x86/i386: Make sure stack-protector segment base is cache aligned

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / x86 / include / asm / processor.h

#ifndef _ASM_X86_PROCESSOR_H
#define _ASM_X86_PROCESSOR_H

#include <asm/processor-flags.h>

/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;

#include <asm/vm86.h>
#include <asm/math_emu.h>
#include <asm/segment.h>
#include <asm/types.h>
#include <asm/sigcontext.h>
#include <asm/current.h>
#include <asm/cpufeature.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgtable_types.h>
#include <asm/percpu.h>
#include <asm/msr.h>
#include <asm/desc_defs.h>
#include <asm/nops.h>
#include <asm/ds.h>

#include <linux/personality.h>
#include <linux/cpumask.h>
#include <linux/cache.h>
#include <linux/threads.h>
#include <linux/init.h>

/*
 * Default implementation of macro that returns current
 * instruction pointer ("program counter").
 */
static inline void *current_text_addr(void)
{
        void *pc;

        asm volatile("mov $1f, %0; 1:":"=r" (pc));

        return pc;
}

#ifdef CONFIG_X86_VSMP
# define ARCH_MIN_TASKALIGN             (1 << INTERNODE_CACHE_SHIFT)
# define ARCH_MIN_MMSTRUCT_ALIGN        (1 << INTERNODE_CACHE_SHIFT)
#else
# define ARCH_MIN_TASKALIGN             16
# define ARCH_MIN_MMSTRUCT_ALIGN        0
#endif

/*
 *  CPU type and hardware bug flags. Kept separately for each CPU.
 *  Members of this structure are referenced in head.S, so think twice
 *  before touching them. [mj]
 */

struct cpuinfo_x86 {
        __u8                    x86;            /* CPU family */
        __u8                    x86_vendor;     /* CPU vendor */
        __u8                    x86_model;
        __u8                    x86_mask;
#ifdef CONFIG_X86_32
        char                    wp_works_ok;    /* It doesn't on 386's */

        /* Problems on some 486Dx4's and old 386's: */
        char                    hlt_works_ok;
        char                    hard_math;
        char                    rfu;
        char                    fdiv_bug;
        char                    f00f_bug;
        char                    coma_bug;
        char                    pad0;
#else
        /* Number of 4K pages in DTLB/ITLB combined(in pages): */
        int                     x86_tlbsize;
#endif
        __u8                    x86_virt_bits;
        __u8                    x86_phys_bits;
        /* CPUID returned core id bits: */
        __u8                    x86_coreid_bits;
        /* Max extended CPUID function supported: */
        __u32                   extended_cpuid_level;
        /* Maximum supported CPUID level, -1=no CPUID: */
        int                     cpuid_level;
        __u32                   x86_capability[NCAPINTS];
        char                    x86_vendor_id[16];
        char                    x86_model_id[64];
        /* in KB - valid for CPUS which support this call: */
        int                     x86_cache_size;
        int                     x86_cache_alignment;    /* In bytes */
        int                     x86_power;
        unsigned long           loops_per_jiffy;
#ifdef CONFIG_SMP
        /* cpus sharing the last level cache: */
        cpumask_var_t           llc_shared_map;
#endif
        /* cpuid returned max cores value: */
        u16                      x86_max_cores;
        u16                     apicid;
        u16                     initial_apicid;
        u16                     x86_clflush_size;
#ifdef CONFIG_SMP
        /* number of cores as seen by the OS: */
        u16                     booted_cores;
        /* Physical processor id: */
        u16                     phys_proc_id;
        /* Core id: */
        u16                     cpu_core_id;
        /* Index into per_cpu list: */
        u16                     cpu_index;
#endif
        unsigned int            x86_hyper_vendor;
} __attribute__((__aligned__(SMP_CACHE_BYTES)));

