arch/x86/include/asm/processor.h

   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 */
   7 struct task_struct;
   8 struct mm_struct;
   9 struct vm86;
  10
  11 #include <asm/math_emu.h>
  12 #include <asm/segment.h>
  13 #include <asm/types.h>
  14 #include <uapi/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 #include <asm/fpu/types.h>
  25
  26 #include <linux/personality.h>
  27 #include <linux/cpumask.h>
  28 #include <linux/cache.h>
  29 #include <linux/threads.h>
  30 #include <linux/math64.h>
  31 #include <linux/err.h>
  32 #include <linux/irqflags.h>
  33
  34 /*
  35  * We handle most unaligned accesses in hardware.  On the other hand
  36  * unaligned DMA can be quite expensive on some Nehalem processors.
  37  *
  38  * Based on this we disable the IP header alignment in network drivers.
  39  */
  40 #define NET_IP_ALIGN    0
  41
  42 #define HBP_NUM 4
  43 /*
  44  * Default implementation of macro that returns current
  45  * instruction pointer ("program counter").
  46  */
  47 static inline void *current_text_addr(void)
  48 {
  49         void *pc;
  50
  51         asm volatile("mov $1f, %0; 1:":"=r" (pc));
  52
  53         return pc;
  54 }
  55
  56 /*
  57  * These alignment constraints are for performance in the vSMP case,
  58  * but in the task_struct case we must also meet hardware imposed
  59  * alignment requirements of the FPU state:
  60  */
  61 #ifdef CONFIG_X86_VSMP
  62 # define ARCH_MIN_TASKALIGN             (1 << INTERNODE_CACHE_SHIFT)
  63 # define ARCH_MIN_MMSTRUCT_ALIGN        (1 << INTERNODE_CACHE_SHIFT)
  64 #else
  65 # define ARCH_MIN_TASKALIGN             __alignof__(union fpregs_state)
  66 # define ARCH_MIN_MMSTRUCT_ALIGN        0
  67 #endif
  68
  69 enum tlb_infos {
  70         ENTRIES,
  71         NR_INFO
  72 };
  73
  74 extern u16 __read_mostly tlb_lli_4k[NR_INFO];
  75 extern u16 __read_mostly tlb_lli_2m[NR_INFO];
  76 extern u16 __read_mostly tlb_lli_4m[NR_INFO];
  77 extern u16 __read_mostly tlb_lld_4k[NR_INFO];
  78 extern u16 __read_mostly tlb_lld_2m[NR_INFO];
  79 extern u16 __read_mostly tlb_lld_4m[NR_INFO];
  80 extern u16 __read_mostly tlb_lld_1g[NR_INFO];
  81
  82 /*
  83  *  CPU type and hardware bug flags. Kept separately for each CPU.
