common_64.c 17 KB

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  1. #include <linux/init.h>
  2. #include <linux/kernel.h>
  3. #include <linux/sched.h>
  4. #include <linux/string.h>
  5. #include <linux/bootmem.h>
  6. #include <linux/bitops.h>
  7. #include <linux/module.h>
  8. #include <linux/kgdb.h>
  9. #include <linux/topology.h>
  10. #include <linux/string.h>
  11. #include <linux/delay.h>
  12. #include <linux/smp.h>
  13. #include <linux/module.h>
  14. #include <linux/percpu.h>
  15. #include <asm/processor.h>
  16. #include <asm/i387.h>
  17. #include <asm/msr.h>
  18. #include <asm/io.h>
  19. #include <asm/linkage.h>
  20. #include <asm/mmu_context.h>
  21. #include <asm/mtrr.h>
  22. #include <asm/mce.h>
  23. #include <asm/pat.h>
  24. #include <asm/numa.h>
  25. #ifdef CONFIG_X86_LOCAL_APIC
  26. #include <asm/mpspec.h>
  27. #include <asm/apic.h>
  28. #include <mach_apic.h>
  29. #endif
  30. #include <asm/pda.h>
  31. #include <asm/pgtable.h>
  32. #include <asm/processor.h>
  33. #include <asm/desc.h>
  34. #include <asm/atomic.h>
  35. #include <asm/proto.h>
  36. #include <asm/sections.h>
  37. #include <asm/setup.h>
  38. #include <asm/genapic.h>
  39. #include "cpu.h"
  40. /* We need valid kernel segments for data and code in long mode too
  41. * IRET will check the segment types kkeil 2000/10/28
  42. * Also sysret mandates a special GDT layout
  43. */
  44. /* The TLS descriptors are currently at a different place compared to i386.
  45. Hopefully nobody expects them at a fixed place (Wine?) */
  46. DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = {
  47. [GDT_ENTRY_KERNEL32_CS] = { { { 0x0000ffff, 0x00cf9b00 } } },
  48. [GDT_ENTRY_KERNEL_CS] = { { { 0x0000ffff, 0x00af9b00 } } },
  49. [GDT_ENTRY_KERNEL_DS] = { { { 0x0000ffff, 0x00cf9300 } } },
  50. [GDT_ENTRY_DEFAULT_USER32_CS] = { { { 0x0000ffff, 0x00cffb00 } } },
  51. [GDT_ENTRY_DEFAULT_USER_DS] = { { { 0x0000ffff, 0x00cff300 } } },
  52. [GDT_ENTRY_DEFAULT_USER_CS] = { { { 0x0000ffff, 0x00affb00 } } },
  53. } };
  54. EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
  55. __u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
  56. /* Current gdt points %fs at the "master" per-cpu area: after this,
  57. * it's on the real one. */
  58. void switch_to_new_gdt(void)
  59. {
  60. struct desc_ptr gdt_descr;
  61. gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
  62. gdt_descr.size = GDT_SIZE - 1;
  63. load_gdt(&gdt_descr);
  64. }
  65. struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
  66. static void __cpuinit default_init(struct cpuinfo_x86 *c)
  67. {
  68. display_cacheinfo(c);
  69. }
  70. static struct cpu_dev __cpuinitdata default_cpu = {
  71. .c_init = default_init,
  72. .c_vendor = "Unknown",
  73. };
  74. static struct cpu_dev *this_cpu __cpuinitdata = &default_cpu;
  75. int __cpuinit get_model_name(struct cpuinfo_x86 *c)
  76. {
  77. unsigned int *v;
  78. if (c->extended_cpuid_level < 0x80000004)
  79. return 0;
  80. v = (unsigned int *) c->x86_model_id;
  81. cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
  82. cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
  83. cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
  84. c->x86_model_id[48] = 0;
  85. return 1;
  86. }
  87. void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
  88. {
  89. unsigned int n, dummy, ebx, ecx, edx;
  90. n = c->extended_cpuid_level;
  91. if (n >= 0x80000005) {
  92. cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
