xref: /linux/arch/x86/include/asm/processor.h (revision cdd30ebb1b9f36159d66f088b61aee264e649d7a)
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.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 enum tlb_infos {
64 	ENTRIES,
65 	NR_INFO
66 };
67 
68 extern u16 __read_mostly tlb_lli_4k[NR_INFO];
69 extern u16 __read_mostly tlb_lli_2m[NR_INFO];
70 extern u16 __read_mostly tlb_lli_4m[NR_INFO];
71 extern u16 __read_mostly tlb_lld_4k[NR_INFO];
72 extern u16 __read_mostly tlb_lld_2m[NR_INFO];
73 extern u16 __read_mostly tlb_lld_4m[NR_INFO];
74 extern u16 __read_mostly tlb_lld_1g[NR_INFO];
75 
76 /*
77  * CPU type and hardware bug flags. Kept separately for each CPU.
78  */
79 
80 struct cpuinfo_topology {
81 	// Real APIC ID read from the local APIC
82 	u32			apicid;
83 	// The initial APIC ID provided by CPUID
84 	u32			initial_apicid;
85 
86 	// Physical package ID
87 	u32			pkg_id;
88 
89 	// Physical die ID on AMD, Relative on Intel
90 	u32			die_id;
91 
92 	// Compute unit ID - AMD specific
93 	u32			cu_id;
94 
95 	// Core ID relative to the package
96 	u32			core_id;
97 
98 	// Logical ID mappings
99 	u32			logical_pkg_id;
100 	u32			logical_die_id;
101 
102 	// AMD Node ID and Nodes per Package info
103 	u32			amd_node_id;
104 
105 	// Cache level topology IDs
106 	u32			llc_id;
107 	u32			l2c_id;
108 
109 	// Hardware defined CPU-type
110 	union {
111 		u32		cpu_type;
112 		struct {
113 			// CPUID.1A.EAX[23-0]
114 			u32	intel_native_model_id	:24;
115 			// CPUID.1A.EAX[31-24]
116 			u32	intel_type		:8;
117 		};
118 		struct {
119 			// CPUID 0x80000026.EBX
120 			u32	amd_num_processors	:16,
121 				amd_power_eff_ranking	:8,
122 				amd_native_model_id	:4,
123 				amd_type		:4;
124 		};
125 	};
126 };
127 
128 struct cpuinfo_x86 {
129 	union {
130 		/*
131 		 * The particular ordering (low-to-high) of (vendor,
132 		 * family, model) is done in case range of models, like
133 		 * it is usually done on AMD, need to be compared.
134 		 */
135 		struct {
136 			__u8	x86_model;
137 			/* CPU family */
138 			__u8	x86;
139 			/* CPU vendor */
140 			__u8	x86_vendor;
141 			__u8	x86_reserved;
142 		};
143 		/* combined vendor, family, model */
144 		__u32		x86_vfm;
145 	};
146 	__u8			x86_stepping;
147 #ifdef CONFIG_X86_64
148 	/* Number of 4K pages in DTLB/ITLB combined(in pages): */
149 	int			x86_tlbsize;
150 #endif
151 #ifdef CONFIG_X86_VMX_FEATURE_NAMES
152 	__u32			vmx_capability[NVMXINTS];
153 #endif
154 	__u8			x86_virt_bits;
155 	__u8			x86_phys_bits;
156 	/* Max extended CPUID function supported: */
157 	__u32			extended_cpuid_level;
158 	/* Maximum supported CPUID level, -1=no CPUID: */
159 	int			cpuid_level;
160 	/*
161 	 * Align to size of unsigned long because the x86_capability array
162 	 * is passed to bitops which require the alignment. Use unnamed
163 	 * union to enforce the array is aligned to size of unsigned long.
