x86/mtrr: Rename main.c to mtrr.c and remove duplicate prefixes

Kbuild uses the first file as the name for KBUILD_MODNAME.
mtrr uses main.c as its first file, so rename that file to mtrr.c
and fixup the Makefile.

Remove the now duplicate "mtrr: " prefixes from the logging calls.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/ae1fa81a0d1fad87571967b91ea90f70f486e853.1525964384.git.joe@perches.com

1 files changed, 886 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c
new file mode 100644
index 000000000000..0c4f4fba9ec1
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.c
@@ -0,0 +1,886 @@
+/*  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).
+*/
+
+#define DEBUG
+
+#include <linux/types.h> /* FIXME: kvm_para.h needs this */
+
+#include <linux/stop_machine.h>
+#include <linux/kvm_para.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+#include <linux/mutex.h>
+#include <linux/init.h>
+#include <linux/sort.h>
+#include <linux/cpu.h>
+#include <linux/pci.h>
+#include <linux/smp.h>
+#include <linux/syscore_ops.h>
+
+#include <asm/cpufeature.h>
+#include <asm/e820/api.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+#include <asm/pat.h>
+
+#include "mtrr.h"
+
+/* arch_phys_wc_add returns an MTRR register index plus this offset. */
+#define MTRR_TO_PHYS_WC_OFFSET 1000
+
+u32 num_var_ranges;
+static bool __mtrr_enabled;
+
+static bool mtrr_enabled(void)
+{
+	return __mtrr_enabled;
+}
+
+unsigned int mtrr_usage_table[MTRR_MAX_VAR_RANGES];
+static DEFINE_MUTEX(mtrr_mutex);
+
+u64 size_or_mask, size_and_mask;
+static bool mtrr_aps_delayed_init;
+
+static const struct mtrr_ops *mtrr_ops[X86_VENDOR_NUM] __ro_after_init;
+
+const struct mtrr_ops *mtrr_if;
+
+static void set_mtrr(unsigned int reg, unsigned long base,
+		     unsigned long size, mtrr_type type);
+
+void __init set_mtrr_ops(const 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;
+
+	dev = pci_get_class(PCI_CLASS_BRIDGE_HOST << 8, NULL);
+	if (dev != 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 &&
+		    dev->revision <= 5) {
+			pr_info("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) {
+			pr_info("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(MSR_MTRRcap, 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;
+	for (i = 0; i < max; i++)
+		mtrr_usage_table[i] = 1;
+}
+
+struct set_mtrr_data {
+	unsigned long	smp_base;
+	unsigned long	smp_size;
+	unsigned int	smp_reg;
+	mtrr_type	smp_type;
+};
+
+/**
+ * mtrr_rendezvous_handler - Work done in the synchronization handler. Executed
+ * by all the CPUs.
+ * @info: pointer to mtrr configuration data
+ *
+ * Returns nothing.
+ */
+static int mtrr_rendezvous_handler(void *info)
+{
+	struct set_mtrr_data *data = info;
+
+	/*
+	 * We use this same function to initialize the mtrrs during boot,
+	 * resume, runtime cpu online and on an explicit request to set a
+	 * specific MTRR.
+	 *
+	 * During boot or suspend, the state of the boot cpu's mtrrs has been
+	 * saved, and we want to replicate that across all the cpus that come
+	 * online (either at the end of boot or resume or during a runtime cpu
+	 * online). If we're doing that, @reg is set to something special and on
+	 * all the cpu's we do mtrr_if->set_all() (On the logical cpu that
+	 * started the boot/resume sequence, this might be a duplicate
+	 * set_all()).
+	 */
+	if (data->smp_reg != ~0U) {
+		mtrr_if->set(data->smp_reg, data->smp_base,
+			     data->smp_size, data->smp_type);
+	} else if (mtrr_aps_delayed_init || !cpu_online(smp_processor_id())) {
+		mtrr_if->set_all();
+	}
+	return 0;
+}
+
+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. Queue work to do the following on all processors:
+ * 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, stop_machine() will ensure that
+ * the rendezvous handler is started on each CPU. And in lockstep they
+ * do the state transition of disabling interrupts, updating MTRR's
+ * (the CPU vendors may each do it differently, so we call mtrr_if->set()
+ * callback and let them take care of it.) and enabling interrupts.