  93. printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), "
  94. "D cache %dK (%d bytes/line)\n",
  95. edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
  96. c->x86_cache_size = (ecx>>24) + (edx>>24);
  97. /* On K8 L1 TLB is inclusive, so don't count it */
  98. c->x86_tlbsize = 0;
  99. }
  100. if (n >= 0x80000006) {
  101. cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
  102. ecx = cpuid_ecx(0x80000006);
  103. c->x86_cache_size = ecx >> 16;
  104. c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
  105. printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
  106. c->x86_cache_size, ecx & 0xFF);
  107. }
  108. }
  109. void __cpuinit detect_ht(struct cpuinfo_x86 *c)
  110. {
  111. #ifdef CONFIG_SMP
  112. u32 eax, ebx, ecx, edx;
  113. int index_msb, core_bits;
  114. cpuid(1, &eax, &ebx, &ecx, &edx);
  115. if (!cpu_has(c, X86_FEATURE_HT))
  116. return;
  117. if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
  118. goto out;
  119. smp_num_siblings = (ebx & 0xff0000) >> 16;
  120. if (smp_num_siblings == 1) {
  121. printk(KERN_INFO "CPU: Hyper-Threading is disabled\n");
  122. } else if (smp_num_siblings > 1) {
  123. if (smp_num_siblings > NR_CPUS) {
  124. printk(KERN_WARNING "CPU: Unsupported number of "
  125. "siblings %d", smp_num_siblings);
  126. smp_num_siblings = 1;
  127. return;
  128. }
  129. index_msb = get_count_order(smp_num_siblings);
  130. c->phys_proc_id = phys_pkg_id(index_msb);
  131. smp_num_siblings = smp_num_siblings / c->x86_max_cores;
  132. index_msb = get_count_order(smp_num_siblings);
  133. core_bits = get_count_order(c->x86_max_cores);
  134. c->cpu_core_id = phys_pkg_id(index_msb) &
  135. ((1 << core_bits) - 1);
  136. }
  137. out:
  138. if ((c->x86_max_cores * smp_num_siblings) > 1) {
  139. printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
  140. c->phys_proc_id);
  141. printk(KERN_INFO "CPU: Processor Core ID: %d\n",
  142. c->cpu_core_id);
  143. }
  144. #endif
  145. }
  146. static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
  147. {
  148. char *v = c->x86_vendor_id;
  149. int i;
  150. static int printed;
  151. for (i = 0; i < X86_VENDOR_NUM; i++) {
  152. if (cpu_devs[i]) {
  153. if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
  154. (cpu_devs[i]->c_ident[1] &&
  155. !strcmp(v, cpu_devs[i]->c_ident[1]))) {
  156. c->x86_vendor = i;
  157. this_cpu = cpu_devs[i];
  158. return;
  159. }
  160. }
  161. }
  162. if (!printed) {
  163. printed++;
  164. printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
  165. printk(KERN_ERR "CPU: Your system may be unstable.\n");
  166. }
  167. c->x86_vendor = X86_VENDOR_UNKNOWN;
  168. }
  169. static void __init early_cpu_support_print(void)
  170. {
  171. int i,j;
  172. struct cpu_dev *cpu_devx;
  173. printk("KERNEL supported cpus:\n");
  174. for (i = 0; i < X86_VENDOR_NUM; i++) {
  175. cpu_devx = cpu_devs[i];
  176. if (!cpu_devx)
  177. continue;
  178. for (j = 0; j < 2; j++) {
  179. if (!cpu_devx->c_ident[j])
  180. continue;
  181. printk(" %s %s\n", cpu_devx->c_vendor,
  182. cpu_devx->c_ident[j]);
  183. }
  184. }
  185. }
  186. static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c);
  187. void __init early_cpu_init(void)
  188. {
  189. struct cpu_vendor_dev *cvdev;
  190. for (cvdev = __x86cpuvendor_start ;
  191. cvdev < __x86cpuvendor_end ;
  192. cvdev++)
  193. cpu_devs[cvdev->vendor] = cvdev->cpu_dev;
  194. early_cpu_support_print();
  195. early_identify_cpu(&boot_cpu_data);