  84  *  Members of this structure are referenced in head.S, so think twice
  85  *  before touching them. [mj]
  86  */
  87
  88 struct cpuinfo_x86 {
  89         __u8                    x86;            /* CPU family */
  90         __u8                    x86_vendor;     /* CPU vendor */
  91         __u8                    x86_model;
  92         __u8                    x86_mask;
  93 #ifdef CONFIG_X86_32
  94         char                    wp_works_ok;    /* It doesn't on 386's */
  95
  96         /* Problems on some 486Dx4's and old 386's: */
  97         char                    rfu;
  98         char                    pad0;
  99         char                    pad1;
 100 #else
 101         /* Number of 4K pages in DTLB/ITLB combined(in pages): */
 102         int                     x86_tlbsize;
 103 #endif
 104         __u8                    x86_virt_bits;
 105         __u8                    x86_phys_bits;
 106         /* CPUID returned core id bits: */
 107         __u8                    x86_coreid_bits;
 108         /* Max extended CPUID function supported: */
 109         __u32                   extended_cpuid_level;
 110         /* Maximum supported CPUID level, -1=no CPUID: */
 111         int                     cpuid_level;
 112         __u32                   x86_capability[NCAPINTS + NBUGINTS];
 113         char                    x86_vendor_id[16];
 114         char                    x86_model_id[64];
 115         /* in KB - valid for CPUS which support this call: */
 116         int                     x86_cache_size;
 117         int                     x86_cache_alignment;    /* In bytes */
 118         /* Cache QoS architectural values: */
 119         int                     x86_cache_max_rmid;     /* max index */
 120         int                     x86_cache_occ_scale;    /* scale to bytes */
 121         int                     x86_power;
 122         unsigned long           loops_per_jiffy;
 123         /* cpuid returned max cores value: */
 124         u16                      x86_max_cores;
 125         u16                     apicid;
 126         u16                     initial_apicid;
 127         u16                     x86_clflush_size;
 128         /* number of cores as seen by the OS: */
 129         u16                     booted_cores;
 130         /* Physical processor id: */
 131         u16                     phys_proc_id;
 132         /* Core id: */
 133         u16                     cpu_core_id;
 134         /* Compute unit id */
 135         u8                      compute_unit_id;
 136         /* Index into per_cpu list: */
 137         u16                     cpu_index;
 138         u32                     microcode;
 139 };
 140
 141 #define X86_VENDOR_INTEL        0
 142 #define X86_VENDOR_CYRIX        1
 143 #define X86_VENDOR_AMD          2
 144 #define X86_VENDOR_UMC          3
 145 #define X86_VENDOR_CENTAUR      5
 146 #define X86_VENDOR_TRANSMETA    7
 147 #define X86_VENDOR_NSC          8
 148 #define X86_VENDOR_NUM          9
 149
 150 #define X86_VENDOR_UNKNOWN      0xff
 151
 152 /*
 153  * capabilities of CPUs
 154  */
 155 extern struct cpuinfo_x86       boot_cpu_data;
 156 extern struct cpuinfo_x86       new_cpu_data;
 157
 158 extern struct tss_struct        doublefault_tss;
 159 extern __u32                    cpu_caps_cleared[NCAPINTS];
 160 extern __u32                    cpu_caps_set[NCAPINTS];
 161
 162 #ifdef CONFIG_SMP
 163 DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
 164 #define cpu_data(cpu)           per_cpu(cpu_info, cpu)
 165 #else
 166 #define cpu_info                boot_cpu_data
 167 #define cpu_data(cpu)           boot_cpu_data
 168 #endif
 169
 170 extern const struct seq_operations cpuinfo_op;
 171
 172 #define cache_line_size()       (boot_cpu_data.x86_cache_alignment)
 173
 174 extern void cpu_detect(struct cpuinfo_x86 *c);
 175
 176 extern void early_cpu_init(void);
 177 extern void identify_boot_cpu(void);
 178 extern void identify_secondary_cpu(struct cpuinfo_x86 *);
 179 extern void print_cpu_info(struct cpuinfo_x86 *);
 180 void print_cpu_msr(struct cpuinfo_x86 *);
 181 extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
 182 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
 183 extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
 184
 185 extern void detect_extended_topology(struct cpuinfo_x86 *c);
 186 extern void detect_ht(struct cpuinfo_x86 *c);
 187
 188 #ifdef CONFIG_X86_32
 189 extern int have_cpuid_p(void);
 190 #else
 191 static inline int have_cpuid_p(void)
 192 {
 193         return 1;
 194 }
 195 #endif
 196 static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
 197                                 unsigned int *ecx, unsigned int *edx)
 198 {
 199         /* ecx is often an input as well as an output. */
 200         asm volatile("cpuid"
 201             : "=a" (*eax),
 202               "=b" (*ebx),
 203               "=c" (*ecx),
 204               "=d" (*edx)
 205             : "0" (*eax), "2" (*ecx)
 206             : "memory");
 207 }
 208
 209 static inline void load_cr3(pgd_t *pgdir)
 210 {
 211         write_cr3(__pa(pgdir));
 212 }
 213
 214 #ifdef CONFIG_X86_32
 215 /* This is the TSS defined by the hardware. */
 216 struct x86_hw_tss {
 217         unsigned short          back_link, __blh;
 218         unsigned long           sp0;
 219         unsigned short          ss0, __ss0h;
 220         unsigned long           sp1;
 221
 222         /*
 223          * We don't use ring 1, so ss1 is a convenient scratch space in
 224          * the same cacheline as sp0.  We use ss1 to cache the value in
 225          * MSR_IA32_SYSENTER_CS.  When we context switch
 226          * MSR_IA32_SYSENTER_CS, we first check if the new value being
 227          * written matches ss1, and, if it's not, then we wrmsr the new
 228          * value and update ss1.
