Merge branch 'linus' into xen-64bit
[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/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
40 #include "cpu.h"
41
42 /* We need valid kernel segments for data and code in long mode too
43 * IRET will check the segment types kkeil 2000/10/28
44 * Also sysret mandates a special GDT layout
45 */
46 /* The TLS descriptors are currently at a different place compared to i386.
47 Hopefully nobody expects them at a fixed place (Wine?) */
48 DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = {
49 [GDT_ENTRY_KERNEL32_CS] = { { { 0x0000ffff, 0x00cf9b00 } } },
50 [GDT_ENTRY_KERNEL_CS] = { { { 0x0000ffff, 0x00af9b00 } } },
51 [GDT_ENTRY_KERNEL_DS] = { { { 0x0000ffff, 0x00cf9300 } } },
52 [GDT_ENTRY_DEFAULT_USER32_CS] = { { { 0x0000ffff, 0x00cffb00 } } },
53 [GDT_ENTRY_DEFAULT_USER_DS] = { { { 0x0000ffff, 0x00cff300 } } },
54 [GDT_ENTRY_DEFAULT_USER_CS] = { { { 0x0000ffff, 0x00affb00 } } },
55 } };
56 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
57
58 __u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
59
60 /* Current gdt points %fs at the "master" per-cpu area: after this,
61 * it's on the real one. */
62 void switch_to_new_gdt(void)
63 {
64 struct desc_ptr gdt_descr;
65
66 gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
67 gdt_descr.size = GDT_SIZE - 1;
68 load_gdt(&gdt_descr);
69 }
70
71 struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};
72
73 static void __cpuinit default_init(struct cpuinfo_x86 *c)
74 {
75 display_cacheinfo(c);
76 }
77
78 static struct cpu_dev __cpuinitdata default_cpu = {
79 .c_init = default_init,
80 .c_vendor = "Unknown",
81 };
82 static struct cpu_dev *this_cpu __cpuinitdata = &default_cpu;
83
84 int __cpuinit get_model_name(struct cpuinfo_x86 *c)
85 {
86 unsigned int *v;
87
88 if (c->extended_cpuid_level < 0x80000004)
89 return 0;
90
91 v = (unsigned int *) c->x86_model_id;
92 cpuid(0x80000002, &v[0], &v[1], &v[2], &v[3]);
93 cpuid(0x80000003, &v[4], &v[5], &v[6], &v[7]);
94 cpuid(0x80000004, &v[8], &v[9], &v[10], &v[11]);
95 c->x86_model_id[48] = 0;
96 return 1;
97 }
98
99
100 void __cpuinit display_cacheinfo(struct cpuinfo_x86 *c)
101 {
102 unsigned int n, dummy, ebx, ecx, edx;
103
104 n = c->extended_cpuid_level;
105
106 if (n >= 0x80000005) {
107 cpuid(0x80000005, &dummy, &ebx, &ecx, &edx);
108 printk(KERN_INFO "CPU: L1 I Cache: %dK (%d bytes/line), "
109 "D cache %dK (%d bytes/line)\n",
110 edx>>24, edx&0xFF, ecx>>24, ecx&0xFF);
111 c->x86_cache_size = (ecx>>24) + (edx>>24);
112 /* On K8 L1 TLB is inclusive, so don't count it */
113 c->x86_tlbsize = 0;
114 }
115
116 if (n >= 0x80000006) {
117 cpuid(0x80000006, &dummy, &ebx, &ecx, &edx);
118 ecx = cpuid_ecx(0x80000006);
119 c->x86_cache_size = ecx >> 16;
120 c->x86_tlbsize += ((ebx >> 16) & 0xfff) + (ebx & 0xfff);
121
122 printk(KERN_INFO "CPU: L2 Cache: %dK (%d bytes/line)\n",
123 c->x86_cache_size, ecx & 0xFF);
124 }
125 }
126
127 void __cpuinit detect_ht(struct cpuinfo_x86 *c)
128 {
129 #ifdef CONFIG_SMP
130 u32 eax, ebx, ecx, edx;
131 int index_msb, core_bits;
132
133 cpuid(1, &eax, &ebx, &ecx, &edx);
134
135
136 if (!cpu_has(c, X86_FEATURE_HT))
137 return;
138 if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
139 goto out;
