i386: move kernel/cpu/mtrr

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

9 files changed, 2621 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/Makefile b/arch/x86/kernel/cpu/mtrr/Makefile
new file mode 100644
index 000000000000..191fc0533649
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/Makefile
@@ -0,0 +1,3 @@
+obj-y		:= main.o if.o generic.o state.o
+obj-$(CONFIG_X86_32) += amd.o cyrix.o centaur.o
+
diff --git a/arch/x86/kernel/cpu/mtrr/amd.c b/arch/x86/kernel/cpu/mtrr/amd.c
new file mode 100644
index 000000000000..0949cdbf848a
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/amd.c
@@ -0,0 +1,121 @@
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+
+#include "mtrr.h"
+
+static void
+amd_get_mtrr(unsigned int reg, unsigned long *base,
+	     unsigned long *size, mtrr_type * type)
+{
+	unsigned long low, high;
+
+	rdmsr(MSR_K6_UWCCR, low, high);
+	/*  Upper dword is region 1, lower is region 0  */
+	if (reg == 1)
+		low = high;
+	/*  The base masks off on the right alignment  */
+	*base = (low & 0xFFFE0000) >> PAGE_SHIFT;
+	*type = 0;
+	if (low & 1)
+		*type = MTRR_TYPE_UNCACHABLE;
+	if (low & 2)
+		*type = MTRR_TYPE_WRCOMB;
+	if (!(low & 3)) {
+		*size = 0;
+		return;
+	}
+	/*
+	 *  This needs a little explaining. The size is stored as an
+	 *  inverted mask of bits of 128K granularity 15 bits long offset
+	 *  2 bits
+	 *
+	 *  So to get a size we do invert the mask and add 1 to the lowest
+	 *  mask bit (4 as its 2 bits in). This gives us a size we then shift
+	 *  to turn into 128K blocks
+	 *
+	 *  eg              111 1111 1111 1100      is 512K
+	 *
+	 *  invert          000 0000 0000 0011
+	 *  +1              000 0000 0000 0100
+	 *  *128K   ...
+	 */
+	low = (~low) & 0x1FFFC;
+	*size = (low + 4) << (15 - PAGE_SHIFT);
+	return;
+}
+
+static void amd_set_mtrr(unsigned int reg, unsigned long base,
+			 unsigned long size, mtrr_type type)
+/*  [SUMMARY] Set variable MTRR register on the local CPU.
+    <reg> The register to set.
+    <base> The base address of the region.
+    <size> The size of the region. If this is 0 the region is disabled.
+    <type> The type of the region.
+    <do_safe> If TRUE, do the change safely. If FALSE, safety measures should
+    be done externally.
+    [RETURNS] Nothing.
+*/
+{
+	u32 regs[2];
+
+	/*
+	 *  Low is MTRR0 , High MTRR 1
+	 */
+	rdmsr(MSR_K6_UWCCR, regs[0], regs[1]);
+	/*
+	 *  Blank to disable
+	 */
+	if (size == 0)
+		regs[reg] = 0;
+	else
+		/* Set the register to the base, the type (off by one) and an
+		   inverted bitmask of the size The size is the only odd
+		   bit. We are fed say 512K We invert this and we get 111 1111
+		   1111 1011 but if you subtract one and invert you get the   
+		   desired 111 1111 1111 1100 mask
+
+		   But ~(x - 1) == ~x + 1 == -x. Two's complement rocks!  */
+		regs[reg] = (-size >> (15 - PAGE_SHIFT) & 0x0001FFFC)
+		    | (base << PAGE_SHIFT) | (type + 1);
+
+	/*
+	 *  The writeback rule is quite specific. See the manual. Its
+	 *  disable local interrupts, write back the cache, set the mtrr
+	 */
+	wbinvd();
+	wrmsr(MSR_K6_UWCCR, regs[0], regs[1]);
+}
+
+static int amd_validate_add_page(unsigned long base, unsigned long size, unsigned int type)
+{
+	/* Apply the K6 block alignment and size rules
+	   In order
+	   o Uncached or gathering only
+	   o 128K or bigger block
+	   o Power of 2 block
+	   o base suitably aligned to the power
+	*/
+	if (type > MTRR_TYPE_WRCOMB || size < (1 << (17 - PAGE_SHIFT))
+	    || (size & ~(size - 1)) - size || (base & (size - 1)))
+		return -EINVAL;
+	return 0;
+}
+
+static struct mtrr_ops amd_mtrr_ops = {
+	.vendor            = X86_VENDOR_AMD,
+	.set               = amd_set_mtrr,
+	.get               = amd_get_mtrr,
+	.get_free_region   = generic_get_free_region,
+	.validate_add_page = amd_validate_add_page,
+	.have_wrcomb       = positive_have_wrcomb,
+};
+
+int __init amd_init_mtrr(void)
+{
+	set_mtrr_ops(&amd_mtrr_ops);
+	return 0;
+}
+
+//arch_initcall(amd_mtrr_init);
diff --git a/arch/x86/kernel/cpu/mtrr/centaur.c b/arch/x86/kernel/cpu/mtrr/centaur.c
new file mode 100644
index 000000000000..cb9aa3a7a7ab
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/centaur.c
@@ -0,0 +1,224 @@
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+#include "mtrr.h"
+
+static struct {
+	unsigned long high;
+	unsigned long low;
+} centaur_mcr[8];
+
+static u8 centaur_mcr_reserved;
+static u8 centaur_mcr_type;	/* 0 for winchip, 1 for winchip2 */
+
+/*
+ *	Report boot time MCR setups 
+ */
+
+static int
+centaur_get_free_region(unsigned long base, unsigned long size, int replace_reg)
+/*  [SUMMARY] Get a free MTRR.
+    <base> The starting (base) address of the region.
+    <size> The size (in bytes) of the region.
+    [RETURNS] The index of the region on success, else -1 on error.
+*/
+{
+	int i, max;
+	mtrr_type ltype;
+	unsigned long lbase, lsize;
+
+	max = num_var_ranges;
+	if (replace_reg >= 0 && replace_reg < max)
+		return replace_reg;
+	for (i = 0; i < max; ++i) {
+		if (centaur_mcr_reserved & (1 << i))
+			continue;
+		mtrr_if->get(i, &lbase, &lsize, &ltype);
+		if (lsize == 0)
+			return i;
+	}
+	return -ENOSPC;
+}
+
+void
+mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
+{
+	centaur_mcr[mcr].low = lo;
+	centaur_mcr[mcr].high = hi;
+}
+
+static void
+centaur_get_mcr(unsigned int reg, unsigned long *base,
+		unsigned long *size, mtrr_type * type)
+{
+	*base = centaur_mcr[reg].high >> PAGE_SHIFT;
+	*size = -(centaur_mcr[reg].low & 0xfffff000) >> PAGE_SHIFT;
+	*type = MTRR_TYPE_WRCOMB;	/*  If it is there, it is write-combining  */
+	if (centaur_mcr_type == 1 && ((centaur_mcr[reg].low & 31) & 2))
+		*type = MTRR_TYPE_UNCACHABLE;
+	if (centaur_mcr_type == 1 && (centaur_mcr[reg].low & 31) == 25)
+		*type = MTRR_TYPE_WRBACK;
+	if (centaur_mcr_type == 0 && (centaur_mcr[reg].low & 31) == 31)
+		*type = MTRR_TYPE_WRBACK;
+
+}
+
+static void centaur_set_mcr(unsigned int reg, unsigned long base,
+			    unsigned long size, mtrr_type type)
+{
+	unsigned long low, high;
+
+	if (size == 0) {
+		/*  Disable  */
+		high = low = 0;
+	} else {
+		high = base << PAGE_SHIFT;
+		if (centaur_mcr_type == 0)
+			low = -size << PAGE_SHIFT | 0x1f;	/* only support write-combining... */
+		else {
+			if (type == MTRR_TYPE_UNCACHABLE)
+				low = -size << PAGE_SHIFT | 0x02;	/* NC */
+			else
+				low = -size << PAGE_SHIFT | 0x09;	/* WWO,WC */
+		}
+	}
+	centaur_mcr[reg].high = high;
+	centaur_mcr[reg].low = low;
+	wrmsr(MSR_IDT_MCR0 + reg, low, high);
+}
+
+#if 0
+/*
+ *	Initialise the later (saner) Winchip MCR variant. In this version
+ *	the BIOS can pass us the registers it has used (but not their values)
+ *	and the control register is read/write
+ */
+
+static void __init
+centaur_mcr1_init(void)
+{
+	unsigned i;
+	u32 lo, hi;
+
+	/* Unfortunately, MCR's are read-only, so there is no way to
+	 * find out what the bios might have done.
+	 */
+
+	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
+	if (((lo >> 17) & 7) == 1) {	/* Type 1 Winchip2 MCR */
+		lo &= ~0x1C0;	/* clear key */
+		lo |= 0x040;	/* set key to 1 */
+		wrmsr(MSR_IDT_MCR_CTRL, lo, hi);	/* unlock MCR */
+	}
+
+	centaur_mcr_type = 1;
+
+	/*
+	 *  Clear any unconfigured MCR's.
+	 */
+
+	for (i = 0; i < 8; ++i) {
+		if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0) {
+			if (!(lo & (1 << (9 + i))))
+				wrmsr(MSR_IDT_MCR0 + i, 0, 0);
+			else
+				/*
+				 *      If the BIOS set up an MCR we cannot see it
+				 *      but we don't wish to obliterate it
+				 */
+				centaur_mcr_reserved |= (1 << i);
+		}
+	}
+	/*  
+	 *  Throw the main write-combining switch... 
+	 *  However if OOSTORE is enabled then people have already done far
+	 *  cleverer things and we should behave. 
+	 */
+
+	lo |= 15;		/* Write combine enables */
+	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
+}
+
+/*
+ *	Initialise the original winchip with read only MCR registers
+ *	no used bitmask for the BIOS to pass on and write only control
+ */
+
+static void __init
+centaur_mcr0_init(void)
+{
+	unsigned i;
+
+	/* Unfortunately, MCR's are read-only, so there is no way to
+	 * find out what the bios might have done.
+	 */
+
+	/* Clear any unconfigured MCR's.
+	 * This way we are sure that the centaur_mcr array contains the actual
+	 * values. The disadvantage is that any BIOS tweaks are thus undone.
