xref: /linux/arch/x86/include/asm/processor.h (revision ff5ccdb8d5bd242f1064c6f7996603e47e28d095)
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/cpuid/types.h>
20 #include <asm/page.h>
21 #include <asm/pgtable_types.h>
22 #include <asm/percpu.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 #include <asm/shstk.h>
31 
32 #include <linux/personality.h>
33 #include <linux/cache.h>
34 #include <linux/threads.h>
35 #include <linux/math64.h>
36 #include <linux/err.h>
37 #include <linux/irqflags.h>
38 #include <linux/mem_encrypt.h>
39 
40 /*
41  * We handle most unaligned accesses in hardware.  On the other hand
42  * unaligned DMA can be quite expensive on some Nehalem processors.
43  *
44  * Based on this we disable the IP header alignment in network drivers.
45  */
46 #define NET_IP_ALIGN	0
47 
48 #define HBP_NUM 4
49 
50 /*
51  * These alignment constraints are for performance in the vSMP case,
52  * but in the task_struct case we must also meet hardware imposed
53  * alignment requirements of the FPU state:
54  */
55 #ifdef CONFIG_X86_VSMP
56 # define ARCH_MIN_TASKALIGN		(1 << INTERNODE_CACHE_SHIFT)
57 # define ARCH_MIN_MMSTRUCT_ALIGN	(1 << INTERNODE_CACHE_SHIFT)
58 #else
59 # define ARCH_MIN_TASKALIGN		__alignof__(union fpregs_state)
60 # define ARCH_MIN_MMSTRUCT_ALIGN	0
61 #endif
62 
63 extern u16 __read_mostly tlb_lli_4k;
64 extern u16 __read_mostly tlb_lli_2m;
65 extern u16 __read_mostly tlb_lli_4m;
66 extern u16 __read_mostly tlb_lld_4k;
67 extern u16 __read_mostly tlb_lld_2m;
68 extern u16 __read_mostly tlb_lld_4m;
69 extern u16 __read_mostly tlb_lld_1g;
70 
71 /*
72  * CPU type and hardware bug flags. Kept separately for each CPU.
73  */
74 
75 struct cpuinfo_topology {
76 	// Real APIC ID read from the local APIC
77 	u32			apicid;
78 	// The initial APIC ID provided by CPUID
79 	u32			initial_apicid;
80 
81 	// Physical package ID
82 	u32			pkg_id;
83 
84 	// Physical die ID on AMD, Relative on Intel
85 	u32			die_id;
86 
87 	// Compute unit ID - AMD specific
88 	u32			cu_id;
89 
90 	// Core ID relative to the package
91 	u32			core_id;
92 
93 	// Logical ID mappings
94 	u32			logical_pkg_id;
95 	u32			logical_die_id;
96 	u32			logical_core_id;
97 
98 	// AMD Node ID and Nodes per Package info
99 	u32			amd_node_id;
100 
101 	// Cache level topology IDs
102 	u32			llc_id;
103 	u32			l2c_id;
104 
105 	// Hardware defined CPU-type
106 	union {
107 		u32		cpu_type;
108 		struct {
109 			// CPUID.1A.EAX[23-0]
110 			u32	intel_native_model_id	:24;
111 			// CPUID.1A.EAX[31-24]
112 			u32	intel_type		:8;
113 		};
114 		struct {
115 			// CPUID 0x80000026.EBX
116 			u32	amd_num_processors	:16,
117 				amd_power_eff_ranking	:8,
118 				amd_native_model_id	:4,
119 				amd_type		:4;
120 		};
121 	};
122 };
123 
124 struct cpuinfo_x86 {
125 	union {
126 		/*
127 		 * The particular ordering (low-to-high) of (vendor,
128 		 * family, model) is done in case range of models, like
129 		 * it is usually done on AMD, need to be compared.
