xref: /openbmc/linux/arch/x86/include/asm/processor.h (revision 0661cb2a)
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 	u32			microcode;
140 	/* Address space bits used by the cache internally */
141 	u8			x86_cache_bits;
142 	unsigned		initialized : 1;
143 } __randomize_layout;
144 
145 struct cpuid_regs {
146 	u32 eax, ebx, ecx, edx;
147 };
148 
149 enum cpuid_regs_idx {
150 	CPUID_EAX = 0,
151 	CPUID_EBX,
152 	CPUID_ECX,
153 	CPUID_EDX,
154 };
155 
156 #define X86_VENDOR_INTEL	0
157 #define X86_VENDOR_CYRIX	1
158 #define X86_VENDOR_AMD		2
159 #define X86_VENDOR_UMC		3
160 #define X86_VENDOR_CENTAUR	5
161 #define X86_VENDOR_TRANSMETA	7
162 #define X86_VENDOR_NSC		8
163 #define X86_VENDOR_HYGON	9
164 #define X86_VENDOR_ZHAOXIN	10
165 #define X86_VENDOR_NUM		11
166 
167 #define X86_VENDOR_UNKNOWN	0xff
168 
169 /*
170  * capabilities of CPUs
171  */
172 extern struct cpuinfo_x86	boot_cpu_data;
173 extern struct cpuinfo_x86	new_cpu_data;
174 
175 extern __u32			cpu_caps_cleared[NCAPINTS + NBUGINTS];
176 extern __u32			cpu_caps_set[NCAPINTS + NBUGINTS];
177 
178 #ifdef CONFIG_SMP
179 DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
180 #define cpu_data(cpu)		per_cpu(cpu_info, cpu)
181 #else
182 #define cpu_info		boot_cpu_data
183 #define cpu_data(cpu)		boot_cpu_data
184 #endif
185 
186 extern const struct seq_operations cpuinfo_op;
187 
188 #define cache_line_size()	(boot_cpu_data.x86_cache_alignment)
189 
190 extern void cpu_detect(struct cpuinfo_x86 *c);
191 
192 static inline unsigned long long l1tf_pfn_limit(void)
193 {
194 	return BIT_ULL(boot_cpu_data.x86_cache_bits - 1 - PAGE_SHIFT);
195 }
196 
197 extern void early_cpu_init(void);
198 extern void identify_boot_cpu(void);
199 extern void identify_secondary_cpu(struct cpuinfo_x86 *);
200 extern void print_cpu_info(struct cpuinfo_x86 *);
201 void print_cpu_msr(struct cpuinfo_x86 *);
202 
203 #ifdef CONFIG_X86_32
204 extern int have_cpuid_p(void);
205 #else
206 static inline int have_cpuid_p(void)
207 {
208 	return 1;
209 }
210 #endif
211 static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
212 				unsigned int *ecx, unsigned int *edx)
213 {
214 	/* ecx is often an input as well as an output. */
215 	asm volatile("cpuid"
216 	    : "=a" (*eax),
217 	      "=b" (*ebx),
218 	      "=c" (*ecx),
219 	      "=d" (*edx)
220 	    : "0" (*eax), "2" (*ecx)
221 	    : "memory");
222 }
223 
224 #define native_cpuid_reg(reg)					\
225 static inline unsigned int native_cpuid_##reg(unsigned int op)	\
226 {								\
227 	unsigned int eax = op, ebx, ecx = 0, edx;		\
228 								\
229 	native_cpuid(&eax, &ebx, &ecx, &edx);			\
230 								\
231 	return reg;						\
232 }
233 
234 /*
235  * Native CPUID functions returning a single datum.
236  */
237 native_cpuid_reg(eax)
238 native_cpuid_reg(ebx)
239 native_cpuid_reg(ecx)
240 native_cpuid_reg(edx)
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(unsigned long, cpu_current_top_of_stack);
425 
426 #ifdef CONFIG_X86_64
427 struct fixed_percpu_data {
428 	/*
429 	 * GCC hardcodes the stack canary as %gs:40.  Since the
430 	 * irq_stack is the object at %gs:0, we reserve the bottom
431 	 * 48 bytes of the irq stack for the canary.
432 	 *
433 	 * Once we are willing to require -mstack-protector-guard-symbol=
434 	 * support for x86_64 stackprotector, we can get rid of this.
