linux/arch/x86/include/asm/processor.h
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   1#ifndef _ASM_X86_PROCESSOR_H
   2#define _ASM_X86_PROCESSOR_H
   3
   4#include <asm/processor-flags.h>
   5
   6/* Forward declaration, a strange C thing */
   7struct task_struct;
   8struct mm_struct;
   9
  10#include <asm/vm86.h>
  11#include <asm/math_emu.h>
  12#include <asm/segment.h>
  13#include <asm/types.h>
  14#include <asm/sigcontext.h>
  15#include <asm/current.h>
  16#include <asm/cpufeature.h>
  17#include <asm/page.h>
  18#include <asm/pgtable_types.h>
  19#include <asm/percpu.h>
  20#include <asm/msr.h>
  21#include <asm/desc_defs.h>
  22#include <asm/nops.h>
  23#include <asm/special_insns.h>
  24
  25#include <linux/personality.h>
  26#include <linux/cpumask.h>
  27#include <linux/cache.h>
  28#include <linux/threads.h>
  29#include <linux/math64.h>
  30#include <linux/err.h>
  31#include <linux/irqflags.h>
  32
  33/*
  34 * We handle most unaligned accesses in hardware.  On the other hand
  35 * unaligned DMA can be quite expensive on some Nehalem processors.
  36 *
  37 * Based on this we disable the IP header alignment in network drivers.
  38 */
  39#define NET_IP_ALIGN    0
  40
  41#define HBP_NUM 4
  42/*
  43 * Default implementation of macro that returns current
  44 * instruction pointer ("program counter").
  45 */
  46static inline void *current_text_addr(void)
  47{
  48        void *pc;
  49
  50        asm volatile("mov $1f, %0; 1:":"=r" (pc));
  51
  52        return pc;
  53}
  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             16
  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];
  75extern s8  __read_mostly tlb_flushall_shift;
  76
  77/*
  78 *  CPU type and hardware bug flags. Kept separately for each CPU.
  79 *  Members of this structure are referenced in head.S, so think twice
  80 *  before touching them. [mj]
  81 */
  82
  83struct cpuinfo_x86 {
  84        __u8                    x86;            /* CPU family */
  85        __u8                    x86_vendor;     /* CPU vendor */
  86        __u8                    x86_model;
  87        __u8                    x86_mask;
  88#ifdef CONFIG_X86_32
  89        char                    wp_works_ok;    /* It doesn't on 386's */
  90
  91        /* Problems on some 486Dx4's and old 386's: */
  92        char                    rfu;
  93        char                    pad0;
  94        char                    pad1;
  95#else
  96        /* Number of 4K pages in DTLB/ITLB combined(in pages): */
  97        int                     x86_tlbsize;
  98#endif
  99        __u8                    x86_virt_bits;
 100        __u8                    x86_phys_bits;
 101        /* CPUID returned core id bits: */
 102        __u8                    x86_coreid_bits;
 103        /* Max extended CPUID function supported: */
 104        __u32                   extended_cpuid_level;
 105        /* Maximum supported CPUID level, -1=no CPUID: */
 106        int                     cpuid_level;
 107        __u32                   x86_capability[NCAPINTS + NBUGINTS];
 108        char                    x86_vendor_id[16];
 109        char                    x86_model_id[64];
 110        /* in KB - valid for CPUS which support this call: */
 111        int                     x86_cache_size;
 112        int                     x86_cache_alignment;    /* In bytes */
 113        int                     x86_power;
 114        unsigned long           loops_per_jiffy;
 115        /* cpuid returned max cores value: */
 116        u16                      x86_max_cores;
 117        u16                     apicid;
 118        u16                     initial_apicid;
 119        u16                     x86_clflush_size;
 120        /* number of cores as seen by the OS: */
 121        u16                     booted_cores;
 122        /* Physical processor id: */
 123        u16                     phys_proc_id;
 124        /* Core id: */
 125        u16                     cpu_core_id;
 126        /* Compute unit id */
 127        u8                      compute_unit_id;
 128        /* Index into per_cpu list: */
 129        u16                     cpu_index;
 130        u32                     microcode;
 131} __attribute__((__aligned__(SMP_CACHE_BYTES)));
 132
 133#define X86_VENDOR_INTEL        0
 134#define X86_VENDOR_CYRIX        1
 135#define X86_VENDOR_AMD          2
 136#define X86_VENDOR_UMC          3
 137#define X86_VENDOR_CENTAUR      5
 138#define X86_VENDOR_TRANSMETA    7
 139#define X86_VENDOR_NSC          8
 140#define X86_VENDOR_NUM          9
 141
 142#define X86_VENDOR_UNKNOWN      0xff
 143
 144/*
 145 * capabilities of CPUs
 146 */
