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/mmu_context.h>
  20. #include <asm/mtrr.h>
  21. #include <asm/mce.h>
  22. #include <asm/pat.h>
  23. #include <asm/numa.h>
  24. #ifdef CONFIG_X86_LOCAL_APIC
  25. #include <asm/mpspec.h>
  26. #include <asm/apic.h>
  27. #include <mach_apic.h>
  28. #endif
  29. #include <asm/pda.h>
  30. #include <asm/pgtable.h>
  31. #include <asm/processor.h>
  32. #include <asm/desc.h>
  33. #include <asm/atomic.h>
  34. #include <asm/proto.h>
  35. #include <asm/sections.h>
  36. #include <asm/setup.h>
  37. #include <asm/genapic.h>
  38. #include "cpu.h"
  39. /* We need valid kernel segments for data and code in long mode too
  40. * IRET will check the segment types kkeil 2000/10/28
  41. * Also sysret mandates a special GDT layout
  42. */
  43. /* The TLS descriptors are currently at a different place compared to i386.
  44. Hopefully nobody expects them at a fixed place (Wine?) */
  45. DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = {
  46. [GDT_ENTRY_KERNEL32_CS] = { { { 0x0000ffff, 0x00cf9b00 } } },
  47. [GDT_ENTRY_KERNEL_CS] = { { { 0x0000ffff, 0x00af9b00 } } },
  48. [GDT_ENTRY_KERNEL_DS] = { { { 0x0000ffff, 0x00cf9300 } } },
  49. [GDT_ENTRY_DEFAULT_USER32_CS] = { { { 0x0000ffff, 0x00cffb00 } } },
  50. [GDT_ENTRY_DEFAULT_USER_DS] = { { { 0x0000ffff, 0x00cff300 } } },
  51. [GDT_ENTRY_DEFAULT_USER_CS] = { { { 0x0000ffff, 0x00affb00 } } },
  52. } };
  53. EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
  54. __u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
  55. /* Current gdt points %fs at the "master" per-cpu area: after this,
  56. * it's on the real one. */
  57. void switch_to_new_gdt(void)
  58. {
  59. struct desc_ptr gdt_descr;
  60. gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
  61. gdt_descr.size = GDT_SIZE - 1;
  62. load_gdt(&gdt_descr);
  63. }
  64. struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
  65. static void __cpuinit default_init(struct cpuinfo_x86 *c)
  66. {
  67. display_cacheinfo(c);
  68. }
  69. static struct cpu_dev __cpuinitdata default_cpu = {
  70. .c_init = default_init,
  71. .c_vendor = "Unknown",
  72. };
  73. static struct cpu_dev *this_cpu __cpuinitdata = &default_cpu;
  74. int __cpuinit get_model_name(struct cpuinfo_x86 *c)
  75. {
  76. unsigned int *v;
  77. if (c->extended_cpuid_level < 0x80000004)
  78. return 0;
  79. v = (unsigned int *) c->x86_model_id;
  80. cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
  81. cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
  82. cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
  83. c->x86_model_id[48] = 0;
  84. return 1;
  85. }
  86. void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
  87. {
  88. unsigned int n, dummy, ebx, ecx, edx;
  89. n = c->extended_cpuid_level;
  90. if (n >= 0x80000005) {
  91. cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
  92. printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), "
  93. "D cache %dK (%d bytes/line)\n",
  94. edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
  95. c->x86_cache_size = (ecx>>24) + (edx>>24);
  96. /* On K8 L1 TLB is inclusive, so don't count it */
  97. c->x86_tlbsize = 0;
  98. }
  99. if (n >= 0x80000006) {
  100. cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
  101. ecx = cpuid_ecx(0x80000006);
  102. c->x86_cache_size = ecx >> 16;
  103. c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
  104. printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
  105. c->x86_cache_size, ecx & 0xFF);
  106. }
  107. }
  108. void __cpuinit detect_ht(struct cpuinfo_x86 *c)
  109. {