+	 *
+	 */
+	for (i = 0; i < 8; ++i) {
+		if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0)
+			wrmsr(MSR_IDT_MCR0 + i, 0, 0);
+	}
+
+	wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);	/* Write only */
+}
+
+/*
+ *	Initialise Winchip series MCR registers
+ */
+
+static void __init
+centaur_mcr_init(void)
+{
+	struct set_mtrr_context ctxt;
+
+	set_mtrr_prepare_save(&ctxt);
+	set_mtrr_cache_disable(&ctxt);
+
+	if (boot_cpu_data.x86_model == 4)
+		centaur_mcr0_init();
+	else if (boot_cpu_data.x86_model == 8 || boot_cpu_data.x86_model == 9)
+		centaur_mcr1_init();
+
+	set_mtrr_done(&ctxt);
+}
+#endif
+
+static int centaur_validate_add_page(unsigned long base, 
+				     unsigned long size, unsigned int type)
+{
+	/*
+	 *  FIXME: Winchip2 supports uncached
+	 */
+	if (type != MTRR_TYPE_WRCOMB && 
+	    (centaur_mcr_type == 0 || type != MTRR_TYPE_UNCACHABLE)) {
+		printk(KERN_WARNING
+		       "mtrr: only write-combining%s supported\n",
+		       centaur_mcr_type ? " and uncacheable are"
+		       : " is");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static struct mtrr_ops centaur_mtrr_ops = {
+	.vendor            = X86_VENDOR_CENTAUR,
+//	.init              = centaur_mcr_init,
+	.set               = centaur_set_mcr,
+	.get               = centaur_get_mcr,
+	.get_free_region   = centaur_get_free_region,
+	.validate_add_page = centaur_validate_add_page,
+	.have_wrcomb       = positive_have_wrcomb,
+};
+
+int __init centaur_init_mtrr(void)
+{
+	set_mtrr_ops(&centaur_mtrr_ops);
+	return 0;
+}
+
+//arch_initcall(centaur_init_mtrr);
diff --git a/arch/x86/kernel/cpu/mtrr/cyrix.c b/arch/x86/kernel/cpu/mtrr/cyrix.c
new file mode 100644
index 000000000000..2287d4863a8a
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/cyrix.c
@@ -0,0 +1,380 @@
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+#include <asm/io.h>
+#include <asm/processor-cyrix.h>
+#include "mtrr.h"
+
+int arr3_protected;
+
+static void
+cyrix_get_arr(unsigned int reg, unsigned long *base,
+	      unsigned long *size, mtrr_type * type)
+{
+	unsigned long flags;
+	unsigned char arr, ccr3, rcr, shift;
+
+	arr = CX86_ARR_BASE + (reg << 1) + reg;	/* avoid multiplication by 3 */
+
+	/* Save flags and disable interrupts */
+	local_irq_save(flags);
+
+	ccr3 = getCx86(CX86_CCR3);
+	setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10);	/* enable MAPEN */
+	((unsigned char *) base)[3] = getCx86(arr);
+	((unsigned char *) base)[2] = getCx86(arr + 1);
+	((unsigned char *) base)[1] = getCx86(arr + 2);
+	rcr = getCx86(CX86_RCR_BASE + reg);
+	setCx86(CX86_CCR3, ccr3);	/* disable MAPEN */
+
+	/* Enable interrupts if it was enabled previously */
+	local_irq_restore(flags);
+	shift = ((unsigned char *) base)[1] & 0x0f;
+	*base >>= PAGE_SHIFT;
+
+	/* Power of two, at least 4K on ARR0-ARR6, 256K on ARR7
+	 * Note: shift==0xf means 4G, this is unsupported.
+	 */
+	if (shift)
+		*size = (reg < 7 ? 0x1UL : 0x40UL) << (shift - 1);
+	else
+		*size = 0;
+
+	/* Bit 0 is Cache Enable on ARR7, Cache Disable on ARR0-ARR6 */
+	if (reg < 7) {
+		switch (rcr) {
+		case 1:
+			*type = MTRR_TYPE_UNCACHABLE;
+			break;
+		case 8:
+			*type = MTRR_TYPE_WRBACK;
+			break;
+		case 9:
+			*type = MTRR_TYPE_WRCOMB;
+			break;
+		case 24:
+		default:
+			*type = MTRR_TYPE_WRTHROUGH;
+			break;
+		}
+	} else {
+		switch (rcr) {
+		case 0:
+			*type = MTRR_TYPE_UNCACHABLE;
+			break;
+		case 8:
+			*type = MTRR_TYPE_WRCOMB;
+			break;
+		case 9:
+			*type = MTRR_TYPE_WRBACK;
+			break;
+		case 25:
+		default:
+			*type = MTRR_TYPE_WRTHROUGH;
+			break;
+		}
+	}
+}
+
+static int
+cyrix_get_free_region(unsigned long base, unsigned long size, int replace_reg)
+/*  [SUMMARY] Get a free ARR.
+    <base> The starting (base) address of the region.
+    <size> The size (in bytes) of the region.
+    [RETURNS] The index of the region on success, else -1 on error.
+*/
+{
+	int i;
+	mtrr_type ltype;
+	unsigned long lbase, lsize;
+
+	switch (replace_reg) {
+	case 7:
+		if (size < 0x40)
+			break;
+	case 6:
+	case 5:
+	case 4:
+		return replace_reg;
+	case 3:
+		if (arr3_protected)
+			break;
+	case 2:
+	case 1:
+	case 0:
+		return replace_reg;
+	}
+	/* If we are to set up a region >32M then look at ARR7 immediately */
+	if (size > 0x2000) {
+		cyrix_get_arr(7, &lbase, &lsize, &ltype);
+		if (lsize == 0)
+			return 7;
+		/*  Else try ARR0-ARR6 first  */
+	} else {
+		for (i = 0; i < 7; i++) {
+			cyrix_get_arr(i, &lbase, &lsize, &ltype);
+			if ((i == 3) && arr3_protected)
+				continue;
+			if (lsize == 0)
+				return i;
+		}
+		/* ARR0-ARR6 isn't free, try ARR7 but its size must be at least 256K */
+		cyrix_get_arr(i, &lbase, &lsize, &ltype);
+		if ((lsize == 0) && (size >= 0x40))
+			return i;
+	}
+	return -ENOSPC;
+}
+
+static u32 cr4 = 0;
+static u32 ccr3;
+
+static void prepare_set(void)
+{
+	u32 cr0;
+
+	/*  Save value of CR4 and clear Page Global Enable (bit 7)  */
+	if ( cpu_has_pge ) {
+		cr4 = read_cr4();
+		write_cr4(cr4 & ~X86_CR4_PGE);
+	}
+
+	/*  Disable and flush caches. Note that wbinvd flushes the TLBs as
+	    a side-effect  */
+	cr0 = read_cr0() | 0x40000000;
+	wbinvd();
+	write_cr0(cr0);
+	wbinvd();
+
+	/* Cyrix ARRs - everything else were excluded at the top */
+	ccr3 = getCx86(CX86_CCR3);
+
+	/* Cyrix ARRs - everything else were excluded at the top */
+	setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10);
+
+}
+
+static void post_set(void)
+{
+	/*  Flush caches and TLBs  */
+	wbinvd();
+
+	/* Cyrix ARRs - everything else was excluded at the top */
+	setCx86(CX86_CCR3, ccr3);
+		
+	/*  Enable caches  */
+	write_cr0(read_cr0() & 0xbfffffff);
+
+	/*  Restore value of CR4  */
+	if ( cpu_has_pge )
+		write_cr4(cr4);
+}
+
+static void cyrix_set_arr(unsigned int reg, unsigned long base,
+			  unsigned long size, mtrr_type type)
+{
+	unsigned char arr, arr_type, arr_size;
+
+	arr = CX86_ARR_BASE + (reg << 1) + reg;	/* avoid multiplication by 3 */
+
+	/* count down from 32M (ARR0-ARR6) or from 2G (ARR7) */
+	if (reg >= 7)
+		size >>= 6;
+
+	size &= 0x7fff;		/* make sure arr_size <= 14 */
+	for (arr_size = 0; size; arr_size++, size >>= 1) ;
+
+	if (reg < 7) {
+		switch (type) {
+		case MTRR_TYPE_UNCACHABLE:
+			arr_type = 1;
+			break;
+		case MTRR_TYPE_WRCOMB:
+			arr_type = 9;
+			break;
+		case MTRR_TYPE_WRTHROUGH:
+			arr_type = 24;
+			break;
+		default:
+			arr_type = 8;
+			break;
+		}
+	} else {
+		switch (type) {
+		case MTRR_TYPE_UNCACHABLE:
+			arr_type = 0;
+			break;
+		case MTRR_TYPE_WRCOMB:
+			arr_type = 8;
+			break;
+		case MTRR_TYPE_WRTHROUGH:
+			arr_type = 25;
+			break;
+		default:
+			arr_type = 9;
+			break;
+		}
+	}
+
+	prepare_set();
+
+	base <<= PAGE_SHIFT;
+	setCx86(arr, ((unsigned char *) &base)[3]);
+	setCx86(arr + 1, ((unsigned char *) &base)[2]);
+	setCx86(arr + 2, (((unsigned char *) &base)[1]) | arr_size);
+	setCx86(CX86_RCR_BASE + reg, arr_type);
+
+	post_set();
+}
+
+typedef struct {
+	unsigned long base;
+	unsigned long size;
+	mtrr_type type;
+} arr_state_t;
+
+static arr_state_t arr_state[8] = {
+	{0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL},
+	{0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}
+};
+
+static unsigned char ccr_state[7] = { 0, 0, 0, 0, 0, 0, 0 };
+
+static void cyrix_set_all(void)
+{
+	int i;
+
+	prepare_set();
+
+	/* the CCRs are not contiguous */
+	for (i = 0; i < 4; i++)
+		setCx86(CX86_CCR0 + i, ccr_state[i]);
+	for (; i < 7; i++)
+		setCx86(CX86_CCR4 + i, ccr_state[i]);
+	for (i = 0; i < 8; i++)
+		cyrix_set_arr(i, arr_state[i].base, 
+			      arr_state[i].size, arr_state[i].type);
+
+	post_set();
+}
+
+#if 0
+/*
+ * On Cyrix 6x86(MX) and M II the ARR3 is special: it has connection
+ * with the SMM (System Management Mode) mode. So we need the following:
+ * Check whether SMI_LOCK (CCR3 bit 0) is set
+ *   if it is set, write a warning message: ARR3 cannot be changed!
+ *     (it cannot be changed until the next processor reset)
+ *   if it is reset, then we can change it, set all the needed bits:
+ *   - disable access to SMM memory through ARR3 range (CCR1 bit 7 reset)
+ *   - disable access to SMM memory (CCR1 bit 2 reset)
+ *   - disable SMM mode (CCR1 bit 1 reset)
+ *   - disable write protection of ARR3 (CCR6 bit 1 reset)
+ *   - (maybe) disable ARR3
+ * Just to be sure, we enable ARR usage by the processor (CCR5 bit 5 set)
+ */
+static void __init
+cyrix_arr_init(void)
+{
+	struct set_mtrr_context ctxt;
+	unsigned char ccr[7];
+	int ccrc[7] = { 0, 0, 0, 0, 0, 0, 0 };
+#ifdef CONFIG_SMP
+	int i;
+#endif
+
+	/* flush cache and enable MAPEN */
+	set_mtrr_prepare_save(&ctxt);
+	set_mtrr_cache_disable(&ctxt);
+
+	/* Save all CCRs locally */
+	ccr[0] = getCx86(CX86_CCR0);
+	ccr[1] = getCx86(CX86_CCR1);
+	ccr[2] = getCx86(CX86_CCR2);
+	ccr[3] = ctxt.ccr3;
+	ccr[4] = getCx86(CX86_CCR4);
+	ccr[5] = getCx86(CX86_CCR5);
+	ccr[6] = getCx86(CX86_CCR6);
+
+	if (ccr[3] & 1) {
+		ccrc[3] = 1;
+		arr3_protected = 1;
+	} else {
+		/* Disable SMM mode (bit 1), access to SMM memory (bit 2) and
+		 * access to SMM memory through ARR3 (bit 7).