435 	 */
436 	char		gs_base[40];
437 	unsigned long	stack_canary;
438 };
439 
440 DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible;
441 DECLARE_INIT_PER_CPU(fixed_percpu_data);
442 
443 static inline unsigned long cpu_kernelmode_gs_base(int cpu)
444 {
445 	return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
446 }
447 
448 DECLARE_PER_CPU(void *, hardirq_stack_ptr);
449 DECLARE_PER_CPU(bool, hardirq_stack_inuse);
450 extern asmlinkage void ignore_sysret(void);
451 
452 /* Save actual FS/GS selectors and bases to current->thread */
453 void current_save_fsgs(void);
454 #else	/* X86_64 */
455 #ifdef CONFIG_STACKPROTECTOR
456 DECLARE_PER_CPU(unsigned long, __stack_chk_guard);
457 #endif
458 DECLARE_PER_CPU(struct irq_stack *, hardirq_stack_ptr);
459 DECLARE_PER_CPU(struct irq_stack *, softirq_stack_ptr);
460 #endif	/* !X86_64 */
461 
462 extern unsigned int fpu_kernel_xstate_size;
463 extern unsigned int fpu_user_xstate_size;
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		sig_on_uaccess_err:1;
520 
521 	/*
522 	 * Protection Keys Register for Userspace.  Loaded immediately on
523 	 * context switch. Store it in thread_struct to avoid a lookup in
524 	 * the tasks's FPU xstate buffer. This value is only valid when a
525 	 * task is scheduled out. For 'current' the authoritative source of
526 	 * PKRU is the hardware itself.
527 	 */
528 	u32			pkru;
529 
530 	/* Floating point and extended processor state */
531 	struct fpu		fpu;
532 	/*
533 	 * WARNING: 'fpu' is dynamically-sized.  It *MUST* be at
534 	 * the end.
535 	 */
536 };
537 
538 /* Whitelist the FPU state from the task_struct for hardened usercopy. */
539 static inline void arch_thread_struct_whitelist(unsigned long *offset,
540 						unsigned long *size)
541 {
542 	*offset = offsetof(struct thread_struct, fpu.state);
543 	*size = fpu_kernel_xstate_size;
544 }
545 
546 static inline void
547 native_load_sp0(unsigned long sp0)
548 {
549 	this_cpu_write(cpu_tss_rw.x86_tss.sp0, sp0);
550 }
551 
552 static __always_inline void native_swapgs(void)
553 {
554 #ifdef CONFIG_X86_64
555 	asm volatile("swapgs" ::: "memory");
556 #endif
557 }
558 
559 static inline unsigned long current_top_of_stack(void)
560 {
561 	/*
562 	 *  We can't read directly from tss.sp0: sp0 on x86_32 is special in
563 	 *  and around vm86 mode and sp0 on x86_64 is special because of the
564 	 *  entry trampoline.
565 	 */
566 	return this_cpu_read_stable(cpu_current_top_of_stack);
567 }
568 
569 static inline bool on_thread_stack(void)
570 {
571 	return (unsigned long)(current_top_of_stack() -
572 			       current_stack_pointer) < THREAD_SIZE;
573 }
574 
575 #ifdef CONFIG_PARAVIRT_XXL
576 #include <asm/paravirt.h>
577 #else
578 #define __cpuid			native_cpuid
579 
580 static inline void load_sp0(unsigned long sp0)
581 {
582 	native_load_sp0(sp0);
583 }
584 
585 #endif /* CONFIG_PARAVIRT_XXL */
586 
587 /* Free all resources held by a thread. */
588 extern void release_thread(struct task_struct *);
589 
590 unsigned long get_wchan(struct task_struct *p);
591 
592 /*
593  * Generic CPUID function
594  * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
595  * resulting in stale register contents being returned.