  110. #ifdef CONFIG_SMP
  111. u32 eax, ebx, ecx, edx;
  112. int index_msb, core_bits;
  113. cpuid(1, &eax, &ebx, &ecx, &edx);
  114. if (!cpu_has(c, X86_FEATURE_HT))
  115. return;
  116. if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
  117. goto out;
  118. smp_num_siblings = (ebx & 0xff0000) >> 16;
  119. if (smp_num_siblings == 1) {
  120. printk(KERN_INFO "CPU: Hyper-Threading is disabled\n");
  121. } else if (smp_num_siblings > 1) {
  122. if (smp_num_siblings > NR_CPUS) {
  123. printk(KERN_WARNING "CPU: Unsupported number of "
  124. "siblings %d", smp_num_siblings);
  125. smp_num_siblings = 1;
  126. return;
  127. }
  128. index_msb = get_count_order(smp_num_siblings);
  129. c->phys_proc_id = phys_pkg_id(index_msb);
  130. smp_num_siblings = smp_num_siblings / c->x86_max_cores;
  131. index_msb = get_count_order(smp_num_siblings);
  132. core_bits = get_count_order(c->x86_max_cores);
  133. c->cpu_core_id = phys_pkg_id(index_msb) &
  134. ((1 << core_bits) - 1);
  135. }
  136. out:
  137. if ((c->x86_max_cores * smp_num_siblings) > 1) {
  138. printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
  139. c->phys_proc_id);
  140. printk(KERN_INFO "CPU: Processor Core ID: %d\n",
  141. c->cpu_core_id);
  142. }
  143. #endif
  144. }
  145. static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
  146. {
  147. char *v = c->x86_vendor_id;
  148. int i;
  149. static int printed;
  150. for (i = 0; i < X86_VENDOR_NUM; i++) {
  151. if (cpu_devs[i]) {
  152. if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
  153. (cpu_devs[i]->c_ident[1] &&
  154. !strcmp(v, cpu_devs[i]->c_ident[1]))) {
  155. c->x86_vendor = i;
  156. this_cpu = cpu_devs[i];
  157. return;
  158. }
  159. }
  160. }
  161. if (!printed) {
  162. printed++;
  163. printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
  164. printk(KERN_ERR "CPU: Your system may be unstable.\n");
  165. }
  166. c->x86_vendor = X86_VENDOR_UNKNOWN;
  167. }
  168. static void __init early_cpu_support_print(void)
  169. {
  170. int i,j;
  171. struct cpu_dev *cpu_devx;
  172. printk("KERNEL supported cpus:\n");
  173. for (i = 0; i < X86_VENDOR_NUM; i++) {
  174. cpu_devx = cpu_devs[i];
  175. if (!cpu_devx)
  176. continue;
  177. for (j = 0; j < 2; j++) {
  178. if (!cpu_devx->c_ident[j])
  179. continue;
  180. printk(" %s %s\n", cpu_devx->c_vendor,
  181. cpu_devx->c_ident[j]);
  182. }
  183. }
  184. }
  185. static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c);
  186. void __init early_cpu_init(void)
  187. {
  188. struct cpu_vendor_dev *cvdev;
  189. for (cvdev = __x86cpuvendor_start ;
  190. cvdev < __x86cpuvendor_end ;
  191. cvdev++)
  192. cpu_devs[cvdev->vendor] = cvdev->cpu_dev;
  193. early_cpu_support_print();
  194. early_identify_cpu(&boot_cpu_data);
  195. }
  196. /* Do some early cpuid on the boot CPU to get some parameter that are
  197. needed before check_bugs. Everything advanced is in identify_cpu
  198. below. */
  199. static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
  200. {
  201. u32 tfms, xlvl;
  202. c->loops_per_jiffy = loops_per_jiffy;
  203. c->x86_cache_size = -1;
  204. c->x86_vendor = X86_VENDOR_UNKNOWN;
  205. c->x86_model = c->x86_mask = 0; /* So far unknown... */
  206. c->x86_vendor_id[0] = '\0'; /* Unset */
  207. c->x86_model_id[0] = '\0'; /* Unset */
  208. c->x86_clflush_size = 64;
  209. c->x86_cache_alignment = c->x86_clflush_size;
  210. c->x86_max_cores = 1;
  211. c->x86_coreid_bits = 0;
  212. c->extended_cpuid_level = 0;
  213. memset(&c->x86_capability, 0, sizeof c->x86_capability);
  214. /* Get vendor name */