130 		 */
131 		struct {
132 			__u8	x86_model;
133 			/* CPU family */
134 			__u8	x86;
135 			/* CPU vendor */
136 			__u8	x86_vendor;
137 			__u8	x86_reserved;
138 		};
139 		/* combined vendor, family, model */
140 		__u32		x86_vfm;
141 	};
142 	__u8			x86_stepping;
143 	union {
144 		// MSR_IA32_PLATFORM_ID[52-50]
145 		__u8			intel_platform_id;
146 		__u8			amd_unused;
147 	};
148 #ifdef CONFIG_X86_64
149 	/* Number of 4K pages in DTLB/ITLB combined(in pages): */
150 	int			x86_tlbsize;
151 #endif
152 #ifdef CONFIG_X86_VMX_FEATURE_NAMES
153 	__u32			vmx_capability[NVMXINTS];
154 #endif
155 	__u8			x86_virt_bits;
156 	__u8			x86_phys_bits;
157 	/* Max extended CPUID function supported: */
158 	__u32			extended_cpuid_level;
159 	/* Maximum supported CPUID level, -1=no CPUID: */
160 	int			cpuid_level;
161 	/*
162 	 * Align to size of unsigned long because the x86_capability array
163 	 * is passed to bitops which require the alignment. Use unnamed
164 	 * union to enforce the array is aligned to size of unsigned long.
165 	 */
166 	union {
167 		__u32		x86_capability[NCAPINTS + NBUGINTS];
168 		unsigned long	x86_capability_alignment;
169 	};
170 	char			x86_vendor_id[16];
171 	char			x86_model_id[64];
172 	struct cpuinfo_topology	topo;
173 	struct cpuid_table	cpuid;
174 	/* in KB - valid for CPUS which support this call: */
175 	unsigned int		x86_cache_size;
176 	int			x86_cache_alignment;	/* In bytes */
177 	/* Cache QoS architectural values, valid only on the BSP: */
178 	int			x86_cache_max_rmid;	/* max index */
179 	int			x86_cache_occ_scale;	/* scale to bytes */
180 	int			x86_cache_mbm_width_offset;
181 	int			x86_power;
182 	unsigned long		loops_per_jiffy;
183 	/* protected processor identification number */
184 	u64			ppin;
185 	u16			x86_clflush_size;
186 	/* number of cores as seen by the OS: */
187 	u16			booted_cores;
188 	/* Index into per_cpu list: */
189 	u16			cpu_index;
190 	/*  Is SMT active on this core? */
191 	bool			smt_active;
192 	u32			microcode;
193 	/* Address space bits used by the cache internally */
194 	u8			x86_cache_bits;
195 	unsigned		initialized : 1;
196 } __randomize_layout;
197 
198 #define X86_VENDOR_INTEL	0
199 #define X86_VENDOR_CYRIX	1
200 #define X86_VENDOR_AMD		2
201 #define X86_VENDOR_UMC		3
202 #define X86_VENDOR_CENTAUR	5
203 #define X86_VENDOR_TRANSMETA	7
204 #define X86_VENDOR_NSC		8
205 #define X86_VENDOR_HYGON	9
206 #define X86_VENDOR_ZHAOXIN	10
207 #define X86_VENDOR_VORTEX	11
208 #define X86_VENDOR_NUM		12
209 
210 #define X86_VENDOR_UNKNOWN	0xff
211 
212 /*
213  * capabilities of CPUs
214  */
215 extern struct cpuinfo_x86	boot_cpu_data;
216 extern struct cpuinfo_x86	new_cpu_data;
217 
218 extern __u32			cpu_caps_cleared[NCAPINTS + NBUGINTS];
219 extern __u32			cpu_caps_set[NCAPINTS + NBUGINTS];
220 
221 DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
222 #define cpu_data(cpu)		per_cpu(cpu_info, cpu)
223 
224 extern const struct seq_operations cpuinfo_op;
225 
226 #define cache_line_size()	(boot_cpu_data.x86_cache_alignment)
227 
228 extern void cpu_detect(struct cpuinfo_x86 *c);
229 
230 static inline unsigned long long l1tf_pfn_limit(void)
231 {
232 	return BIT_ULL(boot_cpu_data.x86_cache_bits - 1 - PAGE_SHIFT);
233 }
234 
235 void init_cpu_devs(void);
236 void get_cpu_vendor(struct cpuinfo_x86 *c);
237 extern void early_cpu_init(void);
238 extern void identify_secondary_cpu(unsigned int cpu);
239 extern void print_cpu_info(struct cpuinfo_x86 *);
240 void print_cpu_msr(struct cpuinfo_x86 *);
241 
242 /*
243  * Friendlier CR3 helpers.
