xref: /openbmc/linux/arch/x86/include/asm/processor.h (revision 34fa67e7)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_PROCESSOR_H
3 #define _ASM_X86_PROCESSOR_H
4 
5 #include <asm/processor-flags.h>
6 
7 /* Forward declaration, a strange C thing */
8 struct task_struct;
9 struct mm_struct;
10 struct io_bitmap;
11 struct vm86;
12 
13 #include <asm/math_emu.h>
14 #include <asm/segment.h>
15 #include <asm/types.h>
16 #include <uapi/asm/sigcontext.h>
17 #include <asm/current.h>
18 #include <asm/cpufeatures.h>
19 #include <asm/page.h>
20 #include <asm/pgtable_types.h>
21 #include <asm/percpu.h>
22 #include <asm/msr.h>
23 #include <asm/desc_defs.h>
24 #include <asm/nops.h>
25 #include <asm/special_insns.h>
26 #include <asm/fpu/types.h>
27 #include <asm/unwind_hints.h>
28 #include <asm/vmxfeatures.h>
29 #include <asm/vdso/processor.h>
30 
31 #include <linux/personality.h>
32 #include <linux/cache.h>
33 #include <linux/threads.h>
34 #include <linux/math64.h>
35 #include <linux/err.h>
36 #include <linux/irqflags.h>
37 #include <linux/mem_encrypt.h>
38 
39 /*
40  * We handle most unaligned accesses in hardware.  On the other hand
41  * unaligned DMA can be quite expensive on some Nehalem processors.
42  *
43  * Based on this we disable the IP header alignment in network drivers.
44  */
45 #define NET_IP_ALIGN	0
46 
47 #define HBP_NUM 4
48 
49 /*
50  * These alignment constraints are for performance in the vSMP case,
51  * but in the task_struct case we must also meet hardware imposed
52  * alignment requirements of the FPU state:
53  */
54 #ifdef CONFIG_X86_VSMP
55 # define ARCH_MIN_TASKALIGN		(1 << INTERNODE_CACHE_SHIFT)
56 # define ARCH_MIN_MMSTRUCT_ALIGN	(1 << INTERNODE_CACHE_SHIFT)
57 #else
58 # define ARCH_MIN_TASKALIGN		__alignof__(union fpregs_state)
59 # define ARCH_MIN_MMSTRUCT_ALIGN	0
60 #endif
61 
62 enum tlb_infos {
63 	ENTRIES,
64 	NR_INFO
65 };
66 
67 extern u16 __read_mostly tlb_lli_4k[NR_INFO];
68 extern u16 __read_mostly tlb_lli_2m[NR_INFO];
69 extern u16 __read_mostly tlb_lli_4m[NR_INFO];
70 extern u16 __read_mostly tlb_lld_4k[NR_INFO];
71 extern u16 __read_mostly tlb_lld_2m[NR_INFO];
72 extern u16 __read_mostly tlb_lld_4m[NR_INFO];
73 extern u16 __read_mostly tlb_lld_1g[NR_INFO];
74 
75 /*
76  *  CPU type and hardware bug flags. Kept separately for each CPU.
77  *  Members of this structure are referenced in head_32.S, so think twice
78  *  before touching them. [mj]
79  */
80 
81 struct cpuinfo_x86 {
82 	__u8			x86;		/* CPU family */
83 	__u8			x86_vendor;	/* CPU vendor */
84 	__u8			x86_model;
85 	__u8			x86_stepping;
86 #ifdef CONFIG_X86_64
87 	/* Number of 4K pages in DTLB/ITLB combined(in pages): */
88 	int			x86_tlbsize;
89 #endif
90 #ifdef CONFIG_X86_VMX_FEATURE_NAMES
91 	__u32			vmx_capability[NVMXINTS];
92 #endif
93 	__u8			x86_virt_bits;
94 	__u8			x86_phys_bits;
95 	/* CPUID returned core id bits: */
96 	__u8			x86_coreid_bits;
97 	__u8			cu_id;
98 	/* Max extended CPUID function supported: */
99 	__u32			extended_cpuid_level;
100 	/* Maximum supported CPUID level, -1=no CPUID: */
101 	int			cpuid_level;
102 	/*
103 	 * Align to size of unsigned long because the x86_capability array
104 	 * is passed to bitops which require the alignment. Use unnamed
105 	 * union to enforce the array is aligned to size of unsigned long.
