arch/x86/kernel/cpu/intel.c - maze/linux - Git at Google

 #include <linux/init.h>
 #include <linux/kernel.h>

 #include <linux/string.h>
 #include <linux/bitops.h>
 #include <linux/smp.h>
 #include <linux/thread_info.h>
 #include <linux/module.h>

 #include <asm/processor.h>
 #include <asm/pgtable.h>
 #include <asm/msr.h>
 #include <asm/uaccess.h>
 #include <asm/ptrace.h>
 #include <asm/ds.h>
 #include <asm/bugs.h>

 #include "cpu.h"

 #ifdef CONFIG_X86_LOCAL_APIC
 #include <asm/mpspec.h>
 #include <asm/apic.h>
 #include <mach_apic.h>
 #endif

 #ifdef CONFIG_X86_INTEL_USERCOPY
 /*
  * Alignment at which movsl is preferred for bulk memory copies.
  */
 struct movsl_mask movsl_mask __read_mostly;
 #endif

 static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
 {
 	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
 	if (c->x86 == 15 && c->x86_cache_alignment == 64)
 		c->x86_cache_alignment = 128;
 	if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
 		(c->x86 == 0x6 && c->x86_model >= 0x0e))
 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 }

 /*
  *	Early probe support logic for ppro memory erratum #50
  *
  *	This is called before we do cpu ident work
  */

 int __cpuinit ppro_with_ram_bug(void)
 {
 	/* Uses data from early_cpu_detect now */
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
 	    boot_cpu_data.x86 == 6 &&
 	    boot_cpu_data.x86_model == 1 &&
 	    boot_cpu_data.x86_mask < 8) {
 		printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
 		return 1;
 	}
 	return 0;
 }


 /*
  * P4 Xeon errata 037 workaround.
  * Hardware prefetcher may cause stale data to be loaded into the cache.
  */
 static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
 {
 	unsigned long lo, hi;

 	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
 		rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
 		if ((lo & (1<<9)) == 0) {
 			printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
 			printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
 			lo |= (1<<9);	/* Disable hw prefetching */
 			wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
 		}
 	}
 }


 /*
  * find out the number of processor cores on the die
  */
 static int __cpuinit num_cpu_cores(struct cpuinfo_x86 *c)
 {
 	unsigned int eax, ebx, ecx, edx;

 	if (c->cpuid_level < 4)
 		return 1;

 	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
 	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
 	if (eax & 0x1f)
 		return ((eax >> 26) + 1);
 	else
 		return 1;
 }

 #ifdef CONFIG_X86_F00F_BUG
 static void __cpuinit trap_init_f00f_bug(void)
 {
 	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);

 	/*
 	 * Update the IDT descriptor and reload the IDT so that
 	 * it uses the read-only mapped virtual address.
 	 */
 	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
 	load_idt(&idt_descr);
 }
 #endif

 static void __cpuinit init_intel(struct cpuinfo_x86 *c)
 {
 	unsigned int l2 = 0;
 	char *p = NULL;

 	early_init_intel(c);

 #ifdef CONFIG_X86_F00F_BUG
 	/*
 	 * All current models of Pentium and Pentium with MMX technology CPUs
 	 * have the F0 0F bug, which lets nonprivileged users lock up the system.
 	 * Note that the workaround only should be initialized once...
 	 */
 	c->f00f_bug = 0;
 	if (!paravirt_enabled() && c->x86 == 5) {
 		static int f00f_workaround_enabled;

 		c->f00f_bug = 1;
 		if (!f00f_workaround_enabled) {
 			trap_init_f00f_bug();
 			printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
 			f00f_workaround_enabled = 1;
 		}
 	}
 #endif

 	l2 = init_intel_cacheinfo(c);
 	if (c->cpuid_level > 9) {
 		unsigned eax = cpuid_eax(10);
 		/* Check for version and the number of counters */
 		if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
 			set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
 	}

 	/* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
 	if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
 		clear_cpu_cap(c, X86_FEATURE_SEP);