244  */
245 static inline unsigned long read_cr3_pa(void)
246 {
247 	return __read_cr3() & CR3_ADDR_MASK;
248 }
249 
250 static inline unsigned long native_read_cr3_pa(void)
251 {
252 	return __native_read_cr3() & CR3_ADDR_MASK;
253 }
254 
255 static inline void load_cr3(pgd_t *pgdir)
256 {
257 	write_cr3(__sme_pa(pgdir));
258 }
259 
260 /*
261  * Note that while the legacy 'TSS' name comes from 'Task State Segment',
262  * on modern x86 CPUs the TSS also holds information important to 64-bit mode,
263  * unrelated to the task-switch mechanism:
264  */
265 #ifdef CONFIG_X86_32
266 /* This is the TSS defined by the hardware. */
267 struct x86_hw_tss {
268 	unsigned short		back_link, __blh;
269 	unsigned long		sp0;
270 	unsigned short		ss0, __ss0h;
271 	unsigned long		sp1;
272 
273 	/*
274 	 * We don't use ring 1, so ss1 is a convenient scratch space in
275 	 * the same cacheline as sp0.  We use ss1 to cache the value in
276 	 * MSR_IA32_SYSENTER_CS.  When we context switch
277 	 * MSR_IA32_SYSENTER_CS, we first check if the new value being
278 	 * written matches ss1, and, if it's not, then we wrmsr the new
279 	 * value and update ss1.
280 	 *
281 	 * The only reason we context switch MSR_IA32_SYSENTER_CS is
282 	 * that we set it to zero in vm86 tasks to avoid corrupting the
283 	 * stack if we were to go through the sysenter path from vm86
284 	 * mode.
285 	 */
286 	unsigned short		ss1;	/* MSR_IA32_SYSENTER_CS */
287 
288 	unsigned short		__ss1h;
289 	unsigned long		sp2;
290 	unsigned short		ss2, __ss2h;
291 	unsigned long		__cr3;
292 	unsigned long		ip;
293 	unsigned long		flags;
294 	unsigned long		ax;
295 	unsigned long		cx;
296 	unsigned long		dx;
297 	unsigned long		bx;
298 	unsigned long		sp;
299 	unsigned long		bp;
300 	unsigned long		si;
301 	unsigned long		di;
302 	unsigned short		es, __esh;
303 	unsigned short		cs, __csh;
304 	unsigned short		ss, __ssh;
305 	unsigned short		ds, __dsh;
306 	unsigned short		fs, __fsh;
307 	unsigned short		gs, __gsh;
308 	unsigned short		ldt, __ldth;
309 	unsigned short		trace;
310 	unsigned short		io_bitmap_base;
311 
312 } __attribute__((packed));
313 #else
314 struct x86_hw_tss {
315 	u32			reserved1;
316 	u64			sp0;
317 	u64			sp1;
318 
319 	/*
320 	 * Since Linux does not use ring 2, the 'sp2' slot is unused by
321 	 * hardware.  entry_SYSCALL_64 uses it as scratch space to stash
322 	 * the user RSP value.
323 	 */
324 	u64			sp2;
325 
326 	u64			reserved2;
327 	u64			ist[7];
328 	u32			reserved3;
329 	u32			reserved4;
330 	u16			reserved5;
331 	u16			io_bitmap_base;
332 
333 } __attribute__((packed));
334 #endif
335 
336 /*
337  * IO-bitmap sizes:
338  */
339 #define IO_BITMAP_BITS			65536
340 #define IO_BITMAP_BYTES			(IO_BITMAP_BITS / BITS_PER_BYTE)
341 #define IO_BITMAP_LONGS			(IO_BITMAP_BYTES / sizeof(long))
342 
343 #define IO_BITMAP_OFFSET_VALID_MAP				\
344 	(offsetof(struct tss_struct, io_bitmap.bitmap) -	\
345 	 offsetof(struct tss_struct, x86_tss))
346 
347 #define IO_BITMAP_OFFSET_VALID_ALL				\
348 	(offsetof(struct tss_struct, io_bitmap.mapall) -	\
349 	 offsetof(struct tss_struct, x86_tss))
350 
351 #ifdef CONFIG_X86_IOPL_IOPERM
352 /*
353  * sizeof(unsigned long) coming from an extra "long" at the end of the
354  * iobitmap. The limit is inclusive, i.e. the last valid byte.