106 	 */
107 	union {
108 		__u32		x86_capability[NCAPINTS + NBUGINTS];
109 		unsigned long	x86_capability_alignment;
110 	};
111 	char			x86_vendor_id[16];
112 	char			x86_model_id[64];
113 	/* in KB - valid for CPUS which support this call: */
114 	unsigned int		x86_cache_size;
115 	int			x86_cache_alignment;	/* In bytes */
116 	/* Cache QoS architectural values, valid only on the BSP: */
117 	int			x86_cache_max_rmid;	/* max index */
118 	int			x86_cache_occ_scale;	/* scale to bytes */
119 	int			x86_cache_mbm_width_offset;
120 	int			x86_power;
121 	unsigned long		loops_per_jiffy;
122 	/* cpuid returned max cores value: */
123 	u16			x86_max_cores;
124 	u16			apicid;
125 	u16			initial_apicid;
126 	u16			x86_clflush_size;
127 	/* number of cores as seen by the OS: */
128 	u16			booted_cores;
129 	/* Physical processor id: */
130 	u16			phys_proc_id;
131 	/* Logical processor id: */
132 	u16			logical_proc_id;
133 	/* Core id: */
134 	u16			cpu_core_id;
135 	u16			cpu_die_id;
136 	u16			logical_die_id;
137 	/* Index into per_cpu list: */
138 	u16			cpu_index;
139 	/*  Is SMT active on this core? */
140 	bool			smt_active;
141 	u32			microcode;
142 	/* Address space bits used by the cache internally */
143 	u8			x86_cache_bits;
144 	unsigned		initialized : 1;
145 } __randomize_layout;
146 
147 struct cpuid_regs {
148 	u32 eax, ebx, ecx, edx;
149 };
150 
151 enum cpuid_regs_idx {
152 	CPUID_EAX = 0,
153 	CPUID_EBX,
154 	CPUID_ECX,
155 	CPUID_EDX,
156 };
157 
158 #define X86_VENDOR_INTEL	0
159 #define X86_VENDOR_CYRIX	1
160 #define X86_VENDOR_AMD		2
161 #define X86_VENDOR_UMC		3
162 #define X86_VENDOR_CENTAUR	5
163 #define X86_VENDOR_TRANSMETA	7
164 #define X86_VENDOR_NSC		8
165 #define X86_VENDOR_HYGON	9
166 #define X86_VENDOR_ZHAOXIN	10
167 #define X86_VENDOR_VORTEX	11
168 #define X86_VENDOR_NUM		12
169 
170 #define X86_VENDOR_UNKNOWN	0xff
171 
172 /*
173  * capabilities of CPUs
174  */
175 extern struct cpuinfo_x86	boot_cpu_data;
176 extern struct cpuinfo_x86	new_cpu_data;
177 
178 extern __u32			cpu_caps_cleared[NCAPINTS + NBUGINTS];
179 extern __u32			cpu_caps_set[NCAPINTS + NBUGINTS];
180 
181 #ifdef CONFIG_SMP
182 DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
183 #define cpu_data(cpu)		per_cpu(cpu_info, cpu)
184 #else
185 #define cpu_info		boot_cpu_data
186 #define cpu_data(cpu)		boot_cpu_data
187 #endif
188 
189 extern const struct seq_operations cpuinfo_op;
190 
191 #define cache_line_size()	(boot_cpu_data.x86_cache_alignment)
192 
193 extern void cpu_detect(struct cpuinfo_x86 *c);
194 
195 static inline unsigned long long l1tf_pfn_limit(void)
196 {
197 	return BIT_ULL(boot_cpu_data.x86_cache_bits - 1 - PAGE_SHIFT);
198 }
199 
200 extern void early_cpu_init(void);
201 extern void identify_boot_cpu(void);
202 extern void identify_secondary_cpu(struct cpuinfo_x86 *);
203 extern void print_cpu_info(struct cpuinfo_x86 *);
204 void print_cpu_msr(struct cpuinfo_x86 *);
205 
206 #ifdef CONFIG_X86_32
207 extern int have_cpuid_p(void);
208 #else
209 static inline int have_cpuid_p(void)
210 {
211 	return 1;
212 }
213 #endif
214 static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
