Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', 'x86/core...
[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / arch / x86 / kernel / cpu / common_64.c
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/delay.h>
11 #include <linux/smp.h>
12 #include <linux/percpu.h>
13 #include <asm/i387.h>
14 #include <asm/msr.h>
15 #include <asm/io.h>
16 #include <asm/linkage.h>
17 #include <asm/mmu_context.h>
18 #include <asm/mtrr.h>
19 #include <asm/mce.h>
20 #include <asm/pat.h>
21 #include <asm/numa.h>
22 #ifdef CONFIG_X86_LOCAL_APIC
23 #include <asm/mpspec.h>
24 #include <asm/apic.h>
25 #include <mach_apic.h>
26 #endif
27 #include <asm/pda.h>
28 #include <asm/pgtable.h>
29 #include <asm/processor.h>
30 #include <asm/desc.h>
31 #include <asm/atomic.h>
32 #include <asm/proto.h>
33 #include <asm/sections.h>
34 #include <asm/setup.h>
35 #include <asm/genapic.h>
36
37 #include "cpu.h"
38
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
55 __u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
56
57 /* Current gdt points %fs at the "master" per-cpu area: after this,
58 * it's on the real one. */
59 void switch_to_new_gdt(void)
60 {
61 struct desc_ptr gdt_descr;
62
63 gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
64 gdt_descr.size = GDT_SIZE - 1;
65 load_gdt(&gdt_descr);
66 }
67
68 struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
69
70 static void __cpuinit default_init(struct cpuinfo_x86 *c)
71 {
72 display_cacheinfo(c);
73 }
74
75 static struct cpu_dev __cpuinitdata default_cpu = {
76 .c_init = default_init,
77 .c_vendor = "Unknown",
78 };
79 static struct cpu_dev *this_cpu __cpuinitdata = &default_cpu;
80
81 int __cpuinit get_model_name(struct cpuinfo_x86 *c)
82 {
83 unsigned int *v;
84
85 if (c->extended_cpuid_level < 0x80000004)
86 return 0;
87
88 v = (unsigned int *) c->x86_model_id;
89 cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
90 cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
91 cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
92 c->x86_model_id[48] = 0;
93 return 1;
94 }
95
96
97 void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
98 {
99 unsigned int n, dummy, ebx, ecx, edx;
100
101 n = c->extended_cpuid_level;
102
103 if (n >= 0x80000005) {
104 cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
105 printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), "
106 "D cache %dK (%d bytes/line)\n",
107 edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
108 c->x86_cache_size = (ecx>>24) + (edx>>24);
109 /* On K8 L1 TLB is inclusive, so don't count it */
110 c->x86_tlbsize = 0;
111 }
112
113 if (n >= 0x80000006) {
114 cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
115 ecx = cpuid_ecx(0x80000006);
116 c->x86_cache_size = ecx >> 16;
117 c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
118
119 printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
120 c->x86_cache_size, ecx & 0xFF);
121 }
122 }
123
124 void __cpuinit detect_ht(struct cpuinfo_x86 *c)
125 {
126 #ifdef CONFIG_SMP
127 u32 eax, ebx, ecx, edx;
128 int index_msb, core_bits;
129
130 cpuid(1, &eax, &ebx, &ecx, &edx);
131
132
133 if (!cpu_has(c, X86_FEATURE_HT))
134 return;
135 if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
136 goto out;
137
138 smp_num_siblings = (ebx & 0xff0000) >> 16;
139
140 if (smp_num_siblings == 1) {
141 printk(KERN_INFO "CPU: Hyper-Threading is disabled\n");
142 } else if (smp_num_siblings > 1) {
143
144 if (smp_num_siblings > NR_CPUS) {
145 printk(KERN_WARNING "CPU: Unsupported number of "
146 "siblings %d", smp_num_siblings);
147 smp_num_siblings = 1;
148 return;
149 }
150
151 index_msb = get_count_order(smp_num_siblings);
152 c->phys_proc_id = phys_pkg_id(index_msb);
153
154 smp_num_siblings = smp_num_siblings / c->x86_max_cores;
155
156 index_msb = get_count_order(smp_num_siblings);