355  */
356 # define __KERNEL_TSS_LIMIT	\
357 	(IO_BITMAP_OFFSET_VALID_ALL + IO_BITMAP_BYTES + \
358 	 sizeof(unsigned long) - 1)
359 #else
360 # define __KERNEL_TSS_LIMIT	\
361 	(offsetof(struct tss_struct, x86_tss) + sizeof(struct x86_hw_tss) - 1)
362 #endif
363 
364 /* Base offset outside of TSS_LIMIT so unpriviledged IO causes #GP */
365 #define IO_BITMAP_OFFSET_INVALID	(__KERNEL_TSS_LIMIT + 1)
366 
367 struct entry_stack {
368 	char	stack[PAGE_SIZE];
369 };
370 
371 struct entry_stack_page {
372 	struct entry_stack stack;
373 } __aligned(PAGE_SIZE);
374 
375 /*
376  * All IO bitmap related data stored in the TSS:
377  */
378 struct x86_io_bitmap {
379 	/* The sequence number of the last active bitmap. */
380 	u64			prev_sequence;
381 
382 	/*
383 	 * Store the dirty size of the last io bitmap offender. The next
384 	 * one will have to do the cleanup as the switch out to a non io
385 	 * bitmap user will just set x86_tss.io_bitmap_base to a value
386 	 * outside of the TSS limit. So for sane tasks there is no need to
387 	 * actually touch the io_bitmap at all.
388 	 */
389 	unsigned int		prev_max;
390 
391 	/*
392 	 * The extra 1 is there because the CPU will access an
393 	 * additional byte beyond the end of the IO permission
394 	 * bitmap. The extra byte must be all 1 bits, and must
395 	 * be within the limit.
396 	 */
397 	unsigned long		bitmap[IO_BITMAP_LONGS + 1];
398 
399 	/*
400 	 * Special I/O bitmap to emulate IOPL(3). All bytes zero,
401 	 * except the additional byte at the end.
402 	 */
403 	unsigned long		mapall[IO_BITMAP_LONGS + 1];
404 };
405 
406 struct tss_struct {
407 	/*
408 	 * The fixed hardware portion.  This must not cross a page boundary
409 	 * at risk of violating the SDM's advice and potentially triggering
410 	 * errata.
411 	 */
412 	struct x86_hw_tss	x86_tss;
413 
414 	struct x86_io_bitmap	io_bitmap;
415 } __aligned(PAGE_SIZE);
416 
417 DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw);
418 
419 /* Per CPU interrupt stacks */
420 struct irq_stack {
421 	char		stack[IRQ_STACK_SIZE];
422 } __aligned(IRQ_STACK_SIZE);
423 
424 DECLARE_PER_CPU_CACHE_HOT(struct irq_stack *, hardirq_stack_ptr);
425 #ifdef CONFIG_X86_64
426 DECLARE_PER_CPU_CACHE_HOT(bool, hardirq_stack_inuse);
427 #else
428 DECLARE_PER_CPU_CACHE_HOT(struct irq_stack *, softirq_stack_ptr);
429 #endif
430 
431 DECLARE_PER_CPU_CACHE_HOT(unsigned long, cpu_current_top_of_stack);
432 /* const-qualified alias provided by the linker. */
433 DECLARE_PER_CPU_CACHE_HOT(const unsigned long __percpu_seg_override,
434 			  const_cpu_current_top_of_stack);
435 
436 #ifdef CONFIG_X86_64
437 static inline unsigned long cpu_kernelmode_gs_base(int cpu)
438 {
439 #ifdef CONFIG_SMP
440 	return per_cpu_offset(cpu);
441 #else
442 	return 0;
443 #endif
444 }
445 
446 extern asmlinkage void entry_SYSCALL32_ignore(void);
447 
448 /* Save actual FS/GS selectors and bases to current->thread */
449 void current_save_fsgs(void);
450 #endif	/* X86_64 */
451 
452 struct perf_event;
453 
454 struct thread_struct {
455 	/* Cached TLS descriptors: */
456 	struct desc_struct	tls_array[GDT_ENTRY_TLS_ENTRIES];
457 #ifdef CONFIG_X86_32
458 	unsigned long		sp0;
459 #endif
460 	unsigned long		sp;
461 #ifdef CONFIG_X86_32
462 	unsigned long		sysenter_cs;
463 #else
464 	unsigned short		es;
465 	unsigned short		ds;
466 	unsigned short		fsindex;
467 	unsigned short		gsindex;
468 #endif
469 
470 #ifdef CONFIG_X86_64
471 	unsigned long		fsbase;
472 	unsigned long		gsbase;
473 #else
474 	/*
475 	 * XXX: this could presumably be unsigned short.  Alternatively,
476 	 * 32-bit kernels could be taught to use fsindex instead.
