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

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

 #include <asm/processor.h>
 #include <asm/msr.h>
 #include <asm/e820.h>
 #include <asm/mtrr.h>

 #include "cpu.h"

 #ifdef CONFIG_X86_OOSTORE

 static u32 __cpuinit power2(u32 x)
 {
 	u32 s = 1;

 	while (s <= x)
 		s <<= 1;

 	return s >>= 1;
 }


 /*
  * Set up an actual MCR
  */
 static void __cpuinit centaur_mcr_insert(int reg, u32 base, u32 size, int key)
 {
 	u32 lo, hi;

 	hi = base & ~0xFFF;
 	lo = ~(size-1);		/* Size is a power of 2 so this makes a mask */
 	lo &= ~0xFFF;		/* Remove the ctrl value bits */
 	lo |= key;		/* Attribute we wish to set */
 	wrmsr(reg+MSR_IDT_MCR0, lo, hi);
 	mtrr_centaur_report_mcr(reg, lo, hi);	/* Tell the mtrr driver */
 }

 /*
  * Figure what we can cover with MCR's
  *
  * Shortcut: We know you can't put 4Gig of RAM on a winchip
  */
 static u32 __cpuinit ramtop(void)
 {
 	u32 clip = 0xFFFFFFFFUL;
 	u32 top = 0;
 	int i;

 	for (i = 0; i < e820.nr_map; i++) {
 		unsigned long start, end;

 		if (e820.map[i].addr > 0xFFFFFFFFUL)
 			continue;
 		/*
 		 * Don't MCR over reserved space. Ignore the ISA hole
 		 * we frob around that catastrophe already
 		 */
 		if (e820.map[i].type == E820_RESERVED) {
 			if (e820.map[i].addr >= 0x100000UL &&
 			    e820.map[i].addr < clip)
 				clip = e820.map[i].addr;
 			continue;
 		}
 		start = e820.map[i].addr;
 		end = e820.map[i].addr + e820.map[i].size;
 		if (start >= end)
 			continue;
 		if (end > top)
 			top = end;
 	}
 	/*
 	 * Everything below 'top' should be RAM except for the ISA hole.
 	 * Because of the limited MCR's we want to map NV/ACPI into our
 	 * MCR range for gunk in RAM
 	 *
 	 * Clip might cause us to MCR insufficient RAM but that is an
 	 * acceptable failure mode and should only bite obscure boxes with
 	 * a VESA hole at 15Mb
 	 *
 	 * The second case Clip sometimes kicks in is when the EBDA is marked
 	 * as reserved. Again we fail safe with reasonable results
 	 */
 	if (top > clip)
 		top = clip;

 	return top;
 }

 /*
  * Compute a set of MCR's to give maximum coverage
  */
 static int __cpuinit centaur_mcr_compute(int nr, int key)
 {
 	u32 mem = ramtop();
 	u32 root = power2(mem);
 	u32 base = root;
 	u32 top = root;
 	u32 floor = 0;
 	int ct = 0;

 	while (ct < nr) {
 		u32 fspace = 0;
 		u32 high;
 		u32 low;

 		/*
 		 * Find the largest block we will fill going upwards
 		 */
 		high = power2(mem-top);

 		/*
 		 * Find the largest block we will fill going downwards
 		 */
 		low = base/2;

 		/*
 		 * Don't fill below 1Mb going downwards as there
 		 * is an ISA hole in the way.
 		 */
 		if (base <= 1024*1024)
 			low = 0;

 		/*
 		 * See how much space we could cover by filling below
 		 * the ISA hole
 		 */

 		if (floor == 0)
 			fspace = 512*1024;
 		else if (floor == 512*1024)
 			fspace = 128*1024;

 		/* And forget ROM space */

 		/*
 		 * Now install the largest coverage we get
 		 */
 		if (fspace > high && fspace > low) {
 			centaur_mcr_insert(ct, floor, fspace, key);
 			floor += fspace;
 		} else if (high > low) {
 			centaur_mcr_insert(ct, top, high, key);
 			top += high;
 		} else if (low > 0) {
 			base -= low;
 			centaur_mcr_insert(ct, base, low, key);
 		} else
 			break;
 		ct++;
 	}
 	/*
 	 * We loaded ct values. We now need to set the mask. The caller
 	 * must do this bit.
 	 */
 	return ct;
 }

 static void __cpuinit centaur_create_optimal_mcr(void)
 {
 	int used;
 	int i;