 	/*
 	 * Names for the Pentium II/Celeron processors
 	 * detectable only by also checking the cache size.
 	 * Dixon is NOT a Celeron.
 	 */
 	if (c->x86 == 6) {
 		switch (c->x86_model) {
 		case 5:
 			if (c->x86_mask == 0) {
 				if (l2 == 0)
 					p = "Celeron (Covington)";
 				else if (l2 == 256)
 					p = "Mobile Pentium II (Dixon)";
 			}
 			break;

 		case 6:
 			if (l2 == 128)
 				p = "Celeron (Mendocino)";
 			else if (c->x86_mask == 0 || c->x86_mask == 5)
 				p = "Celeron-A";
 			break;

 		case 8:
 			if (l2 == 128)
 				p = "Celeron (Coppermine)";
 			break;
 		}
 	}

 	if (p)
 		strcpy(c->x86_model_id, p);

 	c->x86_max_cores = num_cpu_cores(c);

 	detect_ht(c);

 	/* Work around errata */
 	Intel_errata_workarounds(c);

 #ifdef CONFIG_X86_INTEL_USERCOPY
 	/*
 	 * Set up the preferred alignment for movsl bulk memory moves
 	 */
 	switch (c->x86) {
 	case 4:		/* 486: untested */
 		break;
 	case 5:		/* Old Pentia: untested */
 		break;
 	case 6:		/* PII/PIII only like movsl with 8-byte alignment */
 		movsl_mask.mask = 7;
 		break;
 	case 15:	/* P4 is OK down to 8-byte alignment */
 		movsl_mask.mask = 7;
 		break;
 	}
 #endif

 	if (cpu_has_xmm2)
 		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
 	if (c->x86 == 15) {
 		set_cpu_cap(c, X86_FEATURE_P4);
 	}
 	if (c->x86 == 6)
 		set_cpu_cap(c, X86_FEATURE_P3);
 	if (cpu_has_ds) {
 		unsigned int l1;
 		rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
 		if (!(l1 & (1<<11)))
 			set_cpu_cap(c, X86_FEATURE_BTS);
 		if (!(l1 & (1<<12)))
 			set_cpu_cap(c, X86_FEATURE_PEBS);
 	}

 	if (cpu_has_bts)
 		ds_init_intel(c);

 #ifdef CONFIG_X86_NUMAQ
 	numaq_tsc_disable();
 #endif
 }

 static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 {
 	/*
 	 * Intel PIII Tualatin. This comes in two flavours.
 	 * One has 256kb of cache, the other 512. We have no way
 	 * to determine which, so we use a boottime override
 	 * for the 512kb model, and assume 256 otherwise.
 	 */
 	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
 		size = 256;
 	return size;
 }

 static struct cpu_dev intel_cpu_dev __cpuinitdata = {
 	.c_vendor	= "Intel",
 	.c_ident	= { "GenuineIntel" },
 	.c_models = {
 		{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
 		  {
 			  [0] = "486 DX-25/33",
 			  [1] = "486 DX-50",
 			  [2] = "486 SX",
 			  [3] = "486 DX/2",
 			  [4] = "486 SL",
 			  [5] = "486 SX/2",
 			  [7] = "486 DX/2-WB",
 			  [8] = "486 DX/4",
 			  [9] = "486 DX/4-WB"
 		  }
 		},
 		{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
 		  {
 			  [0] = "Pentium 60/66 A-step",
 			  [1] = "Pentium 60/66",
 			  [2] = "Pentium 75 - 200",
 			  [3] = "OverDrive PODP5V83",
 			  [4] = "Pentium MMX",
 			  [7] = "Mobile Pentium 75 - 200",
 			  [8] = "Mobile Pentium MMX"
 		  }
 		},
 		{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
 		  {
 			  [0] = "Pentium Pro A-step",
 			  [1] = "Pentium Pro",
 			  [3] = "Pentium II (Klamath)",
 			  [4] = "Pentium II (Deschutes)",
 			  [5] = "Pentium II (Deschutes)",
 			  [6] = "Mobile Pentium II",
 			  [7] = "Pentium III (Katmai)",
 			  [8] = "Pentium III (Coppermine)",
 			  [10] = "Pentium III (Cascades)",
 			  [11] = "Pentium III (Tualatin)",
 		  }
 		},
 		{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
 		  {
 			  [0] = "Pentium 4 (Unknown)",
 			  [1] = "Pentium 4 (Willamette)",
 			  [2] = "Pentium 4 (Northwood)",
 			  [4] = "Pentium 4 (Foster)",
 			  [5] = "Pentium 4 (Foster)",
 		  }
 		},
 	},
 	.c_early_init   = early_init_intel,
 	.c_init		= init_intel,
 	.c_size_cache	= intel_size_cache,
 };