477 	 */
478 	unsigned long fs;
479 	unsigned long gs;
480 #endif
481 
482 	/* Save middle states of ptrace breakpoints */
483 	struct perf_event	*ptrace_bps[HBP_NUM];
484 	/* Debug status used for traps, single steps, etc... */
485 	unsigned long           virtual_dr6;
486 	/* Keep track of the exact dr7 value set by the user */
487 	unsigned long           ptrace_dr7;
488 	/* Fault info: */
489 	unsigned long		cr2;
490 	unsigned long		trap_nr;
491 	unsigned long		error_code;
492 #ifdef CONFIG_VM86
493 	/* Virtual 86 mode info */
494 	struct vm86		*vm86;
495 #endif
496 	/* IO permissions: */
497 	struct io_bitmap	*io_bitmap;
498 
499 	/*
500 	 * IOPL. Privilege level dependent I/O permission which is
501 	 * emulated via the I/O bitmap to prevent user space from disabling
502 	 * interrupts.
503 	 */
504 	unsigned long		iopl_emul;
505 
506 	unsigned int		iopl_warn:1;
507 
508 	/*
509 	 * Protection Keys Register for Userspace.  Loaded immediately on
510 	 * context switch. Store it in thread_struct to avoid a lookup in
511 	 * the tasks's FPU xstate buffer. This value is only valid when a
512 	 * task is scheduled out. For 'current' the authoritative source of
513 	 * PKRU is the hardware itself.
514 	 */
515 	u32			pkru;
516 
517 #ifdef CONFIG_X86_USER_SHADOW_STACK
518 	unsigned long		features;
519 	unsigned long		features_locked;
520 
521 	struct thread_shstk	shstk;
522 #endif
523 };
524 
525 #ifdef CONFIG_X86_DEBUG_FPU
526 extern struct fpu *x86_task_fpu(struct task_struct *task);
527 #else
528 # define x86_task_fpu(task)	((struct fpu *)((void *)(task) + sizeof(*(task))))
529 #endif
530 
531 extern void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size);
532 
533 static inline void arch_thread_struct_whitelist(unsigned long *offset,
534 						unsigned long *size)
535 {
536 	fpu_thread_struct_whitelist(offset, size);
537 }
538 
539 static inline void
540 native_load_sp0(unsigned long sp0)
541 {
542 	this_cpu_write(cpu_tss_rw.x86_tss.sp0, sp0);
543 }
544 
545 static __always_inline void native_swapgs(void)
546 {
547 #ifdef CONFIG_X86_64
548 	asm volatile("swapgs" ::: "memory");
549 #endif
550 }
551 
552 static __always_inline unsigned long current_top_of_stack(void)
553 {
554 	/*
555 	 *  We can't read directly from tss.sp0: sp0 on x86_32 is special in
556 	 *  and around vm86 mode and sp0 on x86_64 is special because of the
557 	 *  entry trampoline.