 	/*
 	 * Allocate up to 6 mcrs to mark as much of ram as possible
 	 * as write combining and weak write ordered.
 	 *
 	 * To experiment with: Linux never uses stack operations for
 	 * mmio spaces so we could globally enable stack operation wc
 	 *
 	 * Load the registers with type 31 - full write combining, all
 	 * writes weakly ordered.
 	 */
 	used = centaur_mcr_compute(6, 31);

 	/*
 	 * Wipe unused MCRs
 	 */
 	for (i = used; i < 8; i++)
 		wrmsr(MSR_IDT_MCR0+i, 0, 0);
 }

 static void __cpuinit winchip2_create_optimal_mcr(void)
 {
 	u32 lo, hi;
 	int used;
 	int i;

 	/*
 	 * Allocate up to 6 mcrs to mark as much of ram as possible
 	 * as write combining, weak store ordered.
 	 *
 	 * Load the registers with type 25
 	 *	8	-	weak write ordering
 	 *	16	-	weak read ordering
 	 *	1	-	write combining
 	 */
 	used = centaur_mcr_compute(6, 25);

 	/*
 	 * Mark the registers we are using.
 	 */
 	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
 	for (i = 0; i < used; i++)
 		lo |= 1<<(9+i);
 	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);

 	/*
 	 * Wipe unused MCRs
 	 */

 	for (i = used; i < 8; i++)
 		wrmsr(MSR_IDT_MCR0+i, 0, 0);
 }

 /*
  * Handle the MCR key on the Winchip 2.
  */
 static void __cpuinit winchip2_unprotect_mcr(void)
 {
 	u32 lo, hi;
 	u32 key;

 	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
 	lo &= ~0x1C0;	/* blank bits 8-6 */
 	key = (lo>>17) & 7;
 	lo |= key<<6;	/* replace with unlock key */
 	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
 }

 static void __cpuinit winchip2_protect_mcr(void)
 {
 	u32 lo, hi;

 	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
 	lo &= ~0x1C0;	/* blank bits 8-6 */
 	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
 }
 #endif /* CONFIG_X86_OOSTORE */

 #define ACE_PRESENT	(1 << 6)
 #define ACE_ENABLED	(1 << 7)
 #define ACE_FCR		(1 << 28)	/* MSR_VIA_FCR */

 #define RNG_PRESENT	(1 << 2)
 #define RNG_ENABLED	(1 << 3)
 #define RNG_ENABLE	(1 << 6)	/* MSR_VIA_RNG */

 static void __cpuinit init_c3(struct cpuinfo_x86 *c)
 {
 	u32  lo, hi;

 	/* Test for Centaur Extended Feature Flags presence */
 	if (cpuid_eax(0xC0000000) >= 0xC0000001) {
 		u32 tmp = cpuid_edx(0xC0000001);

 		/* enable ACE unit, if present and disabled */
 		if ((tmp & (ACE_PRESENT | ACE_ENABLED)) == ACE_PRESENT) {
 			rdmsr(MSR_VIA_FCR, lo, hi);
 			lo |= ACE_FCR;		/* enable ACE unit */
 			wrmsr(MSR_VIA_FCR, lo, hi);
 			printk(KERN_INFO "CPU: Enabled ACE h/w crypto\n");
 		}

 		/* enable RNG unit, if present and disabled */
 		if ((tmp & (RNG_PRESENT | RNG_ENABLED)) == RNG_PRESENT) {
 			rdmsr(MSR_VIA_RNG, lo, hi);
 			lo |= RNG_ENABLE;	/* enable RNG unit */
 			wrmsr(MSR_VIA_RNG, lo, hi);
 			printk(KERN_INFO "CPU: Enabled h/w RNG\n");
 		}

 		/* store Centaur Extended Feature Flags as
 		 * word 5 of the CPU capability bit array
 		 */
 		c->x86_capability[5] = cpuid_edx(0xC0000001);
 	}

