1 #include <linux/bootmem.h>
2 #include <linux/linkage.h>
3 #include <linux/bitops.h>
4 #include <linux/kernel.h>
5 #include <linux/export.h>
6 #include <linux/percpu.h>
7 #include <linux/string.h>
8 #include <linux/ctype.h>
9 #include <linux/delay.h>
10 #include <linux/sched/mm.h>
11 #include <linux/sched/clock.h>
12 #include <linux/sched/task.h>
13 #include <linux/init.h>
14 #include <linux/kprobes.h>
15 #include <linux/kgdb.h>
16 #include <linux/smp.h>
18 #include <linux/syscore_ops.h>
20 #include <asm/stackprotector.h>
21 #include <asm/perf_event.h>
22 #include <asm/mmu_context.h>
23 #include <asm/archrandom.h>
24 #include <asm/hypervisor.h>
25 #include <asm/processor.h>
26 #include <asm/tlbflush.h>
27 #include <asm/debugreg.h>
28 #include <asm/sections.h>
29 #include <asm/vsyscall.h>
30 #include <linux/topology.h>
31 #include <linux/cpumask.h>
32 #include <asm/pgtable.h>
33 #include <linux/atomic.h>
34 #include <asm/proto.h>
35 #include <asm/setup.h>
38 #include <asm/fpu/internal.h>
40 #include <asm/hwcap2.h>
41 #include <linux/numa.h>
48 #include <asm/microcode.h>
49 #include <asm/microcode_intel.h>
50 #include <asm/intel-family.h>
51 #include <asm/cpu_device_id.h>
53 #ifdef CONFIG_X86_LOCAL_APIC
54 #include <asm/uv/uv.h>
59 u32 elf_hwcap2 __read_mostly
;
61 /* all of these masks are initialized in setup_cpu_local_masks() */
62 cpumask_var_t cpu_initialized_mask
;
63 cpumask_var_t cpu_callout_mask
;
64 cpumask_var_t cpu_callin_mask
;
66 /* representing cpus for which sibling maps can be computed */
67 cpumask_var_t cpu_sibling_setup_mask
;
69 /* Number of siblings per CPU package */
70 int smp_num_siblings
= 1;
71 EXPORT_SYMBOL(smp_num_siblings
);
73 /* Last level cache ID of each logical CPU */
74 DEFINE_PER_CPU_READ_MOSTLY(u16
, cpu_llc_id
) = BAD_APICID
;
76 /* correctly size the local cpu masks */
77 void __init
setup_cpu_local_masks(void)
79 alloc_bootmem_cpumask_var(&cpu_initialized_mask
);
80 alloc_bootmem_cpumask_var(&cpu_callin_mask
);
81 alloc_bootmem_cpumask_var(&cpu_callout_mask
);
82 alloc_bootmem_cpumask_var(&cpu_sibling_setup_mask
);
85 static void default_init(struct cpuinfo_x86
*c
)
88 cpu_detect_cache_sizes(c
);
90 /* Not much we can do here... */
91 /* Check if at least it has cpuid */
92 if (c
->cpuid_level
== -1) {
93 /* No cpuid. It must be an ancient CPU */
95 strcpy(c
->x86_model_id
, "486");
97 strcpy(c
->x86_model_id
, "386");
102 static const struct cpu_dev default_cpu
= {
103 .c_init
= default_init
,
104 .c_vendor
= "Unknown",
105 .c_x86_vendor
= X86_VENDOR_UNKNOWN
,
108 static const struct cpu_dev
*this_cpu
= &default_cpu
;
110 DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page
, gdt_page
) = { .gdt
= {
113 * We need valid kernel segments for data and code in long mode too
114 * IRET will check the segment types kkeil 2000/10/28
115 * Also sysret mandates a special GDT layout
117 * TLS descriptors are currently at a different place compared to i386.
118 * Hopefully nobody expects them at a fixed place (Wine?)
120 [GDT_ENTRY_KERNEL32_CS
] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
121 [GDT_ENTRY_KERNEL_CS
] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
122 [GDT_ENTRY_KERNEL_DS
] = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
123 [GDT_ENTRY_DEFAULT_USER32_CS
] = GDT_ENTRY_INIT(0xc0fb, 0, 0xfffff),
124 [GDT_ENTRY_DEFAULT_USER_DS
] = GDT_ENTRY_INIT(0xc0f3, 0, 0xfffff),
125 [GDT_ENTRY_DEFAULT_USER_CS
] = GDT_ENTRY_INIT(0xa0fb, 0, 0xfffff),
127 [GDT_ENTRY_KERNEL_CS
] = GDT_ENTRY_INIT(0xc09a, 0, 0xfffff),
128 [GDT_ENTRY_KERNEL_DS
] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
129 [GDT_ENTRY_DEFAULT_USER_CS
] = GDT_ENTRY_INIT(0xc0fa, 0, 0xfffff),
130 [GDT_ENTRY_DEFAULT_USER_DS
] = GDT_ENTRY_INIT(0xc0f2, 0, 0xfffff),
132 * Segments used for calling PnP BIOS have byte granularity.
133 * They code segments and data segments have fixed 64k limits,
134 * the transfer segment sizes are set at run time.
137 [GDT_ENTRY_PNPBIOS_CS32
] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
139 [GDT_ENTRY_PNPBIOS_CS16
] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
141 [GDT_ENTRY_PNPBIOS_DS
] = GDT_ENTRY_INIT(0x0092, 0, 0xffff),
143 [GDT_ENTRY_PNPBIOS_TS1
] = GDT_ENTRY_INIT(0x0092, 0, 0),
145 [GDT_ENTRY_PNPBIOS_TS2
] = GDT_ENTRY_INIT(0x0092, 0, 0),
147 * The APM segments have byte granularity and their bases
148 * are set at run time. All have 64k limits.
151 [GDT_ENTRY_APMBIOS_BASE
] = GDT_ENTRY_INIT(0x409a, 0, 0xffff),
153 [GDT_ENTRY_APMBIOS_BASE
+1] = GDT_ENTRY_INIT(0x009a, 0, 0xffff),
155 [GDT_ENTRY_APMBIOS_BASE
+2] = GDT_ENTRY_INIT(0x4092, 0, 0xffff),
157 [GDT_ENTRY_ESPFIX_SS
] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
158 [GDT_ENTRY_PERCPU
] = GDT_ENTRY_INIT(0xc092, 0, 0xfffff),
159 GDT_STACK_CANARY_INIT
162 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page
);
164 static int __init
x86_mpx_setup(char *s
)
166 /* require an exact match without trailing characters */
170 /* do not emit a message if the feature is not present */
171 if (!boot_cpu_has(X86_FEATURE_MPX
))
174 setup_clear_cpu_cap(X86_FEATURE_MPX
);
175 pr_info("nompx: Intel Memory Protection Extensions (MPX) disabled\n");
178 __setup("nompx", x86_mpx_setup
);
181 static int __init
x86_nopcid_setup(char *s
)
183 /* nopcid doesn't accept parameters */
187 /* do not emit a message if the feature is not present */
188 if (!boot_cpu_has(X86_FEATURE_PCID
))
191 setup_clear_cpu_cap(X86_FEATURE_PCID
);
192 pr_info("nopcid: PCID feature disabled\n");
195 early_param("nopcid", x86_nopcid_setup
);
198 static int __init
x86_noinvpcid_setup(char *s
)
200 /* noinvpcid doesn't accept parameters */
204 /* do not emit a message if the feature is not present */
205 if (!boot_cpu_has(X86_FEATURE_INVPCID
))
208 setup_clear_cpu_cap(X86_FEATURE_INVPCID
);
209 pr_info("noinvpcid: INVPCID feature disabled\n");
212 early_param("noinvpcid", x86_noinvpcid_setup
);
215 static int cachesize_override
= -1;
216 static int disable_x86_serial_nr
= 1;
218 static int __init
cachesize_setup(char *str
)
220 get_option(&str
, &cachesize_override
);
223 __setup("cachesize=", cachesize_setup
);
225 static int __init
x86_sep_setup(char *s
)
227 setup_clear_cpu_cap(X86_FEATURE_SEP
);
230 __setup("nosep", x86_sep_setup
);
232 /* Standard macro to see if a specific flag is changeable */
233 static inline int flag_is_changeable_p(u32 flag
)
238 * Cyrix and IDT cpus allow disabling of CPUID
239 * so the code below may return different results
240 * when it is executed before and after enabling
241 * the CPUID. Add "volatile" to not allow gcc to
242 * optimize the subsequent calls to this function.
