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