215 				unsigned int *ecx, unsigned int *edx)
216 {
217 	/* ecx is often an input as well as an output. */
218 	asm volatile("cpuid"
219 	    : "=a" (*eax),
220 	      "=b" (*ebx),
221 	      "=c" (*ecx),
222 	      "=d" (*edx)
223 	    : "0" (*eax), "2" (*ecx)
224 	    : "memory");
225 }
226 
227 #define native_cpuid_reg(reg)					\
228 static inline unsigned int native_cpuid_##reg(unsigned int op)	\
229 {								\
230 	unsigned int eax = op, ebx, ecx = 0, edx;		\
231 								\
232 	native_cpuid(&eax, &ebx, &ecx, &edx);			\
233 								\
234 	return reg;						\
235 }
236 
237 /*
238  * Native CPUID functions returning a single datum.
239  */
240 native_cpuid_reg(eax)
241 native_cpuid_reg(ebx)
242 native_cpuid_reg(ecx)
243 native_cpuid_reg(edx)
244 
245 /*
246  * Friendlier CR3 helpers.
247  */
248 static inline unsigned long read_cr3_pa(void)
249 {
250 	return __read_cr3() & CR3_ADDR_MASK;
251 }
252 
253 static inline unsigned long native_read_cr3_pa(void)
254 {
255 	return __native_read_cr3() & CR3_ADDR_MASK;
256 }
257 
258 static inline void load_cr3(pgd_t *pgdir)
259 {
260 	write_cr3(__sme_pa(pgdir));
261 }
262 
263 /*
264  * Note that while the legacy 'TSS' name comes from 'Task State Segment',
265  * on modern x86 CPUs the TSS also holds information important to 64-bit mode,
266  * unrelated to the task-switch mechanism:
267  */
268 #ifdef CONFIG_X86_32
269 /* This is the TSS defined by the hardware. */
270 struct x86_hw_tss {
271 	unsigned short		back_link, __blh;
272 	unsigned long		sp0;
273 	unsigned short		ss0, __ss0h;
274 	unsigned long		sp1;
275 
276 	/*
277 	 * We don't use ring 1, so ss1 is a convenient scratch space in
278 	 * the same cacheline as sp0.  We use ss1 to cache the value in
279 	 * MSR_IA32_SYSENTER_CS.  When we context switch
280 	 * MSR_IA32_SYSENTER_CS, we first check if the new value being
281 	 * written matches ss1, and, if it's not, then we wrmsr the new
282 	 * value and update ss1.
283 	 *
284 	 * The only reason we context switch MSR_IA32_SYSENTER_CS is
285 	 * that we set it to zero in vm86 tasks to avoid corrupting the
286 	 * stack if we were to go through the sysenter path from vm86
287 	 * mode.
288 	 */
289 	unsigned short		ss1;	/* MSR_IA32_SYSENTER_CS */
290 
291 	unsigned short		__ss1h;
292 	unsigned long		sp2;
293 	unsigned short		ss2, __ss2h;
294 	unsigned long		__cr3;
295 	unsigned long		ip;
296 	unsigned long		flags;
297 	unsigned long		ax;
298 	unsigned long		cx;
299 	unsigned long		dx;
300 	unsigned long		bx;
301 	unsigned long		sp;
302 	unsigned long		bp;
303 	unsigned long		si;
304 	unsigned long		di;
305 	unsigned short		es, __esh;
306 	unsigned short		cs, __csh;
307 	unsigned short		ss, __ssh;
308 	unsigned short		ds, __dsh;
309 	unsigned short		fs, __fsh;
310 	unsigned short		gs, __gsh;
311 	unsigned short		ldt, __ldth;
312 	unsigned short		trace;
313 	unsigned short		io_bitmap_base;
314 
315 } __attribute__((packed));
316 #else
317 struct x86_hw_tss {
318 	u32			reserved1;
319 	u64			sp0;
320 	u64			sp1;
321 
322 	/*
323 	 * Since Linux does not use ring 2, the 'sp2' slot is unused by
324 	 * hardware.  entry_SYSCALL_64 uses it as scratch space to stash
325 	 * the user RSP value.