244 asm volatile ("pushfl \n\t"
255 : "=&r" (f1
), "=&r" (f2
)
258 return ((f1
^f2
) & flag
) != 0;
261 /* Probe for the CPUID instruction */
262 int have_cpuid_p(void)
264 return flag_is_changeable_p(X86_EFLAGS_ID
);
267 static void squash_the_stupid_serial_number(struct cpuinfo_x86
*c
)
269 unsigned long lo
, hi
;
271 if (!cpu_has(c
, X86_FEATURE_PN
) || !disable_x86_serial_nr
)
274 /* Disable processor serial number: */
276 rdmsr(MSR_IA32_BBL_CR_CTL
, lo
, hi
);
278 wrmsr(MSR_IA32_BBL_CR_CTL
, lo
, hi
);
280 pr_notice("CPU serial number disabled.\n");
281 clear_cpu_cap(c
, X86_FEATURE_PN
);
283 /* Disabling the serial number may affect the cpuid level */
284 c
->cpuid_level
= cpuid_eax(0);
287 static int __init
x86_serial_nr_setup(char *s
)
289 disable_x86_serial_nr
= 0;
292 __setup("serialnumber", x86_serial_nr_setup
);
294 static inline int flag_is_changeable_p(u32 flag
)
298 static inline void squash_the_stupid_serial_number(struct cpuinfo_x86
*c
)
303 static __init
int setup_disable_smep(char *arg
)
305 setup_clear_cpu_cap(X86_FEATURE_SMEP
);
306 /* Check for things that depend on SMEP being enabled: */
307 check_mpx_erratum(&boot_cpu_data
);
310 __setup("nosmep", setup_disable_smep
);
312 static __always_inline
void setup_smep(struct cpuinfo_x86
*c
)
314 if (cpu_has(c
, X86_FEATURE_SMEP
))
315 cr4_set_bits(X86_CR4_SMEP
);
318 static __init
int setup_disable_smap(char *arg
)
320 setup_clear_cpu_cap(X86_FEATURE_SMAP
);
323 __setup("nosmap", setup_disable_smap
);
325 static __always_inline
void setup_smap(struct cpuinfo_x86
*c
)
327 unsigned long eflags
= native_save_fl();
329 /* This should have been cleared long ago */
330 BUG_ON(eflags
& X86_EFLAGS_AC
);
332 if (cpu_has(c
, X86_FEATURE_SMAP
)) {
333 #ifdef CONFIG_X86_SMAP
334 cr4_set_bits(X86_CR4_SMAP
);
336 cr4_clear_bits(X86_CR4_SMAP
);
341 static __always_inline
void setup_umip(struct cpuinfo_x86
*c
)
343 /* Check the boot processor, plus build option for UMIP. */
344 if (!cpu_feature_enabled(X86_FEATURE_UMIP
))
347 /* Check the current processor's cpuid bits. */
348 if (!cpu_has(c
, X86_FEATURE_UMIP
))
351 cr4_set_bits(X86_CR4_UMIP
);
353 pr_info("x86/cpu: Activated the Intel User Mode Instruction Prevention (UMIP) CPU feature\n");
359 * Make sure UMIP is disabled in case it was enabled in a
360 * previous boot (e.g., via kexec).
362 cr4_clear_bits(X86_CR4_UMIP
);
366 * Protection Keys are not available in 32-bit mode.
368 static bool pku_disabled
;
370 static __always_inline
void setup_pku(struct cpuinfo_x86
*c
)
372 /* check the boot processor, plus compile options for PKU: */
373 if (!cpu_feature_enabled(X86_FEATURE_PKU
))
375 /* checks the actual processor's cpuid bits: */
376 if (!cpu_has(c
, X86_FEATURE_PKU
))
381 cr4_set_bits(X86_CR4_PKE
);
383 * Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE
384 * cpuid bit to be set. We need to ensure that we
385 * update that bit in this CPU's "cpu_info".
390 #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
391 static __init
int setup_disable_pku(char *arg
)
394 * Do not clear the X86_FEATURE_PKU bit. All of the
395 * runtime checks are against OSPKE so clearing the
398 * This way, we will see "pku" in cpuinfo, but not
399 * "ospke", which is exactly what we want. It shows
400 * that the CPU has PKU, but the OS has not enabled it.
401 * This happens to be exactly how a system would look
402 * if we disabled the config option.
404 pr_info("x86: 'nopku' specified, disabling Memory Protection Keys\n");
408 __setup("nopku", setup_disable_pku
);
409 #endif /* CONFIG_X86_64 */
412 * Some CPU features depend on higher CPUID levels, which may not always
413 * be available due to CPUID level capping or broken virtualization
414 * software. Add those features to this table to auto-disable them.
416 struct cpuid_dependent_feature
{
421 static const struct cpuid_dependent_feature
422 cpuid_dependent_features
[] = {
423 { X86_FEATURE_MWAIT
, 0x00000005 },
424 { X86_FEATURE_DCA
, 0x00000009 },
425 { X86_FEATURE_XSAVE
, 0x0000000d },
429 static void filter_cpuid_features(struct cpuinfo_x86
*c
, bool warn
)
431 const struct cpuid_dependent_feature
*df
;
433 for (df
= cpuid_dependent_features
; df
->feature
; df
++) {
435 if (!cpu_has(c
, df
->feature
))
438 * Note: cpuid_level is set to -1 if unavailable, but
439 * extended_extended_level is set to 0 if unavailable
440 * and the legitimate extended levels are all negative
441 * when signed; hence the weird messing around with
444 if (!((s32
)df
->level
< 0 ?
445 (u32
)df
->level
> (u32
)c
->extended_cpuid_level
:
446 (s32
)df
->level
> (s32
)c
->cpuid_level
))
449 clear_cpu_cap(c
, df
->feature
);
453 pr_warn("CPU: CPU feature " X86_CAP_FMT
" disabled, no CPUID level 0x%x\n",
454 x86_cap_flag(df
->feature
), df
->level
);
459 * Naming convention should be: <Name> [(<Codename>)]
460 * This table only is used unless init_<vendor>() below doesn't set it;
461 * in particular, if CPUID levels 0x80000002..4 are supported, this
465 /* Look up CPU names by table lookup. */
466 static const char *table_lookup_model(struct cpuinfo_x86
*c
)
469 const struct legacy_cpu_model_info
*info
;
471 if (c
->x86_model
>= 16)
472 return NULL
; /* Range check */
477 info
= this_cpu
->legacy_models
;
479 while (info
->family
) {
480 if (info
->family
== c
->x86
)
481 return info
->model_names
[c
->x86_model
];
485 return NULL
; /* Not found */
488 __u32 cpu_caps_cleared
[NCAPINTS
+ NBUGINTS
];
489 __u32 cpu_caps_set
[NCAPINTS
+ NBUGINTS
];
491 void load_percpu_segment(int cpu
)
494 loadsegment(fs
, __KERNEL_PERCPU
);
496 __loadsegment_simple(gs
, 0);
497 wrmsrl(MSR_GS_BASE
, (unsigned long)per_cpu(irq_stack_union
.gs_base
, cpu
));
499 load_stack_canary_segment();
503 /* The 32-bit entry code needs to find cpu_entry_area. */
504 DEFINE_PER_CPU(struct cpu_entry_area
*, cpu_entry_area
);
509 * Special IST stacks which the CPU switches to when it calls
510 * an IST-marked descriptor entry. Up to 7 stacks (hardware
511 * limit), all of them are 4K, except the debug stack which
514 static const unsigned int exception_stack_sizes
[N_EXCEPTION_STACKS
] = {
515 [0 ... N_EXCEPTION_STACKS
- 1] = EXCEPTION_STKSZ
,
516 [DEBUG_STACK
- 1] = DEBUG_STKSZ
520 /* Load the original GDT from the per-cpu structure */
521 void load_direct_gdt(int cpu
)
523 struct desc_ptr gdt_descr
;
525 gdt_descr
.address
= (long)get_cpu_gdt_rw(cpu
);
526 gdt_descr
.size
= GDT_SIZE
- 1;
527 load_gdt(&gdt_descr
);
529 EXPORT_SYMBOL_GPL(load_direct_gdt
);
531 /* Load a fixmap remapping of the per-cpu GDT */
532 void load_fixmap_gdt(int cpu
)
534 struct desc_ptr gdt_descr
;
536 gdt_descr
.address
= (long)get_cpu_gdt_ro(cpu
);
537 gdt_descr
.size
= GDT_SIZE
- 1;
538 load_gdt(&gdt_descr
);
540 EXPORT_SYMBOL_GPL(load_fixmap_gdt
);
543 * Current gdt points %fs at the "master" per-cpu area: after this,
544 * it's on the real one.