+ *
+ * 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 = { .smp_reg = reg,
+				      .smp_base = base,
+				      .smp_size = size,
+				      .smp_type = type
+				    };
+
+	stop_machine(mtrr_rendezvous_handler, &data, cpu_online_mask);
+}
+
+static void set_mtrr_cpuslocked(unsigned int reg, unsigned long base,
+				unsigned long size, mtrr_type type)
+{
+	struct set_mtrr_data data = { .smp_reg = reg,
+				      .smp_base = base,
+				      .smp_size = size,
+				      .smp_type = type
+				    };
+
+	stop_machine_cpuslocked(mtrr_rendezvous_handler, &data, cpu_online_mask);
+}
+
+static void set_mtrr_from_inactive_cpu(unsigned int reg, unsigned long base,
+				      unsigned long size, mtrr_type type)
+{
+	struct set_mtrr_data data = { .smp_reg = reg,
+				      .smp_base = base,
+				      .smp_size = size,
+				      .smp_type = type
+				    };
+
+	stop_machine_from_inactive_cpu(mtrr_rendezvous_handler, &data,
+				       cpu_callout_mask);
+}
+
+/**
+ * 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, bool increment)
+{
+	unsigned long lbase, lsize;
+	int i, replace, error;
+	mtrr_type ltype;
+
+	if (!mtrr_enabled())
+		return -ENXIO;
+
+	error = mtrr_if->validate_add_page(base, size, type);
+	if (error)
+		return error;
+
+	if (type >= MTRR_NUM_TYPES) {
+		pr_warn("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()) {
+		pr_warn("your processor doesn't support write-combining\n");
+		return -ENOSYS;
+	}
+
+	if (!size) {
+		pr_warn("zero sized request\n");
+		return -EINVAL;
+	}
+
+	if ((base | (base + size - 1)) >>
+	    (boot_cpu_data.x86_phys_bits - PAGE_SHIFT)) {
+		pr_warn("base or size exceeds the MTRR width\n");
+		return -EINVAL;
+	}
+
+	error = -EINVAL;
+	replace = -1;
+
+	/* No CPU hotplug when we change MTRR entries */
+	get_online_cpus();
+
+	/* 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;
+			}
+			pr_warn("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;
+			pr_warn("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)
+			++mtrr_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_cpuslocked(i, base, size, type);
+		if (likely(replace < 0)) {
+			mtrr_usage_table[i] = 1;
+		} else {
+			mtrr_usage_table[i] = mtrr_usage_table[replace];
+			if (increment)
+				mtrr_usage_table[i]++;
+			if (unlikely(replace != i)) {
+				set_mtrr_cpuslocked(replace, 0, 0, 0);
+				mtrr_usage_table[replace] = 0;
+			}
+		}
+	} else {
+		pr_info("no more MTRRs available\n");
+	}
+	error = i;
+ out:
+	mutex_unlock(&mtrr_mutex);
+	put_online_cpus();
+	return error;
+}
+
+static int mtrr_check(unsigned long base, unsigned long size)
+{
+	if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1))) {
+		pr_warn("size and base must be multiples of 4 kiB\n");
+		pr_debug("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,
+	     bool increment)
+{
+	if (!mtrr_enabled())
+		return -ENODEV;
+	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_enabled())
+		return -ENODEV;
+
+	max = num_var_ranges;
+	/* No CPU hotplug when we change MTRR entries */
+	get_online_cpus();
+	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) {
+			pr_debug("no MTRR for %lx000,%lx000 found\n",
+				 base, size);
+			goto out;
+		}
+	}
+	if (reg >= max) {
+		pr_warn("register: %d too big\n", reg);
+		goto out;
+	}
+	mtrr_if->get(reg, &lbase, &lsize, &ltype);
+	if (lsize < 1) {
+		pr_warn("MTRR %d not used\n", reg);
+		goto out;
+	}
+	if (mtrr_usage_table[reg] < 1) {
+		pr_warn("reg: %d has count=0\n", reg);
+		goto out;
+	}
+	if (--mtrr_usage_table[reg] < 1)
+		set_mtrr_cpuslocked(reg, 0, 0, 0);
+	error = reg;
+ out:
+	mutex_unlock(&mtrr_mutex);
+	put_online_cpus();
+	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_enabled())
+		return -ENODEV;
+	if (mtrr_check(base, size))
+		return -EINVAL;
+	return mtrr_del_page(reg, base >> PAGE_SHIFT, size >> PAGE_SHIFT);
+}
+
+/**
+ * arch_phys_wc_add - add a WC MTRR and handle errors if PAT is unavailable
+ * @base: Physical base address
+ * @size: Size of region
+ *
+ * If PAT is available, this does nothing.  If PAT is unavailable, it
+ * attempts to add a WC MTRR covering size bytes starting at base and
+ * logs an error if this fails.