 229          *
 230          * The only reason we context switch MSR_IA32_SYSENTER_CS is
 231          * that we set it to zero in vm86 tasks to avoid corrupting the
 232          * stack if we were to go through the sysenter path from vm86
 233          * mode.
 234          */
 235         unsigned short          ss1;    /* MSR_IA32_SYSENTER_CS */
 236
 237         unsigned short          __ss1h;
 238         unsigned long           sp2;
 239         unsigned short          ss2, __ss2h;
 240         unsigned long           __cr3;
 241         unsigned long           ip;
 242         unsigned long           flags;
 243         unsigned long           ax;
 244         unsigned long           cx;
 245         unsigned long           dx;
 246         unsigned long           bx;
 247         unsigned long           sp;
 248         unsigned long           bp;
 249         unsigned long           si;
 250         unsigned long           di;
 251         unsigned short          es, __esh;
 252         unsigned short          cs, __csh;
 253         unsigned short          ss, __ssh;
 254         unsigned short          ds, __dsh;
 255         unsigned short          fs, __fsh;
 256         unsigned short          gs, __gsh;
 257         unsigned short          ldt, __ldth;
 258         unsigned short          trace;
 259         unsigned short          io_bitmap_base;
 260
 261 } __attribute__((packed));
 262 #else
 263 struct x86_hw_tss {
 264         u32                     reserved1;
 265         u64                     sp0;
 266         u64                     sp1;
 267         u64                     sp2;
 268         u64                     reserved2;
 269         u64                     ist[7];
 270         u32                     reserved3;
 271         u32                     reserved4;
 272         u16                     reserved5;
 273         u16                     io_bitmap_base;
 274
 275 } __attribute__((packed)) ____cacheline_aligned;
 276 #endif
 277
 278 /*
 279  * IO-bitmap sizes:
 280  */
 281 #define IO_BITMAP_BITS                  65536
 282 #define IO_BITMAP_BYTES                 (IO_BITMAP_BITS/8)
 283 #define IO_BITMAP_LONGS                 (IO_BITMAP_BYTES/sizeof(long))
 284 #define IO_BITMAP_OFFSET                offsetof(struct tss_struct, io_bitmap)
 285 #define INVALID_IO_BITMAP_OFFSET        0x8000
 286
 287 struct tss_struct {
 288         /*
 289          * The hardware state:
 290          */
 291         struct x86_hw_tss       x86_tss;
 292
 293         /*
 294          * The extra 1 is there because the CPU will access an
 295          * additional byte beyond the end of the IO permission
 296          * bitmap. The extra byte must be all 1 bits, and must
 297          * be within the limit.