  215. cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
  216. (unsigned int *)&c->x86_vendor_id[0],
  217. (unsigned int *)&c->x86_vendor_id[8],
  218. (unsigned int *)&c->x86_vendor_id[4]);
  219. get_cpu_vendor(c);
  220. /* Initialize the standard set of capabilities */
  221. /* Note that the vendor-specific code below might override */
  222. /* Intel-defined flags: level 0x00000001 */
  223. if (c->cpuid_level >= 0x00000001) {
  224. __u32 misc;
  225. cpuid(0x00000001, &tfms, &misc, &c->x86_capability[4],
  226. &c->x86_capability[0]);
  227. c->x86 = (tfms >> 8) & 0xf;
  228. c->x86_model = (tfms >> 4) & 0xf;
  229. c->x86_mask = tfms & 0xf;
  230. if (c->x86 == 0xf)
  231. c->x86 += (tfms >> 20) & 0xff;
  232. if (c->x86 >= 0x6)
  233. c->x86_model += ((tfms >> 16) & 0xF) << 4;
  234. if (test_cpu_cap(c, X86_FEATURE_CLFLSH))
  235. c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
  236. } else {
  237. /* Have CPUID level 0 only - unheard of */
  238. c->x86 = 4;
  239. }
  240. c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xff;
  241. #ifdef CONFIG_SMP
  242. c->phys_proc_id = c->initial_apicid;
  243. #endif
  244. /* AMD-defined flags: level 0x80000001 */
  245. xlvl = cpuid_eax(0x80000000);
  246. c->extended_cpuid_level = xlvl;
  247. if ((xlvl & 0xffff0000) == 0x80000000) {
  248. if (xlvl >= 0x80000001) {
  249. c->x86_capability[1] = cpuid_edx(0x80000001);
  250. c->x86_capability[6] = cpuid_ecx(0x80000001);
  251. }
  252. if (xlvl >= 0x80000004)
  253. get_model_name(c); /* Default name */
  254. }
  255. /* Transmeta-defined flags: level 0x80860001 */
  256. xlvl = cpuid_eax(0x80860000);
  257. if ((xlvl & 0xffff0000) == 0x80860000) {
  258. /* Don't set x86_cpuid_level here for now to not confuse. */
  259. if (xlvl >= 0x80860001)
  260. c->x86_capability[2] = cpuid_edx(0x80860001);
  261. }
  262. c->extended_cpuid_level = cpuid_eax(0x80000000);
  263. if (c->extended_cpuid_level >= 0x80000007)
  264. c->x86_power = cpuid_edx(0x80000007);
  265. if (c->extended_cpuid_level >= 0x80000008) {
  266. u32 eax = cpuid_eax(0x80000008);
  267. c->x86_virt_bits = (eax >> 8) & 0xff;
  268. c->x86_phys_bits = eax & 0xff;
  269. }
  270. /* Assume all 64-bit CPUs support 32-bit syscall */
  271. set_cpu_cap(c, X86_FEATURE_SYSCALL32);
  272. if (c->x86_vendor != X86_VENDOR_UNKNOWN &&
  273. cpu_devs[c->x86_vendor]->c_early_init)
  274. cpu_devs[c->x86_vendor]->c_early_init(c);
  275. validate_pat_support(c);
  276. /* early_param could clear that, but recall get it set again */
  277. if (disable_apic)
  278. clear_cpu_cap(c, X86_FEATURE_APIC);
  279. }
  280. /*
  281. * This does the hard work of actually picking apart the CPU stuff...
  282. */
  283. static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
  284. {
  285. int i;
  286. early_identify_cpu(c);
  287. init_scattered_cpuid_features(c);
  288. c->apicid = phys_pkg_id(0);
  289. /*
  290. * Vendor-specific initialization. In this section we
  291. * canonicalize the feature flags, meaning if there are
  292. * features a certain CPU supports which CPUID doesn't
  293. * tell us, CPUID claiming incorrect flags, or other bugs,
  294. * we handle them here.
  295. *
  296. * At the end of this section, c->x86_capability better
  297. * indicate the features this CPU genuinely supports!
  298. */
  299. if (this_cpu->c_init)
  300. this_cpu->c_init(c);
  301. detect_ht(c);
  302. /*
  303. * On SMP, boot_cpu_data holds the common feature set between
  304. * all CPUs; so make sure that we indicate which features are
  305. * common between the CPUs. The first time this routine gets
  306. * executed, c == &boot_cpu_data.