 147extern struct cpuinfo_x86       boot_cpu_data;
 148extern struct cpuinfo_x86       new_cpu_data;
 149
 150extern struct tss_struct        doublefault_tss;
 151extern __u32                    cpu_caps_cleared[NCAPINTS];
 152extern __u32                    cpu_caps_set[NCAPINTS];
 153
 154#ifdef CONFIG_SMP
 155DECLARE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
 156#define cpu_data(cpu)           per_cpu(cpu_info, cpu)
 157#else
 158#define cpu_info                boot_cpu_data
 159#define cpu_data(cpu)           boot_cpu_data
 160#endif
 161
 162extern const struct seq_operations cpuinfo_op;
 163
 164#define cache_line_size()       (boot_cpu_data.x86_cache_alignment)
 165
 166extern void cpu_detect(struct cpuinfo_x86 *c);
 167extern void fpu_detect(struct cpuinfo_x86 *c);
 168
 169extern void early_cpu_init(void);
 170extern void identify_boot_cpu(void);
 171extern void identify_secondary_cpu(struct cpuinfo_x86 *);
 172extern void print_cpu_info(struct cpuinfo_x86 *);
 173void print_cpu_msr(struct cpuinfo_x86 *);
 174extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
 175extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
 176extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
 177
 178extern void detect_extended_topology(struct cpuinfo_x86 *c);
 179extern void detect_ht(struct cpuinfo_x86 *c);
 180
 181#ifdef CONFIG_X86_32
 182extern int have_cpuid_p(void);
 183#else
 184static inline int have_cpuid_p(void)
 185{
 186        return 1;
 187}
 188#endif
 189static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
 190                                unsigned int *ecx, unsigned int *edx)
 191{
 192        /* ecx is often an input as well as an output. */
 193        asm volatile("cpuid"
 194            : "=a" (*eax),
 195              "=b" (*ebx),
 196              "=c" (*ecx),
 197              "=d" (*edx)
 198            : "0" (*eax), "2" (*ecx)
 199            : "memory");
 200}
 201
 202static inline void load_cr3(pgd_t *pgdir)
 203{
 204        write_cr3(__pa(pgdir));
 205}
 206
 207#ifdef CONFIG_X86_32
 208/* This is the TSS defined by the hardware. */
 209struct x86_hw_tss {
 210        unsigned short          back_link, __blh;
 211        unsigned long           sp0;
 212        unsigned short          ss0, __ss0h;
 213        unsigned long           sp1;
 214        /* ss1 caches MSR_IA32_SYSENTER_CS: */
 215        unsigned short          ss1, __ss1h;
 216        unsigned long           sp2;
 217        unsigned short          ss2, __ss2h;
 218        unsigned long           __cr3;
 219        unsigned long           ip;
 220        unsigned long           flags;
 221        unsigned long           ax;
 222        unsigned long           cx;
 223        unsigned long           dx;
 224        unsigned long           bx;
 225        unsigned long           sp;
 226        unsigned long           bp;
 227        unsigned long           si;
 228        unsigned long           di;
 229        unsigned short          es, __esh;
 230        unsigned short          cs, __csh;
 231        unsigned short          ss, __ssh;
 232        unsigned short          ds, __dsh;
 233        unsigned short          fs, __fsh;
 234        unsigned short          gs, __gsh;
 235        unsigned short          ldt, __ldth;
 236        unsigned short          trace;
 237        unsigned short          io_bitmap_base;
 238
 239} __attribute__((packed));
 240#else
 241struct x86_hw_tss {
 242        u32                     reserved1;
 243        u64                     sp0;
 244        u64                     sp1;
 245        u64                     sp2;
 246        u64                     reserved2;
 247        u64                     ist[7];
 248        u32                     reserved3;
 249        u32                     reserved4;
 250        u16                     reserved5;
 251        u16                     io_bitmap_base;
 252
 253} __attribute__((packed)) ____cacheline_aligned;
 254#endif
 255
 256/*
 257 * IO-bitmap sizes:
 258 */
 259#define IO_BITMAP_BITS                  65536
 260#define IO_BITMAP_BYTES                 (IO_BITMAP_BITS/8)
 261#define IO_BITMAP_LONGS                 (IO_BITMAP_BYTES/sizeof(long))
 262#define IO_BITMAP_OFFSET                offsetof(struct tss_struct, io_bitmap)
 263#define INVALID_IO_BITMAP_OFFSET        0x8000
 264
 265struct tss_struct {
 266        /*
 267         * The hardware state:
 268         */
 269        struct x86_hw_tss       x86_tss;
 270
 271        /*
 272         * The extra 1 is there because the CPU will access an
 273         * additional byte beyond the end of the IO permission
 274         * bitmap. The extra byte must be all 1 bits, and must
 275         * be within the limit.