326 	 */
327 	u64			sp2;
328 
329 	u64			reserved2;
330 	u64			ist[7];
331 	u32			reserved3;
332 	u32			reserved4;
333 	u16			reserved5;
334 	u16			io_bitmap_base;
335 
336 } __attribute__((packed));
337 #endif
338 
339 /*
340  * IO-bitmap sizes:
341  */
342 #define IO_BITMAP_BITS			65536
343 #define IO_BITMAP_BYTES			(IO_BITMAP_BITS / BITS_PER_BYTE)
344 #define IO_BITMAP_LONGS			(IO_BITMAP_BYTES / sizeof(long))
345 
346 #define IO_BITMAP_OFFSET_VALID_MAP				\
347 	(offsetof(struct tss_struct, io_bitmap.bitmap) -	\
348 	 offsetof(struct tss_struct, x86_tss))
349 
350 #define IO_BITMAP_OFFSET_VALID_ALL				\
351 	(offsetof(struct tss_struct, io_bitmap.mapall) -	\
352 	 offsetof(struct tss_struct, x86_tss))
353 
354 #ifdef CONFIG_X86_IOPL_IOPERM
355 /*
356  * sizeof(unsigned long) coming from an extra "long" at the end of the
357  * iobitmap. The limit is inclusive, i.e. the last valid byte.
358  */
359 # define __KERNEL_TSS_LIMIT	\
360 	(IO_BITMAP_OFFSET_VALID_ALL + IO_BITMAP_BYTES + \
361 	 sizeof(unsigned long) - 1)
362 #else
363 # define __KERNEL_TSS_LIMIT	\
364 	(offsetof(struct tss_struct, x86_tss) + sizeof(struct x86_hw_tss) - 1)
365 #endif
366 
367 /* Base offset outside of TSS_LIMIT so unpriviledged IO causes #GP */
368 #define IO_BITMAP_OFFSET_INVALID	(__KERNEL_TSS_LIMIT + 1)
369 
370 struct entry_stack {
371 	char	stack[PAGE_SIZE];
372 };
373 
374 struct entry_stack_page {
375 	struct entry_stack stack;
376 } __aligned(PAGE_SIZE);
377 
378 /*
379  * All IO bitmap related data stored in the TSS:
380  */
381 struct x86_io_bitmap {
382 	/* The sequence number of the last active bitmap. */
383 	u64			prev_sequence;
384 
385 	/*
386 	 * Store the dirty size of the last io bitmap offender. The next
387 	 * one will have to do the cleanup as the switch out to a non io
388 	 * bitmap user will just set x86_tss.io_bitmap_base to a value
389 	 * outside of the TSS limit. So for sane tasks there is no need to
390 	 * actually touch the io_bitmap at all.
391 	 */
392 	unsigned int		prev_max;
393 
394 	/*
395 	 * The extra 1 is there because the CPU will access an
396 	 * additional byte beyond the end of the IO permission
397 	 * bitmap. The extra byte must be all 1 bits, and must
398 	 * be within the limit.
399 	 */
400 	unsigned long		bitmap[IO_BITMAP_LONGS + 1];
401 
402 	/*
403 	 * Special I/O bitmap to emulate IOPL(3). All bytes zero,
404 	 * except the additional byte at the end.
405 	 */
406 	unsigned long		mapall[IO_BITMAP_LONGS + 1];
407 };
408 
409 struct tss_struct {
410 	/*
411 	 * The fixed hardware portion.  This must not cross a page boundary
412 	 * at risk of violating the SDM's advice and potentially triggering
413 	 * errata.