140
141 smp_num_siblings = (ebx & 0xff0000) >> 16;
142
143 if (smp_num_siblings == 1) {
144 printk(KERN_INFO "CPU: Hyper-Threading is disabled\n");
145 } else if (smp_num_siblings > 1) {
146
147 if (smp_num_siblings > NR_CPUS) {
148 printk(KERN_WARNING "CPU: Unsupported number of "
149 "siblings %d", smp_num_siblings);
150 smp_num_siblings = 1;
151 return;
152 }
153
154 index_msb = get_count_order(smp_num_siblings);
155 c->phys_proc_id = phys_pkg_id(index_msb);
156
157 smp_num_siblings = smp_num_siblings / c->x86_max_cores;
158
159 index_msb = get_count_order(smp_num_siblings);
160
161 core_bits = get_count_order(c->x86_max_cores);
162
163 c->cpu_core_id = phys_pkg_id(index_msb) &
164 ((1 << core_bits) - 1);
165 }
166 out:
167 if ((c->x86_max_cores * smp_num_siblings) > 1) {
168 printk(KERN_INFO "CPU: Physical Processor ID: %d\n",
169 c->phys_proc_id);
170 printk(KERN_INFO "CPU: Processor Core ID: %d\n",
171 c->cpu_core_id);
172 }
173
174 #endif
175 }
176
177 static void __cpuinit get_cpu_vendor(struct cpuinfo_x86 *c)
178 {
179 char *v = c->x86_vendor_id;
180 int i;
181 static int printed;
182
183 for (i = 0; i < X86_VENDOR_NUM; i++) {
184 if (cpu_devs[i]) {
185 if (!strcmp(v, cpu_devs[i]->c_ident[0]) ||
186 (cpu_devs[i]->c_ident[1] &&
187 !strcmp(v, cpu_devs[i]->c_ident[1]))) {
188 c->x86_vendor = i;
189 this_cpu = cpu_devs[i];
190 return;
191 }
192 }
193 }
194 if (!printed) {
195 printed++;
196 printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
197 printk(KERN_ERR "CPU: Your system may be unstable.\n");
198 }
199 c->x86_vendor = X86_VENDOR_UNKNOWN;
200 }
201
202 static void __init early_cpu_support_print(void)
203 {
204 int i,j;
205 struct cpu_dev *cpu_devx;
206
207 printk("KERNEL supported cpus:\n");
208 for (i = 0; i < X86_VENDOR_NUM; i++) {
209 cpu_devx = cpu_devs[i];
210 if (!cpu_devx)
211 continue;
212 for (j = 0; j < 2; j++) {
213 if (!cpu_devx->c_ident[j])
214 continue;
215 printk(" %s %s\n", cpu_devx->c_vendor,
216 cpu_devx->c_ident[j]);
217 }
218 }
219 }
220
221 static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c);
222
223 void __init early_cpu_init(void)
224 {
225 struct cpu_vendor_dev *cvdev;
226
227 for (cvdev = __x86cpuvendor_start ;
228 cvdev < __x86cpuvendor_end ;
229 cvdev++)
230 cpu_devs[cvdev->vendor] = cvdev->cpu_dev;
231 early_cpu_support_print();
232 early_identify_cpu(&boot_cpu_data);
233 }
234
235 /* Do some early cpuid on the boot CPU to get some parameter that are
236 needed before check_bugs. Everything advanced is in identify_cpu
237 below. */
238 static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
239 {
240 u32 tfms, xlvl;
241
242 c->loops_per_jiffy = loops_per_jiffy;
243 c->x86_cache_size = -1;
244 c->x86_vendor = X86_VENDOR_UNKNOWN;
245 c->x86_model = c->x86_mask = 0; /* So far unknown... */
246 c->x86_vendor_id[0] = '\0'; /* Unset */
247 c->x86_model_id[0] = '\0'; /* Unset */
248 c->x86_clflush_size = 64;
249 c->x86_cache_alignment = c->x86_clflush_size;
250 c->x86_max_cores = 1;
251 c->x86_coreid_bits = 0;
252 c->extended_cpuid_level = 0;
253 memset(&c->x86_capability, 0, sizeof c->x86_capability);
254
255 /* Get vendor name */
256 cpuid(0x00000000, (unsigned int *)&c->cpuid_level,
257 (unsigned int *)&c->x86_vendor_id[0],