 276         */
 277        unsigned long           io_bitmap[IO_BITMAP_LONGS + 1];
 278
 279        /*
 280         * .. and then another 0x100 bytes for the emergency kernel stack:
 281         */
 282        unsigned long           stack[64];
 283
 284} ____cacheline_aligned;
 285
 286DECLARE_PER_CPU_SHARED_ALIGNED(struct tss_struct, init_tss);
 287
 288/*
 289 * Save the original ist values for checking stack pointers during debugging
 290 */
 291struct orig_ist {
 292        unsigned long           ist[7];
 293};
 294
 295#define MXCSR_DEFAULT           0x1f80
 296
 297struct i387_fsave_struct {
 298        u32                     cwd;    /* FPU Control Word             */
 299        u32                     swd;    /* FPU Status Word              */
 300        u32                     twd;    /* FPU Tag Word                 */
 301        u32                     fip;    /* FPU IP Offset                */
 302        u32                     fcs;    /* FPU IP Selector              */
 303        u32                     foo;    /* FPU Operand Pointer Offset   */
 304        u32                     fos;    /* FPU Operand Pointer Selector */
 305
 306        /* 8*10 bytes for each FP-reg = 80 bytes:                       */
 307        u32                     st_space[20];
 308
 309        /* Software status information [not touched by FSAVE ]:         */
 310        u32                     status;
 311};
 312
 313struct i387_fxsave_struct {
 314        u16                     cwd; /* Control Word                    */
 315        u16                     swd; /* Status Word                     */
 316        u16                     twd; /* Tag Word                        */
 317        u16                     fop; /* Last Instruction Opcode         */
 318        union {
 319                struct {
 320                        u64     rip; /* Instruction Pointer             */
 321                        u64     rdp; /* Data Pointer                    */
 322                };
 323                struct {
 324                        u32     fip; /* FPU IP Offset                   */
 325                        u32     fcs; /* FPU IP Selector                 */
 326                        u32     foo; /* FPU Operand Offset              */
 327                        u32     fos; /* FPU Operand Selector            */
 328                };
 329        };
 330        u32                     mxcsr;          /* MXCSR Register State */
 331        u32                     mxcsr_mask;     /* MXCSR Mask           */
 332
 333        /* 8*16 bytes for each FP-reg = 128 bytes:                      */
 334        u32                     st_space[32];
 335
 336        /* 16*16 bytes for each XMM-reg = 256 bytes:                    */
 337        u32                     xmm_space[64];
 338
 339        u32                     padding[12];
 340
 341        union {
 342                u32             padding1[12];
 343                u32             sw_reserved[12];
 344        };
 345
 346} __attribute__((aligned(16)));
 347
 348struct i387_soft_struct {
 349        u32                     cwd;
 350        u32                     swd;
 351        u32                     twd;
 352        u32                     fip;
 353        u32                     fcs;
 354        u32                     foo;
 355        u32                     fos;
 356        /* 8*10 bytes for each FP-reg = 80 bytes: */
 357        u32                     st_space[20];
 358        u8                      ftop;
 359        u8                      changed;
 360        u8                      lookahead;
 361        u8                      no_update;
 362        u8                      rm;
 363        u8                      alimit;
 364        struct math_emu_info    *info;
 365        u32                     entry_eip;
 366};
 367
 368struct ymmh_struct {
 369        /* 16 * 16 bytes for each YMMH-reg = 256 bytes */
 370        u32 ymmh_space[64];
 371};
 372
 373/* We don't support LWP yet: */
 374struct lwp_struct {
 375        u8 reserved[128];
 376};
 377
 378struct bndregs_struct {
 379        u64 bndregs[8];
 380} __packed;