414 	 */
415 	struct x86_hw_tss	x86_tss;
416 
417 	struct x86_io_bitmap	io_bitmap;
418 } __aligned(PAGE_SIZE);
419 
420 DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw);
421 
422 /* Per CPU interrupt stacks */
423 struct irq_stack {
424 	char		stack[IRQ_STACK_SIZE];
425 } __aligned(IRQ_STACK_SIZE);
426 
427 DECLARE_PER_CPU(unsigned long, cpu_current_top_of_stack);
428 
429 #ifdef CONFIG_X86_64
430 struct fixed_percpu_data {
431 	/*
432 	 * GCC hardcodes the stack canary as %gs:40.  Since the
433 	 * irq_stack is the object at %gs:0, we reserve the bottom
434 	 * 48 bytes of the irq stack for the canary.
435 	 *
436 	 * Once we are willing to require -mstack-protector-guard-symbol=
437 	 * support for x86_64 stackprotector, we can get rid of this.
438 	 */
439 	char		gs_base[40];
440 	unsigned long	stack_canary;
441 };
442 
443 DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible;
444 DECLARE_INIT_PER_CPU(fixed_percpu_data);
445 
446 static inline unsigned long cpu_kernelmode_gs_base(int cpu)
447 {
448 	return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
449 }
450 
451 DECLARE_PER_CPU(void *, hardirq_stack_ptr);
452 DECLARE_PER_CPU(bool, hardirq_stack_inuse);
453 extern asmlinkage void ignore_sysret(void);
454 
455 /* Save actual FS/GS selectors and bases to current->thread */
456 void current_save_fsgs(void);
457 #else	/* X86_64 */
458 #ifdef CONFIG_STACKPROTECTOR
459 DECLARE_PER_CPU(unsigned long, __stack_chk_guard);
460 #endif
461 DECLARE_PER_CPU(struct irq_stack *, hardirq_stack_ptr);
462 DECLARE_PER_CPU(struct irq_stack *, softirq_stack_ptr);
463 #endif	/* !X86_64 */
464 
465 struct perf_event;
466 
467 struct thread_struct {
468 	/* Cached TLS descriptors: */
469 	struct desc_struct	tls_array[GDT_ENTRY_TLS_ENTRIES];
470 #ifdef CONFIG_X86_32
471 	unsigned long		sp0;
472 #endif
473 	unsigned long		sp;
474 #ifdef CONFIG_X86_32
475 	unsigned long		sysenter_cs;
476 #else
477 	unsigned short		es;
478 	unsigned short		ds;
479 	unsigned short		fsindex;
480 	unsigned short		gsindex;
481 #endif
482 
483 #ifdef CONFIG_X86_64
484 	unsigned long		fsbase;
485 	unsigned long		gsbase;
486 #else
487 	/*
488 	 * XXX: this could presumably be unsigned short.  Alternatively,
489 	 * 32-bit kernels could be taught to use fsindex instead.
490 	 */
491 	unsigned long fs;
492 	unsigned long gs;
493 #endif
494 
495 	/* Save middle states of ptrace breakpoints */
496 	struct perf_event	*ptrace_bps[HBP_NUM];
497 	/* Debug status used for traps, single steps, etc... */
498 	unsigned long           virtual_dr6;
499 	/* Keep track of the exact dr7 value set by the user */
500 	unsigned long           ptrace_dr7;
501 	/* Fault info: */
502 	unsigned long		cr2;
503 	unsigned long		trap_nr;
504 	unsigned long		error_code;
505 #ifdef CONFIG_VM86
506 	/* Virtual 86 mode info */
507 	struct vm86		*vm86;
508 #endif
509 	/* IO permissions: */
510 	struct io_bitmap	*io_bitmap;
511 
512 	/*
513 	 * IOPL. Privilege level dependent I/O permission which is
514 	 * emulated via the I/O bitmap to prevent user space from disabling
515 	 * interrupts.