+		 */
+		if (ccr[1] & 0x80) {
+			ccr[1] &= 0x7f;
+			ccrc[1] |= 0x80;
+		}
+		if (ccr[1] & 0x04) {
+			ccr[1] &= 0xfb;
+			ccrc[1] |= 0x04;
+		}
+		if (ccr[1] & 0x02) {
+			ccr[1] &= 0xfd;
+			ccrc[1] |= 0x02;
+		}
+		arr3_protected = 0;
+		if (ccr[6] & 0x02) {
+			ccr[6] &= 0xfd;
+			ccrc[6] = 1;	/* Disable write protection of ARR3 */
+			setCx86(CX86_CCR6, ccr[6]);
+		}
+		/* Disable ARR3. This is safe now that we disabled SMM. */
+		/* cyrix_set_arr_up (3, 0, 0, 0, FALSE); */
+	}
+	/* If we changed CCR1 in memory, change it in the processor, too. */
+	if (ccrc[1])
+		setCx86(CX86_CCR1, ccr[1]);
+
+	/* Enable ARR usage by the processor */
+	if (!(ccr[5] & 0x20)) {
+		ccr[5] |= 0x20;
+		ccrc[5] = 1;
+		setCx86(CX86_CCR5, ccr[5]);
+	}
+#ifdef CONFIG_SMP
+	for (i = 0; i < 7; i++)
+		ccr_state[i] = ccr[i];
+	for (i = 0; i < 8; i++)
+		cyrix_get_arr(i,
+			      &arr_state[i].base, &arr_state[i].size,
+			      &arr_state[i].type);
+#endif
+
+	set_mtrr_done(&ctxt);	/* flush cache and disable MAPEN */
+
+	if (ccrc[5])
+		printk(KERN_INFO "mtrr: ARR usage was not enabled, enabled manually\n");
+	if (ccrc[3])
+		printk(KERN_INFO "mtrr: ARR3 cannot be changed\n");
+/*
+    if ( ccrc[1] & 0x80) printk ("mtrr: SMM memory access through ARR3 disabled\n");
+    if ( ccrc[1] & 0x04) printk ("mtrr: SMM memory access disabled\n");
+    if ( ccrc[1] & 0x02) printk ("mtrr: SMM mode disabled\n");
+*/
+	if (ccrc[6])
+		printk(KERN_INFO "mtrr: ARR3 was write protected, unprotected\n");
+}
+#endif
+
+static struct mtrr_ops cyrix_mtrr_ops = {
+	.vendor            = X86_VENDOR_CYRIX,
+//	.init              = cyrix_arr_init,
+	.set_all	   = cyrix_set_all,
+	.set               = cyrix_set_arr,
+	.get               = cyrix_get_arr,
+	.get_free_region   = cyrix_get_free_region,
+	.validate_add_page = generic_validate_add_page,
+	.have_wrcomb       = positive_have_wrcomb,
+};
+
+int __init cyrix_init_mtrr(void)
+{
+	set_mtrr_ops(&cyrix_mtrr_ops);
+	return 0;
+}
+
+//arch_initcall(cyrix_init_mtrr);
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
new file mode 100644
index 000000000000..56f64e34829f
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -0,0 +1,509 @@
+/* This only handles 32bit MTRR on 32bit hosts. This is strictly wrong
+   because MTRRs can span upto 40 bits (36bits on most modern x86) */ 
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <asm/io.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+#include <asm/system.h>
+#include <asm/cpufeature.h>
+#include <asm/tlbflush.h>
+#include "mtrr.h"
+
+struct mtrr_state {
+	struct mtrr_var_range *var_ranges;
+	mtrr_type fixed_ranges[NUM_FIXED_RANGES];
+	unsigned char enabled;
+	unsigned char have_fixed;
+	mtrr_type def_type;
+};
+
+struct fixed_range_block {
+	int base_msr; /* start address of an MTRR block */
+	int ranges;   /* number of MTRRs in this block  */
+};
+
+static struct fixed_range_block fixed_range_blocks[] = {
+	{ MTRRfix64K_00000_MSR, 1 }, /* one  64k MTRR  */
+	{ MTRRfix16K_80000_MSR, 2 }, /* two  16k MTRRs */
+	{ MTRRfix4K_C0000_MSR,  8 }, /* eight 4k MTRRs */
+	{}
+};
+
+static unsigned long smp_changes_mask;
+static struct mtrr_state mtrr_state = {};
+
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "mtrr."
+
+static int mtrr_show;
+module_param_named(show, mtrr_show, bool, 0);
+
+/*  Get the MSR pair relating to a var range  */
+static void
+get_mtrr_var_range(unsigned int index, struct mtrr_var_range *vr)
+{
+	rdmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi);
+	rdmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi);
+}
+
+static void
+get_fixed_ranges(mtrr_type * frs)
+{
+	unsigned int *p = (unsigned int *) frs;
+	int i;
+
+	rdmsr(MTRRfix64K_00000_MSR, p[0], p[1]);
+
+	for (i = 0; i < 2; i++)
+		rdmsr(MTRRfix16K_80000_MSR + i, p[2 + i * 2], p[3 + i * 2]);
+	for (i = 0; i < 8; i++)
+		rdmsr(MTRRfix4K_C0000_MSR + i, p[6 + i * 2], p[7 + i * 2]);
+}
+
+void mtrr_save_fixed_ranges(void *info)
+{
+	if (cpu_has_mtrr)
+		get_fixed_ranges(mtrr_state.fixed_ranges);
+}
+
+static void print_fixed(unsigned base, unsigned step, const mtrr_type*types)
+{
+	unsigned i;
+
+	for (i = 0; i < 8; ++i, ++types, base += step)
+		printk(KERN_INFO "MTRR %05X-%05X %s\n",
+			base, base + step - 1, mtrr_attrib_to_str(*types));
+}
+
+/*  Grab all of the MTRR state for this CPU into *state  */
+void __init get_mtrr_state(void)
+{
+	unsigned int i;
+	struct mtrr_var_range *vrs;
+	unsigned lo, dummy;
+
+	if (!mtrr_state.var_ranges) {
+		mtrr_state.var_ranges = kmalloc(num_var_ranges * sizeof (struct mtrr_var_range), 
+						GFP_KERNEL);
+		if (!mtrr_state.var_ranges)
+			return;
+	} 
+	vrs = mtrr_state.var_ranges;
+
+	rdmsr(MTRRcap_MSR, lo, dummy);
+	mtrr_state.have_fixed = (lo >> 8) & 1;
+
+	for (i = 0; i < num_var_ranges; i++)
+		get_mtrr_var_range(i, &vrs[i]);
+	if (mtrr_state.have_fixed)
+		get_fixed_ranges(mtrr_state.fixed_ranges);
+
+	rdmsr(MTRRdefType_MSR, lo, dummy);
+	mtrr_state.def_type = (lo & 0xff);
+	mtrr_state.enabled = (lo & 0xc00) >> 10;
+
+	if (mtrr_show) {
+		int high_width;
+
+		printk(KERN_INFO "MTRR default type: %s\n", mtrr_attrib_to_str(mtrr_state.def_type));
+		if (mtrr_state.have_fixed) {
+			printk(KERN_INFO "MTRR fixed ranges %sabled:\n",
+			       mtrr_state.enabled & 1 ? "en" : "dis");
+			print_fixed(0x00000, 0x10000, mtrr_state.fixed_ranges + 0);
+			for (i = 0; i < 2; ++i)
+				print_fixed(0x80000 + i * 0x20000, 0x04000, mtrr_state.fixed_ranges + (i + 1) * 8);
+			for (i = 0; i < 8; ++i)
+				print_fixed(0xC0000 + i * 0x08000, 0x01000, mtrr_state.fixed_ranges + (i + 3) * 8);
+		}
+		printk(KERN_INFO "MTRR variable ranges %sabled:\n",
+		       mtrr_state.enabled & 2 ? "en" : "dis");
+		high_width = ((size_or_mask ? ffs(size_or_mask) - 1 : 32) - (32 - PAGE_SHIFT) + 3) / 4;
+		for (i = 0; i < num_var_ranges; ++i) {
+			if (mtrr_state.var_ranges[i].mask_lo & (1 << 11))
+				printk(KERN_INFO "MTRR %u base %0*X%05X000 mask %0*X%05X000 %s\n",
+				       i,
+				       high_width,
+				       mtrr_state.var_ranges[i].base_hi,
+				       mtrr_state.var_ranges[i].base_lo >> 12,
+				       high_width,
+				       mtrr_state.var_ranges[i].mask_hi,
+				       mtrr_state.var_ranges[i].mask_lo >> 12,
+				       mtrr_attrib_to_str(mtrr_state.var_ranges[i].base_lo & 0xff));
+			else
+				printk(KERN_INFO "MTRR %u disabled\n", i);
+		}
+	}
+}
+
+/*  Some BIOS's are fucked and don't set all MTRRs the same!  */
+void __init mtrr_state_warn(void)
+{
+	unsigned long mask = smp_changes_mask;
+
+	if (!mask)
+		return;
+	if (mask & MTRR_CHANGE_MASK_FIXED)
+		printk(KERN_WARNING "mtrr: your CPUs had inconsistent fixed MTRR settings\n");
+	if (mask & MTRR_CHANGE_MASK_VARIABLE)
+		printk(KERN_WARNING "mtrr: your CPUs had inconsistent variable MTRR settings\n");
+	if (mask & MTRR_CHANGE_MASK_DEFTYPE)
+		printk(KERN_WARNING "mtrr: your CPUs had inconsistent MTRRdefType settings\n");
+	printk(KERN_INFO "mtrr: probably your BIOS does not setup all CPUs.\n");
+	printk(KERN_INFO "mtrr: corrected configuration.\n");
+}
+
+/* Doesn't attempt to pass an error out to MTRR users
+   because it's quite complicated in some cases and probably not
+   worth it because the best error handling is to ignore it. */
+void mtrr_wrmsr(unsigned msr, unsigned a, unsigned b)
+{
+	if (wrmsr_safe(msr, a, b) < 0)
+		printk(KERN_ERR
+			"MTRR: CPU %u: Writing MSR %x to %x:%x failed\n",
+			smp_processor_id(), msr, a, b);
+}
+
+/**
+ * Enable and allow read/write of extended fixed-range MTRR bits on K8 CPUs
+ * see AMD publication no. 24593, chapter 3.2.1 for more information
+ */
+static inline void k8_enable_fixed_iorrs(void)
+{
+	unsigned lo, hi;
+
+	rdmsr(MSR_K8_SYSCFG, lo, hi);
+	mtrr_wrmsr(MSR_K8_SYSCFG, lo
+				| K8_MTRRFIXRANGE_DRAM_ENABLE
+				| K8_MTRRFIXRANGE_DRAM_MODIFY, hi);
+}
+
+/**
+ * Checks and updates an fixed-range MTRR if it differs from the value it
+ * should have. If K8 extenstions are wanted, update the K8 SYSCFG MSR also.
+ * see AMD publication no. 24593, chapter 7.8.1, page 233 for more information
+ * \param msr MSR address of the MTTR which should be checked and updated
+ * \param changed pointer which indicates whether the MTRR needed to be changed
+ * \param msrwords pointer to the MSR values which the MSR should have
+ */
+static void set_fixed_range(int msr, int * changed, unsigned int * msrwords)
+{
+	unsigned lo, hi;
+
+	rdmsr(msr, lo, hi);
+
+	if (lo != msrwords[0] || hi != msrwords[1]) {
+		if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+		    boot_cpu_data.x86 == 15 &&
+		    ((msrwords[0] | msrwords[1]) & K8_MTRR_RDMEM_WRMEM_MASK))
+			k8_enable_fixed_iorrs();
+		mtrr_wrmsr(msr, msrwords[0], msrwords[1]);
+		*changed = TRUE;
+	}
+}
+
+int generic_get_free_region(unsigned long base, unsigned long size, int replace_reg)
+/*  [SUMMARY] Get a free MTRR.