 381
 382struct bndcsr_struct {
 383        u64 cfg_reg_u;
 384        u64 status_reg;
 385} __packed;
 386
 387struct xsave_hdr_struct {
 388        u64 xstate_bv;
 389        u64 reserved1[2];
 390        u64 reserved2[5];
 391} __attribute__((packed));
 392
 393struct xsave_struct {
 394        struct i387_fxsave_struct i387;
 395        struct xsave_hdr_struct xsave_hdr;
 396        struct ymmh_struct ymmh;
 397        struct lwp_struct lwp;
 398        struct bndregs_struct bndregs;
 399        struct bndcsr_struct bndcsr;
 400        /* new processor state extensions will go here */
 401} __attribute__ ((packed, aligned (64)));
 402
 403union thread_xstate {
 404        struct i387_fsave_struct        fsave;
 405        struct i387_fxsave_struct       fxsave;
 406        struct i387_soft_struct         soft;
 407        struct xsave_struct             xsave;
 408};
 409
 410struct fpu {
 411        unsigned int last_cpu;
 412        unsigned int has_fpu;
 413        union thread_xstate *state;
 414};
 415
 416#ifdef CONFIG_X86_64
 417DECLARE_PER_CPU(struct orig_ist, orig_ist);
 418
 419union irq_stack_union {
 420        char irq_stack[IRQ_STACK_SIZE];
 421        /*
 422         * GCC hardcodes the stack canary as %gs:40.  Since the
 423         * irq_stack is the object at %gs:0, we reserve the bottom
 424         * 48 bytes of the irq stack for the canary.
 425         */
 426        struct {
 427                char gs_base[40];
 428                unsigned long stack_canary;
 429        };
 430};
 431
 432DECLARE_PER_CPU_FIRST(union irq_stack_union, irq_stack_union) __visible;
 433DECLARE_INIT_PER_CPU(irq_stack_union);
 434
 435DECLARE_PER_CPU(char *, irq_stack_ptr);
 436DECLARE_PER_CPU(unsigned int, irq_count);
 437extern asmlinkage void ignore_sysret(void);
 438#else   /* X86_64 */
 439#ifdef CONFIG_CC_STACKPROTECTOR
 440/*
 441 * Make sure stack canary segment base is cached-aligned:
 442 *   "For Intel Atom processors, avoid non zero segment base address
 443 *    that is not aligned to cache line boundary at all cost."
 444 * (Optim Ref Manual Assembly/Compiler Coding Rule 15.)
 445 */
 446struct stack_canary {
 447        char __pad[20];         /* canary at %gs:20 */
 448        unsigned long canary;
 449};
 450DECLARE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
 451#endif
 452/*
 453 * per-CPU IRQ handling stacks
 454 */
 455struct irq_stack {
 456        u32                     stack[THREAD_SIZE/sizeof(u32)];
 457} __aligned(THREAD_SIZE);
 458
 459DECLARE_PER_CPU(struct irq_stack *, hardirq_stack);
 460DECLARE_PER_CPU(struct irq_stack *, softirq_stack);
 461#endif  /* X86_64 */
 462
 463extern unsigned int xstate_size;
 464extern void free_thread_xstate(struct task_struct *);
 465extern struct kmem_cache *task_xstate_cachep;
 466
 467struct perf_event;
 468
 469struct thread_struct {
 470        /* Cached TLS descriptors: */
 471        struct desc_struct      tls_array[GDT_ENTRY_TLS_ENTRIES];
 472        unsigned long           sp0;
 473        unsigned long           sp;
 474#ifdef CONFIG_X86_32
 475        unsigned long           sysenter_cs;
 476#else
 477        unsigned long           usersp; /* Copy from PDA */
 478        unsigned short          es;
 479        unsigned short          ds;
 480        unsigned short          fsindex;
 481        unsigned short          gsindex;
 482#endif
 483#ifdef CONFIG_X86_32
 484        unsigned long           ip;
 485#endif
 486#ifdef CONFIG_X86_64
 487        unsigned long           fs;
 488#endif
 489        unsigned long           gs;
 490        /* Save middle states of ptrace breakpoints */
 491        struct perf_event       *ptrace_bps[HBP_NUM];
 492        /* Debug status used for traps, single steps, etc... */
 493        unsigned long           debugreg6;
 494        /* Keep track of the exact dr7 value set by the user */
 495        unsigned long           ptrace_dr7;
 496        /* Fault info: */
 497        unsigned long           cr2;
 498        unsigned long           trap_nr;
 499        unsigned long           error_code;
 500        /* floating point and extended processor state */