164 	 */
165 	union {
166 		__u32		x86_capability[NCAPINTS + NBUGINTS];
167 		unsigned long	x86_capability_alignment;
168 	};
169 	char			x86_vendor_id[16];
170 	char			x86_model_id[64];
171 	struct cpuinfo_topology	topo;
172 	/* in KB - valid for CPUS which support this call: */
173 	unsigned int		x86_cache_size;
174 	int			x86_cache_alignment;	/* In bytes */
175 	/* Cache QoS architectural values, valid only on the BSP: */
176 	int			x86_cache_max_rmid;	/* max index */
177 	int			x86_cache_occ_scale;	/* scale to bytes */
178 	int			x86_cache_mbm_width_offset;
179 	int			x86_power;
180 	unsigned long		loops_per_jiffy;
181 	/* protected processor identification number */
182 	u64			ppin;
183 	u16			x86_clflush_size;
184 	/* number of cores as seen by the OS: */
185 	u16			booted_cores;
186 	/* Index into per_cpu list: */
187 	u16			cpu_index;
188 	/*  Is SMT active on this core? */
189 	bool			smt_active;
190 	u32			microcode;
191 	/* Address space bits used by the cache internally */
192 	u8			x86_cache_bits;
193 	unsigned		initialized : 1;
194 } __randomize_layout;
195 
196 #define X86_VENDOR_INTEL	0
197 #define X86_VENDOR_CYRIX	1
198 #define X86_VENDOR_AMD		2
199 #define X86_VENDOR_UMC		3
200 #define X86_VENDOR_CENTAUR	5
201 #define X86_VENDOR_TRANSMETA	7
202 #define X86_VENDOR_NSC		8
203 #define X86_VENDOR_HYGON	9
204 #define X86_VENDOR_ZHAOXIN	10
205 #define X86_VENDOR_VORTEX	11
206 #define X86_VENDOR_NUM		12
207 
208 #define X86_VENDOR_UNKNOWN	0xff
209 
210 /*
211  * capabilities of CPUs
212  */
213 extern struct cpuinfo_x86	boot_cpu_data;
214 extern struct cpuinfo_x86	new_cpu_data;
215 
216 extern __u32			cpu_caps_cleared[NCAPINTS + NBUGINTS];
217 extern __u32			cpu_caps_set[NCAPINTS + NBUGINTS];
218 
219 DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
220 #define cpu_data(cpu)		per_cpu(cpu_info, cpu)
221 
222 extern const struct seq_operations cpuinfo_op;
223 
224 #define cache_line_size()	(boot_cpu_data.x86_cache_alignment)
225 
226 extern void cpu_detect(struct cpuinfo_x86 *c);
227 
228 static inline unsigned long long l1tf_pfn_limit(void)
229 {
230 	return BIT_ULL(boot_cpu_data.x86_cache_bits - 1 - PAGE_SHIFT);
231 }
232 
233 extern void early_cpu_init(void);
234 extern void identify_secondary_cpu(struct cpuinfo_x86 *);
235 extern void print_cpu_info(struct cpuinfo_x86 *);
236 void print_cpu_msr(struct cpuinfo_x86 *);
237 
238 /*
239  * Friendlier CR3 helpers.
240  */
241 static inline unsigned long read_cr3_pa(void)
242 {
243 	return __read_cr3() & CR3_ADDR_MASK;
244 }
245 
246 static inline unsigned long native_read_cr3_pa(void)
247 {
248 	return __native_read_cr3() & CR3_ADDR_MASK;
249 }
250 
251 static inline void load_cr3(pgd_t *pgdir)
252 {
253 	write_cr3(__sme_pa(pgdir));
254 }
255 
256 /*
257  * Note that while the legacy 'TSS' name comes from 'Task State Segment',
258  * on modern x86 CPUs the TSS also holds information important to 64-bit mode,
259  * unrelated to the task-switch mechanism:
260  */
261 #ifdef CONFIG_X86_32
262 /* This is the TSS defined by the hardware. */
263 struct x86_hw_tss {
264 	unsigned short		back_link, __blh;
265 	unsigned long		sp0;
266 	unsigned short		ss0, __ss0h;
267 	unsigned long		sp1;
268 
269 	/*
270 	 * We don't use ring 1, so ss1 is a convenient scratch space in
271 	 * the same cacheline as sp0.  We use ss1 to cache the value in
272 	 * MSR_IA32_SYSENTER_CS.  When we context switch
273 	 * MSR_IA32_SYSENTER_CS, we first check if the new value being
274 	 * written matches ss1, and, if it's not, then we wrmsr the new
275 	 * value and update ss1.