 	/* Cyrix III family needs CX8 & PGE explicitly enabled. */
 	if (c->x86_model >= 6 && c->x86_model <= 9) {
 		rdmsr(MSR_VIA_FCR, lo, hi);
 		lo |= (1<<1 | 1<<7);
 		wrmsr(MSR_VIA_FCR, lo, hi);
 		set_cpu_cap(c, X86_FEATURE_CX8);
 	}

 	/* Before Nehemiah, the C3's had 3dNOW! */
 	if (c->x86_model >= 6 && c->x86_model < 9)
 		set_cpu_cap(c, X86_FEATURE_3DNOW);

 	display_cacheinfo(c);
 }

 enum {
 		ECX8		= 1<<1,
 		EIERRINT	= 1<<2,
 		DPM		= 1<<3,
 		DMCE		= 1<<4,
 		DSTPCLK		= 1<<5,
 		ELINEAR		= 1<<6,
 		DSMC		= 1<<7,
 		DTLOCK		= 1<<8,
 		EDCTLB		= 1<<8,
 		EMMX		= 1<<9,
 		DPDC		= 1<<11,
 		EBRPRED		= 1<<12,
 		DIC		= 1<<13,
 		DDC		= 1<<14,
 		DNA		= 1<<15,
 		ERETSTK		= 1<<16,
 		E2MMX		= 1<<19,
 		EAMD3D		= 1<<20,
 };

 static void __cpuinit early_init_centaur(struct cpuinfo_x86 *c)
 {
 	switch (c->x86) {
 	case 5:
 		/* Emulate MTRRs using Centaur's MCR. */
 		set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
 		break;
 	}
 }

 static void __cpuinit init_centaur(struct cpuinfo_x86 *c)
 {

 	char *name;
 	u32  fcr_set = 0;
 	u32  fcr_clr = 0;
 	u32  lo, hi, newlo;
 	u32  aa, bb, cc, dd;

 	/*
 	 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
 	 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
 	 */
 	clear_cpu_cap(c, 0*32+31);

 	switch (c->x86) {
 	case 5:
 		switch (c->x86_model) {
 		case 4:
 			name = "C6";
 			fcr_set = ECX8|DSMC|EDCTLB|EMMX|ERETSTK;
 			fcr_clr = DPDC;
 			printk(KERN_NOTICE "Disabling bugged TSC.\n");
 			clear_cpu_cap(c, X86_FEATURE_TSC);
 #ifdef CONFIG_X86_OOSTORE
 			centaur_create_optimal_mcr();
 			/*
 			 * Enable:
 			 *	write combining on non-stack, non-string
 			 *	write combining on string, all types
 			 *	weak write ordering
 			 *
 			 * The C6 original lacks weak read order
 			 *
 			 * Note 0x120 is write only on Winchip 1
 			 */
 			wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);
 #endif
 			break;
 		case 8:
 			switch (c->x86_mask) {
 			default:
 			name = "2";
 				break;
 			case 7 ... 9:
 				name = "2A";
 				break;
 			case 10 ... 15:
 				name = "2B";
 				break;
 			}
 			fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|
 				  E2MMX|EAMD3D;
 			fcr_clr = DPDC;
 #ifdef CONFIG_X86_OOSTORE
 			winchip2_unprotect_mcr();
 			winchip2_create_optimal_mcr();
 			rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
 			/*
 			 * Enable:
 			 *	write combining on non-stack, non-string
 			 *	write combining on string, all types
 			 *	weak write ordering
 			 */
 			lo |= 31;
 			wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
 			winchip2_protect_mcr();
 #endif
 			break;
 		case 9:
 			name = "3";
 			fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK|
 				  E2MMX|EAMD3D;
 			fcr_clr = DPDC;
 #ifdef CONFIG_X86_OOSTORE
 			winchip2_unprotect_mcr();
 			winchip2_create_optimal_mcr();
 			rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
 			/*
 			 * Enable:
 			 *	write combining on non-stack, non-string
 			 *	write combining on string, all types
 			 *	weak write ordering
 			 */
 			lo |= 31;
 			wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
 			winchip2_protect_mcr();
 #endif
 			break;
 		default:
 			name = "??";
 		}