546 void switch_to_new_gdt(int cpu
)
548 /* Load the original GDT */
549 load_direct_gdt(cpu
);
550 /* Reload the per-cpu base */
551 load_percpu_segment(cpu
);
554 static const struct cpu_dev
*cpu_devs
[X86_VENDOR_NUM
] = {};
556 static void get_model_name(struct cpuinfo_x86
*c
)
561 if (c
->extended_cpuid_level
< 0x80000004)
564 v
= (unsigned int *)c
->x86_model_id
;
565 cpuid(0x80000002, &v
[0], &v
[1], &v
[2], &v
[3]);
566 cpuid(0x80000003, &v
[4], &v
[5], &v
[6], &v
[7]);
567 cpuid(0x80000004, &v
[8], &v
[9], &v
[10], &v
[11]);
568 c
->x86_model_id
[48] = 0;
570 /* Trim whitespace */
571 p
= q
= s
= &c
->x86_model_id
[0];
577 /* Note the last non-whitespace index */
587 void detect_num_cpu_cores(struct cpuinfo_x86
*c
)
589 unsigned int eax
, ebx
, ecx
, edx
;
591 c
->x86_max_cores
= 1;
592 if (!IS_ENABLED(CONFIG_SMP
) || c
->cpuid_level
< 4)
595 cpuid_count(4, 0, &eax
, &ebx
, &ecx
, &edx
);
597 c
->x86_max_cores
= (eax
>> 26) + 1;
600 void cpu_detect_cache_sizes(struct cpuinfo_x86
*c
)
602 unsigned int n
, dummy
, ebx
, ecx
, edx
, l2size
;
604 n
= c
->extended_cpuid_level
;
606 if (n
>= 0x80000005) {
607 cpuid(0x80000005, &dummy
, &ebx
, &ecx
, &edx
);
608 c
->x86_cache_size
= (ecx
>>24) + (edx
>>24);
610 /* On K8 L1 TLB is inclusive, so don't count it */
615 if (n
< 0x80000006) /* Some chips just has a large L1. */
618 cpuid(0x80000006, &dummy
, &ebx
, &ecx
, &edx
);
622 c
->x86_tlbsize
+= ((ebx
>> 16) & 0xfff) + (ebx
& 0xfff);
624 /* do processor-specific cache resizing */
625 if (this_cpu
->legacy_cache_size
)
626 l2size
= this_cpu
->legacy_cache_size(c
, l2size
);
628 /* Allow user to override all this if necessary. */
629 if (cachesize_override
!= -1)
630 l2size
= cachesize_override
;
633 return; /* Again, no L2 cache is possible */
636 c
->x86_cache_size
= l2size
;
639 u16 __read_mostly tlb_lli_4k
[NR_INFO
];
640 u16 __read_mostly tlb_lli_2m
[NR_INFO
];
641 u16 __read_mostly tlb_lli_4m
[NR_INFO
];
642 u16 __read_mostly tlb_lld_4k
[NR_INFO
];
643 u16 __read_mostly tlb_lld_2m
[NR_INFO
];
644 u16 __read_mostly tlb_lld_4m
[NR_INFO
];
645 u16 __read_mostly tlb_lld_1g
[NR_INFO
];
647 static void cpu_detect_tlb(struct cpuinfo_x86
*c
)
649 if (this_cpu
->c_detect_tlb
)
650 this_cpu
->c_detect_tlb(c
);
652 pr_info("Last level iTLB entries: 4KB %d, 2MB %d, 4MB %d\n",
653 tlb_lli_4k
[ENTRIES
], tlb_lli_2m
[ENTRIES
],
654 tlb_lli_4m
[ENTRIES
]);
656 pr_info("Last level dTLB entries: 4KB %d, 2MB %d, 4MB %d, 1GB %d\n",
657 tlb_lld_4k
[ENTRIES
], tlb_lld_2m
[ENTRIES
],
658 tlb_lld_4m
[ENTRIES
], tlb_lld_1g
[ENTRIES
]);
661 int detect_ht_early(struct cpuinfo_x86
*c
)
664 u32 eax
, ebx
, ecx
, edx
;
666 if (!cpu_has(c
, X86_FEATURE_HT
))
669 if (cpu_has(c
, X86_FEATURE_CMP_LEGACY
))
672 if (cpu_has(c
, X86_FEATURE_XTOPOLOGY
))
675 cpuid(1, &eax
, &ebx
, &ecx
, &edx
);
677 smp_num_siblings
= (ebx
& 0xff0000) >> 16;
678 if (smp_num_siblings
== 1)
679 pr_info_once("CPU0: Hyper-Threading is disabled\n");
684 void detect_ht(struct cpuinfo_x86
*c
)
687 int index_msb
, core_bits
;
689 if (detect_ht_early(c
) < 0)
692 index_msb
= get_count_order(smp_num_siblings
);
693 c
->phys_proc_id
= apic
->phys_pkg_id(c
->initial_apicid
, index_msb
);
695 smp_num_siblings
= smp_num_siblings
/ c
->x86_max_cores
;
697 index_msb
= get_count_order(smp_num_siblings
);
699 core_bits
= get_count_order(c
->x86_max_cores
);
701 c
->cpu_core_id
= apic
->phys_pkg_id(c
->initial_apicid
, index_msb
) &
702 ((1 << core_bits
) - 1);
706 static void get_cpu_vendor(struct cpuinfo_x86
*c
)
708 char *v
= c
->x86_vendor_id
;
711 for (i
= 0; i
< X86_VENDOR_NUM
; i
++) {
715 if (!strcmp(v
, cpu_devs
[i
]->c_ident
[0]) ||
716 (cpu_devs
[i
]->c_ident
[1] &&
717 !strcmp(v
, cpu_devs
[i
]->c_ident
[1]))) {
719 this_cpu
= cpu_devs
[i
];
720 c
->x86_vendor
= this_cpu
->c_x86_vendor
;
725 pr_err_once("CPU: vendor_id '%s' unknown, using generic init.\n" \
726 "CPU: Your system may be unstable.\n", v
);
728 c
->x86_vendor
= X86_VENDOR_UNKNOWN
;
729 this_cpu
= &default_cpu
;
732 void cpu_detect(struct cpuinfo_x86
*c
)
734 /* Get vendor name */
735 cpuid(0x00000000, (unsigned int *)&c
->cpuid_level
,
736 (unsigned int *)&c
->x86_vendor_id
[0],
737 (unsigned int *)&c
->x86_vendor_id
[8],
738 (unsigned int *)&c
->x86_vendor_id
[4]);
741 /* Intel-defined flags: level 0x00000001 */
742 if (c
->cpuid_level
>= 0x00000001) {
743 u32 junk
, tfms
, cap0
, misc
;
745 cpuid(0x00000001, &tfms
, &misc
, &junk
, &cap0
);
746 c
->x86
= x86_family(tfms
);
747 c
->x86_model
= x86_model(tfms
);
748 c
->x86_stepping
= x86_stepping(tfms
);
750 if (cap0
& (1<<19)) {
751 c
->x86_clflush_size
= ((misc
>> 8) & 0xff) * 8;
752 c
->x86_cache_alignment
= c
->x86_clflush_size
;
757 static void apply_forced_caps(struct cpuinfo_x86
*c
)
761 for (i
= 0; i
< NCAPINTS
+ NBUGINTS
; i
++) {
762 c
->x86_capability
[i
] &= ~cpu_caps_cleared
[i
];
763 c
->x86_capability
[i
] |= cpu_caps_set
[i
];
767 static void init_speculation_control(struct cpuinfo_x86
*c
)
770 * The Intel SPEC_CTRL CPUID bit implies IBRS and IBPB support,
771 * and they also have a different bit for STIBP support. Also,
772 * a hypervisor might have set the individual AMD bits even on
773 * Intel CPUs, for finer-grained selection of what's available.