+    <base> The starting (base) address of the region.
+    <size> The size (in bytes) of the region.
+    [RETURNS] The index of the region on success, else -1 on error.
+*/
+{
+	int i, max;
+	mtrr_type ltype;
+	unsigned long lbase, lsize;
+
+	max = num_var_ranges;
+	if (replace_reg >= 0 && replace_reg < max)
+		return replace_reg;
+	for (i = 0; i < max; ++i) {
+		mtrr_if->get(i, &lbase, &lsize, &ltype);
+		if (lsize == 0)
+			return i;
+	}
+	return -ENOSPC;
+}
+
+static void generic_get_mtrr(unsigned int reg, unsigned long *base,
+			     unsigned long *size, mtrr_type *type)
+{
+	unsigned int mask_lo, mask_hi, base_lo, base_hi;
+
+	rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi);
+	if ((mask_lo & 0x800) == 0) {
+		/*  Invalid (i.e. free) range  */
+		*base = 0;
+		*size = 0;
+		*type = 0;
+		return;
+	}
+
+	rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi);
+
+	/* Work out the shifted address mask. */
+	mask_lo = size_or_mask | mask_hi << (32 - PAGE_SHIFT)
+	    | mask_lo >> PAGE_SHIFT;
+
+	/* This works correctly if size is a power of two, i.e. a
+	   contiguous range. */
+	*size = -mask_lo;
+	*base = base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT;
+	*type = base_lo & 0xff;
+}
+
+/**
+ * Checks and updates the fixed-range MTRRs if they differ from the saved set
+ * \param frs pointer to fixed-range MTRR values, saved by get_fixed_ranges()
+ */
+static int set_fixed_ranges(mtrr_type * frs)
+{
+	unsigned long long *saved = (unsigned long long *) frs;
+	int changed = FALSE;
+	int block=-1, range;
+
+	while (fixed_range_blocks[++block].ranges)
+	    for (range=0; range < fixed_range_blocks[block].ranges; range++)
+		set_fixed_range(fixed_range_blocks[block].base_msr + range,
+		    &changed, (unsigned int *) saved++);
+
+	return changed;
+}
+
+/*  Set the MSR pair relating to a var range. Returns TRUE if
+    changes are made  */
+static int set_mtrr_var_ranges(unsigned int index, struct mtrr_var_range *vr)
+{
+	unsigned int lo, hi;
+	int changed = FALSE;
+
+	rdmsr(MTRRphysBase_MSR(index), lo, hi);
+	if ((vr->base_lo & 0xfffff0ffUL) != (lo & 0xfffff0ffUL)
+	    || (vr->base_hi & (size_and_mask >> (32 - PAGE_SHIFT))) !=
+		(hi & (size_and_mask >> (32 - PAGE_SHIFT)))) {
+		mtrr_wrmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi);
+		changed = TRUE;
+	}
+
+	rdmsr(MTRRphysMask_MSR(index), lo, hi);
+
+	if ((vr->mask_lo & 0xfffff800UL) != (lo & 0xfffff800UL)
+	    || (vr->mask_hi & (size_and_mask >> (32 - PAGE_SHIFT))) !=
+		(hi & (size_and_mask >> (32 - PAGE_SHIFT)))) {
+		mtrr_wrmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi);
+		changed = TRUE;
+	}
+	return changed;
+}
+
+static u32 deftype_lo, deftype_hi;
+
+static unsigned long set_mtrr_state(void)
+/*  [SUMMARY] Set the MTRR state for this CPU.
+    <state> The MTRR state information to read.
+    <ctxt> Some relevant CPU context.
+    [NOTE] The CPU must already be in a safe state for MTRR changes.
+    [RETURNS] 0 if no changes made, else a mask indication what was changed.
+*/
+{
+	unsigned int i;
+	unsigned long change_mask = 0;
+
+	for (i = 0; i < num_var_ranges; i++)
+		if (set_mtrr_var_ranges(i, &mtrr_state.var_ranges[i]))
+			change_mask |= MTRR_CHANGE_MASK_VARIABLE;
+
+	if (mtrr_state.have_fixed && set_fixed_ranges(mtrr_state.fixed_ranges))
+		change_mask |= MTRR_CHANGE_MASK_FIXED;
+
+	/*  Set_mtrr_restore restores the old value of MTRRdefType,
+	   so to set it we fiddle with the saved value  */
+	if ((deftype_lo & 0xff) != mtrr_state.def_type
+	    || ((deftype_lo & 0xc00) >> 10) != mtrr_state.enabled) {
+		deftype_lo = (deftype_lo & ~0xcff) | mtrr_state.def_type | (mtrr_state.enabled << 10);
+		change_mask |= MTRR_CHANGE_MASK_DEFTYPE;
+	}
+
+	return change_mask;
+}
+
+
+static unsigned long cr4 = 0;
+static DEFINE_SPINLOCK(set_atomicity_lock);
+
+/*
+ * Since we are disabling the cache don't allow any interrupts - they
+ * would run extremely slow and would only increase the pain.  The caller must
+ * ensure that local interrupts are disabled and are reenabled after post_set()
+ * has been called.
+ */
+
+static void prepare_set(void) __acquires(set_atomicity_lock)
+{
+	unsigned long cr0;
+
+	/*  Note that this is not ideal, since the cache is only flushed/disabled
+	   for this CPU while the MTRRs are changed, but changing this requires
+	   more invasive changes to the way the kernel boots  */
+
+	spin_lock(&set_atomicity_lock);
+
+	/*  Enter the no-fill (CD=1, NW=0) cache mode and flush caches. */
+	cr0 = read_cr0() | 0x40000000;	/* set CD flag */
+	write_cr0(cr0);
+	wbinvd();
+
+	/*  Save value of CR4 and clear Page Global Enable (bit 7)  */
+	if ( cpu_has_pge ) {
+		cr4 = read_cr4();
+		write_cr4(cr4 & ~X86_CR4_PGE);
+	}
+
+	/* Flush all TLBs via a mov %cr3, %reg; mov %reg, %cr3 */
+	__flush_tlb();
+
+	/*  Save MTRR state */
+	rdmsr(MTRRdefType_MSR, deftype_lo, deftype_hi);
+
+	/*  Disable MTRRs, and set the default type to uncached  */
+	mtrr_wrmsr(MTRRdefType_MSR, deftype_lo & ~0xcff, deftype_hi);
+}
+
+static void post_set(void) __releases(set_atomicity_lock)
+{
+	/*  Flush TLBs (no need to flush caches - they are disabled)  */
+	__flush_tlb();
+
+	/* Intel (P6) standard MTRRs */
+	mtrr_wrmsr(MTRRdefType_MSR, deftype_lo, deftype_hi);
+		
+	/*  Enable caches  */
+	write_cr0(read_cr0() & 0xbfffffff);
+
+	/*  Restore value of CR4  */
+	if ( cpu_has_pge )
+		write_cr4(cr4);
+	spin_unlock(&set_atomicity_lock);
+}
+
+static void generic_set_all(void)
+{
+	unsigned long mask, count;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	prepare_set();
+
+	/* Actually set the state */
+	mask = set_mtrr_state();
+
+	post_set();
+	local_irq_restore(flags);
+
+	/*  Use the atomic bitops to update the global mask  */
+	for (count = 0; count < sizeof mask * 8; ++count) {
+		if (mask & 0x01)
+			set_bit(count, &smp_changes_mask);
+		mask >>= 1;
+	}
+	
+}
+
+static void generic_set_mtrr(unsigned int reg, unsigned long base,
+			     unsigned long size, mtrr_type type)
+/*  [SUMMARY] Set variable MTRR register on the local CPU.
+    <reg> The register to set.
+    <base> The base address of the region.
+    <size> The size of the region. If this is 0 the region is disabled.
+    <type> The type of the region.
+    <do_safe> If TRUE, do the change safely. If FALSE, safety measures should
+    be done externally.
+    [RETURNS] Nothing.
+*/
+{
+	unsigned long flags;
+	struct mtrr_var_range *vr;
+
+	vr = &mtrr_state.var_ranges[reg];
+
+	local_irq_save(flags);
+	prepare_set();
+
+	if (size == 0) {
+		/* The invalid bit is kept in the mask, so we simply clear the
+		   relevant mask register to disable a range. */
+		mtrr_wrmsr(MTRRphysMask_MSR(reg), 0, 0);
+		memset(vr, 0, sizeof(struct mtrr_var_range));
+	} else {
+		vr->base_lo = base << PAGE_SHIFT | type;
+		vr->base_hi = (base & size_and_mask) >> (32 - PAGE_SHIFT);
+		vr->mask_lo = -size << PAGE_SHIFT | 0x800;
+		vr->mask_hi = (-size & size_and_mask) >> (32 - PAGE_SHIFT);
+
+		mtrr_wrmsr(MTRRphysBase_MSR(reg), vr->base_lo, vr->base_hi);
+		mtrr_wrmsr(MTRRphysMask_MSR(reg), vr->mask_lo, vr->mask_hi);
+	}
+
+	post_set();
+	local_irq_restore(flags);
+}
+
+int generic_validate_add_page(unsigned long base, unsigned long size, unsigned int type)
+{
+	unsigned long lbase, last;
+
+	/*  For Intel PPro stepping <= 7, must be 4 MiB aligned 
+	    and not touch 0x70000000->0x7003FFFF */
+	if (is_cpu(INTEL) && boot_cpu_data.x86 == 6 &&
+	    boot_cpu_data.x86_model == 1 &&
+	    boot_cpu_data.x86_mask <= 7) {
+		if (base & ((1 << (22 - PAGE_SHIFT)) - 1)) {
+			printk(KERN_WARNING "mtrr: base(0x%lx000) is not 4 MiB aligned\n", base);
+			return -EINVAL;
+		}
+		if (!(base + size < 0x70000 || base > 0x7003F) &&
+		    (type == MTRR_TYPE_WRCOMB
+		     || type == MTRR_TYPE_WRBACK)) {
+			printk(KERN_WARNING "mtrr: writable mtrr between 0x70000000 and 0x7003FFFF may hang the CPU.\n");
+			return -EINVAL;
+		}
+	}
+
+	/*  Check upper bits of base and last are equal and lower bits are 0
+	    for base and 1 for last  */
+	last = base + size - 1;
+	for (lbase = base; !(lbase & 1) && (last & 1);
+	     lbase = lbase >> 1, last = last >> 1) ;
+	if (lbase != last) {
+		printk(KERN_WARNING "mtrr: base(0x%lx000) is not aligned on a size(0x%lx000) boundary\n",
+		       base, size);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+
+static int generic_have_wrcomb(void)
+{
+	unsigned long config, dummy;
+	rdmsr(MTRRcap_MSR, config, dummy);
+	return (config & (1 << 10));
+}
+
+int positive_have_wrcomb(void)
+{
+	return 1;
+}
+
+/* generic structure...