#define X86_VENDOR_INTEL        0
#define X86_VENDOR_CYRIX        1
#define X86_VENDOR_AMD          2
#define X86_VENDOR_UMC          3
#define X86_VENDOR_CENTAUR      5
#define X86_VENDOR_TRANSMETA    7
#define X86_VENDOR_NSC          8
#define X86_VENDOR_NUM          9

#define X86_VENDOR_UNKNOWN      0xff

#define X86_HYPER_VENDOR_NONE  0
#define X86_HYPER_VENDOR_VMWARE 1

/*
 * capabilities of CPUs
 */
extern struct cpuinfo_x86       boot_cpu_data;
extern struct cpuinfo_x86       new_cpu_data;

extern struct tss_struct        doublefault_tss;
extern __u32                    cleared_cpu_caps[NCAPINTS];

#ifdef CONFIG_SMP
DECLARE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
#define cpu_data(cpu)           per_cpu(cpu_info, cpu)
#define current_cpu_data        __get_cpu_var(cpu_info)
#else
#define cpu_data(cpu)           boot_cpu_data
#define current_cpu_data        boot_cpu_data
#endif

extern const struct seq_operations cpuinfo_op;

static inline int hlt_works(int cpu)
{
#ifdef CONFIG_X86_32
        return cpu_data(cpu).hlt_works_ok;
#else
        return 1;
#endif
}

#define cache_line_size()       (boot_cpu_data.x86_cache_alignment)

extern void cpu_detect(struct cpuinfo_x86 *c);

extern struct pt_regs *idle_regs(struct pt_regs *);

extern void early_cpu_init(void);
extern void identify_boot_cpu(void);
extern void identify_secondary_cpu(struct cpuinfo_x86 *);
extern void print_cpu_info(struct cpuinfo_x86 *);
extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
extern unsigned short num_cache_leaves;

extern void detect_extended_topology(struct cpuinfo_x86 *c);
extern void detect_ht(struct cpuinfo_x86 *c);

static inline void native_cpuid(unsigned int *eax, unsigned int *ebx,
                                unsigned int *ecx, unsigned int *edx)
{
        /* ecx is often an input as well as an output. */
        asm("cpuid"
            : "=a" (*eax),
              "=b" (*ebx),
              "=c" (*ecx),
              "=d" (*edx)
            : "0" (*eax), "2" (*ecx));
}

static inline void load_cr3(pgd_t *pgdir)
{
        write_cr3(__pa(pgdir));
}

#ifdef CONFIG_X86_32
/* This is the TSS defined by the hardware. */
struct x86_hw_tss {
        unsigned short          back_link, __blh;
        unsigned long           sp0;
        unsigned short          ss0, __ss0h;
        unsigned long           sp1;
        /* ss1 caches MSR_IA32_SYSENTER_CS: */
        unsigned short          ss1, __ss1h;
        unsigned long           sp2;
        unsigned short          ss2, __ss2h;
        unsigned long           __cr3;
        unsigned long           ip;
        unsigned long           flags;
        unsigned long           ax;
        unsigned long           cx;
        unsigned long           dx;
        unsigned long           bx;
        unsigned long           sp;
        unsigned long           bp;
        unsigned long           si;
        unsigned long           di;
        unsigned short          es, __esh;
        unsigned short          cs, __csh;
        unsigned short          ss, __ssh;
        unsigned short          ds, __dsh;
        unsigned short          fs, __fsh;
        unsigned short          gs, __gsh;
        unsigned short          ldt, __ldth;
        unsigned short          trace;
        unsigned short          io_bitmap_base;

} __attribute__((packed));
#else
struct x86_hw_tss {
        u32                     reserved1;
        u64                     sp0;
        u64                     sp1;
        u64                     sp2;
        u64                     reserved2;
        u64                     ist[7];
        u32                     reserved3;
        u32                     reserved4;
        u16                     reserved5;
        u16                     io_bitmap_base;