516 	 */
517 	unsigned long		iopl_emul;
518 
519 	unsigned int		iopl_warn:1;
520 	unsigned int		sig_on_uaccess_err:1;
521 
522 	/*
523 	 * Protection Keys Register for Userspace.  Loaded immediately on
524 	 * context switch. Store it in thread_struct to avoid a lookup in
525 	 * the tasks's FPU xstate buffer. This value is only valid when a
526 	 * task is scheduled out. For 'current' the authoritative source of
527 	 * PKRU is the hardware itself.
528 	 */
529 	u32			pkru;
530 
531 	/* Floating point and extended processor state */
532 	struct fpu		fpu;
533 	/*
534 	 * WARNING: 'fpu' is dynamically-sized.  It *MUST* be at
535 	 * the end.
536 	 */
537 };
538 
539 extern void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size);
540 
541 static inline void arch_thread_struct_whitelist(unsigned long *offset,
542 						unsigned long *size)
543 {
544 	fpu_thread_struct_whitelist(offset, size);
545 }
546 
547 static inline void
548 native_load_sp0(unsigned long sp0)
549 {
550 	this_cpu_write(cpu_tss_rw.x86_tss.sp0, sp0);
551 }
552 
553 static __always_inline void native_swapgs(void)
554 {
555 #ifdef CONFIG_X86_64
556 	asm volatile("swapgs" ::: "memory");
557 #endif
558 }
559 
560 static inline unsigned long current_top_of_stack(void)
561 {
562 	/*
563 	 *  We can't read directly from tss.sp0: sp0 on x86_32 is special in
564 	 *  and around vm86 mode and sp0 on x86_64 is special because of the
565 	 *  entry trampoline.
566 	 */
567 	return this_cpu_read_stable(cpu_current_top_of_stack);
568 }
569 
570 static inline bool on_thread_stack(void)
571 {
572 	return (unsigned long)(current_top_of_stack() -
573 			       current_stack_pointer) < THREAD_SIZE;
574 }
575 
576 #ifdef CONFIG_PARAVIRT_XXL
577 #include <asm/paravirt.h>
578 #else
579 #define __cpuid			native_cpuid
580 
581 static inline void load_sp0(unsigned long sp0)
582 {
583 	native_load_sp0(sp0);
584 }
585 
586 #endif /* CONFIG_PARAVIRT_XXL */
587 
588 /* Free all resources held by a thread. */
589 extern void release_thread(struct task_struct *);
590 
591 unsigned long __get_wchan(struct task_struct *p);
592 
593 /*
594  * Generic CPUID function
595  * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
596  * resulting in stale register contents being returned.
597  */
598 static inline void cpuid(unsigned int op,
599 			 unsigned int *eax, unsigned int *ebx,
600 			 unsigned int *ecx, unsigned int *edx)
601 {
602 	*eax = op;
603 	*ecx = 0;
604 	__cpuid(eax, ebx, ecx, edx);
605 }
606 
607 /* Some CPUID calls want 'count' to be placed in ecx */
608 static inline void cpuid_count(unsigned int op, int count,
609 			       unsigned int *eax, unsigned int *ebx,
610 			       unsigned int *ecx, unsigned int *edx)
611 {
612 	*eax = op;
613 	*ecx = count;
614 	__cpuid(eax, ebx, ecx, edx);
615 }
616 
617 /*
618  * CPUID functions returning a single datum
619  */
620 static inline unsigned int cpuid_eax(unsigned int op)
621 {
622 	unsigned int eax, ebx, ecx, edx;
623 
624 	cpuid(op, &eax, &ebx, &ecx, &edx);
625 
626 	return eax;
627 }
628 
629 static inline unsigned int cpuid_ebx(unsigned int op)
630 {
631 	unsigned int eax, ebx, ecx, edx;
632 
633 	cpuid(op, &eax, &ebx, &ecx, &edx);
634 
635 	return ebx;
636 }
637 
638 static inline unsigned int cpuid_ecx(unsigned int op)
639 {
640 	unsigned int eax, ebx, ecx, edx;
641 
642 	cpuid(op, &eax, &ebx, &ecx, &edx);
643 
644 	return ecx;
645 }
646 
647 static inline unsigned int cpuid_edx(unsigned int op)
648 {
649 	unsigned int eax, ebx, ecx, edx;
650 
651 	cpuid(op, &eax, &ebx, &ecx, &edx);
652 
653 	return edx;
654 }
655 