775 if (cpu_has(c
, X86_FEATURE_SPEC_CTRL
)) {
776 set_cpu_cap(c
, X86_FEATURE_IBRS
);
777 set_cpu_cap(c
, X86_FEATURE_IBPB
);
778 set_cpu_cap(c
, X86_FEATURE_MSR_SPEC_CTRL
);
781 if (cpu_has(c
, X86_FEATURE_INTEL_STIBP
))
782 set_cpu_cap(c
, X86_FEATURE_STIBP
);
784 if (cpu_has(c
, X86_FEATURE_SPEC_CTRL_SSBD
) ||
785 cpu_has(c
, X86_FEATURE_VIRT_SSBD
))
786 set_cpu_cap(c
, X86_FEATURE_SSBD
);
788 if (cpu_has(c
, X86_FEATURE_AMD_IBRS
)) {
789 set_cpu_cap(c
, X86_FEATURE_IBRS
);
790 set_cpu_cap(c
, X86_FEATURE_MSR_SPEC_CTRL
);
793 if (cpu_has(c
, X86_FEATURE_AMD_IBPB
))
794 set_cpu_cap(c
, X86_FEATURE_IBPB
);
796 if (cpu_has(c
, X86_FEATURE_AMD_STIBP
)) {
797 set_cpu_cap(c
, X86_FEATURE_STIBP
);
798 set_cpu_cap(c
, X86_FEATURE_MSR_SPEC_CTRL
);
801 if (cpu_has(c
, X86_FEATURE_AMD_SSBD
)) {
802 set_cpu_cap(c
, X86_FEATURE_SSBD
);
803 set_cpu_cap(c
, X86_FEATURE_MSR_SPEC_CTRL
);
804 clear_cpu_cap(c
, X86_FEATURE_VIRT_SSBD
);
808 void get_cpu_cap(struct cpuinfo_x86
*c
)
810 u32 eax
, ebx
, ecx
, edx
;
812 /* Intel-defined flags: level 0x00000001 */
813 if (c
->cpuid_level
>= 0x00000001) {
814 cpuid(0x00000001, &eax
, &ebx
, &ecx
, &edx
);
816 c
->x86_capability
[CPUID_1_ECX
] = ecx
;
817 c
->x86_capability
[CPUID_1_EDX
] = edx
;
820 /* Thermal and Power Management Leaf: level 0x00000006 (eax) */
821 if (c
->cpuid_level
>= 0x00000006)
822 c
->x86_capability
[CPUID_6_EAX
] = cpuid_eax(0x00000006);
824 /* Additional Intel-defined flags: level 0x00000007 */
825 if (c
->cpuid_level
>= 0x00000007) {
826 cpuid_count(0x00000007, 0, &eax
, &ebx
, &ecx
, &edx
);
827 c
->x86_capability
[CPUID_7_0_EBX
] = ebx
;
828 c
->x86_capability
[CPUID_7_ECX
] = ecx
;
829 c
->x86_capability
[CPUID_7_EDX
] = edx
;
832 /* Extended state features: level 0x0000000d */
833 if (c
->cpuid_level
>= 0x0000000d) {
834 cpuid_count(0x0000000d, 1, &eax
, &ebx
, &ecx
, &edx
);
836 c
->x86_capability
[CPUID_D_1_EAX
] = eax
;
839 /* Additional Intel-defined flags: level 0x0000000F */
840 if (c
->cpuid_level
>= 0x0000000F) {
842 /* QoS sub-leaf, EAX=0Fh, ECX=0 */
843 cpuid_count(0x0000000F, 0, &eax
, &ebx
, &ecx
, &edx
);
844 c
->x86_capability
[CPUID_F_0_EDX
] = edx
;
846 if (cpu_has(c
, X86_FEATURE_CQM_LLC
)) {
847 /* will be overridden if occupancy monitoring exists */
848 c
->x86_cache_max_rmid
= ebx
;
850 /* QoS sub-leaf, EAX=0Fh, ECX=1 */
851 cpuid_count(0x0000000F, 1, &eax
, &ebx
, &ecx
, &edx
);
852 c
->x86_capability
[CPUID_F_1_EDX
] = edx
;
854 if ((cpu_has(c
, X86_FEATURE_CQM_OCCUP_LLC
)) ||
855 ((cpu_has(c
, X86_FEATURE_CQM_MBM_TOTAL
)) ||
856 (cpu_has(c
, X86_FEATURE_CQM_MBM_LOCAL
)))) {
857 c
->x86_cache_max_rmid
= ecx
;
858 c
->x86_cache_occ_scale
= ebx
;
861 c
->x86_cache_max_rmid
= -1;
862 c
->x86_cache_occ_scale
= -1;
866 /* AMD-defined flags: level 0x80000001 */
867 eax
= cpuid_eax(0x80000000);
868 c
->extended_cpuid_level
= eax
;
870 if ((eax
& 0xffff0000) == 0x80000000) {
871 if (eax
>= 0x80000001) {
872 cpuid(0x80000001, &eax
, &ebx
, &ecx
, &edx
);
874 c
->x86_capability
[CPUID_8000_0001_ECX
] = ecx
;
875 c
->x86_capability
[CPUID_8000_0001_EDX
] = edx
;
879 if (c
->extended_cpuid_level
>= 0x80000007) {
880 cpuid(0x80000007, &eax
, &ebx
, &ecx
, &edx
);
882 c
->x86_capability
[CPUID_8000_0007_EBX
] = ebx
;
886 if (c
->extended_cpuid_level
>= 0x80000008) {
887 cpuid(0x80000008, &eax
, &ebx
, &ecx
, &edx
);
889 c
->x86_virt_bits
= (eax
>> 8) & 0xff;
890 c
->x86_phys_bits
= eax
& 0xff;
891 c
->x86_capability
[CPUID_8000_0008_EBX
] = ebx
;
894 else if (cpu_has(c
, X86_FEATURE_PAE
) || cpu_has(c
, X86_FEATURE_PSE36
))
895 c
->x86_phys_bits
= 36;
898 if (c
->extended_cpuid_level
>= 0x8000000a)
899 c
->x86_capability
[CPUID_8000_000A_EDX
] = cpuid_edx(0x8000000a);
901 init_scattered_cpuid_features(c
);
902 init_speculation_control(c
);
905 * Clear/Set all flags overridden by options, after probe.
906 * This needs to happen each time we re-probe, which may happen
907 * several times during CPU initialization.