558 	 */
559 	if (IS_ENABLED(CONFIG_USE_X86_SEG_SUPPORT))
560 		return this_cpu_read_const(const_cpu_current_top_of_stack);
561 
562 	return this_cpu_read_stable(cpu_current_top_of_stack);
563 }
564 
565 static __always_inline bool on_thread_stack(void)
566 {
567 	return (unsigned long)(current_top_of_stack() -
568 			       current_stack_pointer) < THREAD_SIZE;
569 }
570 
571 #ifdef CONFIG_PARAVIRT_XXL
572 #include <asm/paravirt.h>
573 #else
574 
575 static inline void load_sp0(unsigned long sp0)
576 {
577 	native_load_sp0(sp0);
578 }
579 
580 #endif /* CONFIG_PARAVIRT_XXL */
581 
582 unsigned long __get_wchan(struct task_struct *p);
583 
584 extern void select_idle_routine(void);
585 extern void amd_e400_c1e_apic_setup(void);
586 
587 extern unsigned long		boot_option_idle_override;
588 
589 enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
590 			 IDLE_POLL};
591 
592 extern void enable_sep_cpu(void);
593 
594 
595 /* Defined in head.S */
596 extern struct desc_ptr		early_gdt_descr;
597 
598 extern void switch_gdt_and_percpu_base(int);
599 extern void load_direct_gdt(int);
600 extern void load_fixmap_gdt(int);
601 extern void cpu_init(void);
602 extern void cpu_init_exception_handling(bool boot_cpu);
603 extern void cpu_init_replace_early_idt(void);
604 extern void cr4_init(void);
605 
606 extern void set_task_blockstep(struct task_struct *task, bool on);
607 
608 /* Boot loader type from the setup header: */
609 extern int			bootloader_type;
610 extern int			bootloader_version;
611 
612 extern char			ignore_fpu_irq;
613 
614 #define HAVE_ARCH_PICK_MMAP_LAYOUT 1
615 #define ARCH_HAS_PREFETCHW
616 
617 #ifdef CONFIG_X86_32
618 # define BASE_PREFETCH		""
619 # define ARCH_HAS_PREFETCH
620 #else
621 # define BASE_PREFETCH		"prefetcht0 %1"
622 #endif
623 
624 /*
625  * Prefetch instructions for Pentium III (+) and AMD Athlon (+)
626  *
627  * It's not worth to care about 3dnow prefetches for the K6
628  * because they are microcoded there and very slow.
629  */
630 static inline void prefetch(const void *x)
631 {
632 	alternative_input(BASE_PREFETCH, "prefetchnta %1",
633 			  X86_FEATURE_XMM,
634 			  "m" (*(const char *)x));
635 }
636 
637 /*
638  * 3dnow prefetch to get an exclusive cache line.
639  * Useful for spinlocks to avoid one state transition in the
640  * cache coherency protocol:
641  */
642 static __always_inline void prefetchw(const void *x)
643 {
644 	alternative_input(BASE_PREFETCH, "prefetchw %1",
645 			  X86_FEATURE_3DNOWPREFETCH,
646 			  "m" (*(const char *)x));
647 }
648 
649 #define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \
650 			   TOP_OF_KERNEL_STACK_PADDING)
651 
652 #define task_top_of_stack(task) ((unsigned long)(task_pt_regs(task) + 1))
653 
654 #define task_pt_regs(task) \
655 ({									\
656 	unsigned long __ptr = (unsigned long)task_stack_page(task);	\
657 	__ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;		\
658 	((struct pt_regs *)__ptr) - 1;					\
659 })
660 
661 #ifdef CONFIG_X86_32
662 #define INIT_THREAD  {							  \
663 	.sp0			= TOP_OF_INIT_STACK,			  \
664 	.sysenter_cs		= __KERNEL_CS,				  \
665 }
666 
667 #else
668 extern unsigned long __top_init_kernel_stack[];
669 
670 #define INIT_THREAD {							\
671 	.sp	= (unsigned long)&__top_init_kernel_stack,		\
672 }
673 
674 #endif /* CONFIG_X86_64 */
675 
676 extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
677 					       unsigned long new_sp);
678 
679 /*
680  * This decides where the kernel will search for a free chunk of vm
681  * space during mmap's.