  196. }
  197. /* Do some early cpuid on the boot CPU to get some parameter that are
  198. needed before check_bugs. Everything advanced is in identify_cpu
  199. below. */
  200. static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
  201. {
  202. u32 tfms, xlvl;
  203. c->loops_per_jiffy = loops_per_jiffy;
  204. c->x86_cache_size = -1;
  205. c->x86_vendor = X86_VENDOR_UNKNOWN;
  206. c->x86_model = c->x86_mask = 0; /* So far unknown... */
  207. c->x86_vendor_id[0] = '\0'; /* Unset */
  208. c->x86_model_id[0] = '\0'; /* Unset */
  209. c->x86_clflush_size = 64;
  210. c->x86_cache_alignment = c->x86_clflush_size;
  211. c->x86_max_cores = 1;
  212. c->x86_coreid_bits = 0;
  213. c->extended_cpuid_level = 0;
  214. memset(&c->x86_capability, 0, sizeof c->x86_capability);
  215. /* Get vendor name */
  216. cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
  217. (unsigned int *)&c->x86_vendor_id[0],
  218. (unsigned int *)&c->x86_vendor_id[8],
  219. (unsigned int *)&c->x86_vendor_id[4]);
  220. get_cpu_vendor(c);
  221. /* Initialize the standard set of capabilities */
  222. /* Note that the vendor-specific code below might override */
  223. /* Intel-defined flags: level 0x00000001 */
  224. if (c->cpuid_level >= 0x00000001) {
  225. __u32 misc;
  226. cpuid(0x00000001, &tfms, &misc, &c->x86_capability[4],
  227. &c->x86_capability[0]);
  228. c->x86 = (tfms >> 8) & 0xf;
  229. c->x86_model = (tfms >> 4) & 0xf;
  230. c->x86_mask = tfms & 0xf;
  231. if (c->x86 == 0xf)
  232. c->x86 += (tfms >> 20) & 0xff;
  233. if (c->x86 >= 0x6)
  234. c->x86_model += ((tfms >> 16) & 0xF) << 4;
  235. if (test_cpu_cap(c, X86_FEATURE_CLFLSH))
  236. c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
  237. } else {
  238. /* Have CPUID level 0 only - unheard of */
  239. c->x86 = 4;
  240. }
  241. c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xff;
  242. #ifdef CONFIG_SMP
  243. c->phys_proc_id = c->initial_apicid;
  244. #endif
  245. /* AMD-defined flags: level 0x80000001 */
  246. xlvl = cpuid_eax(0x80000000);
  247. c->extended_cpuid_level = xlvl;
  248. if ((xlvl & 0xffff0000) == 0x80000000) {
  249. if (xlvl >= 0x80000001) {
  250. c->x86_capability[1] = cpuid_edx(0x80000001);
  251. c->x86_capability[6] = cpuid_ecx(0x80000001);
  252. }
  253. if (xlvl >= 0x80000004)
  254. get_model_name(c); /* Default name */
  255. }
  256. /* Transmeta-defined flags: level 0x80860001 */
  257. xlvl = cpuid_eax(0x80860000);
  258. if ((xlvl & 0xffff0000) == 0x80860000) {
  259. /* Don't set x86_cpuid_level here for now to not confuse. */
  260. if (xlvl >= 0x80860001)
  261. c->x86_capability[2] = cpuid_edx(0x80860001);
  262. }
  263. c->extended_cpuid_level = cpuid_eax(0x80000000);
  264. if (c->extended_cpuid_level >= 0x80000007)
  265. c->x86_power = cpuid_edx(0x80000007);
  266. if (c->extended_cpuid_level >= 0x80000008) {
  267. u32 eax = cpuid_eax(0x80000008);
  268. c->x86_virt_bits = (eax >> 8) & 0xff;
  269. c->x86_phys_bits = eax & 0xff;
  270. }
  271. /* Assume all 64-bit CPUs support 32-bit syscall */
  272. set_cpu_cap(c, X86_FEATURE_SYSCALL32);
  273. if (c->x86_vendor != X86_VENDOR_UNKNOWN &&
  274. cpu_devs[c->x86_vendor]->c_early_init)
  275. cpu_devs[c->x86_vendor]->c_early_init(c);
  276. validate_pat_support(c);
  277. /* early_param could clear that, but recall get it set again */
  278. if (disable_apic)
  279. clear_cpu_cap(c, X86_FEATURE_APIC);
  280. }
  281. /*
  282. * This does the hard work of actually picking apart the CPU stuff...