909 apply_forced_caps(c
);
912 static void identify_cpu_without_cpuid(struct cpuinfo_x86
*c
)
918 * First of all, decide if this is a 486 or higher
919 * It's a 486 if we can modify the AC flag
921 if (flag_is_changeable_p(X86_EFLAGS_AC
))
926 for (i
= 0; i
< X86_VENDOR_NUM
; i
++)
927 if (cpu_devs
[i
] && cpu_devs
[i
]->c_identify
) {
928 c
->x86_vendor_id
[0] = 0;
929 cpu_devs
[i
]->c_identify(c
);
930 if (c
->x86_vendor_id
[0]) {
938 static const __initconst
struct x86_cpu_id cpu_no_speculation
[] = {
939 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SALTWELL
, X86_FEATURE_ANY
},
940 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SALTWELL_TABLET
, X86_FEATURE_ANY
},
941 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_BONNELL_MID
, X86_FEATURE_ANY
},
942 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SALTWELL_MID
, X86_FEATURE_ANY
},
943 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_BONNELL
, X86_FEATURE_ANY
},
944 { X86_VENDOR_CENTAUR
, 5 },
945 { X86_VENDOR_INTEL
, 5 },
946 { X86_VENDOR_NSC
, 5 },
947 { X86_VENDOR_ANY
, 4 },
951 static const __initconst
struct x86_cpu_id cpu_no_meltdown
[] = {
956 /* Only list CPUs which speculate but are non susceptible to SSB */
957 static const __initconst
struct x86_cpu_id cpu_no_spec_store_bypass
[] = {
958 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SILVERMONT
},
959 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_AIRMONT
},
960 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SILVERMONT_X
},
961 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SILVERMONT_MID
},
962 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_CORE_YONAH
},
963 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_XEON_PHI_KNL
},
964 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_XEON_PHI_KNM
},
965 { X86_VENDOR_AMD
, 0x12, },
966 { X86_VENDOR_AMD
, 0x11, },
967 { X86_VENDOR_AMD
, 0x10, },
968 { X86_VENDOR_AMD
, 0xf, },
972 static const __initconst
struct x86_cpu_id cpu_no_l1tf
[] = {
973 /* in addition to cpu_no_speculation */
974 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SILVERMONT
},
975 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SILVERMONT_X
},
976 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_AIRMONT
},
977 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_SILVERMONT_MID
},
978 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_AIRMONT_MID
},
979 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_GOLDMONT
},
980 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_GOLDMONT_X
},
981 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_ATOM_GOLDMONT_PLUS
},
982 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_XEON_PHI_KNL
},
983 { X86_VENDOR_INTEL
, 6, INTEL_FAM6_XEON_PHI_KNM
},
987 static void __init
cpu_set_bug_bits(struct cpuinfo_x86
*c
)
991 if (x86_match_cpu(cpu_no_speculation
))
994 setup_force_cpu_bug(X86_BUG_SPECTRE_V1
);
995 setup_force_cpu_bug(X86_BUG_SPECTRE_V2
);
997 if (cpu_has(c
, X86_FEATURE_ARCH_CAPABILITIES
))
998 rdmsrl(MSR_IA32_ARCH_CAPABILITIES
, ia32_cap
);
1000 if (!x86_match_cpu(cpu_no_spec_store_bypass
) &&
1001 !(ia32_cap
& ARCH_CAP_SSB_NO
) &&
1002 !cpu_has(c
, X86_FEATURE_AMD_SSB_NO
))
1003 setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS
);
1005 if (ia32_cap
& ARCH_CAP_IBRS_ALL
)
1006 setup_force_cpu_cap(X86_FEATURE_IBRS_ENHANCED
);
1008 if (x86_match_cpu(cpu_no_meltdown
))
1011 /* Rogue Data Cache Load? No! */
1012 if (ia32_cap
& ARCH_CAP_RDCL_NO
)
1015 setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN
);
1017 if (x86_match_cpu(cpu_no_l1tf
))
1020 setup_force_cpu_bug(X86_BUG_L1TF
);
1024 * Do minimum CPU detection early.
1025 * Fields really needed: vendor, cpuid_level, family, model, mask,
1027 * The others are not touched to avoid unwanted side effects.
1029 * WARNING: this function is only called on the boot CPU. Don't add code
1030 * here that is supposed to run on all CPUs.
1032 static void __init
early_identify_cpu(struct cpuinfo_x86
*c
)
1034 #ifdef CONFIG_X86_64
1035 c
->x86_clflush_size
= 64;
1036 c
->x86_phys_bits
= 36;
1037 c
->x86_virt_bits
= 48;
1039 c
->x86_clflush_size
= 32;
1040 c
->x86_phys_bits
= 32;
1041 c
->x86_virt_bits
= 32;
1043 c
->x86_cache_alignment
= c
->x86_clflush_size
;
1045 memset(&c
->x86_capability
, 0, sizeof c
->x86_capability
);
1046 c
->extended_cpuid_level
= 0;
1048 /* cyrix could have cpuid enabled via c_identify()*/
1049 if (have_cpuid_p()) {
1053 c
->x86_cache_bits
= c
->x86_phys_bits
;
1054 setup_force_cpu_cap(X86_FEATURE_CPUID
);
1056 if (this_cpu
->c_early_init
)
1057 this_cpu
->c_early_init(c
);
1060 filter_cpuid_features(c
, false);
1062 if (this_cpu
->c_bsp_init
)
1063 this_cpu
->c_bsp_init(c
);
1065 identify_cpu_without_cpuid(c
);
1066 setup_clear_cpu_cap(X86_FEATURE_CPUID
);
1069 setup_force_cpu_cap(X86_FEATURE_ALWAYS
);
1071 cpu_set_bug_bits(c
);
1073 fpu__init_system(c
);
1075 #ifdef CONFIG_X86_32
1077 * Regardless of whether PCID is enumerated, the SDM says
1078 * that it can't be enabled in 32-bit mode.
1080 setup_clear_cpu_cap(X86_FEATURE_PCID
);
1084 void __init
early_cpu_init(void)
1086 const struct cpu_dev
*const *cdev
;
1089 #ifdef CONFIG_PROCESSOR_SELECT
1090 pr_info("KERNEL supported cpus:\n");
1093 for (cdev
= __x86_cpu_dev_start
; cdev
< __x86_cpu_dev_end
; cdev
++) {
1094 const struct cpu_dev
*cpudev
= *cdev
;
1096 if (count
>= X86_VENDOR_NUM
)
1098 cpu_devs
[count
] = cpudev
;
1101 #ifdef CONFIG_PROCESSOR_SELECT
1105 for (j
= 0; j
< 2; j
++) {
1106 if (!cpudev
->c_ident
[j
])
1108 pr_info(" %s %s\n", cpudev
->c_vendor
,
1109 cpudev
->c_ident
[j
]);
1114 early_identify_cpu(&boot_cpu_data
);
1118 * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
1119 * unfortunately, that's not true in practice because of early VIA
1120 * chips and (more importantly) broken virtualizers that are not easy
1121 * to detect. In the latter case it doesn't even *fail* reliably, so
1122 * probing for it doesn't even work. Disable it completely on 32-bit
1123 * unless we can find a reliable way to detect all the broken cases.
1124 * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
1126 static void detect_nopl(struct cpuinfo_x86
*c
)
1128 #ifdef CONFIG_X86_32
1129 clear_cpu_cap(c
, X86_FEATURE_NOPL
);
1131 set_cpu_cap(c
, X86_FEATURE_NOPL
);
1135 static void detect_null_seg_behavior(struct cpuinfo_x86
*c
)
1137 #ifdef CONFIG_X86_64
1139 * Empirically, writing zero to a segment selector on AMD does
1140 * not clear the base, whereas writing zero to a segment
1141 * selector on Intel does clear the base. Intel's behavior
1142 * allows slightly faster context switches in the common case
1143 * where GS is unused by the prev and next threads.
1145 * Since neither vendor documents this anywhere that I can see,
1146 * detect it directly instead of hardcoding the choice by
1149 * I've designated AMD's behavior as the "bug" because it's
1150 * counterintuitive and less friendly.
