x86: move microcode.c to microcode_intel.c

Signed-off-by: Peter Oruba <peter.oruba@amd.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 855 insertions, 0 deletions

diff --git a/arch/x86/kernel/microcode_intel.c b/arch/x86/kernel/microcode_intel.c
new file mode 100644
index 0000000..4e7b2f6
--- /dev/null
+++ b/arch/x86/kernel/microcode_intel.c
@@ -0,0 +1,855 @@
+/*
+ *	Intel CPU Microcode Update Driver for Linux
+ *
+ *	Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
+ *		      2006	Shaohua Li <shaohua.li@intel.com>
+ *
+ *	This driver allows to upgrade microcode on Intel processors
+ *	belonging to IA-32 family - PentiumPro, Pentium II,
+ *	Pentium III, Xeon, Pentium 4, etc.
+ *
+ *	Reference: Section 8.11 of Volume 3a, IA-32 Intel? Architecture
+ *	Software Developer's Manual
+ *	Order Number 253668 or free download from:
+ *
+ *	http://developer.intel.com/design/pentium4/manuals/253668.htm
+ *
+ *	For more information, go to http://www.urbanmyth.org/microcode
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	1.0	16 Feb 2000, Tigran Aivazian <tigran@sco.com>
+ *		Initial release.
+ *	1.01	18 Feb 2000, Tigran Aivazian <tigran@sco.com>
+ *		Added read() support + cleanups.
+ *	1.02	21 Feb 2000, Tigran Aivazian <tigran@sco.com>
+ *		Added 'device trimming' support. open(O_WRONLY) zeroes
+ *		and frees the saved copy of applied microcode.
+ *	1.03	29 Feb 2000, Tigran Aivazian <tigran@sco.com>
+ *		Made to use devfs (/dev/cpu/microcode) + cleanups.
+ *	1.04	06 Jun 2000, Simon Trimmer <simon@veritas.com>
+ *		Added misc device support (now uses both devfs and misc).
+ *		Added MICROCODE_IOCFREE ioctl to clear memory.
+ *	1.05	09 Jun 2000, Simon Trimmer <simon@veritas.com>
+ *		Messages for error cases (non Intel & no suitable microcode).
+ *	1.06	03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
+ *		Removed ->release(). Removed exclusive open and status bitmap.
+ *		Added microcode_rwsem to serialize read()/write()/ioctl().
+ *		Removed global kernel lock usage.
+ *	1.07	07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
+ *		Write 0 to 0x8B msr and then cpuid before reading revision,
+ *		so that it works even if there were no update done by the
+ *		BIOS. Otherwise, reading from 0x8B gives junk (which happened
+ *		to be 0 on my machine which is why it worked even when I
+ *		disabled update by the BIOS)
+ *		Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
+ *	1.08	11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
+ *			     Tigran Aivazian <tigran@veritas.com>
+ *		Intel Pentium 4 processor support and bugfixes.
+ *	1.09	30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
+ *		Bugfix for HT (Hyper-Threading) enabled processors
+ *		whereby processor resources are shared by all logical processors
+ *		in a single CPU package.
+ *	1.10	28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
+ *		Tigran Aivazian <tigran@veritas.com>,
+ *		Serialize updates as required on HT processors due to speculative
+ *		nature of implementation.
+ *	1.11	22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
+ *		Fix the panic when writing zero-length microcode chunk.
+ *	1.12	29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>,
+ *		Jun Nakajima <jun.nakajima@intel.com>
+ *		Support for the microcode updates in the new format.
+ *	1.13	10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
+ *		Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
+ *		because we no longer hold a copy of applied microcode
+ *		in kernel memory.
+ *	1.14	25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
+ *		Fix sigmatch() macro to handle old CPUs with pf == 0.
+ *		Thanks to Stuart Swales for pointing out this bug.