656 extern void select_idle_routine(const struct cpuinfo_x86 *c);
657 extern void amd_e400_c1e_apic_setup(void);
658 
659 extern unsigned long		boot_option_idle_override;
660 
661 enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
662 			 IDLE_POLL};
663 
664 extern void enable_sep_cpu(void);
665 extern int sysenter_setup(void);
666 
667 
668 /* Defined in head.S */
669 extern struct desc_ptr		early_gdt_descr;
670 
671 extern void switch_to_new_gdt(int);
672 extern void load_direct_gdt(int);
673 extern void load_fixmap_gdt(int);
674 extern void load_percpu_segment(int);
675 extern void cpu_init(void);
676 extern void cpu_init_secondary(void);
677 extern void cpu_init_exception_handling(void);
678 extern void cr4_init(void);
679 
680 static inline unsigned long get_debugctlmsr(void)
681 {
682 	unsigned long debugctlmsr = 0;
683 
684 #ifndef CONFIG_X86_DEBUGCTLMSR
685 	if (boot_cpu_data.x86 < 6)
686 		return 0;
687 #endif
688 	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
689 
690 	return debugctlmsr;
691 }
692 
693 static inline void update_debugctlmsr(unsigned long debugctlmsr)
694 {
695 #ifndef CONFIG_X86_DEBUGCTLMSR
696 	if (boot_cpu_data.x86 < 6)
697 		return;
698 #endif
699 	wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
700 }
701 
702 extern void set_task_blockstep(struct task_struct *task, bool on);
703 
704 /* Boot loader type from the setup header: */
705 extern int			bootloader_type;
706 extern int			bootloader_version;
707 
708 extern char			ignore_fpu_irq;
709 
710 #define HAVE_ARCH_PICK_MMAP_LAYOUT 1
711 #define ARCH_HAS_PREFETCHW
712 #define ARCH_HAS_SPINLOCK_PREFETCH
713 
714 #ifdef CONFIG_X86_32
715 # define BASE_PREFETCH		""
716 # define ARCH_HAS_PREFETCH
717 #else
718 # define BASE_PREFETCH		"prefetcht0 %P1"
719 #endif
720 
721 /*
722  * Prefetch instructions for Pentium III (+) and AMD Athlon (+)
723  *
724  * It's not worth to care about 3dnow prefetches for the K6
725  * because they are microcoded there and very slow.
726  */
727 static inline void prefetch(const void *x)
728 {
729 	alternative_input(BASE_PREFETCH, "prefetchnta %P1",
730 			  X86_FEATURE_XMM,
731 			  "m" (*(const char *)x));
732 }
733 
734 /*
735  * 3dnow prefetch to get an exclusive cache line.
736  * Useful for spinlocks to avoid one state transition in the
737  * cache coherency protocol:
738  */
739 static __always_inline void prefetchw(const void *x)
740 {
741 	alternative_input(BASE_PREFETCH, "prefetchw %P1",
742 			  X86_FEATURE_3DNOWPREFETCH,
743 			  "m" (*(const char *)x));
744 }
745 
746 static inline void spin_lock_prefetch(const void *x)
747 {
748 	prefetchw(x);
749 }
750 
751 #define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \
752 			   TOP_OF_KERNEL_STACK_PADDING)
753 
754 #define task_top_of_stack(task) ((unsigned long)(task_pt_regs(task) + 1))
755 
756 #define task_pt_regs(task) \
757 ({									\
758 	unsigned long __ptr = (unsigned long)task_stack_page(task);	\
759 	__ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;		\
760 	((struct pt_regs *)__ptr) - 1;					\
761 })
762 
763 #ifdef CONFIG_X86_32
764 #define INIT_THREAD  {							  \
765 	.sp0			= TOP_OF_INIT_STACK,			  \
766 	.sysenter_cs		= __KERNEL_CS,				  \
767 }
768 
769 #define KSTK_ESP(task)		(task_pt_regs(task)->sp)
770 
771 #else
772 #define INIT_THREAD { }
773 
774 extern unsigned long KSTK_ESP(struct task_struct *task);
775 
776 #endif /* CONFIG_X86_64 */
777 
778 extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
779 					       unsigned long new_sp);
780 
781 /*
782  * This decides where the kernel will search for a free chunk of vm
783  * space during mmap's.