1153 unsigned long old_base
, tmp
;
1154 rdmsrl(MSR_FS_BASE
, old_base
);
1155 wrmsrl(MSR_FS_BASE
, 1);
1157 rdmsrl(MSR_FS_BASE
, tmp
);
1159 set_cpu_bug(c
, X86_BUG_NULL_SEG
);
1160 wrmsrl(MSR_FS_BASE
, old_base
);
1164 static void generic_identify(struct cpuinfo_x86
*c
)
1166 c
->extended_cpuid_level
= 0;
1168 if (!have_cpuid_p())
1169 identify_cpu_without_cpuid(c
);
1171 /* cyrix could have cpuid enabled via c_identify()*/
1172 if (!have_cpuid_p())
1181 c
->x86_cache_bits
= c
->x86_phys_bits
;
1183 if (c
->cpuid_level
>= 0x00000001) {
1184 c
->initial_apicid
= (cpuid_ebx(1) >> 24) & 0xFF;
1185 #ifdef CONFIG_X86_32
1187 c
->apicid
= apic
->phys_pkg_id(c
->initial_apicid
, 0);
1189 c
->apicid
= c
->initial_apicid
;
1192 c
->phys_proc_id
= c
->initial_apicid
;
1195 get_model_name(c
); /* Default name */
1199 detect_null_seg_behavior(c
);
1202 * ESPFIX is a strange bug. All real CPUs have it. Paravirt
1203 * systems that run Linux at CPL > 0 may or may not have the
1204 * issue, but, even if they have the issue, there's absolutely
1205 * nothing we can do about it because we can't use the real IRET
1208 * NB: For the time being, only 32-bit kernels support
1209 * X86_BUG_ESPFIX as such. 64-bit kernels directly choose
1210 * whether to apply espfix using paravirt hooks. If any
1211 * non-paravirt system ever shows up that does *not* have the
1212 * ESPFIX issue, we can change this.
1214 #ifdef CONFIG_X86_32
1215 # ifdef CONFIG_PARAVIRT
1217 extern void native_iret(void);
1218 if (pv_cpu_ops
.iret
== native_iret
)
1219 set_cpu_bug(c
, X86_BUG_ESPFIX
);
1222 set_cpu_bug(c
, X86_BUG_ESPFIX
);
1227 static void x86_init_cache_qos(struct cpuinfo_x86
*c
)
1230 * The heavy lifting of max_rmid and cache_occ_scale are handled
1231 * in get_cpu_cap(). Here we just set the max_rmid for the boot_cpu
1232 * in case CQM bits really aren't there in this CPU.
1234 if (c
!= &boot_cpu_data
) {
1235 boot_cpu_data
.x86_cache_max_rmid
=
1236 min(boot_cpu_data
.x86_cache_max_rmid
,
1237 c
->x86_cache_max_rmid
);
1242 * Validate that ACPI/mptables have the same information about the
1243 * effective APIC id and update the package map.
1245 static void validate_apic_and_package_id(struct cpuinfo_x86
*c
)
1248 unsigned int apicid
, cpu
= smp_processor_id();
1250 apicid
= apic
->cpu_present_to_apicid(cpu
);
1252 if (apicid
!= c
->apicid
) {
1253 pr_err(FW_BUG
"CPU%u: APIC id mismatch. Firmware: %x APIC: %x\n",
1254 cpu
, apicid
, c
->initial_apicid
);
1256 BUG_ON(topology_update_package_map(c
->phys_proc_id
, cpu
));
1258 c
->logical_proc_id
= 0;
1263 * This does the hard work of actually picking apart the CPU stuff...
1265 static void identify_cpu(struct cpuinfo_x86
*c
)
1269 c
->loops_per_jiffy
= loops_per_jiffy
;
1270 c
->x86_cache_size
= 0;
1271 c
->x86_vendor
= X86_VENDOR_UNKNOWN
;
1272 c
->x86_model
= c
->x86_stepping
= 0; /* So far unknown... */
1273 c
->x86_vendor_id
[0] = '\0'; /* Unset */
1274 c
->x86_model_id
[0] = '\0'; /* Unset */
1275 c
->x86_max_cores
= 1;
1276 c
->x86_coreid_bits
= 0;
1278 #ifdef CONFIG_X86_64
1279 c
->x86_clflush_size
= 64;
1280 c
->x86_phys_bits
= 36;
1281 c
->x86_virt_bits
= 48;
1283 c
->cpuid_level
= -1; /* CPUID not detected */
1284 c
->x86_clflush_size
= 32;
1285 c
->x86_phys_bits
= 32;
1286 c
->x86_virt_bits
= 32;
1288 c
->x86_cache_alignment
= c
->x86_clflush_size
;
1289 memset(&c
->x86_capability
, 0, sizeof c
->x86_capability
);
1291 generic_identify(c
);
1293 if (this_cpu
->c_identify
)
1294 this_cpu
->c_identify(c
);
1296 /* Clear/Set all flags overridden by options, after probe */
1297 apply_forced_caps(c
);
1299 #ifdef CONFIG_X86_64
1300 c
->apicid
= apic
->phys_pkg_id(c
->initial_apicid
, 0);
1304 * Vendor-specific initialization. In this section we
1305 * canonicalize the feature flags, meaning if there are
1306 * features a certain CPU supports which CPUID doesn't
1307 * tell us, CPUID claiming incorrect flags, or other bugs,
1308 * we handle them here.
1310 * At the end of this section, c->x86_capability better
1311 * indicate the features this CPU genuinely supports!
1313 if (this_cpu
->c_init
)
1314 this_cpu
->c_init(c
);
1316 /* Disable the PN if appropriate */
1317 squash_the_stupid_serial_number(c
);
1319 /* Set up SMEP/SMAP/UMIP */
1325 * The vendor-specific functions might have changed features.
1326 * Now we do "generic changes."
1329 /* Filter out anything that depends on CPUID levels we don't have */
1330 filter_cpuid_features(c
, true);
1332 /* If the model name is still unset, do table lookup. */
1333 if (!c
->x86_model_id
[0]) {
1335 p
= table_lookup_model(c
);
1337 strcpy(c
->x86_model_id
, p
);
1339 /* Last resort... */
1340 sprintf(c
->x86_model_id
, "%02x/%02x",
1341 c
->x86
, c
->x86_model
);
1344 #ifdef CONFIG_X86_64
1349 x86_init_cache_qos(c
);
1353 * Clear/Set all flags overridden by options, need do it
1354 * before following smp all cpus cap AND.
1356 apply_forced_caps(c
);
1359 * On SMP, boot_cpu_data holds the common feature set between
1360 * all CPUs; so make sure that we indicate which features are
1361 * common between the CPUs. The first time this routine gets
1362 * executed, c == &boot_cpu_data.
1364 if (c
!= &boot_cpu_data
) {
1365 /* AND the already accumulated flags with these */
1366 for (i
= 0; i
< NCAPINTS
; i
++)
1367 boot_cpu_data
.x86_capability
[i
] &= c
->x86_capability
[i
];
1369 /* OR, i.e. replicate the bug flags */
1370 for (i
= NCAPINTS
; i
< NCAPINTS
+ NBUGINTS
; i
++)
1371 c
->x86_capability
[i
] |= boot_cpu_data
.x86_capability
[i
];
1374 /* Init Machine Check Exception if available. */
1377 select_idle_routine(c
);
1380 numa_add_cpu(smp_processor_id());
1385 * Set up the CPU state needed to execute SYSENTER/SYSEXIT instructions
1386 * on 32-bit kernels:
1388 #ifdef CONFIG_X86_32
1389 void enable_sep_cpu(void)
1391 struct tss_struct
*tss
;
1394 if (!boot_cpu_has(X86_FEATURE_SEP
))
1398 tss
= &per_cpu(cpu_tss_rw
, cpu
);
1401 * We cache MSR_IA32_SYSENTER_CS's value in the TSS's ss1 field --
1402 * see the big comment in struct x86_hw_tss's definition.