+ */
+struct mtrr_ops generic_mtrr_ops = {
+	.use_intel_if      = 1,
+	.set_all	   = generic_set_all,
+	.get               = generic_get_mtrr,
+	.get_free_region   = generic_get_free_region,
+	.set               = generic_set_mtrr,
+	.validate_add_page = generic_validate_add_page,
+	.have_wrcomb       = generic_have_wrcomb,
+};
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
new file mode 100644
index 000000000000..c7d8f1756745
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -0,0 +1,439 @@
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/capability.h>
+#include <linux/ctype.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <asm/uaccess.h>
+
+#define LINE_SIZE 80
+
+#include <asm/mtrr.h>
+#include "mtrr.h"
+
+/* RED-PEN: this is accessed without any locking */
+extern unsigned int *usage_table;
+
+
+#define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
+
+static const char *const mtrr_strings[MTRR_NUM_TYPES] =
+{
+    "uncachable",               /* 0 */
+    "write-combining",          /* 1 */
+    "?",                        /* 2 */
+    "?",                        /* 3 */
+    "write-through",            /* 4 */
+    "write-protect",            /* 5 */
+    "write-back",               /* 6 */
+};
+
+const char *mtrr_attrib_to_str(int x)
+{
+	return (x <= 6) ? mtrr_strings[x] : "?";
+}
+
+#ifdef CONFIG_PROC_FS
+
+static int
+mtrr_file_add(unsigned long base, unsigned long size,
+	      unsigned int type, char increment, struct file *file, int page)
+{
+	int reg, max;
+	unsigned int *fcount = FILE_FCOUNT(file); 
+
+	max = num_var_ranges;
+	if (fcount == NULL) {
+		fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
+		if (!fcount)
+			return -ENOMEM;
+		FILE_FCOUNT(file) = fcount;
+	}
+	if (!page) {
+		if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
+			return -EINVAL;
+		base >>= PAGE_SHIFT;
+		size >>= PAGE_SHIFT;
+	}
+	reg = mtrr_add_page(base, size, type, 1);
+	if (reg >= 0)
+		++fcount[reg];
+	return reg;
+}
+
+static int
+mtrr_file_del(unsigned long base, unsigned long size,
+	      struct file *file, int page)
+{
+	int reg;
+	unsigned int *fcount = FILE_FCOUNT(file);
+
+	if (!page) {
+		if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
+			return -EINVAL;
+		base >>= PAGE_SHIFT;
+		size >>= PAGE_SHIFT;
+	}
+	reg = mtrr_del_page(-1, base, size);
+	if (reg < 0)
+		return reg;
+	if (fcount == NULL)
+		return reg;
+	if (fcount[reg] < 1)
+		return -EINVAL;
+	--fcount[reg];
+	return reg;
+}
+
+/* RED-PEN: seq_file can seek now. this is ignored. */
+static ssize_t
+mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
+/*  Format of control line:
+    "base=%Lx size=%Lx type=%s"     OR:
+    "disable=%d"
+*/
+{
+	int i, err;
+	unsigned long reg;
+	unsigned long long base, size;
+	char *ptr;
+	char line[LINE_SIZE];
+	size_t linelen;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	if (!len)
+		return -EINVAL;
+	memset(line, 0, LINE_SIZE);
+	if (len > LINE_SIZE)
+		len = LINE_SIZE;
+	if (copy_from_user(line, buf, len - 1))
+		return -EFAULT;
+	linelen = strlen(line);
+	ptr = line + linelen - 1;
+	if (linelen && *ptr == '\n')
+		*ptr = '\0';
+	if (!strncmp(line, "disable=", 8)) {
+		reg = simple_strtoul(line + 8, &ptr, 0);
+		err = mtrr_del_page(reg, 0, 0);
+		if (err < 0)
+			return err;
+		return len;
+	}
+	if (strncmp(line, "base=", 5))
+		return -EINVAL;
+	base = simple_strtoull(line + 5, &ptr, 0);
+	for (; isspace(*ptr); ++ptr) ;
+	if (strncmp(ptr, "size=", 5))
+		return -EINVAL;
+	size = simple_strtoull(ptr + 5, &ptr, 0);
+	if ((base & 0xfff) || (size & 0xfff))
+		return -EINVAL;
+	for (; isspace(*ptr); ++ptr) ;
+	if (strncmp(ptr, "type=", 5))
+		return -EINVAL;
+	ptr += 5;
+	for (; isspace(*ptr); ++ptr) ;
+	for (i = 0; i < MTRR_NUM_TYPES; ++i) {
+		if (strcmp(ptr, mtrr_strings[i]))
+			continue;
+		base >>= PAGE_SHIFT;
+		size >>= PAGE_SHIFT;
+		err =
+		    mtrr_add_page((unsigned long) base, (unsigned long) size, i,
+				  1);
+		if (err < 0)
+			return err;
+		return len;
+	}
+	return -EINVAL;
+}
+
+static long
+mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
+{
+	int err = 0;
+	mtrr_type type;
+	unsigned long size;
+	struct mtrr_sentry sentry;
+	struct mtrr_gentry gentry;
+	void __user *arg = (void __user *) __arg;
+
+	switch (cmd) {
+	case MTRRIOC_ADD_ENTRY:
+	case MTRRIOC_SET_ENTRY:
+	case MTRRIOC_DEL_ENTRY:
+	case MTRRIOC_KILL_ENTRY:
+	case MTRRIOC_ADD_PAGE_ENTRY:
+	case MTRRIOC_SET_PAGE_ENTRY:
+	case MTRRIOC_DEL_PAGE_ENTRY:
+	case MTRRIOC_KILL_PAGE_ENTRY:
+		if (copy_from_user(&sentry, arg, sizeof sentry))
+			return -EFAULT;
+		break;
+	case MTRRIOC_GET_ENTRY:
+	case MTRRIOC_GET_PAGE_ENTRY:
+		if (copy_from_user(&gentry, arg, sizeof gentry))
+			return -EFAULT;
+		break;
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_ADD_ENTRY:
+	case MTRRIOC32_SET_ENTRY:
+	case MTRRIOC32_DEL_ENTRY:
+	case MTRRIOC32_KILL_ENTRY:
+	case MTRRIOC32_ADD_PAGE_ENTRY:
+	case MTRRIOC32_SET_PAGE_ENTRY:
+	case MTRRIOC32_DEL_PAGE_ENTRY:
+	case MTRRIOC32_KILL_PAGE_ENTRY: {
+		struct mtrr_sentry32 __user *s32 = (struct mtrr_sentry32 __user *)__arg;
+		err = get_user(sentry.base, &s32->base);
+		err |= get_user(sentry.size, &s32->size);
+		err |= get_user(sentry.type, &s32->type);
+		if (err)
+			return err;
+		break;
+	}
+	case MTRRIOC32_GET_ENTRY:
+	case MTRRIOC32_GET_PAGE_ENTRY: {
+		struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
+		err = get_user(gentry.regnum, &g32->regnum);
+		err |= get_user(gentry.base, &g32->base);
+		err |= get_user(gentry.size, &g32->size);
+		err |= get_user(gentry.type, &g32->type);
+		if (err)
+			return err;
+		break;
+	}
+#endif
+	}
+
+	switch (cmd) {
+	default:
+		return -ENOTTY;
+	case MTRRIOC_ADD_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_ADD_ENTRY:
+#endif
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		err =
+		    mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
+				  file, 0);
+		break;
+	case MTRRIOC_SET_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_SET_ENTRY:
+#endif
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		err = mtrr_add(sentry.base, sentry.size, sentry.type, 0);
+		break;
+	case MTRRIOC_DEL_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_DEL_ENTRY:
+#endif
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		err = mtrr_file_del(sentry.base, sentry.size, file, 0);
+		break;
+	case MTRRIOC_KILL_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_KILL_ENTRY:
+#endif
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		err = mtrr_del(-1, sentry.base, sentry.size);
+		break;
+	case MTRRIOC_GET_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_GET_ENTRY:
+#endif
+		if (gentry.regnum >= num_var_ranges)
+			return -EINVAL;
+		mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
+
+		/* Hide entries that go above 4GB */
+		if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
+		    || size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
+			gentry.base = gentry.size = gentry.type = 0;
+		else {
+			gentry.base <<= PAGE_SHIFT;
+			gentry.size = size << PAGE_SHIFT;
+			gentry.type = type;
+		}
+
+		break;
+	case MTRRIOC_ADD_PAGE_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_ADD_PAGE_ENTRY:
+#endif
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		err =
+		    mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
+				  file, 1);
+		break;
+	case MTRRIOC_SET_PAGE_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_SET_PAGE_ENTRY:
+#endif
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		err = mtrr_add_page(sentry.base, sentry.size, sentry.type, 0);
+		break;
+	case MTRRIOC_DEL_PAGE_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_DEL_PAGE_ENTRY:
+#endif
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		err = mtrr_file_del(sentry.base, sentry.size, file, 1);
+		break;
+	case MTRRIOC_KILL_PAGE_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_KILL_PAGE_ENTRY:
+#endif
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		err = mtrr_del_page(-1, sentry.base, sentry.size);
+		break;
+	case MTRRIOC_GET_PAGE_ENTRY:
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_GET_PAGE_ENTRY:
+#endif
+		if (gentry.regnum >= num_var_ranges)
+			return -EINVAL;
+		mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
+		/* Hide entries that would overflow */
+		if (size != (__typeof__(gentry.size))size)
+			gentry.base = gentry.size = gentry.type = 0;
+		else {
+			gentry.size = size;
+			gentry.type = type;
+		}
+		break;
+	}
+
+	if (err)
+		return err;
+
+	switch(cmd) {
+	case MTRRIOC_GET_ENTRY:
+	case MTRRIOC_GET_PAGE_ENTRY:
+		if (copy_to_user(arg, &gentry, sizeof gentry))
+			err = -EFAULT;
+		break;
+#ifdef CONFIG_COMPAT
+	case MTRRIOC32_GET_ENTRY:
+	case MTRRIOC32_GET_PAGE_ENTRY: {
+		struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
+		err = put_user(gentry.base, &g32->base);
+		err |= put_user(gentry.size, &g32->size);
+		err |= put_user(gentry.regnum, &g32->regnum);
+		err |= put_user(gentry.type, &g32->type);
+		break;
+	}
+#endif
+	}
+	return err;
+}
+
+static int
+mtrr_close(struct inode *ino, struct file *file)
+{
+	int i, max;
+	unsigned int *fcount = FILE_FCOUNT(file);
+
+	if (fcount != NULL) {
+		max = num_var_ranges;
+		for (i = 0; i < max; ++i) {
+			while (fcount[i] > 0) {
+				mtrr_del(i, 0, 0);
+				--fcount[i];
+			}
+		}
+		kfree(fcount);
+		FILE_FCOUNT(file) = NULL;
+	}
+	return single_release(ino, file);
+}
+
+static int mtrr_seq_show(struct seq_file *seq, void *offset);
+
+static int mtrr_open(struct inode *inode, struct file *file)
+{
+	if (!mtrr_if) 
+		return -EIO;
+	if (!mtrr_if->get) 
+		return -ENXIO; 
+	return single_open(file, mtrr_seq_show, NULL);
+}
+
+static const struct file_operations mtrr_fops = {
+	.owner   = THIS_MODULE,
+	.open	 = mtrr_open, 
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.write   = mtrr_write,
+	.unlocked_ioctl = mtrr_ioctl,
+	.compat_ioctl = mtrr_ioctl,
+	.release = mtrr_close,
+};
+
+
+static struct proc_dir_entry *proc_root_mtrr;
+
+
+static int mtrr_seq_show(struct seq_file *seq, void *offset)
+{
+	char factor;
+	int i, max, len;
+	mtrr_type type;
+	unsigned long base, size;
+
+	len = 0;
+	max = num_var_ranges;
+	for (i = 0; i < max; i++) {
+		mtrr_if->get(i, &base, &size, &type);
+		if (size == 0)
+			usage_table[i] = 0;
+		else {
+			if (size < (0x100000 >> PAGE_SHIFT)) {
+				/* less than 1MB */
+				factor = 'K';
+				size <<= PAGE_SHIFT - 10;
+			} else {
+				factor = 'M';
+				size >>= 20 - PAGE_SHIFT;
+			}
+			/* RED-PEN: base can be > 32bit */ 
+			len += seq_printf(seq, 
+				   "reg%02i: base=0x%05lx000 (%4luMB), size=%4lu%cB: %s, count=%d\n",
+			     i, base, base >> (20 - PAGE_SHIFT), size, factor,
+			     mtrr_attrib_to_str(type), usage_table[i]);
+		}
+	}
+	return 0;
+}
+
+static int __init mtrr_if_init(void)
+{
+	struct cpuinfo_x86 *c = &boot_cpu_data;
+
+	if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
+	    (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
+	    (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
+	    (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
+		return -ENODEV;
+
+	proc_root_mtrr =
+	    create_proc_entry("mtrr", S_IWUSR | S_IRUGO, &proc_root);
+	if (proc_root_mtrr) {
+		proc_root_mtrr->owner = THIS_MODULE;
+		proc_root_mtrr->proc_fops = &mtrr_fops;
+	}
+	return 0;
+}
+
+arch_initcall(mtrr_if_init);
+#endif			/*  CONFIG_PROC_FS  */
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
new file mode 100644
index 000000000000..c48b6fea5ab4
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -0,0 +1,768 @@
+/*  Generic MTRR (Memory Type Range Register) driver.