} __attribute__((packed)) ____cacheline_aligned;
#endif

/*
 * IO-bitmap sizes:
 */
#define IO_BITMAP_BITS                  65536
#define IO_BITMAP_BYTES                 (IO_BITMAP_BITS/8)
#define IO_BITMAP_LONGS                 (IO_BITMAP_BYTES/sizeof(long))
#define IO_BITMAP_OFFSET                offsetof(struct tss_struct, io_bitmap)
#define INVALID_IO_BITMAP_OFFSET        0x8000

struct tss_struct {
        /*
         * The hardware state:
         */
        struct x86_hw_tss       x86_tss;

        /*
         * The extra 1 is there because the CPU will access an
         * additional byte beyond the end of the IO permission
         * bitmap. The extra byte must be all 1 bits, and must
         * be within the limit.
         */
        unsigned long           io_bitmap[IO_BITMAP_LONGS + 1];

        /*
         * .. and then another 0x100 bytes for the emergency kernel stack:
         */
        unsigned long           stack[64];

} ____cacheline_aligned;

DECLARE_PER_CPU_SHARED_ALIGNED(struct tss_struct, init_tss);

/*
 * Save the original ist values for checking stack pointers during debugging
 */
struct orig_ist {
        unsigned long           ist[7];
};

#define MXCSR_DEFAULT           0x1f80

struct i387_fsave_struct {
        u32                     cwd;    /* FPU Control Word             */
        u32                     swd;    /* FPU Status Word              */
        u32                     twd;    /* FPU Tag Word                 */
        u32                     fip;    /* FPU IP Offset                */
        u32                     fcs;    /* FPU IP Selector              */
        u32                     foo;    /* FPU Operand Pointer Offset   */
        u32                     fos;    /* FPU Operand Pointer Selector */

        /* 8*10 bytes for each FP-reg = 80 bytes:                       */
        u32                     st_space[20];

        /* Software status information [not touched by FSAVE ]:         */
        u32                     status;
};

struct i387_fxsave_struct {
        u16                     cwd; /* Control Word                    */
        u16                     swd; /* Status Word                     */
        u16                     twd; /* Tag Word                        */
        u16                     fop; /* Last Instruction Opcode         */
        union {
                struct {
                        u64     rip; /* Instruction Pointer             */
                        u64     rdp; /* Data Pointer                    */
                };
                struct {
                        u32     fip; /* FPU IP Offset                   */
                        u32     fcs; /* FPU IP Selector                 */
                        u32     foo; /* FPU Operand Offset              */
                        u32     fos; /* FPU Operand Selector            */
                };
        };
        u32                     mxcsr;          /* MXCSR Register State */
        u32                     mxcsr_mask;     /* MXCSR Mask           */

        /* 8*16 bytes for each FP-reg = 128 bytes:                      */
        u32                     st_space[32];

        /* 16*16 bytes for each XMM-reg = 256 bytes:                    */
        u32                     xmm_space[64];

        u32                     padding[12];

        union {
                u32             padding1[12];
                u32             sw_reserved[12];
        };

} __attribute__((aligned(16)));

struct i387_soft_struct {
        u32                     cwd;
        u32                     swd;
        u32                     twd;
        u32                     fip;
        u32                     fcs;
        u32                     foo;
        u32                     fos;
        /* 8*10 bytes for each FP-reg = 80 bytes: */
        u32                     st_space[20];
        u8                      ftop;
        u8                      changed;
        u8                      lookahead;
        u8                      no_update;
        u8                      rm;
        u8                      alimit;
        struct math_emu_info    *info;
        u32                     entry_eip;
};

struct ymmh_struct {
        /* 16 * 16 bytes for each YMMH-reg = 256 bytes */
        u32 ymmh_space[64];
};

struct xsave_hdr_struct {
        u64 xstate_bv;
        u64 reserved1[2];
        u64 reserved2[5];
} __attribute__((packed));

struct xsave_struct {
        struct i387_fxsave_struct i387;
        struct xsave_hdr_struct xsave_hdr;
        struct ymmh_struct ymmh;
        /* new processor state extensions will go here */
} __attribute__ ((packed, aligned (64)));

union thread_xstate {
        struct i387_fsave_struct        fsave;
        struct i387_fxsave_struct       fxsave;
        struct i387_soft_struct         soft;
        struct xsave_struct             xsave;
};