157
158 core_bits = get_count_order(c->x86_max_cores);
159
160 c->cpu_core_id = phys_pkg_id(index_msb) &
161 ((1 << core_bits) - 1);
162 }
163 out:
164 if ((c->x86_max_cores * smp_num_siblings) > 1) {
165 printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
166 c->phys_proc_id);
167 printk(KERN_INFO "CPU: Processor Core ID: %d\n",
168 c->cpu_core_id);
169 }
170
171 #endif
172 }
173
174 static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
175 {
176 char *v = c->x86_vendor_id;
177 int i;
178 static int printed;
179
180 for (i = 0; i < X86_VENDOR_NUM; i++) {
181 if (cpu_devs[i]) {
182 if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
183 (cpu_devs[i]->c_ident[1] &&
184 !strcmp(v, cpu_devs[i]->c_ident[1]))) {
185 c->x86_vendor = i;
186 this_cpu = cpu_devs[i];
187 return;
188 }
189 }
190 }
191 if (!printed) {
192 printed++;
193 printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
194 printk(KERN_ERR "CPU: Your system may be unstable.\n");
195 }
196 c->x86_vendor = X86_VENDOR_UNKNOWN;
197 }
198
199 static void __init early_cpu_support_print(void)
200 {
201 int i,j;
202 struct cpu_dev *cpu_devx;
203
204 printk("KERNEL supported cpus:\n");
205 for (i = 0; i < X86_VENDOR_NUM; i++) {
206 cpu_devx = cpu_devs[i];
207 if (!cpu_devx)
208 continue;
209 for (j = 0; j < 2; j++) {
210 if (!cpu_devx->c_ident[j])
211 continue;
212 printk(" %s %s\n", cpu_devx->c_vendor,
213 cpu_devx->c_ident[j]);
214 }
215 }
216 }
217
218 static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c);
219
220 void __init early_cpu_init(void)
221 {
222 struct cpu_vendor_dev *cvdev;
223
224 for (cvdev = __x86cpuvendor_start ;
225 cvdev < __x86cpuvendor_end ;
226 cvdev++)
227 cpu_devs[cvdev->vendor] = cvdev->cpu_dev;
228 early_cpu_support_print();
229 early_identify_cpu(&boot_cpu_data);
230 }
231
232 /* Do some early cpuid on the boot CPU to get some parameter that are
233 needed before check_bugs. Everything advanced is in identify_cpu
234 below. */
235 static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
236 {
237 u32 tfms, xlvl;
238
239 c->loops_per_jiffy = loops_per_jiffy;
240 c->x86_cache_size = -1;
241 c->x86_vendor = X86_VENDOR_UNKNOWN;
242 c->x86_model = c->x86_mask = 0; /* So far unknown... */
243 c->x86_vendor_id[0] = '\0'; /* Unset */
244 c->x86_model_id[0] = '\0'; /* Unset */
245 c->x86_clflush_size = 64;
246 c->x86_cache_alignment = c->x86_clflush_size;
247 c->x86_max_cores = 1;
248 c->x86_coreid_bits = 0;
249 c->extended_cpuid_level = 0;
250 memset(&c->x86_capability, 0, sizeof c->x86_capability);
251
252 /* Get vendor name */
253 cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
254 (unsigned int *)&c->x86_vendor_id[0],
255 (unsigned int *)&c->x86_vendor_id[8],
256 (unsigned int *)&c->x86_vendor_id[4]);
257
258 get_cpu_vendor(c);
259
260 /* Initialize the standard set of capabilities */
261 /* Note that the vendor-specific code below might override */
262
263 /* Intel-defined flags: level 0x00000001 */
264 if (c->cpuid_level >= 0x00000001) {
265 __u32 misc;
266 cpuid(0x00000001, &tfms, &misc, &c->x86_capability[4],
267 &c->x86_capability[0]);
268 c->x86 = (tfms >> 8) & 0xf;
269 c->x86_model = (tfms >> 4) & 0xf;
270 c->x86_mask = tfms & 0xf;
271 if (c->x86 == 0xf)
272 c->x86 += (tfms >> 20) & 0xff;
273 if (c->x86 >= 0x6)
274 c->x86_model += ((tfms >> 16) & 0xF) << 4;
275 if (test_cpu_cap(c, X86_FEATURE_CLFLSH))
276 c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
277 } else {
278 /* Have CPUID level 0 only - unheard of */
279 c->x86 = 4;
280 }
281
282 c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xff;
283 #ifdef CONFIG_SMP
284 c->phys_proc_id = c->initial_apicid;
285 #endif
286 /* AMD-defined flags: level 0x80000001 */
287 xlvl = cpuid_eax(0x80000000);
288 c->extended_cpuid_level = xlvl;
289 if ((xlvl & 0xffff0000) == 0x80000000) {