1405 tss
->x86_tss
.ss1
= __KERNEL_CS
;
1406 wrmsr(MSR_IA32_SYSENTER_CS
, tss
->x86_tss
.ss1
, 0);
1407 wrmsr(MSR_IA32_SYSENTER_ESP
, (unsigned long)(cpu_entry_stack(cpu
) + 1), 0);
1408 wrmsr(MSR_IA32_SYSENTER_EIP
, (unsigned long)entry_SYSENTER_32
, 0);
1414 void __init
identify_boot_cpu(void)
1416 identify_cpu(&boot_cpu_data
);
1417 #ifdef CONFIG_X86_32
1421 cpu_detect_tlb(&boot_cpu_data
);
1424 void identify_secondary_cpu(struct cpuinfo_x86
*c
)
1426 BUG_ON(c
== &boot_cpu_data
);
1428 #ifdef CONFIG_X86_32
1432 validate_apic_and_package_id(c
);
1433 x86_spec_ctrl_setup_ap();
1436 static __init
int setup_noclflush(char *arg
)
1438 setup_clear_cpu_cap(X86_FEATURE_CLFLUSH
);
1439 setup_clear_cpu_cap(X86_FEATURE_CLFLUSHOPT
);
1442 __setup("noclflush", setup_noclflush
);
1444 void print_cpu_info(struct cpuinfo_x86
*c
)
1446 const char *vendor
= NULL
;
1448 if (c
->x86_vendor
< X86_VENDOR_NUM
) {
1449 vendor
= this_cpu
->c_vendor
;
1451 if (c
->cpuid_level
>= 0)
1452 vendor
= c
->x86_vendor_id
;
1455 if (vendor
&& !strstr(c
->x86_model_id
, vendor
))
1456 pr_cont("%s ", vendor
);
1458 if (c
->x86_model_id
[0])
1459 pr_cont("%s", c
->x86_model_id
);
1461 pr_cont("%d86", c
->x86
);
1463 pr_cont(" (family: 0x%x, model: 0x%x", c
->x86
, c
->x86_model
);
1465 if (c
->x86_stepping
|| c
->cpuid_level
>= 0)
1466 pr_cont(", stepping: 0x%x)\n", c
->x86_stepping
);
1472 * clearcpuid= was already parsed in fpu__init_parse_early_param.
1473 * But we need to keep a dummy __setup around otherwise it would
1474 * show up as an environment variable for init.
1476 static __init
int setup_clearcpuid(char *arg
)
1480 __setup("clearcpuid=", setup_clearcpuid
);
1482 #ifdef CONFIG_X86_64
1483 DEFINE_PER_CPU_FIRST(union irq_stack_union
,
1484 irq_stack_union
) __aligned(PAGE_SIZE
) __visible
;
1487 * The following percpu variables are hot. Align current_task to
1488 * cacheline size such that they fall in the same cacheline.
1490 DEFINE_PER_CPU(struct task_struct
*, current_task
) ____cacheline_aligned
=
1492 EXPORT_PER_CPU_SYMBOL(current_task
);
1494 DEFINE_PER_CPU(char *, irq_stack_ptr
) =
1495 init_per_cpu_var(irq_stack_union
.irq_stack
) + IRQ_STACK_SIZE
;
1497 DEFINE_PER_CPU(unsigned int, irq_count
) __visible
= -1;
1499 DEFINE_PER_CPU(int, __preempt_count
) = INIT_PREEMPT_COUNT
;
1500 EXPORT_PER_CPU_SYMBOL(__preempt_count
);
1502 /* May not be marked __init: used by software suspend */
1503 void syscall_init(void)
1505 extern char _entry_trampoline
[];
1506 extern char entry_SYSCALL_64_trampoline
[];
1508 int cpu
= smp_processor_id();
1509 unsigned long SYSCALL64_entry_trampoline
=
1510 (unsigned long)get_cpu_entry_area(cpu
)->entry_trampoline
+
1511 (entry_SYSCALL_64_trampoline
- _entry_trampoline
);
1513 wrmsr(MSR_STAR
, 0, (__USER32_CS
<< 16) | __KERNEL_CS
);
1514 if (static_cpu_has(X86_FEATURE_PTI
))
1515 wrmsrl(MSR_LSTAR
, SYSCALL64_entry_trampoline
);
1517 wrmsrl(MSR_LSTAR
, (unsigned long)entry_SYSCALL_64
);
1519 #ifdef CONFIG_IA32_EMULATION
1520 wrmsrl(MSR_CSTAR
, (unsigned long)entry_SYSCALL_compat
);
1522 * This only works on Intel CPUs.
1523 * On AMD CPUs these MSRs are 32-bit, CPU truncates MSR_IA32_SYSENTER_EIP.
1524 * This does not cause SYSENTER to jump to the wrong location, because
1525 * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
1527 wrmsrl_safe(MSR_IA32_SYSENTER_CS
, (u64
)__KERNEL_CS
);
1528 wrmsrl_safe(MSR_IA32_SYSENTER_ESP
, (unsigned long)(cpu_entry_stack(cpu
) + 1));
1529 wrmsrl_safe(MSR_IA32_SYSENTER_EIP
, (u64
)entry_SYSENTER_compat
);
1531 wrmsrl(MSR_CSTAR
, (unsigned long)ignore_sysret
);
1532 wrmsrl_safe(MSR_IA32_SYSENTER_CS
, (u64
)GDT_ENTRY_INVALID_SEG
);
1533 wrmsrl_safe(MSR_IA32_SYSENTER_ESP
, 0ULL);
1534 wrmsrl_safe(MSR_IA32_SYSENTER_EIP
, 0ULL);
1537 /* Flags to clear on syscall */
1538 wrmsrl(MSR_SYSCALL_MASK
,
1539 X86_EFLAGS_TF
|X86_EFLAGS_DF
|X86_EFLAGS_IF
|
1540 X86_EFLAGS_IOPL
|X86_EFLAGS_AC
|X86_EFLAGS_NT
);
1544 * Copies of the original ist values from the tss are only accessed during
1545 * debugging, no special alignment required.
1547 DEFINE_PER_CPU(struct orig_ist
, orig_ist
);
1549 static DEFINE_PER_CPU(unsigned long, debug_stack_addr
);
1550 DEFINE_PER_CPU(int, debug_stack_usage
);
1552 int is_debug_stack(unsigned long addr
)
1554 return __this_cpu_read(debug_stack_usage
) ||
1555 (addr
<= __this_cpu_read(debug_stack_addr
) &&
1556 addr
> (__this_cpu_read(debug_stack_addr
) - DEBUG_STKSZ
));
1558 NOKPROBE_SYMBOL(is_debug_stack
);
1560 DEFINE_PER_CPU(u32
, debug_idt_ctr
);
1562 void debug_stack_set_zero(void)
1564 this_cpu_inc(debug_idt_ctr
);
1567 NOKPROBE_SYMBOL(debug_stack_set_zero
);
1569 void debug_stack_reset(void)
1571 if (WARN_ON(!this_cpu_read(debug_idt_ctr
)))
1573 if (this_cpu_dec_return(debug_idt_ctr
) == 0)
1576 NOKPROBE_SYMBOL(debug_stack_reset
);
1578 #else /* CONFIG_X86_64 */
1580 DEFINE_PER_CPU(struct task_struct
*, current_task
) = &init_task
;
1581 EXPORT_PER_CPU_SYMBOL(current_task
);
1582 DEFINE_PER_CPU(int, __preempt_count
) = INIT_PREEMPT_COUNT
;
1583 EXPORT_PER_CPU_SYMBOL(__preempt_count
);
1586 * On x86_32, vm86 modifies tss.sp0, so sp0 isn't a reliable way to find
1587 * the top of the kernel stack. Use an extra percpu variable to track the
1588 * top of the kernel stack directly.