#ifdef CONFIG_X86_64
DECLARE_PER_CPU(struct orig_ist, orig_ist);

union irq_stack_union {
        char irq_stack[IRQ_STACK_SIZE];
        /*
         * GCC hardcodes the stack canary as %gs:40.  Since the
         * irq_stack is the object at %gs:0, we reserve the bottom
         * 48 bytes of the irq stack for the canary.
         */
        struct {
                char gs_base[40];
                unsigned long stack_canary;
        };
};

DECLARE_PER_CPU_FIRST(union irq_stack_union, irq_stack_union);
DECLARE_INIT_PER_CPU(irq_stack_union);

DECLARE_PER_CPU(char *, irq_stack_ptr);
DECLARE_PER_CPU(unsigned int, irq_count);
extern unsigned long kernel_eflags;
extern asmlinkage void ignore_sysret(void);
#else   /* X86_64 */
#ifdef CONFIG_CC_STACKPROTECTOR
/*
 * Make sure stack canary segment base is cached-aligned:
 *   "For Intel Atom processors, avoid non zero segment base address
 *    that is not aligned to cache line boundary at all cost."
 * (Optim Ref Manual Assembly/Compiler Coding Rule 15.)
 */
struct stack_canary {
        char __pad[20];         /* canary at %gs:20 */
        unsigned long canary;
};
DECLARE_PER_CPU(struct stack_canary, stack_canary) ____cacheline_aligned;
#endif
#endif  /* X86_64 */

extern unsigned int xstate_size;
extern void free_thread_xstate(struct task_struct *);
extern struct kmem_cache *task_xstate_cachep;
extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
extern unsigned short num_cache_leaves;

struct thread_struct {
        /* Cached TLS descriptors: */
        struct desc_struct      tls_array[GDT_ENTRY_TLS_ENTRIES];
        unsigned long           sp0;
        unsigned long           sp;
#ifdef CONFIG_X86_32
        unsigned long           sysenter_cs;
#else
        unsigned long           usersp; /* Copy from PDA */
        unsigned short          es;
        unsigned short          ds;
        unsigned short          fsindex;
        unsigned short          gsindex;
#endif
        unsigned long           ip;
        unsigned long           fs;
        unsigned long           gs;
        /* Hardware debugging registers: */
        unsigned long           debugreg0;
        unsigned long           debugreg1;
        unsigned long           debugreg2;
        unsigned long           debugreg3;
        unsigned long           debugreg6;
        unsigned long           debugreg7;
        /* Fault info: */
        unsigned long           cr2;
        unsigned long           trap_no;
        unsigned long           error_code;
        /* floating point and extended processor state */
        union thread_xstate     *xstate;
#ifdef CONFIG_X86_32
        /* Virtual 86 mode info */
        struct vm86_struct __user *vm86_info;
        unsigned long           screen_bitmap;
        unsigned long           v86flags;
        unsigned long           v86mask;
        unsigned long           saved_sp0;
        unsigned int            saved_fs;
        unsigned int            saved_gs;
#endif
        /* IO permissions: */
        unsigned long           *io_bitmap_ptr;
        unsigned long           iopl;
        /* Max allowed port in the bitmap, in bytes: */
        unsigned                io_bitmap_max;
/* MSR_IA32_DEBUGCTLMSR value to switch in if TIF_DEBUGCTLMSR is set.  */
        unsigned long   debugctlmsr;
#ifdef CONFIG_X86_DS
/* Debug Store context; see include/asm-x86/ds.h; goes into MSR_IA32_DS_AREA */
        struct ds_context       *ds_ctx;
#endif /* CONFIG_X86_DS */
#ifdef CONFIG_X86_PTRACE_BTS
/* the signal to send on a bts buffer overflow */
        unsigned int    bts_ovfl_signal;
#endif /* CONFIG_X86_PTRACE_BTS */
};