290 if (xlvl >= 0x80000001) {
291 c->x86_capability[1] = cpuid_edx(0x80000001);
292 c->x86_capability[6] = cpuid_ecx(0x80000001);
293 }
294 if (xlvl >= 0x80000004)
295 get_model_name(c); /* Default name */
296 }
297
298 /* Transmeta-defined flags: level 0x80860001 */
299 xlvl = cpuid_eax(0x80860000);
300 if ((xlvl & 0xffff0000) == 0x80860000) {
301 /* Don't set x86_cpuid_level here for now to not confuse. */
302 if (xlvl >= 0x80860001)
303 c->x86_capability[2] = cpuid_edx(0x80860001);
304 }
305
306 if (c->extended_cpuid_level >= 0x80000007)
307 c->x86_power = cpuid_edx(0x80000007);
308
309 if (c->extended_cpuid_level >= 0x80000008) {
310 u32 eax = cpuid_eax(0x80000008);
311
312 c->x86_virt_bits = (eax >> 8) & 0xff;
313 c->x86_phys_bits = eax & 0xff;
314 }
315
316 if (c->x86_vendor != X86_VENDOR_UNKNOWN &&
317 cpu_devs[c->x86_vendor]->c_early_init)
318 cpu_devs[c->x86_vendor]->c_early_init(c);
319
320 validate_pat_support(c);
321 }
322
323 /*
324 * This does the hard work of actually picking apart the CPU stuff...
325 */
326 static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
327 {
328 int i;
329
330 early_identify_cpu(c);
331
332 init_scattered_cpuid_features(c);
333
334 c->apicid = phys_pkg_id(0);
335
336 /*
337 * Vendor-specific initialization. In this section we
338 * canonicalize the feature flags, meaning if there are
339 * features a certain CPU supports which CPUID doesn't
340 * tell us, CPUID claiming incorrect flags, or other bugs,
341 * we handle them here.
342 *
343 * At the end of this section, c->x86_capability better
344 * indicate the features this CPU genuinely supports!
345 */
346 if (this_cpu->c_init)
347 this_cpu->c_init(c);
348
349 detect_ht(c);
350
351 /*
352 * On SMP, boot_cpu_data holds the common feature set between
353 * all CPUs; so make sure that we indicate which features are
354 * common between the CPUs. The first time this routine gets
355 * executed, c == &boot_cpu_data.
356 */
357 if (c != &boot_cpu_data) {
358 /* AND the already accumulated flags with these */
359 for (i = 0; i < NCAPINTS; i++)
360 boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
361 }
362
363 /* Clear all flags overriden by options */
364 for (i = 0; i < NCAPINTS; i++)
365 c->x86_capability[i] &= ~cleared_cpu_caps[i];
366
367 #ifdef CONFIG_X86_MCE
368 mcheck_init(c);
369 #endif
370 select_idle_routine(c);
371
372 #ifdef CONFIG_NUMA
373 numa_add_cpu(smp_processor_id());
374 #endif
375
376 }
377
378 void __cpuinit identify_boot_cpu(void)
379 {
380 identify_cpu(&boot_cpu_data);
381 }
382
383 void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
384 {
385 BUG_ON(c == &boot_cpu_data);
386 identify_cpu(c);
387 mtrr_ap_init();
388 }
389
390 static __init int setup_noclflush(char *arg)
391 {
392 setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
393 return 1;
394 }
395 __setup("noclflush", setup_noclflush);
396
397 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
398 {
399 if (c->x86_model_id[0])
400 printk(KERN_CONT "%s", c->x86_model_id);
401
402 if (c->x86_mask || c->cpuid_level >= 0)
403 printk(KERN_CONT " stepping %02x\n", c->x86_mask);
404 else
405 printk(KERN_CONT "\n");
406 }
407
408 static __init int setup_disablecpuid(char *arg)
409 {
410 int bit;
411 if (get_option(&arg, &bit) && bit < NCAPINTS*32)
412 setup_clear_cpu_cap(bit);
413 else
414 return 0;
415 return 1;
416 }
417 __setup("clearcpuid=", setup_disablecpuid);
418
419 cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
420
421 struct x8664_pda **_cpu_pda __read_mostly;
422 EXPORT_SYMBOL(_cpu_pda);
423
424 struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
425
426 char boot_cpu_stack[IRQSTACKSIZE] __page_aligned_bss;
427
428 unsigned long __supported_pte_mask __read_mostly = ~0UL;
429 EXPORT_SYMBOL_GPL(__supported_pte_mask);
430
431 static int do_not_nx __cpuinitdata;