258 (unsigned int *)&c->x86_vendor_id[8],
259 (unsigned int *)&c->x86_vendor_id[4]);
260
261 get_cpu_vendor(c);
262
263 /* Initialize the standard set of capabilities */
264 /* Note that the vendor-specific code below might override */
265
266 /* Intel-defined flags: level 0x00000001 */
267 if (c->cpuid_level >= 0x00000001) {
268 __u32 misc;
269 cpuid(0x00000001, &tfms, &misc, &c->x86_capability[4],
270 &c->x86_capability[0]);
271 c->x86 = (tfms >> 8) & 0xf;
272 c->x86_model = (tfms >> 4) & 0xf;
273 c->x86_mask = tfms & 0xf;
274 if (c->x86 == 0xf)
275 c->x86 += (tfms >> 20) & 0xff;
276 if (c->x86 >= 0x6)
277 c->x86_model += ((tfms >> 16) & 0xF) << 4;
278 if (test_cpu_cap(c, X86_FEATURE_CLFLSH))
279 c->x86_clflush_size = ((misc >> 8) & 0xff) * 8;
280 } else {
281 /* Have CPUID level 0 only - unheard of */
282 c->x86 = 4;
283 }
284
285 c->initial_apicid = (cpuid_ebx(1) >> 24) & 0xff;
286 #ifdef CONFIG_SMP
287 c->phys_proc_id = c->initial_apicid;
288 #endif
289 /* AMD-defined flags: level 0x80000001 */
290 xlvl = cpuid_eax(0x80000000);
291 c->extended_cpuid_level = xlvl;
292 if ((xlvl & 0xffff0000) == 0x80000000) {
293 if (xlvl >= 0x80000001) {
294 c->x86_capability[1] = cpuid_edx(0x80000001);
295 c->x86_capability[6] = cpuid_ecx(0x80000001);
296 }
297 if (xlvl >= 0x80000004)
298 get_model_name(c); /* Default name */
299 }
300
301 /* Transmeta-defined flags: level 0x80860001 */
302 xlvl = cpuid_eax(0x80860000);
303 if ((xlvl & 0xffff0000) == 0x80860000) {
304 /* Don't set x86_cpuid_level here for now to not confuse. */
305 if (xlvl >= 0x80860001)
306 c->x86_capability[2] = cpuid_edx(0x80860001);
307 }
308
309 c->extended_cpuid_level = cpuid_eax(0x80000000);
310 if (c->extended_cpuid_level >= 0x80000007)
311 c->x86_power = cpuid_edx(0x80000007);
312
313 if (c->extended_cpuid_level >= 0x80000008) {
314 u32 eax = cpuid_eax(0x80000008);
315
316 c->x86_virt_bits = (eax >> 8) & 0xff;
317 c->x86_phys_bits = eax & 0xff;
318 }
319
320 if (c->x86_vendor != X86_VENDOR_UNKNOWN &&
321 cpu_devs[c->x86_vendor]->c_early_init)
322 cpu_devs[c->x86_vendor]->c_early_init(c);
323
324 validate_pat_support(c);
325
326 /* early_param could clear that, but recall get it set again */
327 if (disable_apic)
328 clear_cpu_cap(c, X86_FEATURE_APIC);
329 }
330
331 /*
332 * This does the hard work of actually picking apart the CPU stuff...
333 */
334 static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
335 {
336 int i;
337
338 early_identify_cpu(c);
339
340 init_scattered_cpuid_features(c);
341
342 c->apicid = phys_pkg_id(0);
343
344 /*
345 * Vendor-specific initialization. In this section we
346 * canonicalize the feature flags, meaning if there are
347 * features a certain CPU supports which CPUID doesn't
348 * tell us, CPUID claiming incorrect flags, or other bugs,
349 * we handle them here.
350 *
351 * At the end of this section, c->x86_capability better
352 * indicate the features this CPU genuinely supports!
353 */
354 if (this_cpu->c_init)
355 this_cpu->c_init(c);
356
357 detect_ht(c);
358
359 /*
360 * On SMP, boot_cpu_data holds the common feature set between
361 * all CPUs; so make sure that we indicate which features are
362 * common between the CPUs. The first time this routine gets
363 * executed, c == &boot_cpu_data.
