 547 } 548 549 cap |= (AV_SPARC_MUL32 | AV_SPARC_DIV32 | AV_SPARC_V8PLUS); 550 551 mdesc_caps = mdesc_cpu_hwcap_list(); 552 if (!mdesc_caps) { 553 if (tlb_type == spitfire) 554 cap |= AV_SPARC_VIS; 555 if (tlb_type == cheetah || tlb_type == cheetah_plus) 556 cap |= AV_SPARC_VIS | AV_SPARC_VIS2; 557 if (tlb_type == cheetah_plus) { 558 unsigned long impl, ver; 559 560 __asm__ __volatile__("rdpr %%ver, %0" : "=r" (ver)); 561 impl = ((ver >> 32) & 0xffff); 562 if (impl == PANTHER_IMPL) 563 cap |= AV_SPARC_POPC; 564 } 565 if (tlb_type == hypervisor) { 566 if (sun4v_chip_type == SUN4V_CHIP_NIAGARA1) 567 cap |= AV_SPARC_ASI_BLK_INIT; 568 if (sun4v_chip_type == SUN4V_CHIP_NIAGARA2 || 569 sun4v_chip_type == SUN4V_CHIP_NIAGARA3 || 570 sun4v_chip_type == SUN4V_CHIP_NIAGARA4 || 571 sun4v_chip_type == SUN4V_CHIP_NIAGARA5 || 572 sun4v_chip_type == SUN4V_CHIP_SPARC_M6 || 573 sun4v_chip_type == SUN4V_CHIP_SPARC_M7 || 574 sun4v_chip_type == SUN4V_CHIP_SPARC_M8 || 575 sun4v_chip_type == SUN4V_CHIP_SPARC_SN || 576 sun4v_chip_type == SUN4V_CHIP_SPARC64X) 577 cap |= (AV_SPARC_VIS | AV_SPARC_VIS2 | 578 AV_SPARC_ASI_BLK_INIT | 579 AV_SPARC_POPC); 580 if (sun4v_chip_type == SUN4V_CHIP_NIAGARA3 || 581 sun4v_chip_type == SUN4V_CHIP_NIAGARA4 || 582 sun4v_chip_type == SUN4V_CHIP_NIAGARA5 || 583 sun4v_chip_type == SUN4V_CHIP_SPARC_M6 || 584 sun4v_chip_type == SUN4V_CHIP_SPARC_M7 || 585 sun4v_chip_type == SUN4V_CHIP_SPARC_M8 || 586 sun4v_chip_type == SUN4V_CHIP_SPARC_SN || 587 sun4v_chip_type == SUN4V_CHIP_SPARC64X) 588 cap |= (AV_SPARC_VIS3 | AV_SPARC_HPC | 589 AV_SPARC_FMAF); 590 } 591 } 592 sparc64_elf_hwcap = cap | mdesc_caps; 593 594 report_hwcaps(sparc64_elf_hwcap); 595 596 if (sparc64_elf_hwcap & AV_SPARC_POPC) 597 popc_patch(); 598 if (sparc64_elf_hwcap & AV_SPARC_PAUSE) 599 pause_patch(); 600 } 601 602 void __init alloc_irqstack_bootmem(void) 603 { 604 unsigned int i, node; 605 606 for_each_possible_cpu(i) { 607 node = cpu_to_node(i); 608 609 softirq_stack[i] = memblock_alloc_node(THREAD_SIZE, 610 THREAD_SIZE, node); 611 if (!softirq_stack[i]) 612 panic("%s: Failed to allocate %lu bytes align=%lx nid=%d\n", 613 __func__, THREAD_SIZE, THREAD_SIZE, node); 614 hardirq_stack[i] = memblock_alloc_node(THREAD_SIZE, 615 THREAD_SIZE, node); 616 if (!hardirq_stack[i]) 617 panic("%s: Failed to allocate %lu bytes align=%lx nid=%d\n", 618 __func__, THREAD_SIZE, THREAD_SIZE, node); 619 } 620 } 621 622 void __init setup_arch(char **cmdline_p) 623 { 624 /* Initialize PROM console and command line. */ 625 *cmdline_p = prom_getbootargs(); 626 strscpy(boot_command_line, *cmdline_p, COMMAND_LINE_SIZE); 627 parse_early_param(); 628 629 boot_flags_init(*cmdline_p); 630 #ifdef CONFIG_EARLYFB 631 if (btext_find_display()) 632 #endif 633 register_console(&prom_early_console); 634 635 if (tlb_type == hypervisor) 636 pr_info("ARCH: SUN4V\n"); 637 else 638 pr_info("ARCH: SUN4U\n"); 639 640 idprom_init(); 641 642 if (!root_flags) 643 root_mountflags &= ~MS_RDONLY; 644 ROOT_DEV = old_decode_dev(root_dev); 645 #ifdef CONFIG_BLK_DEV_RAM 646 rd_image_start = ram_flags & RAMDISK_IMAGE_START_MASK; 647 #endif 648 649 #ifdef CONFIG_IP_PNP 650 if (!ic_set_manually) { 651 phandle chosen = prom_finddevice("/chosen"); 652 u32 cl, sv, gw; 653 654 cl = prom_getintdefault (chosen, "client-ip", 0); 655 sv = prom_getintdefault (chosen, "server-ip", 0); 656 gw = prom_getintdefault (chosen, "gateway-ip", 0); 657 if (cl && sv) { 658 ic_myaddr = cl; 659 ic_servaddr = sv; 660 if (gw) 661 ic_gateway = gw; 662 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_RARP) 663 ic_proto_enabled = 0; 664 #endif 665 } 666 } 667 #endif 668 669 /* Get boot processor trap_block[] setup. */ 670 init_cur_cpu_trap(current_thread_info()); 671 672 paging_init(); 673 init_sparc64_elf_hwcap(); 674 smp_fill_in_cpu_possible_map(); 675 /* 676 * Once the OF device tree and MDESC have been setup and nr_cpus has 677 * been parsed, we know the list of possible cpus. Therefore we can 678 * allocate the IRQ stacks. 679 */ 680 alloc_irqstack_bootmem(); 681 } 682 683 extern int stop_a_enabled; 684 685 void sun_do_break(void) 686 { 687 if (!stop_a_enabled) 688 return; 689 690 prom_printf("\n"); 691 flush_user_windows(); 692 693 prom_cmdline(); 694 } 695 EXPORT_SYMBOL(sun_do_break); 696 697 int stop_a_enabled = 1; 698 EXPORT_SYMBOL(stop_a_enabled); 699