+
+    Copyright (C) 1997-2000  Richard Gooch
+    Copyright (c) 2002	     Patrick Mochel
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+    Richard Gooch may be reached by email at  rgooch@atnf.csiro.au
+    The postal address is:
+      Richard Gooch, c/o ATNF, P. O. Box 76, Epping, N.S.W., 2121, Australia.
+
+    Source: "Pentium Pro Family Developer's Manual, Volume 3:
+    Operating System Writer's Guide" (Intel document number 242692),
+    section 11.11.7
+
+    This was cleaned and made readable by Patrick Mochel <mochel@osdl.org> 
+    on 6-7 March 2002. 
+    Source: Intel Architecture Software Developers Manual, Volume 3: 
+    System Programming Guide; Section 9.11. (1997 edition - PPro).
+*/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/mutex.h>
+
+#include <asm/mtrr.h>
+
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+#include <asm/msr.h>
+#include "mtrr.h"
+
+u32 num_var_ranges = 0;
+
+unsigned int *usage_table;
+static DEFINE_MUTEX(mtrr_mutex);
+
+u64 size_or_mask, size_and_mask;
+
+static struct mtrr_ops * mtrr_ops[X86_VENDOR_NUM] = {};
+
+struct mtrr_ops * mtrr_if = NULL;
+
+static void set_mtrr(unsigned int reg, unsigned long base,
+		     unsigned long size, mtrr_type type);
+
+#ifndef CONFIG_X86_64
+extern int arr3_protected;
+#else
+#define arr3_protected 0
+#endif
+
+void set_mtrr_ops(struct mtrr_ops * ops)
+{
+	if (ops->vendor && ops->vendor < X86_VENDOR_NUM)
+		mtrr_ops[ops->vendor] = ops;
+}
+
+/*  Returns non-zero if we have the write-combining memory type  */
+static int have_wrcomb(void)
+{
+	struct pci_dev *dev;
+	u8 rev;
+	
+	if ((dev = pci_get_class(PCI_CLASS_BRIDGE_HOST << 8, NULL)) != NULL) {
+		/* ServerWorks LE chipsets < rev 6 have problems with write-combining
+		   Don't allow it and leave room for other chipsets to be tagged */
+		if (dev->vendor == PCI_VENDOR_ID_SERVERWORKS &&
+		    dev->device == PCI_DEVICE_ID_SERVERWORKS_LE) {
+			pci_read_config_byte(dev, PCI_CLASS_REVISION, &rev);
+			if (rev <= 5) {
+				printk(KERN_INFO "mtrr: Serverworks LE rev < 6 detected. Write-combining disabled.\n");
+				pci_dev_put(dev);
+				return 0;
+			}
+		}
+		/* Intel 450NX errata # 23. Non ascending cacheline evictions to
+		   write combining memory may resulting in data corruption */
+		if (dev->vendor == PCI_VENDOR_ID_INTEL &&
+		    dev->device == PCI_DEVICE_ID_INTEL_82451NX) {
+			printk(KERN_INFO "mtrr: Intel 450NX MMC detected. Write-combining disabled.\n");
+			pci_dev_put(dev);
+			return 0;
+		}
+		pci_dev_put(dev);
+	}		
+	return (mtrr_if->have_wrcomb ? mtrr_if->have_wrcomb() : 0);
+}
+
+/*  This function returns the number of variable MTRRs  */
+static void __init set_num_var_ranges(void)
+{
+	unsigned long config = 0, dummy;
+
+	if (use_intel()) {
+		rdmsr(MTRRcap_MSR, config, dummy);
+	} else if (is_cpu(AMD))
+		config = 2;
+	else if (is_cpu(CYRIX) || is_cpu(CENTAUR))
+		config = 8;
+	num_var_ranges = config & 0xff;
+}
+
+static void __init init_table(void)
+{
+	int i, max;
+
+	max = num_var_ranges;
+	if ((usage_table = kmalloc(max * sizeof *usage_table, GFP_KERNEL))
+	    == NULL) {
+		printk(KERN_ERR "mtrr: could not allocate\n");
+		return;
+	}
+	for (i = 0; i < max; i++)
+		usage_table[i] = 1;
+}
+
+struct set_mtrr_data {
+	atomic_t	count;
+	atomic_t	gate;
+	unsigned long	smp_base;
+	unsigned long	smp_size;
+	unsigned int	smp_reg;
+	mtrr_type	smp_type;
+};
+
+#ifdef CONFIG_SMP
+
+static void ipi_handler(void *info)
+/*  [SUMMARY] Synchronisation handler. Executed by "other" CPUs.
+    [RETURNS] Nothing.
+*/
+{
+	struct set_mtrr_data *data = info;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	atomic_dec(&data->count);
+	while(!atomic_read(&data->gate))
+		cpu_relax();
+
+	/*  The master has cleared me to execute  */
+	if (data->smp_reg != ~0U) 
+		mtrr_if->set(data->smp_reg, data->smp_base, 
+			     data->smp_size, data->smp_type);
+	else
+		mtrr_if->set_all();
+
+	atomic_dec(&data->count);
+	while(atomic_read(&data->gate))
+		cpu_relax();
+
+	atomic_dec(&data->count);
+	local_irq_restore(flags);
+}
+
+#endif
+
+static inline int types_compatible(mtrr_type type1, mtrr_type type2) {
+	return type1 == MTRR_TYPE_UNCACHABLE ||
+	       type2 == MTRR_TYPE_UNCACHABLE ||
+	       (type1 == MTRR_TYPE_WRTHROUGH && type2 == MTRR_TYPE_WRBACK) ||
+	       (type1 == MTRR_TYPE_WRBACK && type2 == MTRR_TYPE_WRTHROUGH);
+}
+
+/**
+ * set_mtrr - update mtrrs on all processors
+ * @reg:	mtrr in question
+ * @base:	mtrr base
+ * @size:	mtrr size
+ * @type:	mtrr type
+ *
+ * This is kinda tricky, but fortunately, Intel spelled it out for us cleanly:
+ * 
+ * 1. Send IPI to do the following:
+ * 2. Disable Interrupts
+ * 3. Wait for all procs to do so 
+ * 4. Enter no-fill cache mode
+ * 5. Flush caches
+ * 6. Clear PGE bit
+ * 7. Flush all TLBs
+ * 8. Disable all range registers
+ * 9. Update the MTRRs
+ * 10. Enable all range registers
+ * 11. Flush all TLBs and caches again
+ * 12. Enter normal cache mode and reenable caching
+ * 13. Set PGE 
+ * 14. Wait for buddies to catch up
+ * 15. Enable interrupts.
+ * 
+ * What does that mean for us? Well, first we set data.count to the number
+ * of CPUs. As each CPU disables interrupts, it'll decrement it once. We wait
+ * until it hits 0 and proceed. We set the data.gate flag and reset data.count.
+ * Meanwhile, they are waiting for that flag to be set. Once it's set, each 
+ * CPU goes through the transition of updating MTRRs. The CPU vendors may each do it 
+ * differently, so we call mtrr_if->set() callback and let them take care of it.
+ * When they're done, they again decrement data->count and wait for data.gate to 
+ * be reset. 
+ * When we finish, we wait for data.count to hit 0 and toggle the data.gate flag.
+ * Everyone then enables interrupts and we all continue on.
+ *
+ * Note that the mechanism is the same for UP systems, too; all the SMP stuff
+ * becomes nops.
+ */
+static void set_mtrr(unsigned int reg, unsigned long base,
+		     unsigned long size, mtrr_type type)
+{
+	struct set_mtrr_data data;
+	unsigned long flags;
+
+	data.smp_reg = reg;
+	data.smp_base = base;
+	data.smp_size = size;
+	data.smp_type = type;
+	atomic_set(&data.count, num_booting_cpus() - 1);
+	/* make sure data.count is visible before unleashing other CPUs */
+	smp_wmb();
+	atomic_set(&data.gate,0);
+
+	/*  Start the ball rolling on other CPUs  */
+	if (smp_call_function(ipi_handler, &data, 1, 0) != 0)
+		panic("mtrr: timed out waiting for other CPUs\n");
+
+	local_irq_save(flags);
+
+	while(atomic_read(&data.count))
+		cpu_relax();
+
+	/* ok, reset count and toggle gate */
+	atomic_set(&data.count, num_booting_cpus() - 1);
+	smp_wmb();
+	atomic_set(&data.gate,1);
+
+	/* do our MTRR business */
+
+	/* HACK!
+	 * We use this same function to initialize the mtrrs on boot.
+	 * The state of the boot cpu's mtrrs has been saved, and we want
+	 * to replicate across all the APs. 
+	 * If we're doing that @reg is set to something special...
+	 */
+	if (reg != ~0U) 
+		mtrr_if->set(reg,base,size,type);
+
+	/* wait for the others */
+	while(atomic_read(&data.count))
+		cpu_relax();
+
+	atomic_set(&data.count, num_booting_cpus() - 1);
+	smp_wmb();
+	atomic_set(&data.gate,0);
+
+	/*
+	 * Wait here for everyone to have seen the gate change
+	 * So we're the last ones to touch 'data'
+	 */
+	while(atomic_read(&data.count))
+		cpu_relax();
+
+	local_irq_restore(flags);
+}
+
+/**
+ *	mtrr_add_page - Add a memory type region
+ *	@base: Physical base address of region in pages (in units of 4 kB!)
+ *	@size: Physical size of region in pages (4 kB)
+ *	@type: Type of MTRR desired
+ *	@increment: If this is true do usage counting on the region
+ *
+ *	Memory type region registers control the caching on newer Intel and
+ *	non Intel processors. This function allows drivers to request an
+ *	MTRR is added. The details and hardware specifics of each processor's
+ *	implementation are hidden from the caller, but nevertheless the 
+ *	caller should expect to need to provide a power of two size on an
+ *	equivalent power of two boundary.
+ *
+ *	If the region cannot be added either because all regions are in use
+ *	or the CPU cannot support it a negative value is returned. On success
+ *	the register number for this entry is returned, but should be treated
+ *	as a cookie only.
+ *
+ *	On a multiprocessor machine the changes are made to all processors.