static inline unsigned long native_get_debugreg(int regno)
{
        unsigned long val = 0;  /* Damn you, gcc! */

        switch (regno) {
        case 0:
                asm("mov %%db0, %0" :"=r" (val));
                break;
        case 1:
                asm("mov %%db1, %0" :"=r" (val));
                break;
        case 2:
                asm("mov %%db2, %0" :"=r" (val));
                break;
        case 3:
                asm("mov %%db3, %0" :"=r" (val));
                break;
        case 6:
                asm("mov %%db6, %0" :"=r" (val));
                break;
        case 7:
                asm("mov %%db7, %0" :"=r" (val));
                break;
        default:
                BUG();
        }
        return val;
}

static inline void native_set_debugreg(int regno, unsigned long value)
{
        switch (regno) {
        case 0:
                asm("mov %0, %%db0"     ::"r" (value));
                break;
        case 1:
                asm("mov %0, %%db1"     ::"r" (value));
                break;
        case 2:
                asm("mov %0, %%db2"     ::"r" (value));
                break;
        case 3:
                asm("mov %0, %%db3"     ::"r" (value));
                break;
        case 6:
                asm("mov %0, %%db6"     ::"r" (value));
                break;
        case 7:
                asm("mov %0, %%db7"     ::"r" (value));
                break;
        default:
                BUG();
        }
}

/*
 * Set IOPL bits in EFLAGS from given mask
 */
static inline void native_set_iopl_mask(unsigned mask)
{
#ifdef CONFIG_X86_32
        unsigned int reg;

        asm volatile ("pushfl;"
                      "popl %0;"
                      "andl %1, %0;"
                      "orl %2, %0;"
                      "pushl %0;"
                      "popfl"
                      : "=&r" (reg)
                      : "i" (~X86_EFLAGS_IOPL), "r" (mask));
#endif
}

static inline void
native_load_sp0(struct tss_struct *tss, struct thread_struct *thread)
{
        tss->x86_tss.sp0 = thread->sp0;
#ifdef CONFIG_X86_32
        /* Only happens when SEP is enabled, no need to test "SEP"arately: */
        if (unlikely(tss->x86_tss.ss1 != thread->sysenter_cs)) {
                tss->x86_tss.ss1 = thread->sysenter_cs;
                wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
        }
#endif
}

static inline void native_swapgs(void)
{
#ifdef CONFIG_X86_64
        asm volatile("swapgs" ::: "memory");
#endif
}

#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else
#define __cpuid                 native_cpuid
#define paravirt_enabled()      0

/*
 * These special macros can be used to get or set a debugging register
 */
#define get_debugreg(var, register)                             \
        (var) = native_get_debugreg(register)
#define set_debugreg(value, register)                           \
        native_set_debugreg(register, value)

static inline void load_sp0(struct tss_struct *tss,
                            struct thread_struct *thread)
{
        native_load_sp0(tss, thread);
}

#define set_iopl_mask native_set_iopl_mask
#endif /* CONFIG_PARAVIRT */

/*
 * Save the cr4 feature set we're using (ie
 * Pentium 4MB enable and PPro Global page
 * enable), so that any CPU's that boot up
 * after us can get the correct flags.
 */
extern unsigned long            mmu_cr4_features;

static inline void set_in_cr4(unsigned long mask)
{
        unsigned cr4;

        mmu_cr4_features |= mask;
        cr4 = read_cr4();
        cr4 |= mask;
        write_cr4(cr4);
}

static inline void clear_in_cr4(unsigned long mask)
{
        unsigned cr4;

        mmu_cr4_features &= ~mask;
        cr4 = read_cr4();
        cr4 &= ~mask;
        write_cr4(cr4);
}

typedef struct {
        unsigned long           seg;
} mm_segment_t;