276 	 *
277 	 * The only reason we context switch MSR_IA32_SYSENTER_CS is
278 	 * that we set it to zero in vm86 tasks to avoid corrupting the
279 	 * stack if we were to go through the sysenter path from vm86
280 	 * mode.
281 	 */
282 	unsigned short		ss1;	/* MSR_IA32_SYSENTER_CS */
283 
284 	unsigned short		__ss1h;
285 	unsigned long		sp2;
286 	unsigned short		ss2, __ss2h;
287 	unsigned long		__cr3;
288 	unsigned long		ip;
289 	unsigned long		flags;
290 	unsigned long		ax;
291 	unsigned long		cx;
292 	unsigned long		dx;
293 	unsigned long		bx;
294 	unsigned long		sp;
295 	unsigned long		bp;
296 	unsigned long		si;
297 	unsigned long		di;
298 	unsigned short		es, __esh;
299 	unsigned short		cs, __csh;
300 	unsigned short		ss, __ssh;
301 	unsigned short		ds, __dsh;
302 	unsigned short		fs, __fsh;
303 	unsigned short		gs, __gsh;
304 	unsigned short		ldt, __ldth;
305 	unsigned short		trace;
306 	unsigned short		io_bitmap_base;
307 
308 } __attribute__((packed));
309 #else
310 struct x86_hw_tss {
311 	u32			reserved1;
312 	u64			sp0;
313 	u64			sp1;
314 
315 	/*
316 	 * Since Linux does not use ring 2, the 'sp2' slot is unused by
317 	 * hardware.  entry_SYSCALL_64 uses it as scratch space to stash
318 	 * the user RSP value.
319 	 */
320 	u64			sp2;
321 
322 	u64			reserved2;
323 	u64			ist[7];
324 	u32			reserved3;
325 	u32			reserved4;
326 	u16			reserved5;
327 	u16			io_bitmap_base;
328 
329 } __attribute__((packed));
330 #endif
331 
332 /*
333  * IO-bitmap sizes:
334  */
335 #define IO_BITMAP_BITS			65536
336 #define IO_BITMAP_BYTES			(IO_BITMAP_BITS / BITS_PER_BYTE)
337 #define IO_BITMAP_LONGS			(IO_BITMAP_BYTES / sizeof(long))
338 
339 #define IO_BITMAP_OFFSET_VALID_MAP				\
340 	(offsetof(struct tss_struct, io_bitmap.bitmap) -	\
341 	 offsetof(struct tss_struct, x86_tss))
342 
343 #define IO_BITMAP_OFFSET_VALID_ALL				\
344 	(offsetof(struct tss_struct, io_bitmap.mapall) -	\
345 	 offsetof(struct tss_struct, x86_tss))
346 
347 #ifdef CONFIG_X86_IOPL_IOPERM
348 /*
349  * sizeof(unsigned long) coming from an extra "long" at the end of the
350  * iobitmap. The limit is inclusive, i.e. the last valid byte.
351  */
352 # define __KERNEL_TSS_LIMIT	\
353 	(IO_BITMAP_OFFSET_VALID_ALL + IO_BITMAP_BYTES + \
354 	 sizeof(unsigned long) - 1)
355 #else
356 # define __KERNEL_TSS_LIMIT	\
357 	(offsetof(struct tss_struct, x86_tss) + sizeof(struct x86_hw_tss) - 1)
358 #endif
359 
360 /* Base offset outside of TSS_LIMIT so unpriviledged IO causes #GP */
361 #define IO_BITMAP_OFFSET_INVALID	(__KERNEL_TSS_LIMIT + 1)
362 
363 struct entry_stack {
364 	char	stack[PAGE_SIZE];
365 };
366 
367 struct entry_stack_page {
368 	struct entry_stack stack;
369 } __aligned(PAGE_SIZE);
370 
371 /*
372  * All IO bitmap related data stored in the TSS:
373  */
374 struct x86_io_bitmap {
375 	/* The sequence number of the last active bitmap. */
376 	u64			prev_sequence;
377 
378 	/*
379 	 * Store the dirty size of the last io bitmap offender. The next
380 	 * one will have to do the cleanup as the switch out to a non io
381 	 * bitmap user will just set x86_tss.io_bitmap_base to a value
382 	 * outside of the TSS limit. So for sane tasks there is no need to
383 	 * actually touch the io_bitmap at all.