 298          */
 299         unsigned long           io_bitmap[IO_BITMAP_LONGS + 1];
 300
 301         /*
 302          * Space for the temporary SYSENTER stack:
 303          */
 304         unsigned long           SYSENTER_stack[64];
 305
 306 } ____cacheline_aligned;
 307
 308 DECLARE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss);
 309
 310 #ifdef CONFIG_X86_32
 311 DECLARE_PER_CPU(unsigned long, cpu_current_top_of_stack);
 312 #endif
 313
 314 /*
 315  * Save the original ist values for checking stack pointers during debugging
 316  */
 317 struct orig_ist {
 318         unsigned long           ist[7];
 319 };
 320
 321 #ifdef CONFIG_X86_64
 322 DECLARE_PER_CPU(struct orig_ist, orig_ist);
 323
 324 union irq_stack_union {
 325         char irq_stack[IRQ_STACK_SIZE];
 326         /*
 327          * GCC hardcodes the stack canary as %gs:40.  Since the
 328          * irq_stack is the object at %gs:0, we reserve the bottom
 329          * 48 bytes of the irq stack for the canary.
 330          */
 331         struct {
 332                 char gs_base[40];
 333                 unsigned long stack_canary;
 334         };
 335 };
 336
 337 DECLARE_PER_CPU_FIRST(union irq_stack_union, irq_stack_union) __visible;
 338 DECLARE_INIT_PER_CPU(irq_stack_union);
 339
 340 DECLARE_PER_CPU(char *, irq_stack_ptr);
 341 DECLARE_PER_CPU(unsigned int, irq_count);
 342 extern asmlinkage void ignore_sysret(void);
 343 #else   /* X86_64 */
 344 #ifdef CONFIG_CC_STACKPROTECTOR
 345 /*
 346  * Make sure stack canary segment base is cached-aligned:
 347  *   "For Intel Atom processors, avoid non zero segment base address
 348  *    that is not aligned to cache line boundary at all cost."
 349  * (Optim Ref Manual Assembly/Compiler Coding Rule 15.)
 350  */
 351 struct stack_canary {
 352         char __pad[20];         /* canary at %gs:20 */
 353         unsigned long canary;
 354 };
 355 DECLARE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
 356 #endif
 357 /*
 358  * per-CPU IRQ handling stacks
 359  */
 360 struct irq_stack {
 361         u32                     stack[THREAD_SIZE/sizeof(u32)];
 362 } __aligned(THREAD_SIZE);
 363
 364 DECLARE_PER_CPU(struct irq_stack *, hardirq_stack);
 365 DECLARE_PER_CPU(struct irq_stack *, softirq_stack);
 366 #endif  /* X86_64 */
 367
 368 extern unsigned int xstate_size;
 369
 370 struct perf_event;
 371
 372 struct thread_struct {
 373         /* Cached TLS descriptors: */
 374         struct desc_struct      tls_array[GDT_ENTRY_TLS_ENTRIES];
 375         unsigned long           sp0;
 376         unsigned long           sp;
 377 #ifdef CONFIG_X86_32
 378         unsigned long           sysenter_cs;
 379 #else
 380         unsigned short          es;
 381         unsigned short          ds;
 382         unsigned short          fsindex;
 383         unsigned short          gsindex;
 384 #endif
 385 #ifdef CONFIG_X86_32
 386         unsigned long           ip;
 387 #endif
 388 #ifdef CONFIG_X86_64
 389         unsigned long           fs;
 390 #endif
 391         unsigned long           gs;
 392
 393         /* Save middle states of ptrace breakpoints */
 394         struct perf_event       *ptrace_bps[HBP_NUM];
 395         /* Debug status used for traps, single steps, etc... */
 396         unsigned long           debugreg6;
 397         /* Keep track of the exact dr7 value set by the user */
 398         unsigned long           ptrace_dr7;
 399         /* Fault info: */
 400         unsigned long           cr2;
 401         unsigned long           trap_nr;
 402         unsigned long           error_code;
 403 #ifdef CONFIG_VM86
 404         /* Virtual 86 mode info */
 405         struct vm86             *vm86;
 406 #endif
 407         /* IO permissions: */
 408         unsigned long           *io_bitmap_ptr;
 409         unsigned long           iopl;
 410         /* Max allowed port in the bitmap, in bytes: */
 411         unsigned                io_bitmap_max;
 412
 413         /* Floating point and extended processor state */
 414         struct fpu              fpu;
 415         /*
 416          * WARNING: 'fpu' is dynamically-sized.  It *MUST* be at
 417          * the end.