/*
 * create a kernel thread without removing it from tasklists
 */
extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);

/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);

/* Prepare to copy thread state - unlazy all lazy state */
extern void prepare_to_copy(struct task_struct *tsk);

unsigned long get_wchan(struct task_struct *p);

/*
 * Generic CPUID function
 * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
 * resulting in stale register contents being returned.
 */
static inline void cpuid(unsigned int op,
                         unsigned int *eax, unsigned int *ebx,
                         unsigned int *ecx, unsigned int *edx)
{
        *eax = op;
        *ecx = 0;
        __cpuid(eax, ebx, ecx, edx);
}

/* Some CPUID calls want 'count' to be placed in ecx */
static inline void cpuid_count(unsigned int op, int count,
                               unsigned int *eax, unsigned int *ebx,
                               unsigned int *ecx, unsigned int *edx)
{
        *eax = op;
        *ecx = count;
        __cpuid(eax, ebx, ecx, edx);
}

/*
 * CPUID functions returning a single datum
 */
static inline unsigned int cpuid_eax(unsigned int op)
{
        unsigned int eax, ebx, ecx, edx;

        cpuid(op, &eax, &ebx, &ecx, &edx);

        return eax;
}

static inline unsigned int cpuid_ebx(unsigned int op)
{
        unsigned int eax, ebx, ecx, edx;

        cpuid(op, &eax, &ebx, &ecx, &edx);

        return ebx;
}

static inline unsigned int cpuid_ecx(unsigned int op)
{
        unsigned int eax, ebx, ecx, edx;

        cpuid(op, &eax, &ebx, &ecx, &edx);

        return ecx;
}

static inline unsigned int cpuid_edx(unsigned int op)
{
        unsigned int eax, ebx, ecx, edx;

        cpuid(op, &eax, &ebx, &ecx, &edx);

        return edx;
}

/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
static inline void rep_nop(void)
{
        asm volatile("rep; nop" ::: "memory");
}

static inline void cpu_relax(void)
{
        rep_nop();
}

/* Stop speculative execution: */
static inline void sync_core(void)
{
        int tmp;

        asm volatile("cpuid" : "=a" (tmp) : "0" (1)
                     : "ebx", "ecx", "edx", "memory");
}

static inline void __monitor(const void *eax, unsigned long ecx,
                             unsigned long edx)
{
        /* "monitor %eax, %ecx, %edx;" */
        asm volatile(".byte 0x0f, 0x01, 0xc8;"
                     :: "a" (eax), "c" (ecx), "d"(edx));
}

static inline void __mwait(unsigned long eax, unsigned long ecx)
{
        /* "mwait %eax, %ecx;" */
        asm volatile(".byte 0x0f, 0x01, 0xc9;"
                     :: "a" (eax), "c" (ecx));
}

static inline void __sti_mwait(unsigned long eax, unsigned long ecx)
{
        trace_hardirqs_on();
        /* "mwait %eax, %ecx;" */
        asm volatile("sti; .byte 0x0f, 0x01, 0xc9;"
                     :: "a" (eax), "c" (ecx));
}

extern void mwait_idle_with_hints(unsigned long eax, unsigned long ecx);

extern void select_idle_routine(const struct cpuinfo_x86 *c);
extern void init_c1e_mask(void);

extern unsigned long            boot_option_idle_override;
extern unsigned long            idle_halt;
extern unsigned long            idle_nomwait;

