x86, um: ... and asm-x86 move

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 936 insertions, 0 deletions

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
new file mode 100644
index 00000000000..ee7cbb30773
--- /dev/null
+++ b/arch/x86/include/asm/processor.h
@@ -0,0 +1,936 @@
+#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/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;
+	__u8			x86_virt_bits;
+	__u8			x86_phys_bits;
+#endif
+	/* 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_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
+} __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
+
+/*
+ * 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(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
+#define INVALID_IO_BITMAP_OFFSET_LAZY	0x9000
+
+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];
+	/*
+	 * Cache the current maximum and the last task that used the bitmap:
+	 */
+	unsigned long		io_bitmap_max;
+	struct thread_struct	*io_bitmap_owner;
+
+	/*
+	 * .. and then another 0x100 bytes for the emergency kernel stack:
+	 */
+	unsigned long		stack[64];
+
+} ____cacheline_aligned;
+
+DECLARE_PER_CPU(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 info		*info;
+	u32			entry_eip;
+};
+
+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;
+	/* 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);
+#endif
+
+extern void print_cpu_info(struct cpuinfo_x86 *);
+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 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(void);
+extern void cpu_init(void);
+extern void init_gdt(int cpu);
+
+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 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_SIZE64	((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_SIZE64)
+#define TASK_SIZE_OF(child)	((test_tsk_thread_flag(child, TIF_IA32)) ? \
+					IA32_PAGE_OFFSET : TASK_SIZE64)
+
+#define STACK_TOP		TASK_SIZE
+#define STACK_TOP_MAX		TASK_SIZE64
+
+#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 */