 418          */
 419 };
 420
 421 /*
 422  * Set IOPL bits in EFLAGS from given mask
 423  */
 424 static inline void native_set_iopl_mask(unsigned mask)
 425 {
 426 #ifdef CONFIG_X86_32
 427         unsigned int reg;
 428
 429         asm volatile ("pushfl;"
 430                       "popl %0;"
 431                       "andl %1, %0;"
 432                       "orl %2, %0;"
 433                       "pushl %0;"
 434                       "popfl"
 435                       : "=&r" (reg)
 436                       : "i" (~X86_EFLAGS_IOPL), "r" (mask));
 437 #endif
 438 }
 439
 440 static inline void
 441 native_load_sp0(struct tss_struct *tss, struct thread_struct *thread)
 442 {
 443         tss->x86_tss.sp0 = thread->sp0;
 444 #ifdef CONFIG_X86_32
 445         /* Only happens when SEP is enabled, no need to test "SEP"arately: */
 446         if (unlikely(tss->x86_tss.ss1 != thread->sysenter_cs)) {
 447                 tss->x86_tss.ss1 = thread->sysenter_cs;
 448                 wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
 449         }
 450 #endif
 451 }
 452
 453 static inline void native_swapgs(void)
 454 {
 455 #ifdef CONFIG_X86_64
 456         asm volatile("swapgs" ::: "memory");
 457 #endif
 458 }
 459
 460 static inline unsigned long current_top_of_stack(void)
 461 {
 462 #ifdef CONFIG_X86_64
 463         return this_cpu_read_stable(cpu_tss.x86_tss.sp0);
 464 #else
 465         /* sp0 on x86_32 is special in and around vm86 mode. */
 466         return this_cpu_read_stable(cpu_current_top_of_stack);
 467 #endif
 468 }
 469
 470 #ifdef CONFIG_PARAVIRT
 471 #include <asm/paravirt.h>
 472 #else
 473 #define __cpuid                 native_cpuid
 474 #define paravirt_enabled()      0
 475 #define paravirt_has(x)         0
 476
 477 static inline void load_sp0(struct tss_struct *tss,
 478                             struct thread_struct *thread)
 479 {
 480         native_load_sp0(tss, thread);
 481 }
 482
 483 #define set_iopl_mask native_set_iopl_mask
 484 #endif /* CONFIG_PARAVIRT */
 485
 486 typedef struct {
 487         unsigned long           seg;
 488 } mm_segment_t;
 489
 490
 491 /* Free all resources held by a thread. */
 492 extern void release_thread(struct task_struct *);
 493
 494 unsigned long get_wchan(struct task_struct *p);
 495
 496 /*
 497  * Generic CPUID function
 498  * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
 499  * resulting in stale register contents being returned.