 501        struct fpu              fpu;
 502#ifdef CONFIG_X86_32
 503        /* Virtual 86 mode info */
 504        struct vm86_struct __user *vm86_info;
 505        unsigned long           screen_bitmap;
 506        unsigned long           v86flags;
 507        unsigned long           v86mask;
 508        unsigned long           saved_sp0;
 509        unsigned int            saved_fs;
 510        unsigned int            saved_gs;
 511#endif
 512        /* IO permissions: */
 513        unsigned long           *io_bitmap_ptr;
 514        unsigned long           iopl;
 515        /* Max allowed port in the bitmap, in bytes: */
 516        unsigned                io_bitmap_max;
 517        /*
 518         * fpu_counter contains the number of consecutive context switches
 519         * that the FPU is used. If this is over a threshold, the lazy fpu
 520         * saving becomes unlazy to save the trap. This is an unsigned char
 521         * so that after 256 times the counter wraps and the behavior turns
 522         * lazy again; this to deal with bursty apps that only use FPU for
 523         * a short time
 524         */
 525        unsigned char fpu_counter;
 526};
 527
 528/*
 529 * Set IOPL bits in EFLAGS from given mask
 530 */
 531static inline void native_set_iopl_mask(unsigned mask)
 532{
 533#ifdef CONFIG_X86_32
 534        unsigned int reg;
 535
 536        asm volatile ("pushfl;"
 537                      "popl %0;"
 538                      "andl %1, %0;"
 539                      "orl %2, %0;"
 540                      "pushl %0;"
 541                      "popfl"
 542                      : "=&r" (reg)
 543                      : "i" (~X86_EFLAGS_IOPL), "r" (mask));
 544#endif
 545}
 546
 547static inline void
 548native_load_sp0(struct tss_struct *tss, struct thread_struct *thread)
 549{
 550        tss->x86_tss.sp0 = thread->sp0;
 551#ifdef CONFIG_X86_32
 552        /* Only happens when SEP is enabled, no need to test "SEP"arately: */
 553        if (unlikely(tss->x86_tss.ss1 != thread->sysenter_cs)) {
 554                tss->x86_tss.ss1 = thread->sysenter_cs;
 555                wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
 556        }
 557#endif
 558}
 559
 560static inline void native_swapgs(void)
 561{
 562#ifdef CONFIG_X86_64
 563        asm volatile("swapgs" ::: "memory");
 564#endif
 565}
 566
 567#ifdef CONFIG_PARAVIRT
 568#include <asm/paravirt.h>
 569#else
 570#define __cpuid                 native_cpuid
 571#define paravirt_enabled()      0
 572
 573static inline void load_sp0(struct tss_struct *tss,
 574                            struct thread_struct *thread)
 575{
 576        native_load_sp0(tss, thread);
 577}
 578
 579#define set_iopl_mask native_set_iopl_mask
 580#endif /* CONFIG_PARAVIRT */
 581
 582/*
 583 * Save the cr4 feature set we're using (ie
 584 * Pentium 4MB enable and PPro Global page
 585 * enable), so that any CPU's that boot up
 586 * after us can get the correct flags.
 587 */
 588extern unsigned long mmu_cr4_features;
 589extern u32 *trampoline_cr4_features;
 590
 591static inline void set_in_cr4(unsigned long mask)
 592{
 593        unsigned long cr4;
 594
 595        mmu_cr4_features |= mask;
 596        if (trampoline_cr4_features)
 597                *trampoline_cr4_features = mmu_cr4_features;
 598        cr4 = read_cr4();
 599        cr4 |= mask;
 600        write_cr4(cr4);
 601}
 602
 603static inline void clear_in_cr4(unsigned long mask)
 604{
 605        unsigned long cr4;
 606
 607        mmu_cr4_features &= ~mask;
 608        if (trampoline_cr4_features)
 609                *trampoline_cr4_features = mmu_cr4_features;
 610        cr4 = read_cr4();
 611        cr4 &= ~mask;
 612        write_cr4(cr4);
 613}
 614
 615typedef struct {
 616        unsigned long           seg;
 617} mm_segment_t;
 618
 619
 620/* Free all resources held by a thread. */
 621extern void release_thread(struct task_struct *);
 622
 623unsigned long get_wchan(struct task_struct *p);
 624
 625/*
 626 * Generic CPUID function
 627 * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
 628 * resulting in stale register contents being returned.