+ *	This is required on x86 by the Intel processors.
+ *
+ *	The available types are
+ *
+ *	%MTRR_TYPE_UNCACHABLE	-	No caching
+ *
+ *	%MTRR_TYPE_WRBACK	-	Write data back in bursts whenever
+ *
+ *	%MTRR_TYPE_WRCOMB	-	Write data back soon but allow bursts
+ *
+ *	%MTRR_TYPE_WRTHROUGH	-	Cache reads but not writes
+ *
+ *	BUGS: Needs a quiet flag for the cases where drivers do not mind
+ *	failures and do not wish system log messages to be sent.
+ */
+
+int mtrr_add_page(unsigned long base, unsigned long size, 
+		  unsigned int type, char increment)
+{
+	int i, replace, error;
+	mtrr_type ltype;
+	unsigned long lbase, lsize;
+
+	if (!mtrr_if)
+		return -ENXIO;
+		
+	if ((error = mtrr_if->validate_add_page(base,size,type)))
+		return error;
+
+	if (type >= MTRR_NUM_TYPES) {
+		printk(KERN_WARNING "mtrr: type: %u invalid\n", type);
+		return -EINVAL;
+	}
+
+	/*  If the type is WC, check that this processor supports it  */
+	if ((type == MTRR_TYPE_WRCOMB) && !have_wrcomb()) {
+		printk(KERN_WARNING
+		       "mtrr: your processor doesn't support write-combining\n");
+		return -ENOSYS;
+	}
+
+	if (!size) {
+		printk(KERN_WARNING "mtrr: zero sized request\n");
+		return -EINVAL;
+	}
+
+	if (base & size_or_mask || size & size_or_mask) {
+		printk(KERN_WARNING "mtrr: base or size exceeds the MTRR width\n");
+		return -EINVAL;
+	}
+
+	error = -EINVAL;
+	replace = -1;
+
+	/* No CPU hotplug when we change MTRR entries */
+	lock_cpu_hotplug();
+	/*  Search for existing MTRR  */
+	mutex_lock(&mtrr_mutex);
+	for (i = 0; i < num_var_ranges; ++i) {
+		mtrr_if->get(i, &lbase, &lsize, &ltype);
+		if (!lsize || base > lbase + lsize - 1 || base + size - 1 < lbase)
+			continue;
+		/*  At this point we know there is some kind of overlap/enclosure  */
+		if (base < lbase || base + size - 1 > lbase + lsize - 1) {
+			if (base <= lbase && base + size - 1 >= lbase + lsize - 1) {
+				/*  New region encloses an existing region  */
+				if (type == ltype) {
+					replace = replace == -1 ? i : -2;
+					continue;
+				}
+				else if (types_compatible(type, ltype))
+					continue;
+			}
+			printk(KERN_WARNING
+			       "mtrr: 0x%lx000,0x%lx000 overlaps existing"
+			       " 0x%lx000,0x%lx000\n", base, size, lbase,
+			       lsize);
+			goto out;
+		}
+		/*  New region is enclosed by an existing region  */
+		if (ltype != type) {
+			if (types_compatible(type, ltype))
+				continue;
+			printk (KERN_WARNING "mtrr: type mismatch for %lx000,%lx000 old: %s new: %s\n",
+			     base, size, mtrr_attrib_to_str(ltype),
+			     mtrr_attrib_to_str(type));
+			goto out;
+		}
+		if (increment)
+			++usage_table[i];
+		error = i;
+		goto out;
+	}
+	/*  Search for an empty MTRR  */
+	i = mtrr_if->get_free_region(base, size, replace);
+	if (i >= 0) {
+		set_mtrr(i, base, size, type);
+		if (likely(replace < 0))
+			usage_table[i] = 1;
+		else {
+			usage_table[i] = usage_table[replace] + !!increment;
+			if (unlikely(replace != i)) {
+				set_mtrr(replace, 0, 0, 0);
+				usage_table[replace] = 0;
+			}
+		}
+	} else
+		printk(KERN_INFO "mtrr: no more MTRRs available\n");
+	error = i;
+ out:
+	mutex_unlock(&mtrr_mutex);
+	unlock_cpu_hotplug();
+	return error;
+}
+
+static int mtrr_check(unsigned long base, unsigned long size)
+{
+	if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1))) {
+		printk(KERN_WARNING
+			"mtrr: size and base must be multiples of 4 kiB\n");
+		printk(KERN_DEBUG
+			"mtrr: size: 0x%lx  base: 0x%lx\n", size, base);
+		dump_stack();
+		return -1;
+	}
+	return 0;
+}
+
+/**
+ *	mtrr_add - Add a memory type region
+ *	@base: Physical base address of region
+ *	@size: Physical size of region
+ *	@type: Type of MTRR desired
+ *	@increment: If this is true do usage counting on the region
+ *
+ *	Memory type region registers control the caching on newer Intel and
+ *	non Intel processors. This function allows drivers to request an
+ *	MTRR is added. The details and hardware specifics of each processor's
+ *	implementation are hidden from the caller, but nevertheless the 
+ *	caller should expect to need to provide a power of two size on an
+ *	equivalent power of two boundary.
+ *
+ *	If the region cannot be added either because all regions are in use
+ *	or the CPU cannot support it a negative value is returned. On success
+ *	the register number for this entry is returned, but should be treated
+ *	as a cookie only.
+ *
+ *	On a multiprocessor machine the changes are made to all processors.
+ *	This is required on x86 by the Intel processors.
+ *
+ *	The available types are
+ *
+ *	%MTRR_TYPE_UNCACHABLE	-	No caching
+ *
+ *	%MTRR_TYPE_WRBACK	-	Write data back in bursts whenever
+ *
+ *	%MTRR_TYPE_WRCOMB	-	Write data back soon but allow bursts
+ *
+ *	%MTRR_TYPE_WRTHROUGH	-	Cache reads but not writes
+ *
+ *	BUGS: Needs a quiet flag for the cases where drivers do not mind
+ *	failures and do not wish system log messages to be sent.
+ */
+
+int
+mtrr_add(unsigned long base, unsigned long size, unsigned int type,
+	 char increment)
+{
+	if (mtrr_check(base, size))
+		return -EINVAL;
+	return mtrr_add_page(base >> PAGE_SHIFT, size >> PAGE_SHIFT, type,
+			     increment);
+}
+
+/**
+ *	mtrr_del_page - delete a memory type region
+ *	@reg: Register returned by mtrr_add
+ *	@base: Physical base address
+ *	@size: Size of region
+ *
+ *	If register is supplied then base and size are ignored. This is
+ *	how drivers should call it.
+ *
+ *	Releases an MTRR region. If the usage count drops to zero the 
+ *	register is freed and the region returns to default state.
+ *	On success the register is returned, on failure a negative error
+ *	code.
+ */
+
+int mtrr_del_page(int reg, unsigned long base, unsigned long size)
+{
+	int i, max;
+	mtrr_type ltype;
+	unsigned long lbase, lsize;
+	int error = -EINVAL;
+
+	if (!mtrr_if)
+		return -ENXIO;
+
+	max = num_var_ranges;
+	/* No CPU hotplug when we change MTRR entries */
+	lock_cpu_hotplug();
+	mutex_lock(&mtrr_mutex);
+	if (reg < 0) {
+		/*  Search for existing MTRR  */
+		for (i = 0; i < max; ++i) {
+			mtrr_if->get(i, &lbase, &lsize, &ltype);
+			if (lbase == base && lsize == size) {
+				reg = i;
+				break;
+			}
+		}
+		if (reg < 0) {
+			printk(KERN_DEBUG "mtrr: no MTRR for %lx000,%lx000 found\n", base,
+			       size);
+			goto out;
+		}
+	}
+	if (reg >= max) {
+		printk(KERN_WARNING "mtrr: register: %d too big\n", reg);
+		goto out;
+	}
+	if (is_cpu(CYRIX) && !use_intel()) {
+		if ((reg == 3) && arr3_protected) {
+			printk(KERN_WARNING "mtrr: ARR3 cannot be changed\n");
+			goto out;
+		}
+	}
+	mtrr_if->get(reg, &lbase, &lsize, &ltype);
+	if (lsize < 1) {
+		printk(KERN_WARNING "mtrr: MTRR %d not used\n", reg);
+		goto out;
+	}
+	if (usage_table[reg] < 1) {
+		printk(KERN_WARNING "mtrr: reg: %d has count=0\n", reg);
+		goto out;
+	}
+	if (--usage_table[reg] < 1)
+		set_mtrr(reg, 0, 0, 0);
+	error = reg;
+ out:
+	mutex_unlock(&mtrr_mutex);
+	unlock_cpu_hotplug();
+	return error;
+}
+/**
+ *	mtrr_del - delete a memory type region
+ *	@reg: Register returned by mtrr_add
+ *	@base: Physical base address
+ *	@size: Size of region
+ *
+ *	If register is supplied then base and size are ignored. This is
+ *	how drivers should call it.
+ *
+ *	Releases an MTRR region. If the usage count drops to zero the 
+ *	register is freed and the region returns to default state.
+ *	On success the register is returned, on failure a negative error
+ *	code.
+ */
+
+int
+mtrr_del(int reg, unsigned long base, unsigned long size)
+{
+	if (mtrr_check(base, size))
+		return -EINVAL;
+	return mtrr_del_page(reg, base >> PAGE_SHIFT, size >> PAGE_SHIFT);
+}
+
+EXPORT_SYMBOL(mtrr_add);
+EXPORT_SYMBOL(mtrr_del);
+
+/* HACK ALERT!
+ * These should be called implicitly, but we can't yet until all the initcall
+ * stuff is done...
+ */
+extern void amd_init_mtrr(void);
+extern void cyrix_init_mtrr(void);
+extern void centaur_init_mtrr(void);
+
+static void __init init_ifs(void)
+{
+#ifndef CONFIG_X86_64
+	amd_init_mtrr();
+	cyrix_init_mtrr();
+	centaur_init_mtrr();
+#endif
+}
+
+/* The suspend/resume methods are only for CPU without MTRR. CPU using generic
+ * MTRR driver doesn't require this
+ */
+struct mtrr_value {
+	mtrr_type	ltype;
+	unsigned long	lbase;
+	unsigned long	lsize;
+};
+
+static struct mtrr_value * mtrr_state;
+
+static int mtrr_save(struct sys_device * sysdev, pm_message_t state)
+{
+	int i;
+	int size = num_var_ranges * sizeof(struct mtrr_value);
+
+	mtrr_state = kzalloc(size,GFP_ATOMIC);
+	if (!mtrr_state)
+		return -ENOMEM;
+
+	for (i = 0; i < num_var_ranges; i++) {
+		mtrr_if->get(i,
+			     &mtrr_state[i].lbase,
+			     &mtrr_state[i].lsize,
+			     &mtrr_state[i].ltype);
+	}
+	return 0;
+}
+
+static int mtrr_restore(struct sys_device * sysdev)
+{
+	int i;
+
+	for (i = 0; i < num_var_ranges; i++) {
+		if (mtrr_state[i].lsize) 
+			set_mtrr(i,
+				 mtrr_state[i].lbase,
+				 mtrr_state[i].lsize,
+				 mtrr_state[i].ltype);
+	}
+	kfree(mtrr_state);
+	return 0;
+}
+
+
+
+static struct sysdev_driver mtrr_sysdev_driver = {
+	.suspend	= mtrr_save,
+	.resume		= mtrr_restore,
+};
+
+
+/**
+ * mtrr_bp_init - initialize mtrrs on the boot CPU
+ *
+ * This needs to be called early; before any of the other CPUs are 
+ * initialized (i.e. before smp_init()).