 cpu_vendor_dev_register(X86_VENDOR_INTEL, &intel_cpu_dev);

 #ifndef CONFIG_X86_CMPXCHG
 unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
 {
 	u8 prev;
 	unsigned long flags;

 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
 	local_irq_save(flags);
 	prev = *(u8 *)ptr;
 	if (prev == old)
 		*(u8 *)ptr = new;
 	local_irq_restore(flags);
 	return prev;
 }
 EXPORT_SYMBOL(cmpxchg_386_u8);

 unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
 {
 	u16 prev;
 	unsigned long flags;

 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
 	local_irq_save(flags);
 	prev = *(u16 *)ptr;
 	if (prev == old)
 		*(u16 *)ptr = new;
 	local_irq_restore(flags);
 	return prev;
 }
 EXPORT_SYMBOL(cmpxchg_386_u16);

 unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
 {
 	u32 prev;
 	unsigned long flags;

 	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
 	local_irq_save(flags);
 	prev = *(u32 *)ptr;
 	if (prev == old)
 		*(u32 *)ptr = new;
 	local_irq_restore(flags);
 	return prev;
 }
 EXPORT_SYMBOL(cmpxchg_386_u32);
 #endif

 #ifndef CONFIG_X86_CMPXCHG64
 unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
 {
 	u64 prev;
 	unsigned long flags;

 	/* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
 	local_irq_save(flags);
 	prev = *(u64 *)ptr;
 	if (prev == old)
 		*(u64 *)ptr = new;
 	local_irq_restore(flags);
 	return prev;
 }
 EXPORT_SYMBOL(cmpxchg_486_u64);
 #endif

 /* arch_initcall(intel_cpu_init); */
	#include <linux/init.h>
	#include <linux/kernel.h>

	#include <linux/string.h>
	#include <linux/bitops.h>
	#include <linux/smp.h>
	#include <linux/thread_info.h>
	#include <linux/module.h>

	#include <asm/processor.h>
	#include <asm/pgtable.h>
	#include <asm/msr.h>
	#include <asm/uaccess.h>
	#include <asm/ptrace.h>
	#include <asm/ds.h>
	#include <asm/bugs.h>

	#include "cpu.h"

	#ifdef CONFIG_X86_LOCAL_APIC
	#include <asm/mpspec.h>
	#include <asm/apic.h>
	#include <mach_apic.h>
	#endif

	#ifdef CONFIG_X86_INTEL_USERCOPY
	/*
	* Alignment at which movsl is preferred for bulk memory copies.
	*/
	struct movsl_mask movsl_mask __read_mostly;
	#endif

	static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
	{
	/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
	if (c->x86 == 15 && c->x86_cache_alignment == 64)
	c->x86_cache_alignment = 128;
	if ((c->x86 == 0xf && c->x86_model >= 0x03) \|\|
	(c->x86 == 0x6 && c->x86_model >= 0x0e))
	set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
	}

	/*
	* Early probe support logic for ppro memory erratum #50
	*
	* This is called before we do cpu ident work
	*/

	int __cpuinit ppro_with_ram_bug(void)
	{
	/* Uses data from early_cpu_detect now */
	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
	boot_cpu_data.x86 == 6 &&
	boot_cpu_data.x86_model == 1 &&
	boot_cpu_data.x86_mask < 8) {
	printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
	return 1;
	}
	return 0;
	}