 629 */
 630static inline void cpuid(unsigned int op,
 631                         unsigned int *eax, unsigned int *ebx,
 632                         unsigned int *ecx, unsigned int *edx)
 633{
 634        *eax = op;
 635        *ecx = 0;
 636        __cpuid(eax, ebx, ecx, edx);
 637}
 638
 639/* Some CPUID calls want 'count' to be placed in ecx */
 640static inline void cpuid_count(unsigned int op, int count,
 641                               unsigned int *eax, unsigned int *ebx,
 642                               unsigned int *ecx, unsigned int *edx)
 643{
 644        *eax = op;
 645        *ecx = count;
 646        __cpuid(eax, ebx, ecx, edx);
 647}
 648
 649/*
 650 * CPUID functions returning a single datum
 651 */
 652static inline unsigned int cpuid_eax(unsigned int op)
 653{
 654        unsigned int eax, ebx, ecx, edx;
 655
 656        cpuid(op, &eax, &ebx, &ecx, &edx);
 657
 658        return eax;
 659}
 660
 661static inline unsigned int cpuid_ebx(unsigned int op)
 662{
 663        unsigned int eax, ebx, ecx, edx;
 664
 665        cpuid(op, &eax, &ebx, &ecx, &edx);
 666
 667        return ebx;
 668}
 669
 670static inline unsigned int cpuid_ecx(unsigned int op)
 671{
 672        unsigned int eax, ebx, ecx, edx;
 673
 674        cpuid(op, &eax, &ebx, &ecx, &edx);
 675
 676        return ecx;
 677}
 678
 679static inline unsigned int cpuid_edx(unsigned int op)
 680{
 681        unsigned int eax, ebx, ecx, edx;
 682
 683        cpuid(op, &eax, &ebx, &ecx, &edx);
 684
 685        return edx;
 686}
 687
 688/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
 689static inline void rep_nop(void)
 690{
 691        asm volatile("rep; nop" ::: "memory");
 692}
 693
 694static inline void cpu_relax(void)
 695{
 696        rep_nop();
 697}
 698
 699/* Stop speculative execution and prefetching of modified code. */
 700static inline void sync_core(void)
 701{
 702        int tmp;
 703
 704#ifdef CONFIG_M486
 705        /*
 706         * Do a CPUID if available, otherwise do a jump.  The jump
 707         * can conveniently enough be the jump around CPUID.
 708         */
 709        asm volatile("cmpl %2,%1\n\t"
 710                     "jl 1f\n\t"
 711                     "cpuid\n"
 712                     "1:"
 713                     : "=a" (tmp)
 714                     : "rm" (boot_cpu_data.cpuid_level), "ri" (0), "0" (1)
 715                     : "ebx", "ecx", "edx", "memory");
 716#else
 717        /*
 718         * CPUID is a barrier to speculative execution.
 719         * Prefetched instructions are automatically
 720         * invalidated when modified.