682  */
683 #define __TASK_UNMAPPED_BASE(task_size)	(PAGE_ALIGN(task_size / 3))
684 #define TASK_UNMAPPED_BASE		__TASK_UNMAPPED_BASE(TASK_SIZE_LOW)
685 
686 #define KSTK_EIP(task)		(task_pt_regs(task)->ip)
687 #define KSTK_ESP(task)		(task_pt_regs(task)->sp)
688 
689 /* Get/set a process' ability to use the timestamp counter instruction */
690 #define GET_TSC_CTL(adr)	get_tsc_mode((adr))
691 #define SET_TSC_CTL(val)	set_tsc_mode((val))
692 
693 extern int get_tsc_mode(unsigned long adr);
694 extern int set_tsc_mode(unsigned int val);
695 
696 DECLARE_PER_CPU(u64, msr_misc_features_shadow);
697 
698 static inline u32 per_cpu_llc_id(unsigned int cpu)
699 {
700 	return per_cpu(cpu_info.topo.llc_id, cpu);
701 }
702 
703 static inline u32 per_cpu_l2c_id(unsigned int cpu)
704 {
705 	return per_cpu(cpu_info.topo.l2c_id, cpu);
706 }
707 
708 static inline u32 per_cpu_core_id(unsigned int cpu)
709 {
710 	return per_cpu(cpu_info.topo.core_id, cpu);
711 }
712 
713 #ifdef CONFIG_CPU_SUP_AMD
714 /*
715  * Issue a DIV 0/1 insn to clear any division data from previous DIV
716  * operations.
717  */
718 static __always_inline void amd_clear_divider(void)
719 {
720 	asm volatile(ALTERNATIVE("", "div %2\n\t", X86_BUG_DIV0)
721 		     :: "a" (0), "d" (0), "r" (1));
722 }
723 
724 extern void amd_check_microcode(void);
725 #else
726 static inline void amd_clear_divider(void)		{ }
727 static inline void amd_check_microcode(void)		{ }
728 #endif
729 
730 extern unsigned long arch_align_stack(unsigned long sp);
731 void free_init_pages(const char *what, unsigned long begin, unsigned long end);
732 extern void free_kernel_image_pages(const char *what, void *begin, void *end);
733 
734 void default_idle(void);
735 #ifdef	CONFIG_XEN
736 bool xen_set_default_idle(void);
737 #else
738 #define xen_set_default_idle 0
739 #endif
740 
741 void __noreturn stop_this_cpu(void *dummy);
742 extern bool x86_hypervisor_present;
743 void microcode_check(struct cpuinfo_x86 *prev_info);
744 void store_cpu_caps(struct cpuinfo_x86 *info);
745 
746 DECLARE_PER_CPU(bool, cache_state_incoherent);
747 
748 enum l1tf_mitigations {
749 	L1TF_MITIGATION_OFF,
750 	L1TF_MITIGATION_AUTO,
751 	L1TF_MITIGATION_FLUSH_NOWARN,
752 	L1TF_MITIGATION_FLUSH,
753 	L1TF_MITIGATION_FLUSH_NOSMT,
754 	L1TF_MITIGATION_FULL,
755 	L1TF_MITIGATION_FULL_FORCE
756 };
757 
758 extern enum l1tf_mitigations l1tf_mitigation;
759 
760 enum mds_mitigations {
761 	MDS_MITIGATION_OFF,
762 	MDS_MITIGATION_AUTO,
763 	MDS_MITIGATION_FULL,
764 	MDS_MITIGATION_VMWERV,
765 };
766 
767 extern bool gds_ucode_mitigated(void);
768 
769 /*
770  * Make previous memory operations globally visible before
771  * a WRMSR.
772  *
773  * MFENCE makes writes visible, but only affects load/store
774  * instructions.  WRMSR is unfortunately not a load/store
775  * instruction and is unaffected by MFENCE.  The LFENCE ensures
776  * that the WRMSR is not reordered.
777  *
778  * Most WRMSRs are full serializing instructions themselves and
779  * do not require this barrier.  This is only required for the
780  * IA32_TSC_DEADLINE and X2APIC MSRs.
781  */
782 static inline void weak_wrmsr_fence(void)
783 {
784 	alternative("mfence; lfence", "", ALT_NOT(X86_FEATURE_APIC_MSRS_FENCE));
785 }
786 
787 #endif /* _ASM_X86_PROCESSOR_H */
788