1590 DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack
) =
1591 (unsigned long)&init_thread_union
+ THREAD_SIZE
;
1592 EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack
);
1594 #ifdef CONFIG_CC_STACKPROTECTOR
1595 DEFINE_PER_CPU_ALIGNED(struct stack_canary
, stack_canary
);
1598 #endif /* CONFIG_X86_64 */
1601 * Clear all 6 debug registers:
1603 static void clear_all_debug_regs(void)
1607 for (i
= 0; i
< 8; i
++) {
1608 /* Ignore db4, db5 */
1609 if ((i
== 4) || (i
== 5))
1618 * Restore debug regs if using kgdbwait and you have a kernel debugger
1619 * connection established.
1621 static void dbg_restore_debug_regs(void)
1623 if (unlikely(kgdb_connected
&& arch_kgdb_ops
.correct_hw_break
))
1624 arch_kgdb_ops
.correct_hw_break();
1626 #else /* ! CONFIG_KGDB */
1627 #define dbg_restore_debug_regs()
1628 #endif /* ! CONFIG_KGDB */
1630 static void wait_for_master_cpu(int cpu
)
1634 * wait for ACK from master CPU before continuing
1635 * with AP initialization
1637 WARN_ON(cpumask_test_and_set_cpu(cpu
, cpu_initialized_mask
));
1638 while (!cpumask_test_cpu(cpu
, cpu_callout_mask
))
1644 * cpu_init() initializes state that is per-CPU. Some data is already
1645 * initialized (naturally) in the bootstrap process, such as the GDT
1646 * and IDT. We reload them nevertheless, this function acts as a
1647 * 'CPU state barrier', nothing should get across.
1648 * A lot of state is already set up in PDA init for 64 bit
1650 #ifdef CONFIG_X86_64
1654 struct orig_ist
*oist
;
1655 struct task_struct
*me
;
1656 struct tss_struct
*t
;
1658 int cpu
= raw_smp_processor_id();
1661 wait_for_master_cpu(cpu
);
1664 * Initialize the CR4 shadow before doing anything that could
1672 t
= &per_cpu(cpu_tss_rw
, cpu
);
1673 oist
= &per_cpu(orig_ist
, cpu
);
1676 if (this_cpu_read(numa_node
) == 0 &&
1677 early_cpu_to_node(cpu
) != NUMA_NO_NODE
)
1678 set_numa_node(early_cpu_to_node(cpu
));
1683 pr_debug("Initializing CPU#%d\n", cpu
);
1685 cr4_clear_bits(X86_CR4_VME
|X86_CR4_PVI
|X86_CR4_TSD
|X86_CR4_DE
);
1688 * Initialize the per-CPU GDT with the boot GDT,
1689 * and set up the GDT descriptor:
1692 switch_to_new_gdt(cpu
);
1697 memset(me
->thread
.tls_array
, 0, GDT_ENTRY_TLS_ENTRIES
* 8);
1700 wrmsrl(MSR_FS_BASE
, 0);
1701 wrmsrl(MSR_KERNEL_GS_BASE
, 0);
1708 * set up and load the per-CPU TSS
1710 if (!oist
->ist
[0]) {
1711 char *estacks
= get_cpu_entry_area(cpu
)->exception_stacks
;
1713 for (v
= 0; v
< N_EXCEPTION_STACKS
; v
++) {
1714 estacks
+= exception_stack_sizes
[v
];
1715 oist
->ist
[v
] = t
->x86_tss
.ist
[v
] =
1716 (unsigned long)estacks
;
1717 if (v
== DEBUG_STACK
-1)
1718 per_cpu(debug_stack_addr
, cpu
) = (unsigned long)estacks
;
1722 t
->x86_tss
.io_bitmap_base
= IO_BITMAP_OFFSET
;
1725 * <= is required because the CPU will access up to
1726 * 8 bits beyond the end of the IO permission bitmap.
1728 for (i
= 0; i
<= IO_BITMAP_LONGS
; i
++)
1729 t
->io_bitmap
[i
] = ~0UL;
1732 me
->active_mm
= &init_mm
;
1734 initialize_tlbstate_and_flush();
1735 enter_lazy_tlb(&init_mm
, me
);
1738 * Initialize the TSS. sp0 points to the entry trampoline stack
1739 * regardless of what task is running.
1741 set_tss_desc(cpu
, &get_cpu_entry_area(cpu
)->tss
.x86_tss
);
1743 load_sp0((unsigned long)(cpu_entry_stack(cpu
) + 1));
1745 load_mm_ldt(&init_mm
);
1747 clear_all_debug_regs();
1748 dbg_restore_debug_regs();
1755 load_fixmap_gdt(cpu
);
1762 int cpu
= smp_processor_id();
1763 struct task_struct
*curr
= current
;
1764 struct tss_struct
*t
= &per_cpu(cpu_tss_rw
, cpu
);
1766 wait_for_master_cpu(cpu
);
1769 * Initialize the CR4 shadow before doing anything that could
1774 show_ucode_info_early();
1776 pr_info("Initializing CPU#%d\n", cpu
);
1778 if (cpu_feature_enabled(X86_FEATURE_VME
) ||
1779 boot_cpu_has(X86_FEATURE_TSC
) ||
1780 boot_cpu_has(X86_FEATURE_DE
))
1781 cr4_clear_bits(X86_CR4_VME
|X86_CR4_PVI
|X86_CR4_TSD
|X86_CR4_DE
);
1784 switch_to_new_gdt(cpu
);
1787 * Set up and load the per-CPU TSS and LDT
1790 curr
->active_mm
= &init_mm
;
1792 initialize_tlbstate_and_flush();
1793 enter_lazy_tlb(&init_mm
, curr
);
1796 * Initialize the TSS. sp0 points to the entry trampoline stack
1797 * regardless of what task is running.
1799 set_tss_desc(cpu
, &get_cpu_entry_area(cpu
)->tss
.x86_tss
);
1801 load_sp0((unsigned long)(cpu_entry_stack(cpu
) + 1));
1803 load_mm_ldt(&init_mm
);
1805 t
->x86_tss
.io_bitmap_base
= IO_BITMAP_OFFSET
;
1807 #ifdef CONFIG_DOUBLEFAULT
1808 /* Set up doublefault TSS pointer in the GDT */
1809 __set_tss_desc(cpu
, GDT_ENTRY_DOUBLEFAULT_TSS
, &doublefault_tss
);
1812 clear_all_debug_regs();
1813 dbg_restore_debug_regs();
1817 load_fixmap_gdt(cpu
);
1821 static void bsp_resume(void)
1823 if (this_cpu
->c_bsp_resume
)
1824 this_cpu
->c_bsp_resume(&boot_cpu_data
);
1827 static struct syscore_ops cpu_syscore_ops
= {
1828 .resume
= bsp_resume
,
1831 static int __init
init_cpu_syscore(void)
1833 register_syscore_ops(&cpu_syscore_ops
);
1836 core_initcall(init_cpu_syscore
);
1839 * The microcode loader calls this upon late microcode load to recheck features,
1840 * only when microcode has been updated. Caller holds microcode_mutex and CPU
1843 void microcode_check(void)
1845 struct cpuinfo_x86 info
;
1847 perf_check_microcode();
1849 /* Reload CPUID max function as it might've changed. */
1850 info
.cpuid_level
= cpuid_eax(0);
1853 * Copy all capability leafs to pick up the synthetic ones so that
1854 * memcmp() below doesn't fail on that. The ones coming from CPUID will
1855 * get overwritten in get_cpu_cap().
1857 memcpy(&info
.x86_capability
, &boot_cpu_data
.x86_capability
, sizeof(info
.x86_capability
));
1861 if (!memcmp(&info
.x86_capability
, &boot_cpu_data
.x86_capability
, sizeof(info
.x86_capability
)))
1864 pr_warn("x86/CPU: CPU features have changed after loading microcode, but might not take effect.\n");
1865 pr_warn("x86/CPU: Please consider either early loading through initrd/built-in or a potential BIOS update.\n");