	/*
	* P4 Xeon errata 037 workaround.
	* Hardware prefetcher may cause stale data to be loaded into the cache.
	*/
	static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
	{
	unsigned long lo, hi;

	if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
	rdmsr(MSR_IA32_MISC_ENABLE, lo, hi);
	if ((lo & (1<<9)) == 0) {
	printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
	printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
	lo \|= (1<<9); /* Disable hw prefetching */
	wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
	}
	}
	}


	/*
	* find out the number of processor cores on the die
	*/
	static int __cpuinit num_cpu_cores(struct cpuinfo_x86 *c)
	{
	unsigned int eax, ebx, ecx, edx;

	if (c->cpuid_level < 4)
	return 1;

	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
	if (eax & 0x1f)
	return ((eax >> 26) + 1);
	else
	return 1;
	}

	#ifdef CONFIG_X86_F00F_BUG
	static void __cpuinit trap_init_f00f_bug(void)
	{
	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);

	/*
	* Update the IDT descriptor and reload the IDT so that
	* it uses the read-only mapped virtual address.
	*/
	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
	load_idt(&idt_descr);
	}
	#endif

	static void __cpuinit init_intel(struct cpuinfo_x86 *c)
	{
	unsigned int l2 = 0;
	char *p = NULL;

	early_init_intel(c);

	#ifdef CONFIG_X86_F00F_BUG
	/*
	* All current models of Pentium and Pentium with MMX technology CPUs
	* have the F0 0F bug, which lets nonprivileged users lock up the system.
	* Note that the workaround only should be initialized once...
	*/
	c->f00f_bug = 0;
	if (!paravirt_enabled() && c->x86 == 5) {
	static int f00f_workaround_enabled;

	c->f00f_bug = 1;
	if (!f00f_workaround_enabled) {
	trap_init_f00f_bug();
	printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
	f00f_workaround_enabled = 1;
	}
	}
	#endif

	l2 = init_intel_cacheinfo(c);
	if (c->cpuid_level > 9) {
	unsigned eax = cpuid_eax(10);
	/* Check for version and the number of counters */
	if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
	set_cpu_cap(c, X86_FEATURE_ARCH_PERFMON);
	}

	/* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
	if ((c->x86<<8 \| c->x86_model<<4 \| c->x86_mask) < 0x633)
	clear_cpu_cap(c, X86_FEATURE_SEP);

	/*
	* Names for the Pentium II/Celeron processors
	* detectable only by also checking the cache size.
	* Dixon is NOT a Celeron.
	*/
	if (c->x86 == 6) {
	switch (c->x86_model) {
	case 5:
	if (c->x86_mask == 0) {
	if (l2 == 0)
	p = "Celeron (Covington)";
	else if (l2 == 256)
	p = "Mobile Pentium II (Dixon)";
	}
	break;

	case 6:
	if (l2 == 128)
	p = "Celeron (Mendocino)";
	else if (c->x86_mask == 0 \|\| c->x86_mask == 5)
	p = "Celeron-A";
	break;

	case 8:
	if (l2 == 128)
	p = "Celeron (Coppermine)";
	break;
	}
	}

	if (p)
	strcpy(c->x86_model_id, p);

	c->x86_max_cores = num_cpu_cores(c);

	detect_ht(c);

	/* Work around errata */
	Intel_errata_workarounds(c);

	#ifdef CONFIG_X86_INTEL_USERCOPY
	/*
	* Set up the preferred alignment for movsl bulk memory moves
	*/
	switch (c->x86) {
	case 4: /* 486: untested */
	break;
	case 5: /* Old Pentia: untested */
	break;
	case 6: /* PII/PIII only like movsl with 8-byte alignment */
	movsl_mask.mask = 7;
	break;
	case 15: /* P4 is OK down to 8-byte alignment */
	movsl_mask.mask = 7;
	break;
	}
	#endif

	if (cpu_has_xmm2)
	set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
	if (c->x86 == 15) {
	set_cpu_cap(c, X86_FEATURE_P4);
	}
	if (c->x86 == 6)
	set_cpu_cap(c, X86_FEATURE_P3);
	if (cpu_has_ds) {
	unsigned int l1;
	rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
	if (!(l1 & (1<<11)))
	set_cpu_cap(c, X86_FEATURE_BTS);
	if (!(l1 & (1<<12)))
	set_cpu_cap(c, X86_FEATURE_PEBS);
	}

	if (cpu_has_bts)
	ds_init_intel(c);