 500  */
 501 static inline void cpuid(unsigned int op,
 502                          unsigned int *eax, unsigned int *ebx,
 503                          unsigned int *ecx, unsigned int *edx)
 504 {
 505         *eax = op;
 506         *ecx = 0;
 507         __cpuid(eax, ebx, ecx, edx);
 508 }
 509
 510 /* Some CPUID calls want 'count' to be placed in ecx */
 511 static inline void cpuid_count(unsigned int op, int count,
 512                                unsigned int *eax, unsigned int *ebx,
 513                                unsigned int *ecx, unsigned int *edx)
 514 {
 515         *eax = op;
 516         *ecx = count;
 517         __cpuid(eax, ebx, ecx, edx);
 518 }
 519
 520 /*
 521  * CPUID functions returning a single datum
 522  */
 523 static inline unsigned int cpuid_eax(unsigned int op)
 524 {
 525         unsigned int eax, ebx, ecx, edx;
 526
 527         cpuid(op, &eax, &ebx, &ecx, &edx);
 528
 529         return eax;
 530 }
 531
 532 static inline unsigned int cpuid_ebx(unsigned int op)
 533 {
 534         unsigned int eax, ebx, ecx, edx;
 535
 536         cpuid(op, &eax, &ebx, &ecx, &edx);
 537
 538         return ebx;
 539 }
 540
 541 static inline unsigned int cpuid_ecx(unsigned int op)
 542 {
 543         unsigned int eax, ebx, ecx, edx;
 544
 545         cpuid(op, &eax, &ebx, &ecx, &edx);
 546
 547         return ecx;
 548 }
 549
 550 static inline unsigned int cpuid_edx(unsigned int op)
 551 {
 552         unsigned int eax, ebx, ecx, edx;
 553
 554         cpuid(op, &eax, &ebx, &ecx, &edx);
 555
 556         return edx;
 557 }
 558
 559 /* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
 560 static __always_inline void rep_nop(void)
 561 {
 562         asm volatile("rep; nop" ::: "memory");
 563 }
 564
 565 static __always_inline void cpu_relax(void)
 566 {
 567         rep_nop();
 568 }
 569
 570 #define cpu_relax_lowlatency() cpu_relax()
 571
 572 /* Stop speculative execution and prefetching of modified code. */
 573 static inline void sync_core(void)
 574 {
 575         int tmp;
 576
 577 #ifdef CONFIG_M486
 578         /*
 579          * Do a CPUID if available, otherwise do a jump.  The jump
 580          * can conveniently enough be the jump around CPUID.
 581          */
 582         asm volatile("cmpl %2,%1\n\t"
 583                      "jl 1f\n\t"
 584                      "cpuid\n"
 585                      "1:"
 586                      : "=a" (tmp)
 587                      : "rm" (boot_cpu_data.cpuid_level), "ri" (0), "0" (1)
 588                      : "ebx", "ecx", "edx", "memory");
 589 #else
 590         /*
 591          * CPUID is a barrier to speculative execution.
 592          * Prefetched instructions are automatically
 593          * invalidated when modified.
 594          */
 595         asm volatile("cpuid"
 596                      : "=a" (tmp)
 597                      : "0" (1)
 598                      : "ebx", "ecx", "edx", "memory");
 599 #endif
 600 }
 601
 602 extern void select_idle_routine(const struct cpuinfo_x86 *c);
 603 extern void init_amd_e400_c1e_mask(void);
 604
 605 extern unsigned long            boot_option_idle_override;
 606 extern bool                     amd_e400_c1e_detected;
 607
 608 enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
 609                          IDLE_POLL};
 610
 611 extern void enable_sep_cpu(void);
 612 extern int sysenter_setup(void);
 613
 614 extern void early_trap_init(void);
 615 void early_trap_pf_init(void);
 616
 617 /* Defined in head.S */
 618 extern struct desc_ptr          early_gdt_descr;
 619
 620 extern void cpu_set_gdt(int);
 621 extern void switch_to_new_gdt(int);
 622 extern void load_percpu_segment(int);
 623 extern void cpu_init(void);
 624
 625 static inline unsigned long get_debugctlmsr(void)
 626 {
 627         unsigned long debugctlmsr = 0;
 628
 629 #ifndef CONFIG_X86_DEBUGCTLMSR
 630         if (boot_cpu_data.x86 < 6)
 631                 return 0;
 632 #endif
 633         rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
 634
 635         return debugctlmsr;
 636 }
 637
 638 static inline void update_debugctlmsr(unsigned long debugctlmsr)
 639 {
 640 #ifndef CONFIG_X86_DEBUGCTLMSR
 641         if (boot_cpu_data.x86 < 6)
 642                 return;
 643 #endif
 644         wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
 645 }
 646
 647 extern void set_task_blockstep(struct task_struct *task, bool on);
 648
 649 /* Boot loader type from the setup header: */
 650 extern int                      bootloader_type;
 651 extern int                      bootloader_version;
 652
 653 extern char                     ignore_fpu_irq;
 654
 655 #define HAVE_ARCH_PICK_MMAP_LAYOUT 1
 656 #define ARCH_HAS_PREFETCHW
 657 #define ARCH_HAS_SPINLOCK_PREFETCH
 658
 659 #ifdef CONFIG_X86_32
 660 # define BASE_PREFETCH          ""
 661 # define ARCH_HAS_PREFETCH
 662 #else
 663 # define BASE_PREFETCH          "prefetcht0 %P1"
 664 #endif
 665
 666 /*
 667  * Prefetch instructions for Pentium III (+) and AMD Athlon (+)
 668  *
 669  * It's not worth to care about 3dnow prefetches for the K6
 670  * because they are microcoded there and very slow.