432
433 /* noexec=on|off
434 Control non executable mappings for 64bit processes.
435
436 on Enable(default)
437 off Disable
438 */
439 static int __init nonx_setup(char *str)
440 {
441 if (!str)
442 return -EINVAL;
443 if (!strncmp(str, "on", 2)) {
444 __supported_pte_mask |= _PAGE_NX;
445 do_not_nx = 0;
446 } else if (!strncmp(str, "off", 3)) {
447 do_not_nx = 1;
448 __supported_pte_mask &= ~_PAGE_NX;
449 }
450 return 0;
451 }
452 early_param("noexec", nonx_setup);
453
454 int force_personality32;
455
456 /* noexec32=on|off
457 Control non executable heap for 32bit processes.
458 To control the stack too use noexec=off
459
460 on PROT_READ does not imply PROT_EXEC for 32bit processes (default)
461 off PROT_READ implies PROT_EXEC
462 */
463 static int __init nonx32_setup(char *str)
464 {
465 if (!strcmp(str, "on"))
466 force_personality32 &= ~READ_IMPLIES_EXEC;
467 else if (!strcmp(str, "off"))
468 force_personality32 |= READ_IMPLIES_EXEC;
469 return 1;
470 }
471 __setup("noexec32=", nonx32_setup);
472
473 void pda_init(int cpu)
474 {
475 struct x8664_pda *pda = cpu_pda(cpu);
476
477 /* Setup up data that may be needed in __get_free_pages early */
478 loadsegment(fs, 0);
479 loadsegment(gs, 0);
480 /* Memory clobbers used to order PDA accessed */
481 mb();
482 wrmsrl(MSR_GS_BASE, pda);
483 mb();
484
485 pda->cpunumber = cpu;
486 pda->irqcount = -1;
487 pda->kernelstack = (unsigned long)stack_thread_info() -
488 PDA_STACKOFFSET + THREAD_SIZE;
489 pda->active_mm = &init_mm;
490 pda->mmu_state = 0;
491
492 if (cpu == 0) {
493 /* others are initialized in smpboot.c */
494 pda->pcurrent = &init_task;
495 pda->irqstackptr = boot_cpu_stack;
496 } else {
497 pda->irqstackptr = (char *)
498 __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
499 if (!pda->irqstackptr)
500 panic("cannot allocate irqstack for cpu %d", cpu);
501
502 if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
503 pda->nodenumber = cpu_to_node(cpu);
504 }
505
506 pda->irqstackptr += IRQSTACKSIZE-64;
507 }
508
509 char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
510 DEBUG_STKSZ] __page_aligned_bss;
511
512 extern asmlinkage void ignore_sysret(void);
513
514 /* May not be marked __init: used by software suspend */
515 void syscall_init(void)
516 {
517 /*
518 * LSTAR and STAR live in a bit strange symbiosis.
519 * They both write to the same internal register. STAR allows to
520 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
521 */
522 wrmsrl(MSR_STAR, ((u64)__USER32_CS)<<48 | ((u64)__KERNEL_CS)<<32);
523 wrmsrl(MSR_LSTAR, system_call);
524 wrmsrl(MSR_CSTAR, ignore_sysret);
525
526 #ifdef CONFIG_IA32_EMULATION
527 syscall32_cpu_init();
528 #endif
529
530 /* Flags to clear on syscall */
531 wrmsrl(MSR_SYSCALL_MASK,
532 X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
533 }
534
535 void __cpuinit check_efer(void)
536 {
537 unsigned long efer;
538
539 rdmsrl(MSR_EFER, efer);
540 if (!(efer & EFER_NX) || do_not_nx)
541 __supported_pte_mask &= ~_PAGE_NX;
542 }
543
544 unsigned long kernel_eflags;
545
546 /*
547 * Copies of the original ist values from the tss are only accessed during
548 * debugging, no special alignment required.