 721         */
 722        asm volatile("cpuid"
 723                     : "=a" (tmp)
 724                     : "0" (1)
 725                     : "ebx", "ecx", "edx", "memory");
 726#endif
 727}
 728
 729extern void select_idle_routine(const struct cpuinfo_x86 *c);
 730extern void init_amd_e400_c1e_mask(void);
 731
 732extern unsigned long            boot_option_idle_override;
 733extern bool                     amd_e400_c1e_detected;
 734
 735enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
 736                         IDLE_POLL};
 737
 738extern void enable_sep_cpu(void);
 739extern int sysenter_setup(void);
 740
 741extern void early_trap_init(void);
 742void early_trap_pf_init(void);
 743
 744/* Defined in head.S */
 745extern struct desc_ptr          early_gdt_descr;
 746
 747extern void cpu_set_gdt(int);
 748extern void switch_to_new_gdt(int);
 749extern void load_percpu_segment(int);
 750extern void cpu_init(void);
 751
 752static inline unsigned long get_debugctlmsr(void)
 753{
 754        unsigned long debugctlmsr = 0;
 755
 756#ifndef CONFIG_X86_DEBUGCTLMSR
 757        if (boot_cpu_data.x86 < 6)
 758                return 0;
 759#endif
 760        rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
 761
 762        return debugctlmsr;
 763}
 764
 765static inline void update_debugctlmsr(unsigned long debugctlmsr)
 766{
 767#ifndef CONFIG_X86_DEBUGCTLMSR
 768        if (boot_cpu_data.x86 < 6)
 769                return;
 770#endif
 771        wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
 772}
 773
 774extern void set_task_blockstep(struct task_struct *task, bool on);
 775
 776/*
 777 * from system description table in BIOS. Mostly for MCA use, but
 778 * others may find it useful:
 779 */
 780extern unsigned int             machine_id;
 781extern unsigned int             machine_submodel_id;
 782extern unsigned int             BIOS_revision;
 783
 784/* Boot loader type from the setup header: */
 785extern int                      bootloader_type;
 786extern int                      bootloader_version;
 787
 788extern char                     ignore_fpu_irq;
 789
 790#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
 791#define ARCH_HAS_PREFETCHW
 792#define ARCH_HAS_SPINLOCK_PREFETCH
 793
 794#ifdef CONFIG_X86_32
 795# define BASE_PREFETCH          ASM_NOP4
 796# define ARCH_HAS_PREFETCH
 797#else
 798# define BASE_PREFETCH          "prefetcht0 (%1)"
 799#endif
 800
 801/*
 802 * Prefetch instructions for Pentium III (+) and AMD Athlon (+)
 803 *
 804 * It's not worth to care about 3dnow prefetches for the K6
 805 * because they are microcoded there and very slow.
 806 */
 807static inline void prefetch(const void *x)
 808{
 809        alternative_input(BASE_PREFETCH,
 810                          "prefetchnta (%1)",
 811                          X86_FEATURE_XMM,
 812                          "r" (x));
 813}
 814
 815/*
 816 * 3dnow prefetch to get an exclusive cache line.
 817 * Useful for spinlocks to avoid one state transition in the
 818 * cache coherency protocol:
 819 */
 820static inline void prefetchw(const void *x)
 821{
 822        alternative_input(BASE_PREFETCH,
 823                          "prefetchw (%1)",
 824                          X86_FEATURE_3DNOW,
 825                          "r" (x));
 826}
 827
 828static inline void spin_lock_prefetch(const void *x)
 829{
 830        prefetchw(x);
 831}
 832
 833#ifdef CONFIG_X86_32
 834/*
 835 * User space process size: 3GB (default).
 836 */
 837#define TASK_SIZE               PAGE_OFFSET
 838#define TASK_SIZE_MAX           TASK_SIZE
 839#define STACK_TOP               TASK_SIZE
 840#define STACK_TOP_MAX           STACK_TOP
 841
 842#define INIT_THREAD  {                                                    \
 843        .sp0                    = sizeof(init_stack) + (long)&init_stack, \
 844        .vm86_info              = NULL,                                   \
 845        .sysenter_cs            = __KERNEL_CS,                            \
 846        .io_bitmap_ptr          = NULL,                                   \
 847}
 848
 849/*
 850 * Note that the .io_bitmap member must be extra-big. This is because
 851 * the CPU will access an additional byte beyond the end of the IO
 852 * permission bitmap. The extra byte must be all 1 bits, and must
 853 * be within the limit.
 854 */
 855#define INIT_TSS  {                                                       \
 856        .x86_tss = {                                                      \
 857                .sp0            = sizeof(init_stack) + (long)&init_stack, \
 858                .ss0            = __KERNEL_DS,                            \
 859                .ss1            = __KERNEL_CS,                            \
 860                .io_bitmap_base = INVALID_IO_BITMAP_OFFSET,               \
 861         },                                                               \
 862        .io_bitmap              = { [0 ... IO_BITMAP_LONGS] = ~0 },       \
 863}
 864
 865extern unsigned long thread_saved_pc(struct task_struct *tsk);
 866
 867#define THREAD_SIZE_LONGS      (THREAD_SIZE/sizeof(unsigned long))
 868#define KSTK_TOP(info)                                                 \
 869({                                                                     \
 870       unsigned long *__ptr = (unsigned long *)(info);                 \
 871       (unsigned long)(&__ptr[THREAD_SIZE_LONGS]);                     \
 872})
 873
 874/*
 875 * The below -8 is to reserve 8 bytes on top of the ring0 stack.