  307. */
  308. if (c != &boot_cpu_data) {
  309. /* AND the already accumulated flags with these */
  310. for (i = 0; i < NCAPINTS; i++)
  311. boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
  312. }
  313. /* Clear all flags overriden by options */
  314. for (i = 0; i < NCAPINTS; i++)
  315. c->x86_capability[i] &= ~cleared_cpu_caps[i];
  316. #ifdef CONFIG_X86_MCE
  317. mcheck_init(c);
  318. #endif
  319. select_idle_routine(c);
  320. #ifdef CONFIG_NUMA
  321. numa_add_cpu(smp_processor_id());
  322. #endif
  323. }
  324. void __cpuinit identify_boot_cpu(void)
  325. {
  326. identify_cpu(&boot_cpu_data);
  327. }
  328. void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
  329. {
  330. BUG_ON(c == &boot_cpu_data);
  331. identify_cpu(c);
  332. mtrr_ap_init();
  333. }
  334. static __init int setup_noclflush(char *arg)
  335. {
  336. setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
  337. return 1;
  338. }
  339. __setup("noclflush", setup_noclflush);
  340. void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
  341. {
  342. if (c->x86_model_id[0])
  343. printk(KERN_CONT "%s", c->x86_model_id);
  344. if (c->x86_mask || c->cpuid_level >= 0)
  345. printk(KERN_CONT " stepping %02x\n", c->x86_mask);
  346. else
  347. printk(KERN_CONT "\n");
  348. }
  349. static __init int setup_disablecpuid(char *arg)
  350. {
  351. int bit;
  352. if (get_option(&arg, &bit) && bit < NCAPINTS*32)
  353. setup_clear_cpu_cap(bit);
  354. else
  355. return 0;
  356. return 1;
  357. }
  358. __setup("clearcpuid=", setup_disablecpuid);
  359. cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
  360. struct x8664_pda **_cpu_pda __read_mostly;
  361. EXPORT_SYMBOL(_cpu_pda);
  362. struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
  363. char boot_cpu_stack[IRQSTACKSIZE] __page_aligned_bss;
  364. unsigned long __supported_pte_mask __read_mostly = ~0UL;
  365. EXPORT_SYMBOL_GPL(__supported_pte_mask);
  366. static int do_not_nx __cpuinitdata;
  367. /* noexec=on|off
  368. Control non executable mappings for 64bit processes.
  369. on Enable(default)
  370. off Disable
  371. */
  372. static int __init nonx_setup(char *str)
  373. {
  374. if (!str)
  375. return -EINVAL;
  376. if (!strncmp(str, "on", 2)) {
  377. __supported_pte_mask |= _PAGE_NX;
  378. do_not_nx = 0;
  379. } else if (!strncmp(str, "off", 3)) {
  380. do_not_nx = 1;
  381. __supported_pte_mask &= ~_PAGE_NX;
  382. }
  383. return 0;
  384. }
  385. early_param("noexec", nonx_setup);
  386. int force_personality32;
  387. /* noexec32=on|off
  388. Control non executable heap for 32bit processes.
  389. To control the stack too use noexec=off
  390. on PROT_READ does not imply PROT_EXEC for 32bit processes (default)
  391. off PROT_READ implies PROT_EXEC
  392. */
  393. static int __init nonx32_setup(char *str)
  394. {
  395. if (!strcmp(str, "on"))
  396. force_personality32 &= ~READ_IMPLIES_EXEC;
  397. else if (!strcmp(str, "off"))
  398. force_personality32 |= READ_IMPLIES_EXEC;
  399. return 1;
  400. }
  401. __setup("noexec32=", nonx32_setup);
  402. void pda_init(int cpu)
  403. {
  404. struct x8664_pda *pda = cpu_pda(cpu);
  405. /* Setup up data that may be needed in __get_free_pages early */
  406. loadsegment(fs, 0);
  407. loadsegment(gs, 0);
  408. /* Memory clobbers used to order PDA accessed */
  409. mb();
  410. wrmsrl(MSR_GS_BASE, pda);
  411. mb();
  412. pda->cpunumber = cpu;
  413. pda->irqcount = -1;
  414. pda->kernelstack = (unsigned long)stack_thread_info() -
  415. PDA_STACKOFFSET + THREAD_SIZE;
  416. pda->active_mm = &init_mm;
  417. pda->mmu_state = 0;
  418. if (cpu == 0) {
  419. /* others are initialized in smpboot.c */
  420. pda->pcurrent = &init_task;
  421. pda->irqstackptr = boot_cpu_stack;
  422. } else {
  423. pda->irqstackptr = (char *)
  424. __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
  425. if (!pda->irqstackptr)
  426. panic("cannot allocate irqstack for cpu %d", cpu);
  427. if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
  428. pda->nodenumber = cpu_to_node(cpu);
  429. }
  430. pda->irqstackptr += IRQSTACKSIZE-64;
  431. }
  432. char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
  433. DEBUG_STKSZ]
  434. __attribute__((section(".bss.page_aligned")));
  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. }