 		rdmsr(MSR_IDT_FCR1, lo, hi);
 		newlo = (lo|fcr_set) & (~fcr_clr);

 		if (newlo != lo) {
 			printk(KERN_INFO "Centaur FCR was 0x%X now 0x%X\n",
 				lo, newlo);
 			wrmsr(MSR_IDT_FCR1, newlo, hi);
 		} else {
 			printk(KERN_INFO "Centaur FCR is 0x%X\n", lo);
 		}
 		/* Emulate MTRRs using Centaur's MCR. */
 		set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
 		/* Report CX8 */
 		set_cpu_cap(c, X86_FEATURE_CX8);
 		/* Set 3DNow! on Winchip 2 and above. */
 		if (c->x86_model >= 8)
 			set_cpu_cap(c, X86_FEATURE_3DNOW);
 		/* See if we can find out some more. */
 		if (cpuid_eax(0x80000000) >= 0x80000005) {
 			/* Yes, we can. */
 			cpuid(0x80000005, &aa, &bb, &cc, &dd);
 			/* Add L1 data and code cache sizes. */
 			c->x86_cache_size = (cc>>24)+(dd>>24);
 		}
 		sprintf(c->x86_model_id, "WinChip %s", name);
 		break;

 	case 6:
 		init_c3(c);
 		break;
 	}
 }

 static unsigned int __cpuinit
 centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size)
 {
 	/* VIA C3 CPUs (670-68F) need further shifting. */
 	if ((c->x86 == 6) && ((c->x86_model == 7) || (c->x86_model == 8)))
 		size >>= 8;

 	/*
 	 * There's also an erratum in Nehemiah stepping 1, which
 	 * returns '65KB' instead of '64KB'
 	 *  - Note, it seems this may only be in engineering samples.
 	 */
 	if ((c->x86 == 6) && (c->x86_model == 9) &&
 				(c->x86_mask == 1) && (size == 65))
 		size -= 1;

 	return size;
 }

 static struct cpu_dev centaur_cpu_dev __cpuinitdata = {
 	.c_vendor	= "Centaur",
 	.c_ident	= { "CentaurHauls" },
 	.c_early_init	= early_init_centaur,
 	.c_init		= init_centaur,
 	.c_size_cache	= centaur_size_cache,
 	.c_x86_vendor	= X86_VENDOR_CENTAUR,
 };

 cpu_dev_register(centaur_cpu_dev);
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/bitops.h>

	#include <asm/processor.h>
	#include <asm/msr.h>
	#include <asm/e820.h>
	#include <asm/mtrr.h>

	#include "cpu.h"

	#ifdef CONFIG_X86_OOSTORE

	static u32 __cpuinit power2(u32 x)
	{
	u32 s = 1;

	while (s <= x)
	s <<= 1;

	return s >>= 1;
	}


	/*
	* Set up an actual MCR
	*/
	static void __cpuinit centaur_mcr_insert(int reg, u32 base, u32 size, int key)
	{
	u32 lo, hi;

	hi = base & ~0xFFF;
	lo = ~(size-1); /* Size is a power of 2 so this makes a mask */
	lo &= ~0xFFF; /* Remove the ctrl value bits */
	lo \|= key; /* Attribute we wish to set */
	wrmsr(reg+MSR_IDT_MCR0, lo, hi);
	mtrr_centaur_report_mcr(reg, lo, hi); /* Tell the mtrr driver */
	}

	/*
	* Figure what we can cover with MCR's
	*
	* Shortcut: We know you can't put 4Gig of RAM on a winchip
	*/
	static u32 __cpuinit ramtop(void)
	{
	u32 clip = 0xFFFFFFFFUL;
	u32 top = 0;
	int i;

	for (i = 0; i < e820.nr_map; i++) {
	unsigned long start, end;