/*
 * on systems with caches, caches must be flashed as the absolute
 * last instruction before going into a suspended halt.  Otherwise,
 * dirty data can linger in the cache and become stale on resume,
 * leading to strange errors.
 *
 * perform a variety of operations to guarantee that the compiler
 * will not reorder instructions.  wbinvd itself is serializing
 * so the processor will not reorder.
 *
 * Systems without cache can just go into halt.
 */
static inline void wbinvd_halt(void)
{
        mb();
        /* check for clflush to determine if wbinvd is legal */
        if (cpu_has_clflush)
                asm volatile("cli; wbinvd; 1: hlt; jmp 1b" : : : "memory");
        else
                while (1)
                        halt();
}

extern void enable_sep_cpu(void);
extern int sysenter_setup(void);

/* Defined in head.S */
extern struct desc_ptr          early_gdt_descr;

extern void cpu_set_gdt(int);
extern void switch_to_new_gdt(int);
extern void load_percpu_segment(int);
extern void cpu_init(void);

static inline unsigned long get_debugctlmsr(void)
{
    unsigned long debugctlmsr = 0;

#ifndef CONFIG_X86_DEBUGCTLMSR
        if (boot_cpu_data.x86 < 6)
                return 0;
#endif
        rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);

    return debugctlmsr;
}

static inline void update_debugctlmsr(unsigned long debugctlmsr)
{
#ifndef CONFIG_X86_DEBUGCTLMSR
        if (boot_cpu_data.x86 < 6)
                return;
#endif
        wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr);
}

/*
 * from system description table in BIOS. Mostly for MCA use, but
 * others may find it useful:
 */
extern unsigned int             machine_id;
extern unsigned int             machine_submodel_id;
extern unsigned int             BIOS_revision;

/* Boot loader type from the setup header: */
extern int                      bootloader_type;

extern char                     ignore_fpu_irq;

#define HAVE_ARCH_PICK_MMAP_LAYOUT 1
#define ARCH_HAS_PREFETCHW
#define ARCH_HAS_SPINLOCK_PREFETCH

#ifdef CONFIG_X86_32
# define BASE_PREFETCH          ASM_NOP4
# define ARCH_HAS_PREFETCH
#else
# define BASE_PREFETCH          "prefetcht0 (%1)"
#endif

/*
 * Prefetch instructions for Pentium III (+) and AMD Athlon (+)
 *
 * It's not worth to care about 3dnow prefetches for the K6
 * because they are microcoded there and very slow.
 */
static inline void prefetch(const void *x)
{
        alternative_input(BASE_PREFETCH,
                          "prefetchnta (%1)",
                          X86_FEATURE_XMM,
                          "r" (x));
}

/*
 * 3dnow prefetch to get an exclusive cache line.
 * Useful for spinlocks to avoid one state transition in the
 * cache coherency protocol:
 */
static inline void prefetchw(const void *x)
{
        alternative_input(BASE_PREFETCH,
                          "prefetchw (%1)",
                          X86_FEATURE_3DNOW,
                          "r" (x));
}

static inline void spin_lock_prefetch(const void *x)
{
        prefetchw(x);
}

#ifdef CONFIG_X86_32
/*
 * User space process size: 3GB (default).
 */
#define TASK_SIZE               PAGE_OFFSET
#define TASK_SIZE_MAX           TASK_SIZE
#define STACK_TOP               TASK_SIZE
#define STACK_TOP_MAX           STACK_TOP

#define INIT_THREAD  {                                                    \
        .sp0                    = sizeof(init_stack) + (long)&init_stack, \
        .vm86_info              = NULL,                                   \
        .sysenter_cs            = __KERNEL_CS,                            \
        .io_bitmap_ptr          = NULL,                                   \
        .fs                     = __KERNEL_PERCPU,                        \
}