384 	 */
385 	unsigned int		prev_max;
386 
387 	/*
388 	 * The extra 1 is there because the CPU will access an
389 	 * additional byte beyond the end of the IO permission
390 	 * bitmap. The extra byte must be all 1 bits, and must
391 	 * be within the limit.
392 	 */
393 	unsigned long		bitmap[IO_BITMAP_LONGS + 1];
394 
395 	/*
396 	 * Special I/O bitmap to emulate IOPL(3). All bytes zero,
397 	 * except the additional byte at the end.
398 	 */
399 	unsigned long		mapall[IO_BITMAP_LONGS + 1];
400 };
401 
402 struct tss_struct {
403 	/*
404 	 * The fixed hardware portion.  This must not cross a page boundary
405 	 * at risk of violating the SDM's advice and potentially triggering
406 	 * errata.
407 	 */
408 	struct x86_hw_tss	x86_tss;
409 
410 	struct x86_io_bitmap	io_bitmap;
411 } __aligned(PAGE_SIZE);
412 
413 DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw);
414 
415 /* Per CPU interrupt stacks */
416 struct irq_stack {
417 	char		stack[IRQ_STACK_SIZE];
418 } __aligned(IRQ_STACK_SIZE);
419 
420 #ifdef CONFIG_X86_64
421 struct fixed_percpu_data {
422 	/*
423 	 * GCC hardcodes the stack canary as %gs:40.  Since the
424 	 * irq_stack is the object at %gs:0, we reserve the bottom
425 	 * 48 bytes of the irq stack for the canary.
426 	 *
427 	 * Once we are willing to require -mstack-protector-guard-symbol=
428 	 * support for x86_64 stackprotector, we can get rid of this.
429 	 */
430 	char		gs_base[40];
431 	unsigned long	stack_canary;
432 };
433 
434 DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible;
435 DECLARE_INIT_PER_CPU(fixed_percpu_data);
436 
437 static inline unsigned long cpu_kernelmode_gs_base(int cpu)
438 {
439 	return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
440 }
441 
442 extern asmlinkage void entry_SYSCALL32_ignore(void);
443 
444 /* Save actual FS/GS selectors and bases to current->thread */
445 void current_save_fsgs(void);
446 #else	/* X86_64 */
447 #ifdef CONFIG_STACKPROTECTOR
448 DECLARE_PER_CPU(unsigned long, __stack_chk_guard);
449 #endif
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 	/* Floating point and extended processor state */
525 	struct fpu		fpu;
526 	/*
527 	 * WARNING: 'fpu' is dynamically-sized.  It *MUST* be at
528 	 * the end.
529 	 */
530 };
531 
532 extern void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size);
533 
534 static inline void arch_thread_struct_whitelist(unsigned long *offset,
535 						unsigned long *size)
536 {
537 	fpu_thread_struct_whitelist(offset, size);
538 }
539 
540 static inline void
541 native_load_sp0(unsigned long sp0)
542 {
543 	this_cpu_write(cpu_tss_rw.x86_tss.sp0, sp0);
544 }
545 
546 static __always_inline void native_swapgs(void)
547 {
548 #ifdef CONFIG_X86_64
549 	asm volatile("swapgs" ::: "memory");
550 #endif
551 }
552 
553 static __always_inline unsigned long current_top_of_stack(void)
554 {
555 	/*
556 	 *  We can't read directly from tss.sp0: sp0 on x86_32 is special in
557 	 *  and around vm86 mode and sp0 on x86_64 is special because of the
558 	 *  entry trampoline.