  283. */
  284. static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
  285. {
  286. int i;
  287. early_identify_cpu(c);
  288. init_scattered_cpuid_features(c);
  289. c->apicid = phys_pkg_id(0);
  290. /*
  291. * Vendor-specific initialization. In this section we
  292. * canonicalize the feature flags, meaning if there are
  293. * features a certain CPU supports which CPUID doesn't
  294. * tell us, CPUID claiming incorrect flags, or other bugs,
  295. * we handle them here.
  296. *
  297. * At the end of this section, c->x86_capability better
  298. * indicate the features this CPU genuinely supports!
  299. */
  300. if (this_cpu->c_init)
  301. this_cpu->c_init(c);
  302. detect_ht(c);
  303. /*
  304. * On SMP, boot_cpu_data holds the common feature set between
  305. * all CPUs; so make sure that we indicate which features are
  306. * common between the CPUs. The first time this routine gets
  307. * executed, c == &boot_cpu_data.
  308. */
  309. if (c != &boot_cpu_data) {
  310. /* AND the already accumulated flags with these */
  311. for (i = 0; i < NCAPINTS; i++)
  312. boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
  313. }
  314. /* Clear all flags overriden by options */
  315. for (i = 0; i < NCAPINTS; i++)
  316. c->x86_capability[i] &= ~cleared_cpu_caps[i];
  317. #ifdef CONFIG_X86_MCE
  318. mcheck_init(c);
  319. #endif
  320. select_idle_routine(c);
  321. #ifdef CONFIG_NUMA
  322. numa_add_cpu(smp_processor_id());
  323. #endif
  324. }
  325. void __cpuinit identify_boot_cpu(void)
  326. {
  327. identify_cpu(&boot_cpu_data);
  328. }
  329. void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
  330. {
  331. BUG_ON(c == &boot_cpu_data);
  332. identify_cpu(c);
  333. mtrr_ap_init();
  334. }
  335. static __init int setup_noclflush(char *arg)
  336. {
  337. setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
  338. return 1;
  339. }
  340. __setup("noclflush", setup_noclflush);
  341. void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
  342. {
  343. if (c->x86_model_id[0])
  344. printk(KERN_CONT "%s", c->x86_model_id);
  345. if (c->x86_mask || c->cpuid_level >= 0)
  346. printk(KERN_CONT " stepping %02x\n", c->x86_mask);
  347. else
  348. printk(KERN_CONT "\n");
  349. }
  350. static __init int setup_disablecpuid(char *arg)
  351. {
  352. int bit;
  353. if (get_option(&arg, &bit) && bit < NCAPINTS*32)
  354. setup_clear_cpu_cap(bit);
  355. else
  356. return 0;
  357. return 1;
  358. }
  359. __setup("clearcpuid=", setup_disablecpuid);
  360. cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
  361. struct x8664_pda **_cpu_pda __read_mostly;
  362. EXPORT_SYMBOL(_cpu_pda);
  363. struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
  364. char boot_cpu_stack[IRQSTACKSIZE] __page_aligned_bss;
  365. unsigned long __supported_pte_mask __read_mostly = ~0UL;
  366. EXPORT_SYMBOL_GPL(__supported_pte_mask);
  367. static int do_not_nx __cpuinitdata;