/*
 * Note that the .io_bitmap member must be extra-big. This is because
 * the CPU will access an additional byte beyond the end of the IO
 * permission bitmap. The extra byte must be all 1 bits, and must
 * be within the limit.
 */
#define INIT_TSS  {                                                       \
        .x86_tss = {                                                      \
                .sp0            = sizeof(init_stack) + (long)&init_stack, \
                .ss0            = __KERNEL_DS,                            \
                .ss1            = __KERNEL_CS,                            \
                .io_bitmap_base = INVALID_IO_BITMAP_OFFSET,               \
         },                                                               \
        .io_bitmap              = { [0 ... IO_BITMAP_LONGS] = ~0 },       \
}

extern unsigned long thread_saved_pc(struct task_struct *tsk);

#define THREAD_SIZE_LONGS      (THREAD_SIZE/sizeof(unsigned long))
#define KSTK_TOP(info)                                                 \
({                                                                     \
       unsigned long *__ptr = (unsigned long *)(info);                 \
       (unsigned long)(&__ptr[THREAD_SIZE_LONGS]);                     \
})

/*
 * The below -8 is to reserve 8 bytes on top of the ring0 stack.
 * This is necessary to guarantee that the entire "struct pt_regs"
 * is accessable even if the CPU haven't stored the SS/ESP registers
 * on the stack (interrupt gate does not save these registers
 * when switching to the same priv ring).
 * Therefore beware: accessing the ss/esp fields of the
 * "struct pt_regs" is possible, but they may contain the
 * completely wrong values.
 */
#define task_pt_regs(task)                                             \
({                                                                     \
       struct pt_regs *__regs__;                                       \
       __regs__ = (struct pt_regs *)(KSTK_TOP(task_stack_page(task))-8); \
       __regs__ - 1;                                                   \
})

#define KSTK_ESP(task)          (task_pt_regs(task)->sp)

#else
/*
 * User space process size. 47bits minus one guard page.
 */
#define TASK_SIZE_MAX   ((1UL << 47) - PAGE_SIZE)

/* This decides where the kernel will search for a free chunk of vm
 * space during mmap's.
 */
#define IA32_PAGE_OFFSET        ((current->personality & ADDR_LIMIT_3GB) ? \
                                        0xc0000000 : 0xFFFFe000)

#define TASK_SIZE               (test_thread_flag(TIF_IA32) ? \
                                        IA32_PAGE_OFFSET : TASK_SIZE_MAX)
#define TASK_SIZE_OF(child)     ((test_tsk_thread_flag(child, TIF_IA32)) ? \
                                        IA32_PAGE_OFFSET : TASK_SIZE_MAX)

#define STACK_TOP               TASK_SIZE
#define STACK_TOP_MAX           TASK_SIZE_MAX

#define INIT_THREAD  { \
        .sp0 = (unsigned long)&init_stack + sizeof(init_stack) \
}

#define INIT_TSS  { \
        .x86_tss.sp0 = (unsigned long)&init_stack + sizeof(init_stack) \
}

/*
 * Return saved PC of a blocked thread.
 * What is this good for? it will be always the scheduler or ret_from_fork.
 */
#define thread_saved_pc(t)      (*(unsigned long *)((t)->thread.sp - 8))

#define task_pt_regs(tsk)       ((struct pt_regs *)(tsk)->thread.sp0 - 1)
#define KSTK_ESP(tsk)           -1 /* sorry. doesn't work for syscall. */
#endif /* CONFIG_X86_64 */

extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
                                               unsigned long new_sp);

/*
 * This decides where the kernel will search for a free chunk of vm
 * space during mmap's.
 */
#define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 3))

#define KSTK_EIP(task)          (task_pt_regs(task)->ip)

/* Get/set a process' ability to use the timestamp counter instruction */
#define GET_TSC_CTL(adr)        get_tsc_mode((adr))
#define SET_TSC_CTL(val)        set_tsc_mode((val))

extern int get_tsc_mode(unsigned long adr);
extern int set_tsc_mode(unsigned int val);

#endif /* _ASM_X86_PROCESSOR_H */