559 	 */
560 	if (IS_ENABLED(CONFIG_USE_X86_SEG_SUPPORT))
561 		return this_cpu_read_const(const_pcpu_hot.top_of_stack);
562 
563 	return this_cpu_read_stable(pcpu_hot.top_of_stack);
564 }
565 
566 static __always_inline bool on_thread_stack(void)
567 {
568 	return (unsigned long)(current_top_of_stack() -
569 			       current_stack_pointer) < THREAD_SIZE;
570 }
571 
572 #ifdef CONFIG_PARAVIRT_XXL
573 #include <asm/paravirt.h>
574 #else
575 
576 static inline void load_sp0(unsigned long sp0)
577 {
578 	native_load_sp0(sp0);
579 }
580 
581 #endif /* CONFIG_PARAVIRT_XXL */
582 
583 unsigned long __get_wchan(struct task_struct *p);
584 
585 extern void select_idle_routine(void);
586 extern void amd_e400_c1e_apic_setup(void);
587 
588 extern unsigned long		boot_option_idle_override;
589 
590 enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
591 			 IDLE_POLL};
592 
593 extern void enable_sep_cpu(void);
594 
595 
596 /* Defined in head.S */
597 extern struct desc_ptr		early_gdt_descr;
598 
599 extern void switch_gdt_and_percpu_base(int);
600 extern void load_direct_gdt(int);
601 extern void load_fixmap_gdt(int);
602 extern void cpu_init(void);
603 extern void cpu_init_exception_handling(bool boot_cpu);
604 extern void cpu_init_replace_early_idt(void);
605 extern void cr4_init(void);
606 
607 extern void set_task_blockstep(struct task_struct *task, bool on);
608 
609 /* Boot loader type from the setup header: */
610 extern int			bootloader_type;
611 extern int			bootloader_version;
612 
613 extern char			ignore_fpu_irq;
614 
615 #define HAVE_ARCH_PICK_MMAP_LAYOUT 1
616 #define ARCH_HAS_PREFETCHW
617 
618 #ifdef CONFIG_X86_32
619 # define BASE_PREFETCH		""
620 # define ARCH_HAS_PREFETCH
621 #else
622 # define BASE_PREFETCH		"prefetcht0 %1"
623 #endif
624 
625 /*
626  * Prefetch instructions for Pentium III (+) and AMD Athlon (+)
627  *
628  * It's not worth to care about 3dnow prefetches for the K6
629  * because they are microcoded there and very slow.
630  */
631 static inline void prefetch(const void *x)
632 {
633 	alternative_input(BASE_PREFETCH, "prefetchnta %1",
634 			  X86_FEATURE_XMM,
635 			  "m" (*(const char *)x));
636 }
637 
638 /*
639  * 3dnow prefetch to get an exclusive cache line.
640  * Useful for spinlocks to avoid one state transition in the
641  * cache coherency protocol:
642  */
643 static __always_inline void prefetchw(const void *x)
644 {
645 	alternative_input(BASE_PREFETCH, "prefetchw %1",
646 			  X86_FEATURE_3DNOWPREFETCH,
647 			  "m" (*(const char *)x));
648 }
649 
650 #define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \
651 			   TOP_OF_KERNEL_STACK_PADDING)
652 
653 #define task_top_of_stack(task) ((unsigned long)(task_pt_regs(task) + 1))
654 
655 #define task_pt_regs(task) \
656 ({									\
657 	unsigned long __ptr = (unsigned long)task_stack_page(task);	\
658 	__ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;		\
659 	((struct pt_regs *)__ptr) - 1;					\
660 })
661 
662 #ifdef CONFIG_X86_32
663 #define INIT_THREAD  {							  \
664 	.sp0			= TOP_OF_INIT_STACK,			  \
665 	.sysenter_cs		= __KERNEL_CS,				  \
666 }
667 
668 #define KSTK_ESP(task)		(task_pt_regs(task)->sp)
669 
670 #else
671 extern unsigned long __top_init_kernel_stack[];
672 
673 #define INIT_THREAD {							\
674 	.sp	= (unsigned long)&__top_init_kernel_stack,		\
675 }
676 
677 extern unsigned long KSTK_ESP(struct task_struct *task);
678 
679 #endif /* CONFIG_X86_64 */
680 
681 extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
682 					       unsigned long new_sp);
683 
684 /*
685  * This decides where the kernel will search for a free chunk of vm
686  * space during mmap's.