596  */
597 static inline void cpuid(unsigned int op,
598 			 unsigned int *eax, unsigned int *ebx,
599 			 unsigned int *ecx, unsigned int *edx)
600 {
601 	*eax = op;
602 	*ecx = 0;
603 	__cpuid(eax, ebx, ecx, edx);
604 }
605 
606 /* Some CPUID calls want 'count' to be placed in ecx */
607 static inline void cpuid_count(unsigned int op, int count,
608 			       unsigned int *eax, unsigned int *ebx,
609 			       unsigned int *ecx, unsigned int *edx)
610 {
611 	*eax = op;
612 	*ecx = count;
613 	__cpuid(eax, ebx, ecx, edx);
614 }
615 
616 /*
617  * CPUID functions returning a single datum
618  */
619 static inline unsigned int cpuid_eax(unsigned int op)
620 {
621 	unsigned int eax, ebx, ecx, edx;
622 
623 	cpuid(op, &eax, &ebx, &ecx, &edx);
624 
625 	return eax;
626 }
627 
628 static inline unsigned int cpuid_ebx(unsigned int op)
629 {
630 	unsigned int eax, ebx, ecx, edx;
631 
632 	cpuid(op, &eax, &ebx, &ecx, &edx);
633 
634 	return ebx;
635 }
636 
637 static inline unsigned int cpuid_ecx(unsigned int op)
638 {
639 	unsigned int eax, ebx, ecx, edx;
640 
641 	cpuid(op, &eax, &ebx, &ecx, &edx);
642 
643 	return ecx;
644 }
645 
646 static inline unsigned int cpuid_edx(unsigned int op)
647 {
648 	unsigned int eax, ebx, ecx, edx;
649 
650 	cpuid(op, &eax, &ebx, &ecx, &edx);
651 
652 	return edx;
653 }
654 
655 extern void select_idle_routine(const struct cpuinfo_x86 *c);
656 extern void amd_e400_c1e_apic_setup(void);
657 
658 extern unsigned long		boot_option_idle_override;
659 
660 enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
661 			 IDLE_POLL};
662 
663 extern void enable_sep_cpu(void);
664 extern int sysenter_setup(void);
665 
666 
667 /* Defined in head.S */
668 extern struct desc_ptr		early_gdt_descr;
669 
670 extern void switch_to_new_gdt(int);
671 extern void load_direct_gdt(int);
672 extern void load_fixmap_gdt(int);
673 extern void load_percpu_segment(int);
674 extern void cpu_init(void);
675 extern void cpu_init_secondary(void);
676 extern void cpu_init_exception_handling(void);
677 extern void cr4_init(void);
678 
679 static inline unsigned long get_debugctlmsr(void)
680 {
681 	unsigned long debugctlmsr = 0;
682 
683 #ifndef CONFIG_X86_DEBUGCTLMSR
684 	if (boot_cpu_data.x86 < 6)
685 		return 0;
686 #endif
687 	rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
688 
689 	return debugctlmsr;
690 }
691 
692 static inline void update_debugctlmsr(unsigned long debugctlmsr)
693 {
694 #ifndef CONFIG_X86_DEBUGCTLMSR
695 	if (boot_cpu_data.x86 < 6)
696 		return;
697 #endif
698 	wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
699 }
700 
701 extern void set_task_blockstep(struct task_struct *task, bool on);
702 
703 /* Boot loader type from the setup header: */
704 extern int			bootloader_type;
705 extern int			bootloader_version;
706 
707 extern char			ignore_fpu_irq;
708 
709 #define HAVE_ARCH_PICK_MMAP_LAYOUT 1
710 #define ARCH_HAS_PREFETCHW
711 #define ARCH_HAS_SPINLOCK_PREFETCH
712 
713 #ifdef CONFIG_X86_32
714 # define BASE_PREFETCH		""
715 # define ARCH_HAS_PREFETCH
716 #else
717 # define BASE_PREFETCH		"prefetcht0 %P1"
718 #endif
719 
720 /*
721  * Prefetch instructions for Pentium III (+) and AMD Athlon (+)
722  *
723  * It's not worth to care about 3dnow prefetches for the K6
724  * because they are microcoded there and very slow.
725  */
726 static inline void prefetch(const void *x)
727 {
728 	alternative_input(BASE_PREFETCH, "prefetchnta %P1",
729 			  X86_FEATURE_XMM,
730 			  "m" (*(const char *)x));
731 }
732 
733 /*
734  * 3dnow prefetch to get an exclusive cache line.