	if (e820.map[i].addr > 0xFFFFFFFFUL)
	continue;
	/*
	* Don't MCR over reserved space. Ignore the ISA hole
	* we frob around that catastrophe already
	*/
	if (e820.map[i].type == E820_RESERVED) {
	if (e820.map[i].addr >= 0x100000UL &&
	e820.map[i].addr < clip)
	clip = e820.map[i].addr;
	continue;
	}
	start = e820.map[i].addr;
	end = e820.map[i].addr + e820.map[i].size;
	if (start >= end)
	continue;
	if (end > top)
	top = end;
	}
	/*
	* Everything below 'top' should be RAM except for the ISA hole.
	* Because of the limited MCR's we want to map NV/ACPI into our
	* MCR range for gunk in RAM
	*
	* Clip might cause us to MCR insufficient RAM but that is an
	* acceptable failure mode and should only bite obscure boxes with
	* a VESA hole at 15Mb
	*
	* The second case Clip sometimes kicks in is when the EBDA is marked
	* as reserved. Again we fail safe with reasonable results
	*/
	if (top > clip)
	top = clip;

	return top;
	}

	/*
	* Compute a set of MCR's to give maximum coverage
	*/
	static int __cpuinit centaur_mcr_compute(int nr, int key)
	{
	u32 mem = ramtop();
	u32 root = power2(mem);
	u32 base = root;
	u32 top = root;
	u32 floor = 0;
	int ct = 0;

	while (ct < nr) {
	u32 fspace = 0;
	u32 high;
	u32 low;

	/*
	* Find the largest block we will fill going upwards
	*/
	high = power2(mem-top);

	/*
	* Find the largest block we will fill going downwards
	*/
	low = base/2;

	/*
	* Don't fill below 1Mb going downwards as there
	* is an ISA hole in the way.
	*/
	if (base <= 1024*1024)
	low = 0;

	/*
	* See how much space we could cover by filling below
	* the ISA hole
	*/

	if (floor == 0)
	fspace = 512*1024;
	else if (floor == 512*1024)
	fspace = 128*1024;

	/* And forget ROM space */

	/*
	* Now install the largest coverage we get
	*/
	if (fspace > high && fspace > low) {
	centaur_mcr_insert(ct, floor, fspace, key);
	floor += fspace;
	} else if (high > low) {
	centaur_mcr_insert(ct, top, high, key);
	top += high;
	} else if (low > 0) {
	base -= low;
	centaur_mcr_insert(ct, base, low, key);
	} else
	break;
	ct++;
	}
	/*
	* We loaded ct values. We now need to set the mask. The caller
	* must do this bit.
	*/
	return ct;
	}

	static void __cpuinit centaur_create_optimal_mcr(void)
	{
	int used;
	int i;

	/*
	* Allocate up to 6 mcrs to mark as much of ram as possible
	* as write combining and weak write ordered.
	*
	* To experiment with: Linux never uses stack operations for
	* mmio spaces so we could globally enable stack operation wc
	*
	* Load the registers with type 31 - full write combining, all
	* writes weakly ordered.
	*/
	used = centaur_mcr_compute(6, 31);

	/*
	* Wipe unused MCRs
	*/
	for (i = used; i < 8; i++)
	wrmsr(MSR_IDT_MCR0+i, 0, 0);
	}

	static void __cpuinit winchip2_create_optimal_mcr(void)
	{
	u32 lo, hi;
	int used;
	int i;

	/*
	* Allocate up to 6 mcrs to mark as much of ram as possible
	* as write combining, weak store ordered.
	*
	* Load the registers with type 25
	* 8 - weak write ordering
	* 16 - weak read ordering
	* 1 - write combining
	*/
	used = centaur_mcr_compute(6, 25);

	/*
	* Mark the registers we are using.
	*/
	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
	for (i = 0; i < used; i++)
	lo \|= 1<<(9+i);
	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);

	/*
	* Wipe unused MCRs
	*/

	for (i = used; i < 8; i++)
	wrmsr(MSR_IDT_MCR0+i, 0, 0);
	}

	/*
	* Handle the MCR key on the Winchip 2.
	*/
	static void __cpuinit winchip2_unprotect_mcr(void)
	{
	u32 lo, hi;
	u32 key;

	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
	lo &= ~0x1C0; /* blank bits 8-6 */
	key = (lo>>17) & 7;
	lo \|= key<<6; /* replace with unlock key */
	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
	}

	static void __cpuinit winchip2_protect_mcr(void)
	{
	u32 lo, hi;