 671  */
 672 static inline void prefetch(const void *x)
 673 {
 674         alternative_input(BASE_PREFETCH, "prefetchnta %P1",
 675                           X86_FEATURE_XMM,
 676                           "m" (*(const char *)x));
 677 }
 678
 679 /*
 680  * 3dnow prefetch to get an exclusive cache line.
 681  * Useful for spinlocks to avoid one state transition in the
 682  * cache coherency protocol:
 683  */
 684 static inline void prefetchw(const void *x)
 685 {
 686         alternative_input(BASE_PREFETCH, "prefetchw %P1",
 687                           X86_FEATURE_3DNOWPREFETCH,
 688                           "m" (*(const char *)x));
 689 }
 690
 691 static inline void spin_lock_prefetch(const void *x)
 692 {
 693         prefetchw(x);
 694 }
 695
 696 #define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \
 697                            TOP_OF_KERNEL_STACK_PADDING)
 698
 699 #ifdef CONFIG_X86_32
 700 /*
 701  * User space process size: 3GB (default).
 702  */
 703 #define TASK_SIZE               PAGE_OFFSET
 704 #define TASK_SIZE_MAX           TASK_SIZE
 705 #define STACK_TOP               TASK_SIZE
 706 #define STACK_TOP_MAX           STACK_TOP
 707
 708 #define INIT_THREAD  {                                                    \
 709         .sp0                    = TOP_OF_INIT_STACK,                      \
 710         .sysenter_cs            = __KERNEL_CS,                            \
 711         .io_bitmap_ptr          = NULL,                                   \
 712 }
 713
 714 extern unsigned long thread_saved_pc(struct task_struct *tsk);
 715
 716 /*
 717  * TOP_OF_KERNEL_STACK_PADDING reserves 8 bytes on top of the ring0 stack.
 718  * This is necessary to guarantee that the entire "struct pt_regs"
 719  * is accessible even if the CPU haven't stored the SS/ESP registers
 720  * on the stack (interrupt gate does not save these registers
 721  * when switching to the same priv ring).
 722  * Therefore beware: accessing the ss/esp fields of the
 723  * "struct pt_regs" is possible, but they may contain the
 724  * completely wrong values.
 725  */
 726 #define task_pt_regs(task) \
 727 ({                                                                      \
 728         unsigned long __ptr = (unsigned long)task_stack_page(task);     \
 729         __ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;             \
 730         ((struct pt_regs *)__ptr) - 1;                                  \
 731 })
 732
 733 #define KSTK_ESP(task)          (task_pt_regs(task)->sp)
 734
 735 #else
 736 /*
 737  * User space process size. 47bits minus one guard page.  The guard
 738  * page is necessary on Intel CPUs: if a SYSCALL instruction is at
 739  * the highest possible canonical userspace address, then that
 740  * syscall will enter the kernel with a non-canonical return
 741  * address, and SYSRET will explode dangerously.  We avoid this
 742  * particular problem by preventing anything from being mapped
 743  * at the maximum canonical address.