687  */
688 #define __TASK_UNMAPPED_BASE(task_size)	(PAGE_ALIGN(task_size / 3))
689 #define TASK_UNMAPPED_BASE		__TASK_UNMAPPED_BASE(TASK_SIZE_LOW)
690 
691 #define KSTK_EIP(task)		(task_pt_regs(task)->ip)
692 
693 /* Get/set a process' ability to use the timestamp counter instruction */
694 #define GET_TSC_CTL(adr)	get_tsc_mode((adr))
695 #define SET_TSC_CTL(val)	set_tsc_mode((val))
696 
697 extern int get_tsc_mode(unsigned long adr);
698 extern int set_tsc_mode(unsigned int val);
699 
700 DECLARE_PER_CPU(u64, msr_misc_features_shadow);
701 
702 static inline u32 per_cpu_llc_id(unsigned int cpu)
703 {
704 	return per_cpu(cpu_info.topo.llc_id, cpu);
705 }
706 
707 static inline u32 per_cpu_l2c_id(unsigned int cpu)
708 {
709 	return per_cpu(cpu_info.topo.l2c_id, cpu);
710 }
711 
712 #ifdef CONFIG_CPU_SUP_AMD
713 /*
714  * Issue a DIV 0/1 insn to clear any division data from previous DIV
715  * operations.
716  */
717 static __always_inline void amd_clear_divider(void)
718 {
719 	asm volatile(ALTERNATIVE("", "div %2\n\t", X86_BUG_DIV0)
720 		     :: "a" (0), "d" (0), "r" (1));
721 }
722 
723 extern void amd_check_microcode(void);
724 #else
725 static inline void amd_clear_divider(void)		{ }
726 static inline void amd_check_microcode(void)		{ }
727 #endif
728 
729 extern unsigned long arch_align_stack(unsigned long sp);
730 void free_init_pages(const char *what, unsigned long begin, unsigned long end);
731 extern void free_kernel_image_pages(const char *what, void *begin, void *end);
732 
733 void default_idle(void);
734 #ifdef	CONFIG_XEN
735 bool xen_set_default_idle(void);
736 #else
737 #define xen_set_default_idle 0
738 #endif
739 
740 void __noreturn stop_this_cpu(void *dummy);
741 void microcode_check(struct cpuinfo_x86 *prev_info);
742 void store_cpu_caps(struct cpuinfo_x86 *info);
743 
744 enum l1tf_mitigations {
745 	L1TF_MITIGATION_OFF,
746 	L1TF_MITIGATION_FLUSH_NOWARN,
747 	L1TF_MITIGATION_FLUSH,
748 	L1TF_MITIGATION_FLUSH_NOSMT,
749 	L1TF_MITIGATION_FULL,
750 	L1TF_MITIGATION_FULL_FORCE
751 };
752 
753 extern enum l1tf_mitigations l1tf_mitigation;
754 
755 enum mds_mitigations {
756 	MDS_MITIGATION_OFF,
757 	MDS_MITIGATION_FULL,
758 	MDS_MITIGATION_VMWERV,
759 };
760 
761 extern bool gds_ucode_mitigated(void);
762 
763 /*
764  * Make previous memory operations globally visible before
765  * a WRMSR.
766  *
767  * MFENCE makes writes visible, but only affects load/store
768  * instructions.  WRMSR is unfortunately not a load/store
769  * instruction and is unaffected by MFENCE.  The LFENCE ensures
770  * that the WRMSR is not reordered.
771  *
772  * Most WRMSRs are full serializing instructions themselves and
773  * do not require this barrier.  This is only required for the
774  * IA32_TSC_DEADLINE and X2APIC MSRs.
775  */
776 static inline void weak_wrmsr_fence(void)
777 {
778 	alternative("mfence; lfence", "", ALT_NOT(X86_FEATURE_APIC_MSRS_FENCE));
779 }
780 
781 #endif /* _ASM_X86_PROCESSOR_H */
782