	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
	lo &= ~0x1C0; /* blank bits 8-6 */
	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
	}
	#endif /* CONFIG_X86_OOSTORE */

	#define ACE_PRESENT (1 << 6)
	#define ACE_ENABLED (1 << 7)
	#define ACE_FCR (1 << 28) /* MSR_VIA_FCR */

	#define RNG_PRESENT (1 << 2)
	#define RNG_ENABLED (1 << 3)
	#define RNG_ENABLE (1 << 6) /* MSR_VIA_RNG */

	static void __cpuinit init_c3(struct cpuinfo_x86 *c)
	{
	u32 lo, hi;

	/* Test for Centaur Extended Feature Flags presence */
	if (cpuid_eax(0xC0000000) >= 0xC0000001) {
	u32 tmp = cpuid_edx(0xC0000001);

	/* enable ACE unit, if present and disabled */
	if ((tmp & (ACE_PRESENT \| ACE_ENABLED)) == ACE_PRESENT) {
	rdmsr(MSR_VIA_FCR, lo, hi);
	lo \|= ACE_FCR; /* enable ACE unit */
	wrmsr(MSR_VIA_FCR, lo, hi);
	printk(KERN_INFO "CPU: Enabled ACE h/w crypto\n");
	}

	/* enable RNG unit, if present and disabled */
	if ((tmp & (RNG_PRESENT \| RNG_ENABLED)) == RNG_PRESENT) {
	rdmsr(MSR_VIA_RNG, lo, hi);
	lo \|= RNG_ENABLE; /* enable RNG unit */
	wrmsr(MSR_VIA_RNG, lo, hi);
	printk(KERN_INFO "CPU: Enabled h/w RNG\n");
	}

	/* store Centaur Extended Feature Flags as
	* word 5 of the CPU capability bit array
	*/
	c->x86_capability[5] = cpuid_edx(0xC0000001);
	}

	/* Cyrix III family needs CX8 & PGE explicitly enabled. */
	if (c->x86_model >= 6 && c->x86_model <= 9) {
	rdmsr(MSR_VIA_FCR, lo, hi);
	lo \|= (1<<1 \| 1<<7);
	wrmsr(MSR_VIA_FCR, lo, hi);
	set_cpu_cap(c, X86_FEATURE_CX8);
	}

	/* Before Nehemiah, the C3's had 3dNOW! */
	if (c->x86_model >= 6 && c->x86_model < 9)
	set_cpu_cap(c, X86_FEATURE_3DNOW);

	display_cacheinfo(c);
	}

	enum {
	ECX8 = 1<<1,
	EIERRINT = 1<<2,
	DPM = 1<<3,
	DMCE = 1<<4,
	DSTPCLK = 1<<5,
	ELINEAR = 1<<6,
	DSMC = 1<<7,
	DTLOCK = 1<<8,
	EDCTLB = 1<<8,
	EMMX = 1<<9,
	DPDC = 1<<11,
	EBRPRED = 1<<12,
	DIC = 1<<13,
	DDC = 1<<14,
	DNA = 1<<15,
	ERETSTK = 1<<16,
	E2MMX = 1<<19,
	EAMD3D = 1<<20,
	};

	static void __cpuinit early_init_centaur(struct cpuinfo_x86 *c)
	{
	switch (c->x86) {
	case 5:
	/* Emulate MTRRs using Centaur's MCR. */
	set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
	break;
	}
	}

	static void __cpuinit init_centaur(struct cpuinfo_x86 *c)
	{

	char *name;
	u32 fcr_set = 0;
	u32 fcr_clr = 0;
	u32 lo, hi, newlo;
	u32 aa, bb, cc, dd;