+ *
+ * The called should provide a power of two size on an equivalent
+ * power of two boundary.
+ *
+ * Drivers must store the return value to pass to mtrr_del_wc_if_needed,
+ * but drivers should not try to interpret that return value.
+ */
+int arch_phys_wc_add(unsigned long base, unsigned long size)
+{
+	int ret;
+
+	if (pat_enabled() || !mtrr_enabled())
+		return 0;  /* Success!  (We don't need to do anything.) */
+
+	ret = mtrr_add(base, size, MTRR_TYPE_WRCOMB, true);
+	if (ret < 0) {
+		pr_warn("Failed to add WC MTRR for [%p-%p]; performance may suffer.",
+			(void *)base, (void *)(base + size - 1));
+		return ret;
+	}
+	return ret + MTRR_TO_PHYS_WC_OFFSET;
+}
+EXPORT_SYMBOL(arch_phys_wc_add);
+
+/*
+ * arch_phys_wc_del - undoes arch_phys_wc_add
+ * @handle: Return value from arch_phys_wc_add
+ *
+ * This cleans up after mtrr_add_wc_if_needed.
+ *
+ * The API guarantees that mtrr_del_wc_if_needed(error code) and
+ * mtrr_del_wc_if_needed(0) do nothing.
+ */
+void arch_phys_wc_del(int handle)
+{
+	if (handle >= 1) {
+		WARN_ON(handle < MTRR_TO_PHYS_WC_OFFSET);
+		mtrr_del(handle - MTRR_TO_PHYS_WC_OFFSET, 0, 0);
+	}
+}
+EXPORT_SYMBOL(arch_phys_wc_del);
+
+/*
+ * arch_phys_wc_index - translates arch_phys_wc_add's return value
+ * @handle: Return value from arch_phys_wc_add
+ *
+ * This will turn the return value from arch_phys_wc_add into an mtrr
+ * index suitable for debugging.
+ *
+ * Note: There is no legitimate use for this function, except possibly
+ * in printk line.  Alas there is an illegitimate use in some ancient
+ * drm ioctls.
+ */
+int arch_phys_wc_index(int handle)
+{
+	if (handle < MTRR_TO_PHYS_WC_OFFSET)
+		return -1;
+	else
+		return handle - MTRR_TO_PHYS_WC_OFFSET;
+}
+EXPORT_SYMBOL_GPL(arch_phys_wc_index);
+
+/*
+ * HACK ALERT!
+ * These should be called implicitly, but we can't yet until all the initcall
+ * stuff is done...
+ */
+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_value[MTRR_MAX_VAR_RANGES];
+
+static int mtrr_save(void)
+{
+	int i;
+
+	for (i = 0; i < num_var_ranges; i++) {
+		mtrr_if->get(i, &mtrr_value[i].lbase,
+				&mtrr_value[i].lsize,
+				&mtrr_value[i].ltype);
+	}
+	return 0;
+}
+
+static void mtrr_restore(void)
+{
+	int i;
+
+	for (i = 0; i < num_var_ranges; i++) {
+		if (mtrr_value[i].lsize) {
+			set_mtrr(i, mtrr_value[i].lbase,
+				    mtrr_value[i].lsize,
+				    mtrr_value[i].ltype);
+		}
+	}
+}
+
+
+
+static struct syscore_ops mtrr_syscore_ops = {
+	.suspend	= mtrr_save,
+	.resume		= mtrr_restore,
+};
+
+int __initdata changed_by_mtrr_cleanup;
+
+#define SIZE_OR_MASK_BITS(n)  (~((1ULL << ((n) - PAGE_SHIFT)) - 1))
+/**
+ * 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)
+{
+	u32 phys_addr;
+
+	init_ifs();
+
+	phys_addr = 32;
+
+	if (boot_cpu_has(X86_FEATURE_MTRR)) {
+		mtrr_if = &generic_mtrr_ops;
+		size_or_mask = SIZE_OR_MASK_BITS(36);
+		size_and_mask = 0x00f00000;
+		phys_addr = 36;
+
+		/*
+		 * This is an AMD specific MSR, but we assume(hope?) that
+		 * Intel will implement it too when they extend the address
+		 * bus of the Xeon.