  368. /* noexec=on|off
  369. Control non executable mappings for 64bit processes.
  370. on Enable(default)
  371. off Disable
  372. */
  373. static int __init nonx_setup(char *str)
  374. {
  375. if (!str)
  376. return -EINVAL;
  377. if (!strncmp(str, "on", 2)) {
  378. __supported_pte_mask |= _PAGE_NX;
  379. do_not_nx = 0;
  380. } else if (!strncmp(str, "off", 3)) {
  381. do_not_nx = 1;
  382. __supported_pte_mask &= ~_PAGE_NX;
  383. }
  384. return 0;
  385. }
  386. early_param("noexec", nonx_setup);
  387. int force_personality32;
  388. /* noexec32=on|off
  389. Control non executable heap for 32bit processes.
  390. To control the stack too use noexec=off
  391. on PROT_READ does not imply PROT_EXEC for 32bit processes (default)
  392. off PROT_READ implies PROT_EXEC
  393. */
  394. static int __init nonx32_setup(char *str)
  395. {
  396. if (!strcmp(str, "on"))
  397. force_personality32 &= ~READ_IMPLIES_EXEC;
  398. else if (!strcmp(str, "off"))
  399. force_personality32 |= READ_IMPLIES_EXEC;
  400. return 1;
  401. }
  402. __setup("noexec32=", nonx32_setup);
  403. void pda_init(int cpu)
  404. {
  405. struct x8664_pda *pda = cpu_pda(cpu);
  406. /* Setup up data that may be needed in __get_free_pages early */
  407. loadsegment(fs, 0);
  408. loadsegment(gs, 0);
  409. /* Memory clobbers used to order PDA accessed */
  410. mb();
  411. wrmsrl(MSR_GS_BASE, pda);
  412. mb();
  413. pda->cpunumber = cpu;
  414. pda->irqcount = -1;
  415. pda->kernelstack = (unsigned long)stack_thread_info() -
  416. PDA_STACKOFFSET + THREAD_SIZE;
  417. pda->active_mm = &init_mm;
  418. pda->mmu_state = 0;
  419. if (cpu == 0) {
  420. /* others are initialized in smpboot.c */
  421. pda->pcurrent = &init_task;
  422. pda->irqstackptr = boot_cpu_stack;
  423. } else {
  424. pda->irqstackptr = (char *)
  425. __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
  426. if (!pda->irqstackptr)
  427. panic("cannot allocate irqstack for cpu %d", cpu);
  428. if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
  429. pda->nodenumber = cpu_to_node(cpu);
  430. }
  431. pda->irqstackptr += IRQSTACKSIZE-64;
  432. }
  433. char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
  434. DEBUG_STKSZ] __page_aligned_bss;
  435. extern asmlinkage void ignore_sysret(void);
  436. /* May not be marked __init: used by software suspend */
  437. void syscall_init(void)
  438. {
  439. /*
  440. * LSTAR and STAR live in a bit strange symbiosis.
  441. * They both write to the same internal register. STAR allows to
  442. * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
  443. */
  444. wrmsrl(MSR_STAR, ((u64)__USER32_CS)<<48 | ((u64)__KERNEL_CS)<<32);
  445. wrmsrl(MSR_LSTAR, system_call);
  446. wrmsrl(MSR_CSTAR, ignore_sysret);
  447. #ifdef CONFIG_IA32_EMULATION
  448. syscall32_cpu_init();
  449. #endif
  450. /* Flags to clear on syscall */
  451. wrmsrl(MSR_SYSCALL_MASK,
  452. X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
  453. }
  454. void __cpuinit check_efer(void)
  455. {
  456. unsigned long efer;
  457. rdmsrl(MSR_EFER, efer);
  458. if (!(efer & EFER_NX) || do_not_nx)
  459. __supported_pte_mask &= ~_PAGE_NX;
  460. }
  461. unsigned long kernel_eflags;
  462. /*
  463. * Copies of the original ist values from the tss are only accessed during
  464. * debugging, no special alignment required.
