i386: move kernel/cpu/mtrr

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

1 files changed, 768 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
new file mode 100644
index 00000000000..c48b6fea5ab
--- /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);