	/*
	* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
	* 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
	*/
	clear_cpu_cap(c, 0*32+31);

	switch (c->x86) {
	case 5:
	switch (c->x86_model) {
	case 4:
	name = "C6";
	fcr_set = ECX8\|DSMC\|EDCTLB\|EMMX\|ERETSTK;
	fcr_clr = DPDC;
	printk(KERN_NOTICE "Disabling bugged TSC.\n");
	clear_cpu_cap(c, X86_FEATURE_TSC);
	#ifdef CONFIG_X86_OOSTORE
	centaur_create_optimal_mcr();
	/*
	* Enable:
	* write combining on non-stack, non-string
	* write combining on string, all types
	* weak write ordering
	*
	* The C6 original lacks weak read order
	*
	* Note 0x120 is write only on Winchip 1
	*/
	wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);
	#endif
	break;
	case 8:
	switch (c->x86_mask) {
	default:
	name = "2";
	break;
	case 7 ... 9:
	name = "2A";
	break;
	case 10 ... 15:
	name = "2B";
	break;
	}
	fcr_set = ECX8\|DSMC\|DTLOCK\|EMMX\|EBRPRED\|ERETSTK\|
	E2MMX\|EAMD3D;
	fcr_clr = DPDC;
	#ifdef CONFIG_X86_OOSTORE
	winchip2_unprotect_mcr();
	winchip2_create_optimal_mcr();
	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
	/*
	* Enable:
	* write combining on non-stack, non-string
	* write combining on string, all types
	* weak write ordering
	*/
	lo \|= 31;
	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
	winchip2_protect_mcr();
	#endif
	break;
	case 9:
	name = "3";
	fcr_set = ECX8\|DSMC\|DTLOCK\|EMMX\|EBRPRED\|ERETSTK\|
	E2MMX\|EAMD3D;
	fcr_clr = DPDC;
	#ifdef CONFIG_X86_OOSTORE
	winchip2_unprotect_mcr();
	winchip2_create_optimal_mcr();
	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
	/*
	* Enable:
	* write combining on non-stack, non-string
	* write combining on string, all types
	* weak write ordering
	*/
	lo \|= 31;
	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
	winchip2_protect_mcr();
	#endif
	break;
	default:
	name = "??";
	}

	rdmsr(MSR_IDT_FCR1, lo, hi);
	newlo = (lo\|fcr_set) & (~fcr_clr);

	if (newlo != lo) {
	printk(KERN_INFO "Centaur FCR was 0x%X now 0x%X\n",
	lo, newlo);
	wrmsr(MSR_IDT_FCR1, newlo, hi);
	} else {
	printk(KERN_INFO "Centaur FCR is 0x%X\n", lo);
	}
	/* Emulate MTRRs using Centaur's MCR. */
	set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR);
	/* Report CX8 */
	set_cpu_cap(c, X86_FEATURE_CX8);
	/* Set 3DNow! on Winchip 2 and above. */
	if (c->x86_model >= 8)
	set_cpu_cap(c, X86_FEATURE_3DNOW);
	/* See if we can find out some more. */
	if (cpuid_eax(0x80000000) >= 0x80000005) {
	/* Yes, we can. */
	cpuid(0x80000005, &aa, &bb, &cc, &dd);
	/* Add L1 data and code cache sizes. */
	c->x86_cache_size = (cc>>24)+(dd>>24);
	}
	sprintf(c->x86_model_id, "WinChip %s", name);
	break;

	case 6:
	init_c3(c);
	break;
	}
	}

	static unsigned int __cpuinit
	centaur_size_cache(struct cpuinfo_x86 *c, unsigned int size)
	{
	/* VIA C3 CPUs (670-68F) need further shifting. */
	if ((c->x86 == 6) && ((c->x86_model == 7) \|\| (c->x86_model == 8)))
	size >>= 8;

	/*
	* There's also an erratum in Nehemiah stepping 1, which
	* returns '65KB' instead of '64KB'
	* - Note, it seems this may only be in engineering samples.
	*/
	if ((c->x86 == 6) && (c->x86_model == 9) &&
	(c->x86_mask == 1) && (size == 65))
	size -= 1;

	return size;
	}

	static struct cpu_dev centaur_cpu_dev __cpuinitdata = {
	.c_vendor = "Centaur",
	.c_ident = { "CentaurHauls" },
	.c_early_init = early_init_centaur,
	.c_init = init_centaur,
	.c_size_cache = centaur_size_cache,
	.c_x86_vendor = X86_VENDOR_CENTAUR,
	};

	cpu_dev_register(centaur_cpu_dev);