+ * 
+ */
+void __init mtrr_bp_init(void)
+{
+	init_ifs();
+
+	if (cpu_has_mtrr) {
+		mtrr_if = &generic_mtrr_ops;
+		size_or_mask = 0xff000000;	/* 36 bits */
+		size_and_mask = 0x00f00000;
+
+		/* This is an AMD specific MSR, but we assume(hope?) that
+		   Intel will implement it to when they extend the address
+		   bus of the Xeon. */
+		if (cpuid_eax(0x80000000) >= 0x80000008) {
+			u32 phys_addr;
+			phys_addr = cpuid_eax(0x80000008) & 0xff;
+			/* CPUID workaround for Intel 0F33/0F34 CPU */
+			if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+			    boot_cpu_data.x86 == 0xF &&
+			    boot_cpu_data.x86_model == 0x3 &&
+			    (boot_cpu_data.x86_mask == 0x3 ||
+			     boot_cpu_data.x86_mask == 0x4))
+				phys_addr = 36;
+
+			size_or_mask = ~((1ULL << (phys_addr - PAGE_SHIFT)) - 1);
+			size_and_mask = ~size_or_mask & 0xfffff00000ULL;
+		} else if (boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR &&
+			   boot_cpu_data.x86 == 6) {
+			/* VIA C* family have Intel style MTRRs, but
+			   don't support PAE */
+			size_or_mask = 0xfff00000;	/* 32 bits */
+			size_and_mask = 0;
+		}
+	} else {
+		switch (boot_cpu_data.x86_vendor) {
+		case X86_VENDOR_AMD:
+			if (cpu_has_k6_mtrr) {
+				/* Pre-Athlon (K6) AMD CPU MTRRs */
+				mtrr_if = mtrr_ops[X86_VENDOR_AMD];
+				size_or_mask = 0xfff00000;	/* 32 bits */
+				size_and_mask = 0;
+			}
+			break;
+		case X86_VENDOR_CENTAUR:
+			if (cpu_has_centaur_mcr) {
+				mtrr_if = mtrr_ops[X86_VENDOR_CENTAUR];
+				size_or_mask = 0xfff00000;	/* 32 bits */
+				size_and_mask = 0;
+			}
+			break;
+		case X86_VENDOR_CYRIX:
+			if (cpu_has_cyrix_arr) {
+				mtrr_if = mtrr_ops[X86_VENDOR_CYRIX];
+				size_or_mask = 0xfff00000;	/* 32 bits */
+				size_and_mask = 0;
+			}
+			break;
+		default:
+			break;
+		}
+	}
+
+	if (mtrr_if) {
+		set_num_var_ranges();
+		init_table();
+		if (use_intel())
+			get_mtrr_state();
+	}
+}
+
+void mtrr_ap_init(void)
+{
+	unsigned long flags;
+
+	if (!mtrr_if || !use_intel())
+		return;
+	/*
+	 * Ideally we should hold mtrr_mutex here to avoid mtrr entries changed,
+	 * but this routine will be called in cpu boot time, holding the lock
+	 * breaks it. This routine is called in two cases: 1.very earily time
+	 * of software resume, when there absolutely isn't mtrr entry changes;
+	 * 2.cpu hotadd time. We let mtrr_add/del_page hold cpuhotplug lock to
+	 * prevent mtrr entry changes
+	 */
+	local_irq_save(flags);
+
+	mtrr_if->set_all();
+
+	local_irq_restore(flags);
+}
+
+/**
+ * Save current fixed-range MTRR state of the BSP
+ */
+void mtrr_save_state(void)
+{
+	int cpu = get_cpu();
+
+	if (cpu == 0)
+		mtrr_save_fixed_ranges(NULL);
+	else
+		smp_call_function_single(0, mtrr_save_fixed_ranges, NULL, 1, 1);
+	put_cpu();
+}
+
+static int __init mtrr_init_finialize(void)
+{
+	if (!mtrr_if)
+		return 0;
+	if (use_intel())
+		mtrr_state_warn();
+	else {
+		/* The CPUs haven't MTRR and seemes not support SMP. They have
+		 * specific drivers, we use a tricky method to support
+		 * suspend/resume for them.
+		 * TBD: is there any system with such CPU which supports
+		 * suspend/resume?  if no, we should remove the code.
+		 */
+		sysdev_driver_register(&cpu_sysdev_class,
+			&mtrr_sysdev_driver);
+	}
+	return 0;
+}
+subsys_initcall(mtrr_init_finialize);
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h
new file mode 100644
index 000000000000..289dfe6030e3
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.h
@@ -0,0 +1,98 @@
+/*
+ * local mtrr defines.
+ */
+
+#ifndef TRUE
+#define TRUE  1
+#define FALSE 0
+#endif
+
+#define MTRRcap_MSR     0x0fe
+#define MTRRdefType_MSR 0x2ff
+
+#define MTRRphysBase_MSR(reg) (0x200 + 2 * (reg))
+#define MTRRphysMask_MSR(reg) (0x200 + 2 * (reg) + 1)
+
+#define NUM_FIXED_RANGES 88
+#define MTRRfix64K_00000_MSR 0x250
+#define MTRRfix16K_80000_MSR 0x258
+#define MTRRfix16K_A0000_MSR 0x259
+#define MTRRfix4K_C0000_MSR 0x268
+#define MTRRfix4K_C8000_MSR 0x269
+#define MTRRfix4K_D0000_MSR 0x26a
+#define MTRRfix4K_D8000_MSR 0x26b
+#define MTRRfix4K_E0000_MSR 0x26c
+#define MTRRfix4K_E8000_MSR 0x26d
+#define MTRRfix4K_F0000_MSR 0x26e
+#define MTRRfix4K_F8000_MSR 0x26f
+
+#define MTRR_CHANGE_MASK_FIXED     0x01
+#define MTRR_CHANGE_MASK_VARIABLE  0x02
+#define MTRR_CHANGE_MASK_DEFTYPE   0x04
+
+/* In the Intel processor's MTRR interface, the MTRR type is always held in
+   an 8 bit field: */
+typedef u8 mtrr_type;
+
+struct mtrr_ops {
+	u32	vendor;
+	u32	use_intel_if;
+//	void	(*init)(void);
+	void	(*set)(unsigned int reg, unsigned long base,
+		       unsigned long size, mtrr_type type);
+	void	(*set_all)(void);
+
+	void	(*get)(unsigned int reg, unsigned long *base,
+		       unsigned long *size, mtrr_type * type);
+	int	(*get_free_region)(unsigned long base, unsigned long size,
+				   int replace_reg);
+	int	(*validate_add_page)(unsigned long base, unsigned long size,
+				     unsigned int type);
+	int	(*have_wrcomb)(void);
+};
+
+extern int generic_get_free_region(unsigned long base, unsigned long size,
+				   int replace_reg);
+extern int generic_validate_add_page(unsigned long base, unsigned long size,
+				     unsigned int type);
+
+extern struct mtrr_ops generic_mtrr_ops;
+
+extern int positive_have_wrcomb(void);
+
+/* library functions for processor-specific routines */
+struct set_mtrr_context {
+	unsigned long flags;
+	unsigned long cr4val;
+	u32 deftype_lo;
+	u32 deftype_hi;
+	u32 ccr3;
+};
+
+struct mtrr_var_range {
+	u32 base_lo;
+	u32 base_hi;
+	u32 mask_lo;
+	u32 mask_hi;
+};
+
+void set_mtrr_done(struct set_mtrr_context *ctxt);
+void set_mtrr_cache_disable(struct set_mtrr_context *ctxt);
+void set_mtrr_prepare_save(struct set_mtrr_context *ctxt);
+
+void get_mtrr_state(void);
+
+extern void set_mtrr_ops(struct mtrr_ops * ops);
+
+extern u64 size_or_mask, size_and_mask;
+extern struct mtrr_ops * mtrr_if;
+
+#define is_cpu(vnd)	(mtrr_if && mtrr_if->vendor == X86_VENDOR_##vnd)
+#define use_intel()	(mtrr_if && mtrr_if->use_intel_if == 1)
+
+extern unsigned int num_var_ranges;
+
+void mtrr_state_warn(void);
+const char *mtrr_attrib_to_str(int x);
+void mtrr_wrmsr(unsigned, unsigned, unsigned);
+
diff --git a/arch/x86/kernel/cpu/mtrr/state.c b/arch/x86/kernel/cpu/mtrr/state.c
new file mode 100644
index 000000000000..c9014ca4a575
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/state.c
@@ -0,0 +1,79 @@
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <asm/io.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+#include <asm-i386/processor-cyrix.h>
+#include "mtrr.h"
+
+
+/*  Put the processor into a state where MTRRs can be safely set  */
+void set_mtrr_prepare_save(struct set_mtrr_context *ctxt)
+{
+	unsigned int cr0;
+
+	/*  Disable interrupts locally  */
+	local_irq_save(ctxt->flags);
+
+	if (use_intel() || is_cpu(CYRIX)) {
+
+		/*  Save value of CR4 and clear Page Global Enable (bit 7)  */
+		if ( cpu_has_pge ) {
+			ctxt->cr4val = read_cr4();
+			write_cr4(ctxt->cr4val & ~X86_CR4_PGE);
+		}
+
+		/*  Disable and flush caches. Note that wbinvd flushes the TLBs as
+		    a side-effect  */
+		cr0 = read_cr0() | 0x40000000;
+		wbinvd();
+		write_cr0(cr0);
+		wbinvd();
+
+		if (use_intel())
+			/*  Save MTRR state */
+			rdmsr(MTRRdefType_MSR, ctxt->deftype_lo, ctxt->deftype_hi);
+		else
+			/* Cyrix ARRs - everything else were excluded at the top */
+			ctxt->ccr3 = getCx86(CX86_CCR3);
+	}
+}
+
+void set_mtrr_cache_disable(struct set_mtrr_context *ctxt)
+{
+	if (use_intel()) 
+		/*  Disable MTRRs, and set the default type to uncached  */
+		mtrr_wrmsr(MTRRdefType_MSR, ctxt->deftype_lo & 0xf300UL,
+		      ctxt->deftype_hi);
+	else if (is_cpu(CYRIX))
+		/* Cyrix ARRs - everything else were excluded at the top */
+		setCx86(CX86_CCR3, (ctxt->ccr3 & 0x0f) | 0x10);
+}
+
+/*  Restore the processor after a set_mtrr_prepare  */
+void set_mtrr_done(struct set_mtrr_context *ctxt)
+{
+	if (use_intel() || is_cpu(CYRIX)) {
+
+		/*  Flush caches and TLBs  */
+		wbinvd();
+
+		/*  Restore MTRRdefType  */
+		if (use_intel())
+			/* Intel (P6) standard MTRRs */
+			mtrr_wrmsr(MTRRdefType_MSR, ctxt->deftype_lo, ctxt->deftype_hi);
+		else
+			/* Cyrix ARRs - everything else was excluded at the top */
+			setCx86(CX86_CCR3, ctxt->ccr3);
+		
+		/*  Enable caches  */
+		write_cr0(read_cr0() & 0xbfffffff);
+
+		/*  Restore value of CR4  */
+		if ( cpu_has_pge )
+			write_cr4(ctxt->cr4val);
+	}
+	/*  Re-enable interrupts locally (if enabled previously)  */
+	local_irq_restore(ctxt->flags);
+}
+