+		 */
+		if (cpuid_eax(0x80000000) >= 0x80000008) {
+			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_stepping == 0x3 ||
+			     boot_cpu_data.x86_stepping == 0x4))
+				phys_addr = 36;
+
+			size_or_mask = SIZE_OR_MASK_BITS(phys_addr);
+			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 = SIZE_OR_MASK_BITS(32);
+			size_and_mask = 0;
+			phys_addr = 32;
+		}
+	} else {
+		switch (boot_cpu_data.x86_vendor) {
+		case X86_VENDOR_AMD:
+			if (cpu_feature_enabled(X86_FEATURE_K6_MTRR)) {
+				/* Pre-Athlon (K6) AMD CPU MTRRs */
+				mtrr_if = mtrr_ops[X86_VENDOR_AMD];
+				size_or_mask = SIZE_OR_MASK_BITS(32);
+				size_and_mask = 0;
+			}
+			break;
+		case X86_VENDOR_CENTAUR:
+			if (cpu_feature_enabled(X86_FEATURE_CENTAUR_MCR)) {
+				mtrr_if = mtrr_ops[X86_VENDOR_CENTAUR];
+				size_or_mask = SIZE_OR_MASK_BITS(32);
+				size_and_mask = 0;
+			}
+			break;
+		case X86_VENDOR_CYRIX:
+			if (cpu_feature_enabled(X86_FEATURE_CYRIX_ARR)) {
+				mtrr_if = mtrr_ops[X86_VENDOR_CYRIX];
+				size_or_mask = SIZE_OR_MASK_BITS(32);
+				size_and_mask = 0;
+			}
+			break;
+		default:
+			break;
+		}
+	}
+
+	if (mtrr_if) {
+		__mtrr_enabled = true;
+		set_num_var_ranges();
+		init_table();
+		if (use_intel()) {
+			/* BIOS may override */
+			__mtrr_enabled = get_mtrr_state();
+
+			if (mtrr_enabled())
+				mtrr_bp_pat_init();
+
+			if (mtrr_cleanup(phys_addr)) {
+				changed_by_mtrr_cleanup = 1;
+				mtrr_if->set_all();
+			}
+		}
+	}
+
+	if (!mtrr_enabled()) {
+		pr_info("Disabled\n");
+
+		/*
+		 * PAT initialization relies on MTRR's rendezvous handler.
+		 * Skip PAT init until the handler can initialize both
+		 * features independently.
+		 */
+		pat_disable("MTRRs disabled, skipping PAT initialization too.");
+	}
+}
+
+void mtrr_ap_init(void)
+{
+	if (!mtrr_enabled())
+		return;
+
+	if (!use_intel() || mtrr_aps_delayed_init)
+		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
+	 */
+	set_mtrr_from_inactive_cpu(~0U, 0, 0, 0);
+}
+
+/**
+ * Save current fixed-range MTRR state of the first cpu in cpu_online_mask.
+ */
+void mtrr_save_state(void)
+{
+	int first_cpu;
+
+	if (!mtrr_enabled())
+		return;
+
+	first_cpu = cpumask_first(cpu_online_mask);
+	smp_call_function_single(first_cpu, mtrr_save_fixed_ranges, NULL, 1);
+}
+
+void set_mtrr_aps_delayed_init(void)
+{
+	if (!mtrr_enabled())
+		return;
+	if (!use_intel())
+		return;
+
+	mtrr_aps_delayed_init = true;
+}
+
+/*
+ * Delayed MTRR initialization for all AP's
+ */
+void mtrr_aps_init(void)
+{
+	if (!use_intel() || !mtrr_enabled())
+		return;
+
+	/*
+	 * Check if someone has requested the delay of AP MTRR initialization,
+	 * by doing set_mtrr_aps_delayed_init(), prior to this point. If not,
+	 * then we are done.
+	 */
+	if (!mtrr_aps_delayed_init)
+		return;
+
+	set_mtrr(~0U, 0, 0, 0);
+	mtrr_aps_delayed_init = false;
+}
+
+void mtrr_bp_restore(void)
+{
+	if (!use_intel() || !mtrr_enabled())
+		return;
+
+	mtrr_if->set_all();
+}
+
+static int __init mtrr_init_finialize(void)
+{
+	if (!mtrr_enabled())
+		return 0;
+
+	if (use_intel()) {
+		if (!changed_by_mtrr_cleanup)
+			mtrr_state_warn();
+		return 0;
+	}
+
+	/*
+	 * The CPU has no MTRR and seems to 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.
+	 */
+	register_syscore_ops(&mtrr_syscore_ops);
+
+	return 0;
+}
+subsys_initcall(mtrr_init_finialize);