364 */
365 if (c != &boot_cpu_data) {
366 /* AND the already accumulated flags with these */
367 for (i = 0; i < NCAPINTS; i++)
368 boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
369 }
370
371 /* Clear all flags overriden by options */
372 for (i = 0; i < NCAPINTS; i++)
373 c->x86_capability[i] &= ~cleared_cpu_caps[i];
374
375 #ifdef CONFIG_X86_MCE
376 mcheck_init(c);
377 #endif
378 select_idle_routine(c);
379
380 #ifdef CONFIG_NUMA
381 numa_add_cpu(smp_processor_id());
382 #endif
383
384 }
385
386 void __cpuinit identify_boot_cpu(void)
387 {
388 identify_cpu(&boot_cpu_data);
389 }
390
391 void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)
392 {
393 BUG_ON(c == &boot_cpu_data);
394 identify_cpu(c);
395 mtrr_ap_init();
396 }
397
398 static __init int setup_noclflush(char *arg)
399 {
400 setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
401 return 1;
402 }
403 __setup("noclflush", setup_noclflush);
404
405 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
406 {
407 if (c->x86_model_id[0])
408 printk(KERN_CONT "%s", c->x86_model_id);
409
410 if (c->x86_mask || c->cpuid_level >= 0)
411 printk(KERN_CONT " stepping %02x\n", c->x86_mask);
412 else
413 printk(KERN_CONT "\n");
414 }
415
416 static __init int setup_disablecpuid(char *arg)
417 {
418 int bit;
419 if (get_option(&arg, &bit) && bit < NCAPINTS*32)
420 setup_clear_cpu_cap(bit);
421 else
422 return 0;
423 return 1;
424 }
425 __setup("clearcpuid=", setup_disablecpuid);
426
427 cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
428
429 struct x8664_pda **_cpu_pda __read_mostly;
430 EXPORT_SYMBOL(_cpu_pda);
431
432 struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
433
434 char boot_cpu_stack[IRQSTACKSIZE] __page_aligned_bss;
435
436 unsigned long __supported_pte_mask __read_mostly = ~0UL;
437 EXPORT_SYMBOL_GPL(__supported_pte_mask);
438
439 static int do_not_nx __cpuinitdata;
440
441 /* noexec=on|off
442 Control non executable mappings for 64bit processes.
443
444 on Enable(default)
445 off Disable
446 */
447 static int __init nonx_setup(char *str)
448 {
449 if (!str)
450 return -EINVAL;
451 if (!strncmp(str, "on", 2)) {
452 __supported_pte_mask |= _PAGE_NX;
453 do_not_nx = 0;
454 } else if (!strncmp(str, "off", 3)) {
455 do_not_nx = 1;
456 __supported_pte_mask &= ~_PAGE_NX;
457 }
458 return 0;
459 }
460 early_param("noexec", nonx_setup);
461
462 int force_personality32;
463
464 /* noexec32=on|off
465 Control non executable heap for 32bit processes.
466 To control the stack too use noexec=off
467
468 on PROT_READ does not imply PROT_EXEC for 32bit processes (default)
469 off PROT_READ implies PROT_EXEC
470 */
471 static int __init nonx32_setup(char *str)
472 {
473 if (!strcmp(str, "on"))
474 force_personality32 &= ~READ_IMPLIES_EXEC;
475 else if (!strcmp(str, "off"))
476 force_personality32 |= READ_IMPLIES_EXEC;
477 return 1;
478 }
479 __setup("noexec32=", nonx32_setup);
480
481 void pda_init(int cpu)
482 {
483 struct x8664_pda *pda = cpu_pda(cpu);
484
485 /* Setup up data that may be needed in __get_free_pages early */
486 loadsegment(fs, 0);
487 loadsegment(gs, 0);
488 /* Memory clobbers used to order PDA accessed */
489 mb();
490 wrmsrl(MSR_GS_BASE, pda);
491 mb();
492
493 pda->cpunumber = cpu;
494 pda->irqcount = -1;
495 pda->kernelstack = (unsigned long)stack_thread_info() -
496 PDA_STACKOFFSET + THREAD_SIZE;
497 pda->active_mm = &init_mm;
498 pda->mmu_state = 0;
499
500 if (cpu == 0) {
501 /* others are initialized in smpboot.c */
502 pda->pcurrent = &init_task;
503 pda->irqstackptr = boot_cpu_stack;
504 } else {
505 pda->irqstackptr = (char *)
506 __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
507 if (!pda->irqstackptr)
508 panic("cannot allocate irqstack for cpu %d", cpu);
509
510 if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
511 pda->nodenumber = cpu_to_node(cpu);
512 }
513
514 pda->irqstackptr += IRQSTACKSIZE-64;
515 }
516
517 char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
518 DEBUG_STKSZ] __page_aligned_bss;
519
520 extern asmlinkage void ignore_sysret(void);
521
522 /* May not be marked __init: used by software suspend */
523 void syscall_init(void)
524 {
525 /*
526 * LSTAR and STAR live in a bit strange symbiosis.