 876 * This is necessary to guarantee that the entire "struct pt_regs"
 877 * is accessible even if the CPU haven't stored the SS/ESP registers
 878 * on the stack (interrupt gate does not save these registers
 879 * when switching to the same priv ring).
 880 * Therefore beware: accessing the ss/esp fields of the
 881 * "struct pt_regs" is possible, but they may contain the
 882 * completely wrong values.
 883 */
 884#define task_pt_regs(task)                                             \
 885({                                                                     \
 886       struct pt_regs *__regs__;                                       \
 887       __regs__ = (struct pt_regs *)(KSTK_TOP(task_stack_page(task))-8); \
 888       __regs__ - 1;                                                   \
 889})
 890
 891#define KSTK_ESP(task)          (task_pt_regs(task)->sp)
 892
 893#else
 894/*
 895 * User space process size. 47bits minus one guard page.
 896 */
 897#define TASK_SIZE_MAX   ((1UL << 47) - PAGE_SIZE)
 898
 899/* This decides where the kernel will search for a free chunk of vm
 900 * space during mmap's.
 901 */
 902#define IA32_PAGE_OFFSET        ((current->personality & ADDR_LIMIT_3GB) ? \
 903                                        0xc0000000 : 0xFFFFe000)
 904
 905#define TASK_SIZE               (test_thread_flag(TIF_ADDR32) ? \
 906                                        IA32_PAGE_OFFSET : TASK_SIZE_MAX)
 907#define TASK_SIZE_OF(child)     ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
 908                                        IA32_PAGE_OFFSET : TASK_SIZE_MAX)
 909
 910#define STACK_TOP               TASK_SIZE
 911#define STACK_TOP_MAX           TASK_SIZE_MAX
 912
 913#define INIT_THREAD  { \
 914        .sp0 = (unsigned long)&init_stack + sizeof(init_stack) \
 915}
 916
 917#define INIT_TSS  { \
 918        .x86_tss.sp0 = (unsigned long)&init_stack + sizeof(init_stack) \
 919}
 920
 921/*
 922 * Return saved PC of a blocked thread.
 923 * What is this good for? it will be always the scheduler or ret_from_fork.
 924 */
 925#define thread_saved_pc(t)      (*(unsigned long *)((t)->thread.sp - 8))
 926
 927#define task_pt_regs(tsk)       ((struct pt_regs *)(tsk)->thread.sp0 - 1)
 928extern unsigned long KSTK_ESP(struct task_struct *task);
 929
 930/*
 931 * User space RSP while inside the SYSCALL fast path
 932 */
 933DECLARE_PER_CPU(unsigned long, old_rsp);
 934
 935#endif /* CONFIG_X86_64 */
 936
 937extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
 938                                               unsigned long new_sp);
 939
 940/*
 941 * This decides where the kernel will search for a free chunk of vm
 942 * space during mmap's.
 943 */
 944#define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 3))
 945
 946#define KSTK_EIP(task)          (task_pt_regs(task)->ip)
 947
 948/* Get/set a process' ability to use the timestamp counter instruction */
 949#define GET_TSC_CTL(adr)        get_tsc_mode((adr))
 950#define SET_TSC_CTL(val)        set_tsc_mode((val))
 951
 952extern int get_tsc_mode(unsigned long adr);
 953extern int set_tsc_mode(unsigned int val);
 954
 955extern u16 amd_get_nb_id(int cpu);
 956
 957static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
 958{
 959        uint32_t base, eax, signature[3];
 960
 961        for (base = 0x40000000; base < 0x40010000; base += 0x100) {
 962                cpuid(base, &eax, &signature[0], &signature[1], &signature[2]);
 963
 964                if (!memcmp(sig, signature, 12) &&
 965                    (leaves == 0 || ((eax - base) >= leaves)))
 966                        return base;
 967        }
 968
 969        return 0;
 970}
 971
 972extern unsigned long arch_align_stack(unsigned long sp);
 973extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
 974
 975void default_idle(void);
 976#ifdef  CONFIG_XEN
 977bool xen_set_default_idle(void);
 978#else
 979#define xen_set_default_idle 0
 980#endif
 981
 982void stop_this_cpu(void *dummy);
 983void df_debug(struct pt_regs *regs, long error_code);
 984#endif /* _ASM_X86_PROCESSOR_H */
 985