	#ifdef CONFIG_X86_NUMAQ
	numaq_tsc_disable();
	#endif
	}

	static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
	{
	/*
	* Intel PIII Tualatin. This comes in two flavours.
	* One has 256kb of cache, the other 512. We have no way
	* to determine which, so we use a boottime override
	* for the 512kb model, and assume 256 otherwise.
	*/
	if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
	size = 256;
	return size;
	}

	static struct cpu_dev intel_cpu_dev __cpuinitdata = {
	.c_vendor = "Intel",
	.c_ident = { "GenuineIntel" },
	.c_models = {
	{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
	{
	[0] = "486 DX-25/33",
	[1] = "486 DX-50",
	[2] = "486 SX",
	[3] = "486 DX/2",
	[4] = "486 SL",
	[5] = "486 SX/2",
	[7] = "486 DX/2-WB",
	[8] = "486 DX/4",
	[9] = "486 DX/4-WB"
	}
	},
	{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
	{
	[0] = "Pentium 60/66 A-step",
	[1] = "Pentium 60/66",
	[2] = "Pentium 75 - 200",
	[3] = "OverDrive PODP5V83",
	[4] = "Pentium MMX",
	[7] = "Mobile Pentium 75 - 200",
	[8] = "Mobile Pentium MMX"
	}
	},
	{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
	{
	[0] = "Pentium Pro A-step",
	[1] = "Pentium Pro",
	[3] = "Pentium II (Klamath)",
	[4] = "Pentium II (Deschutes)",
	[5] = "Pentium II (Deschutes)",
	[6] = "Mobile Pentium II",
	[7] = "Pentium III (Katmai)",
	[8] = "Pentium III (Coppermine)",
	[10] = "Pentium III (Cascades)",
	[11] = "Pentium III (Tualatin)",
	}
	},
	{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
	{
	[0] = "Pentium 4 (Unknown)",
	[1] = "Pentium 4 (Willamette)",
	[2] = "Pentium 4 (Northwood)",
	[4] = "Pentium 4 (Foster)",
	[5] = "Pentium 4 (Foster)",
	}
	},
	},
	.c_early_init = early_init_intel,
	.c_init = init_intel,
	.c_size_cache = intel_size_cache,
	};

	cpu_vendor_dev_register(X86_VENDOR_INTEL, &intel_cpu_dev);

	#ifndef CONFIG_X86_CMPXCHG
	unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
	{
	u8 prev;
	unsigned long flags;

	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
	local_irq_save(flags);
	prev = (u8 )ptr;
	if (prev == old)
	(u8 )ptr = new;
	local_irq_restore(flags);
	return prev;
	}
	EXPORT_SYMBOL(cmpxchg_386_u8);

	unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
	{
	u16 prev;
	unsigned long flags;

	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
	local_irq_save(flags);
	prev = (u16 )ptr;
	if (prev == old)
	(u16 )ptr = new;
	local_irq_restore(flags);
	return prev;
	}
	EXPORT_SYMBOL(cmpxchg_386_u16);

	unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
	{
	u32 prev;
	unsigned long flags;

	/* Poor man's cmpxchg for 386. Unsuitable for SMP */
	local_irq_save(flags);
	prev = (u32 )ptr;
	if (prev == old)
	(u32 )ptr = new;
	local_irq_restore(flags);
	return prev;
	}
	EXPORT_SYMBOL(cmpxchg_386_u32);
	#endif

	#ifndef CONFIG_X86_CMPXCHG64
	unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
	{
	u64 prev;
	unsigned long flags;

	/* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
	local_irq_save(flags);
	prev = (u64 )ptr;
	if (prev == old)
	(u64 )ptr = new;
	local_irq_restore(flags);
	return prev;
	}
	EXPORT_SYMBOL(cmpxchg_486_u64);
	#endif

	/* arch_initcall(intel_cpu_init); */