784  */
785 #define __TASK_UNMAPPED_BASE(task_size)	(PAGE_ALIGN(task_size / 3))
786 #define TASK_UNMAPPED_BASE		__TASK_UNMAPPED_BASE(TASK_SIZE_LOW)
787 
788 #define KSTK_EIP(task)		(task_pt_regs(task)->ip)
789 
790 /* Get/set a process' ability to use the timestamp counter instruction */
791 #define GET_TSC_CTL(adr)	get_tsc_mode((adr))
792 #define SET_TSC_CTL(val)	set_tsc_mode((val))
793 
794 extern int get_tsc_mode(unsigned long adr);
795 extern int set_tsc_mode(unsigned int val);
796 
797 DECLARE_PER_CPU(u64, msr_misc_features_shadow);
798 
799 extern u16 get_llc_id(unsigned int cpu);
800 
801 #ifdef CONFIG_CPU_SUP_AMD
802 extern u32 amd_get_nodes_per_socket(void);
803 extern u32 amd_get_highest_perf(void);
804 #else
805 static inline u32 amd_get_nodes_per_socket(void)	{ return 0; }
806 static inline u32 amd_get_highest_perf(void)		{ return 0; }
807 #endif
808 
809 #define for_each_possible_hypervisor_cpuid_base(function) \
810 	for (function = 0x40000000; function < 0x40010000; function += 0x100)
811 
812 static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
813 {
814 	uint32_t base, eax, signature[3];
815 
816 	for_each_possible_hypervisor_cpuid_base(base) {
817 		cpuid(base, &eax, &signature[0], &signature[1], &signature[2]);
818 
819 		if (!memcmp(sig, signature, 12) &&
820 		    (leaves == 0 || ((eax - base) >= leaves)))
821 			return base;
822 	}
823 
824 	return 0;
825 }
826 
827 extern unsigned long arch_align_stack(unsigned long sp);
828 void free_init_pages(const char *what, unsigned long begin, unsigned long end);
829 extern void free_kernel_image_pages(const char *what, void *begin, void *end);
830 
831 void default_idle(void);
832 #ifdef	CONFIG_XEN
833 bool xen_set_default_idle(void);
834 #else
835 #define xen_set_default_idle 0
836 #endif
837 
838 void stop_this_cpu(void *dummy);
839 void microcode_check(void);
840 
841 enum l1tf_mitigations {
842 	L1TF_MITIGATION_OFF,
843 	L1TF_MITIGATION_FLUSH_NOWARN,
844 	L1TF_MITIGATION_FLUSH,
845 	L1TF_MITIGATION_FLUSH_NOSMT,
846 	L1TF_MITIGATION_FULL,
847 	L1TF_MITIGATION_FULL_FORCE
848 };
849 
850 extern enum l1tf_mitigations l1tf_mitigation;
851 
852 enum mds_mitigations {
853 	MDS_MITIGATION_OFF,
854 	MDS_MITIGATION_FULL,
855 	MDS_MITIGATION_VMWERV,
856 };
857 
858 #ifdef CONFIG_X86_SGX
859 int arch_memory_failure(unsigned long pfn, int flags);
860 #define arch_memory_failure arch_memory_failure
861 
862 bool arch_is_platform_page(u64 paddr);
863 #define arch_is_platform_page arch_is_platform_page
864 #endif
865 
866 #endif /* _ASM_X86_PROCESSOR_H */
867