735  * Useful for spinlocks to avoid one state transition in the
736  * cache coherency protocol:
737  */
738 static __always_inline void prefetchw(const void *x)
739 {
740 	alternative_input(BASE_PREFETCH, "prefetchw %P1",
741 			  X86_FEATURE_3DNOWPREFETCH,
742 			  "m" (*(const char *)x));
743 }
744 
745 static inline void spin_lock_prefetch(const void *x)
746 {
747 	prefetchw(x);
748 }
749 
750 #define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \
751 			   TOP_OF_KERNEL_STACK_PADDING)
752 
753 #define task_top_of_stack(task) ((unsigned long)(task_pt_regs(task) + 1))
754 
755 #define task_pt_regs(task) \
756 ({									\
757 	unsigned long __ptr = (unsigned long)task_stack_page(task);	\
758 	__ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;		\
759 	((struct pt_regs *)__ptr) - 1;					\
760 })
761 
762 #ifdef CONFIG_X86_32
763 #define INIT_THREAD  {							  \
764 	.sp0			= TOP_OF_INIT_STACK,			  \
765 	.sysenter_cs		= __KERNEL_CS,				  \
766 }
767 
768 #define KSTK_ESP(task)		(task_pt_regs(task)->sp)
769 
770 #else
771 #define INIT_THREAD { }
772 
773 extern unsigned long KSTK_ESP(struct task_struct *task);
774 
775 #endif /* CONFIG_X86_64 */
776 
777 extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
778 					       unsigned long new_sp);
779 
780 /*
781  * This decides where the kernel will search for a free chunk of vm
782  * space during mmap's.
783  */
784 #define __TASK_UNMAPPED_BASE(task_size)	(PAGE_ALIGN(task_size / 3))
785 #define TASK_UNMAPPED_BASE		__TASK_UNMAPPED_BASE(TASK_SIZE_LOW)
786 
787 #define KSTK_EIP(task)		(task_pt_regs(task)->ip)
788 
789 /* Get/set a process' ability to use the timestamp counter instruction */
790 #define GET_TSC_CTL(adr)	get_tsc_mode((adr))
791 #define SET_TSC_CTL(val)	set_tsc_mode((val))
792 
793 extern int get_tsc_mode(unsigned long adr);
794 extern int set_tsc_mode(unsigned int val);
795 
796 DECLARE_PER_CPU(u64, msr_misc_features_shadow);
797 
798 #ifdef CONFIG_CPU_SUP_AMD
799 extern u32 amd_get_nodes_per_socket(void);
800 extern u32 amd_get_highest_perf(void);
801 #else
802 static inline u32 amd_get_nodes_per_socket(void)	{ return 0; }
803 static inline u32 amd_get_highest_perf(void)		{ return 0; }
804 #endif
805 
806 static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
807 {
808 	uint32_t base, eax, signature[3];
809 
810 	for (base = 0x40000000; base < 0x40010000; base += 0x100) {
811 		cpuid(base, &eax, &signature[0], &signature[1], &signature[2]);
812 
813 		if (!memcmp(sig, signature, 12) &&
814 		    (leaves == 0 || ((eax - base) >= leaves)))
815 			return base;
816 	}
817 
818 	return 0;
819 }
820 
821 extern unsigned long arch_align_stack(unsigned long sp);
822 void free_init_pages(const char *what, unsigned long begin, unsigned long end);
823 extern void free_kernel_image_pages(const char *what, void *begin, void *end);
824 
825 void default_idle(void);
826 #ifdef	CONFIG_XEN
827 bool xen_set_default_idle(void);
828 #else
829 #define xen_set_default_idle 0
830 #endif
831 
832 void stop_this_cpu(void *dummy);
833 void microcode_check(void);
834 
835 enum l1tf_mitigations {
836 	L1TF_MITIGATION_OFF,
837 	L1TF_MITIGATION_FLUSH_NOWARN,
838 	L1TF_MITIGATION_FLUSH,
839 	L1TF_MITIGATION_FLUSH_NOSMT,
840 	L1TF_MITIGATION_FULL,
841 	L1TF_MITIGATION_FULL_FORCE
842 };
843 
844 extern enum l1tf_mitigations l1tf_mitigation;
845 
846 enum mds_mitigations {
847 	MDS_MITIGATION_OFF,
848 	MDS_MITIGATION_FULL,
849 	MDS_MITIGATION_VMWERV,
850 };
851 
852 #endif /* _ASM_X86_PROCESSOR_H */
853