 744  */
 745 #define TASK_SIZE_MAX   ((1UL << 47) - PAGE_SIZE)
 746
 747 /* This decides where the kernel will search for a free chunk of vm
 748  * space during mmap's.
 749  */
 750 #define IA32_PAGE_OFFSET        ((current->personality & ADDR_LIMIT_3GB) ? \
 751                                         0xc0000000 : 0xFFFFe000)
 752
 753 #define TASK_SIZE               (test_thread_flag(TIF_ADDR32) ? \
 754                                         IA32_PAGE_OFFSET : TASK_SIZE_MAX)
 755 #define TASK_SIZE_OF(child)     ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
 756                                         IA32_PAGE_OFFSET : TASK_SIZE_MAX)
 757
 758 #define STACK_TOP               TASK_SIZE
 759 #define STACK_TOP_MAX           TASK_SIZE_MAX
 760
 761 #define INIT_THREAD  { \
 762         .sp0 = TOP_OF_INIT_STACK \
 763 }
 764
 765 /*
 766  * Return saved PC of a blocked thread.
 767  * What is this good for? it will be always the scheduler or ret_from_fork.
 768  */
 769 #define thread_saved_pc(t)      (*(unsigned long *)((t)->thread.sp - 8))
 770
 771 #define task_pt_regs(tsk)       ((struct pt_regs *)(tsk)->thread.sp0 - 1)
 772 extern unsigned long KSTK_ESP(struct task_struct *task);
 773
 774 #endif /* CONFIG_X86_64 */
 775
 776 extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
 777                                                unsigned long new_sp);
 778
 779 /*
 780  * This decides where the kernel will search for a free chunk of vm
 781  * space during mmap's.
 782  */
 783 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 3))
 784
 785 #define KSTK_EIP(task)          (task_pt_regs(task)->ip)
 786
 787 /* Get/set a process' ability to use the timestamp counter instruction */
 788 #define GET_TSC_CTL(adr)        get_tsc_mode((adr))
 789 #define SET_TSC_CTL(val)        set_tsc_mode((val))
 790
 791 extern int get_tsc_mode(unsigned long adr);
 792 extern int set_tsc_mode(unsigned int val);
 793
 794 /* Register/unregister a process' MPX related resource */
 795 #define MPX_ENABLE_MANAGEMENT() mpx_enable_management()
 796 #define MPX_DISABLE_MANAGEMENT()        mpx_disable_management()
 797
 798 #ifdef CONFIG_X86_INTEL_MPX
 799 extern int mpx_enable_management(void);
 800 extern int mpx_disable_management(void);
 801 #else
 802 static inline int mpx_enable_management(void)
 803 {
 804         return -EINVAL;
 805 }
 806 static inline int mpx_disable_management(void)
 807 {
 808         return -EINVAL;
 809 }
 810 #endif /* CONFIG_X86_INTEL_MPX */
 811
 812 extern u16 amd_get_nb_id(int cpu);
 813 extern u32 amd_get_nodes_per_socket(void);
 814
 815 static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
 816 {
 817         uint32_t base, eax, signature[3];
 818
 819         for (base = 0x40000000; base < 0x40010000; base += 0x100) {
 820                 cpuid(base, &eax, &signature[0], &signature[1], &signature[2]);
 821
 822                 if (!memcmp(sig, signature, 12) &&
 823                     (leaves == 0 || ((eax - base) >= leaves)))
 824                         return base;
 825         }
 826
 827         return 0;
 828 }
 829
 830 extern unsigned long arch_align_stack(unsigned long sp);
 831 extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
 832
 833 void default_idle(void);
 834 #ifdef  CONFIG_XEN
 835 bool xen_set_default_idle(void);
 836 #else
 837 #define xen_set_default_idle 0
 838 #endif
 839
 840 void stop_this_cpu(void *dummy);
 841 void df_debug(struct pt_regs *regs, long error_code);
 842 #endif /* _ASM_X86_PROCESSOR_H */