  465. */
  466. DEFINE_PER_CPU(struct orig_ist, orig_ist);
  467. /*
  468. * cpu_init() initializes state that is per-CPU. Some data is already
  469. * initialized (naturally) in the bootstrap process, such as the GDT
  470. * and IDT. We reload them nevertheless, this function acts as a
  471. * 'CPU state barrier', nothing should get across.
  472. * A lot of state is already set up in PDA init.
  473. */
  474. void __cpuinit cpu_init(void)
  475. {
  476. int cpu = stack_smp_processor_id();
  477. struct tss_struct *t = &per_cpu(init_tss, cpu);
  478. struct orig_ist *orig_ist = &per_cpu(orig_ist, cpu);
  479. unsigned long v;
  480. char *estacks = NULL;
  481. struct task_struct *me;
  482. int i;
  483. /* CPU 0 is initialised in head64.c */
  484. if (cpu != 0)
  485. pda_init(cpu);
  486. else
  487. estacks = boot_exception_stacks;
  488. me = current;
  489. if (cpu_test_and_set(cpu, cpu_initialized))
  490. panic("CPU#%d already initialized!\n", cpu);
  491. printk(KERN_INFO "Initializing CPU#%d\n", cpu);
  492. clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
  493. /*
  494. * Initialize the per-CPU GDT with the boot GDT,
  495. * and set up the GDT descriptor:
  496. */
  497. switch_to_new_gdt();
  498. load_idt((const struct desc_ptr *)&idt_descr);
  499. memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
  500. syscall_init();
  501. wrmsrl(MSR_FS_BASE, 0);
  502. wrmsrl(MSR_KERNEL_GS_BASE, 0);
  503. barrier();
  504. check_efer();
  505. /*
  506. * set up and load the per-CPU TSS
  507. */
  508. for (v = 0; v < N_EXCEPTION_STACKS; v++) {
  509. static const unsigned int order[N_EXCEPTION_STACKS] = {
  510. [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
  511. [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
  512. };
  513. if (cpu) {
  514. estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
  515. if (!estacks)
  516. panic("Cannot allocate exception stack %ld %d\n",
  517. v, cpu);
  518. }
  519. estacks += PAGE_SIZE << order[v];
  520. orig_ist->ist[v] = t->x86_tss.ist[v] = (unsigned long)estacks;
  521. }
  522. t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
  523. /*
  524. * <= is required because the CPU will access up to
  525. * 8 bits beyond the end of the IO permission bitmap.
  526. */
  527. for (i = 0; i <= IO_BITMAP_LONGS; i++)
  528. t->io_bitmap[i] = ~0UL;
  529. atomic_inc(&init_mm.mm_count);
  530. me->active_mm = &init_mm;
  531. if (me->mm)
  532. BUG();
  533. enter_lazy_tlb(&init_mm, me);
  534. load_sp0(t, &current->thread);
  535. set_tss_desc(cpu, t);
  536. load_TR_desc();
  537. load_LDT(&init_mm.context);
  538. #ifdef CONFIG_KGDB
  539. /*
  540. * If the kgdb is connected no debug regs should be altered. This
  541. * is only applicable when KGDB and a KGDB I/O module are built
  542. * into the kernel and you are using early debugging with
  543. * kgdbwait. KGDB will control the kernel HW breakpoint registers.
  544. */
  545. if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
  546. arch_kgdb_ops.correct_hw_break();
  547. else {
  548. #endif
  549. /*
  550. * Clear all 6 debug registers:
  551. */
  552. set_debugreg(0UL, 0);
  553. set_debugreg(0UL, 1);
  554. set_debugreg(0UL, 2);
  555. set_debugreg(0UL, 3);
  556. set_debugreg(0UL, 6);
  557. set_debugreg(0UL, 7);
  558. #ifdef CONFIG_KGDB
  559. /* If the kgdb is connected no debug regs should be altered. */
  560. }
  561. #endif
  562. fpu_init();
  563. raw_local_save_flags(kernel_eflags);
  564. if (is_uv_system())
  565. uv_cpu_init();
  566. }