527 * They both write to the same internal register. STAR allows to
528 * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
529 */
530 wrmsrl(MSR_STAR, ((u64)__USER32_CS)<<48 | ((u64)__KERNEL_CS)<<32);
531 wrmsrl(MSR_LSTAR, system_call);
532 wrmsrl(MSR_CSTAR, ignore_sysret);
533
534 #ifdef CONFIG_IA32_EMULATION
535 syscall32_cpu_init();
536 #endif
537
538 /* Flags to clear on syscall */
539 wrmsrl(MSR_SYSCALL_MASK,
540 X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
541 }
542
543 void __cpuinit check_efer(void)
544 {
545 unsigned long efer;
546
547 rdmsrl(MSR_EFER, efer);
548 if (!(efer & EFER_NX) || do_not_nx)
549 __supported_pte_mask &= ~_PAGE_NX;
550 }
551
552 unsigned long kernel_eflags;
553
554 /*
555 * Copies of the original ist values from the tss are only accessed during
556 * debugging, no special alignment required.
557 */
558 DEFINE_PER_CPU(struct orig_ist, orig_ist);
559
560 /*
561 * cpu_init() initializes state that is per-CPU. Some data is already
562 * initialized (naturally) in the bootstrap process, such as the GDT
563 * and IDT. We reload them nevertheless, this function acts as a
564 * 'CPU state barrier', nothing should get across.
565 * A lot of state is already set up in PDA init.
566 */
567 void __cpuinit cpu_init(void)
568 {
569 int cpu = stack_smp_processor_id();
570 struct tss_struct *t = &per_cpu(init_tss, cpu);
571 struct orig_ist *orig_ist = &per_cpu(orig_ist, cpu);
572 unsigned long v;
573 char *estacks = NULL;
574 struct task_struct *me;
575 int i;
576
577 /* CPU 0 is initialised in head64.c */
578 if (cpu != 0)
579 pda_init(cpu);
580 else
581 estacks = boot_exception_stacks;
582
583 me = current;
584
585 if (cpu_test_and_set(cpu, cpu_initialized))
586 panic("CPU#%d already initialized!\n", cpu);
587
588 printk(KERN_INFO "Initializing CPU#%d\n", cpu);
589
590 clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
591
592 /*
593 * Initialize the per-CPU GDT with the boot GDT,
594 * and set up the GDT descriptor:
595 */
596
597 switch_to_new_gdt();
598 load_idt((const struct desc_ptr *)&idt_descr);
599
600 memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
601 syscall_init();
602
603 wrmsrl(MSR_FS_BASE, 0);
604 wrmsrl(MSR_KERNEL_GS_BASE, 0);
605 barrier();
606
607 check_efer();
608
609 /*
610 * set up and load the per-CPU TSS
611 */
612 for (v = 0; v < N_EXCEPTION_STACKS; v++) {
613 static const unsigned int order[N_EXCEPTION_STACKS] = {
614 [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
615 [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
616 };
617 if (cpu) {
618 estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
619 if (!estacks)
620 panic("Cannot allocate exception stack %ld %d\n",
621 v, cpu);
622 }
623 estacks += PAGE_SIZE << order[v];
624 orig_ist->ist[v] = t->x86_tss.ist[v] = (unsigned long)estacks;
625 }
626
627 t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
628 /*
629 * <= is required because the CPU will access up to
630 * 8 bits beyond the end of the IO permission bitmap.
631 */
632 for (i = 0; i <= IO_BITMAP_LONGS; i++)
633 t->io_bitmap[i] = ~0UL;
634
635 atomic_inc(&init_mm.mm_count);
636 me->active_mm = &init_mm;
637 if (me->mm)
638 BUG();
639 enter_lazy_tlb(&init_mm, me);
640
641 load_sp0(t, &current->thread);
642 set_tss_desc(cpu, t);
643 load_TR_desc();
644 load_LDT(&init_mm.context);
645
646 #ifdef CONFIG_KGDB
647 /*
648 * If the kgdb is connected no debug regs should be altered. This
649 * is only applicable when KGDB and a KGDB I/O module are built
650 * into the kernel and you are using early debugging with
651 * kgdbwait. KGDB will control the kernel HW breakpoint registers.
652 */
653 if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
654 arch_kgdb_ops.correct_hw_break();
655 else {
656 #endif
657 /*
658 * Clear all 6 debug registers:
659 */
660
661 set_debugreg(0UL, 0);
662 set_debugreg(0UL, 1);
663 set_debugreg(0UL, 2);
664 set_debugreg(0UL, 3);
665 set_debugreg(0UL, 6);
666 set_debugreg(0UL, 7);
667 #ifdef CONFIG_KGDB
668 /* If the kgdb is connected no debug regs should be altered. */
669 }
670 #endif
671
672 fpu_init();
673
674 raw_local_save_flags(kernel_eflags);
675
676 if (is_uv_system())
677 uv_cpu_init();
678 }