549 */
550 DEFINE_PER_CPU(struct orig_ist, orig_ist);
551
552 /*
553 * cpu_init() initializes state that is per-CPU. Some data is already
554 * initialized (naturally) in the bootstrap process, such as the GDT
555 * and IDT. We reload them nevertheless, this function acts as a
556 * 'CPU state barrier', nothing should get across.
557 * A lot of state is already set up in PDA init.
558 */
559 void __cpuinit cpu_init(void)
560 {
561 int cpu = stack_smp_processor_id();
562 struct tss_struct *t = &per_cpu(init_tss, cpu);
563 struct orig_ist *orig_ist = &per_cpu(orig_ist, cpu);
564 unsigned long v;
565 char *estacks = NULL;
566 struct task_struct *me;
567 int i;
568
569 /* CPU 0 is initialised in head64.c */
570 if (cpu != 0)
571 pda_init(cpu);
572 else
573 estacks = boot_exception_stacks;
574
575 me = current;
576
577 if (cpu_test_and_set(cpu, cpu_initialized))
578 panic("CPU#%d already initialized!\n", cpu);
579
580 printk(KERN_INFO "Initializing CPU#%d\n", cpu);
581
582 clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
583
584 /*
585 * Initialize the per-CPU GDT with the boot GDT,
586 * and set up the GDT descriptor:
587 */
588
589 switch_to_new_gdt();
590 load_idt((const struct desc_ptr *)&idt_descr);
591
592 memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
593 syscall_init();
594
595 wrmsrl(MSR_FS_BASE, 0);
596 wrmsrl(MSR_KERNEL_GS_BASE, 0);
597 barrier();
598
599 check_efer();
600
601 /*
602 * set up and load the per-CPU TSS
603 */
604 for (v = 0; v < N_EXCEPTION_STACKS; v++) {
605 static const unsigned int order[N_EXCEPTION_STACKS] = {
606 [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
607 [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
608 };
609 if (cpu) {
610 estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
611 if (!estacks)
612 panic("Cannot allocate exception stack %ld %d\n",
613 v, cpu);
614 }
615 estacks += PAGE_SIZE << order[v];
616 orig_ist->ist[v] = t->x86_tss.ist[v] = (unsigned long)estacks;
617 }
618
619 t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
620 /*
621 * <= is required because the CPU will access up to
622 * 8 bits beyond the end of the IO permission bitmap.
623 */
624 for (i = 0; i <= IO_BITMAP_LONGS; i++)
625 t->io_bitmap[i] = ~0UL;
626
627 atomic_inc(&init_mm.mm_count);
628 me->active_mm = &init_mm;
629 if (me->mm)
630 BUG();
631 enter_lazy_tlb(&init_mm, me);
632
633 load_sp0(t, &current->thread);
634 set_tss_desc(cpu, t);
635 load_TR_desc();
636 load_LDT(&init_mm.context);
637
638 #ifdef CONFIG_KGDB
639 /*
640 * If the kgdb is connected no debug regs should be altered. This
641 * is only applicable when KGDB and a KGDB I/O module are built
642 * into the kernel and you are using early debugging with
643 * kgdbwait. KGDB will control the kernel HW breakpoint registers.
644 */
645 if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
646 arch_kgdb_ops.correct_hw_break();
647 else {
648 #endif
649 /*
650 * Clear all 6 debug registers:
651 */
652
653 set_debugreg(0UL, 0);
654 set_debugreg(0UL, 1);
655 set_debugreg(0UL, 2);
656 set_debugreg(0UL, 3);
657 set_debugreg(0UL, 6);
658 set_debugreg(0UL, 7);
659 #ifdef CONFIG_KGDB
660 /* If the kgdb is connected no debug regs should be altered. */
661 }
662 #endif
663
664 fpu_init();
665
666 raw_local_save_flags(kernel_eflags);
667
668 if (is_uv_system())
669 uv_cpu_init();
670 }