+ */
+
+//#define DEBUG /* pr_debug */
+#include <linux/capability.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/cpumask.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/miscdevice.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/mutex.h>
+#include <linux/cpu.h>
+#include <linux/firmware.h>
+#include <linux/platform_device.h>
+
+#include <asm/msr.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+#include <asm/microcode.h>
+
+MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
+MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
+MODULE_LICENSE("GPL");
+
+#define MICROCODE_VERSION 	"1.14a"
+
+#define DEFAULT_UCODE_DATASIZE 	(2000) 	  /* 2000 bytes */
+#define MC_HEADER_SIZE		(sizeof (struct microcode_header))  	  /* 48 bytes */
+#define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
+#define EXT_HEADER_SIZE		(sizeof (struct extended_sigtable)) /* 20 bytes */
+#define EXT_SIGNATURE_SIZE	(sizeof (struct extended_signature)) /* 12 bytes */
+#define DWSIZE			(sizeof (u32))
+#define get_totalsize(mc) \
+	(((struct microcode *)mc)->hdr.totalsize ? \
+	 ((struct microcode *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
+#define get_datasize(mc) \
+	(((struct microcode *)mc)->hdr.datasize ? \
+	 ((struct microcode *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
+
+#define sigmatch(s1, s2, p1, p2) \
+	(((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
+
+#define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
+
+/* serialize access to the physical write to MSR 0x79 */
+static DEFINE_SPINLOCK(microcode_update_lock);
+
+/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
+static DEFINE_MUTEX(microcode_mutex);
+
+static struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
+
+static void collect_cpu_info(int cpu_num)
+{
+	struct cpuinfo_x86 *c = &cpu_data(cpu_num);
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+	unsigned int val[2];
+
+	/* We should bind the task to the CPU */
+	BUG_ON(raw_smp_processor_id() != cpu_num);
+	uci->pf = uci->rev = 0;
+	uci->mc = NULL;
+	uci->valid = 1;
+
+	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
+	    	cpu_has(c, X86_FEATURE_IA64)) {
+		printk(KERN_ERR "microcode: CPU%d not a capable Intel "
+			"processor\n", cpu_num);
+		uci->valid = 0;
+		return;
+	}
+
+	uci->sig = cpuid_eax(0x00000001);
+
+	if ((c->x86_model >= 5) || (c->x86 > 6)) {
+		/* get processor flags from MSR 0x17 */
+		rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
+		uci->pf = 1 << ((val[1] >> 18) & 7);
+	}
+
+	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+	/* see notes above for revision 1.07.  Apparent chip bug */
+	sync_core();
+	/* get the current revision from MSR 0x8B */
+	rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
+	pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
+			uci->sig, uci->pf, uci->rev);
+}
+
+static inline int microcode_update_match(int cpu_num,
+	struct microcode_header *mc_header, int sig, int pf)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+
+	if (!sigmatch(sig, uci->sig, pf, uci->pf)
+		|| mc_header->rev <= uci->rev)
+		return 0;
+	return 1;
+}
+
+static int microcode_sanity_check(void *mc)
+{
+	struct microcode_header *mc_header = mc;
+	struct extended_sigtable *ext_header = NULL;
+	struct extended_signature *ext_sig;
+	unsigned long total_size, data_size, ext_table_size;
+	int sum, orig_sum, ext_sigcount = 0, i;
+
+	total_size = get_totalsize(mc_header);
+	data_size = get_datasize(mc_header);
+	if (data_size + MC_HEADER_SIZE > total_size) {
+		printk(KERN_ERR "microcode: error! "
+			"Bad data size in microcode data file\n");
+		return -EINVAL;
+	}
+
+	if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
+		printk(KERN_ERR "microcode: error! "
+			"Unknown microcode update format\n");
+		return -EINVAL;
+	}
+	ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
+	if (ext_table_size) {
+		if ((ext_table_size < EXT_HEADER_SIZE)
+		 || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
+			printk(KERN_ERR "microcode: error! "
+				"Small exttable size in microcode data file\n");
+			return -EINVAL;
+		}
+		ext_header = mc + MC_HEADER_SIZE + data_size;
+		if (ext_table_size != exttable_size(ext_header)) {
+			printk(KERN_ERR "microcode: error! "
+				"Bad exttable size in microcode data file\n");
+			return -EFAULT;
+		}
+		ext_sigcount = ext_header->count;
+	}
+
+	/* check extended table checksum */
+	if (ext_table_size) {
+		int ext_table_sum = 0;
+		int *ext_tablep = (int *)ext_header;
+
+		i = ext_table_size / DWSIZE;
+		while (i--)
+			ext_table_sum += ext_tablep[i];
+		if (ext_table_sum) {
+			printk(KERN_WARNING "microcode: aborting, "
+				"bad extended signature table checksum\n");
+			return -EINVAL;
+		}
+	}
+
+	/* calculate the checksum */
+	orig_sum = 0;
+	i = (MC_HEADER_SIZE + data_size) / DWSIZE;
+	while (i--)
+		orig_sum += ((int *)mc)[i];
+	if (orig_sum) {
+		printk(KERN_ERR "microcode: aborting, bad checksum\n");
+		return -EINVAL;
+	}
+	if (!ext_table_size)
+		return 0;
+	/* check extended signature checksum */
+	for (i = 0; i < ext_sigcount; i++) {
+		ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
+			  EXT_SIGNATURE_SIZE * i;
+		sum = orig_sum
+			- (mc_header->sig + mc_header->pf + mc_header->cksum)
+			+ (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
+		if (sum) {
+			printk(KERN_ERR "microcode: aborting, bad checksum\n");
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+/*
+ * return 0 - no update found
+ * return 1 - found update
+ * return < 0 - error
+ */
+static int get_maching_microcode(void *mc, int cpu)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+	struct microcode_header *mc_header = mc;
+	struct extended_sigtable *ext_header;
+	unsigned long total_size = get_totalsize(mc_header);
+	int ext_sigcount, i;
+	struct extended_signature *ext_sig;
+	void *new_mc;
+
+	if (microcode_update_match(cpu, mc_header,
+			mc_header->sig, mc_header->pf))
+		goto find;
+
+	if (total_size <= get_datasize(mc_header) + MC_HEADER_SIZE)
+		return 0;
+
+	ext_header = mc + get_datasize(mc_header) + MC_HEADER_SIZE;
+	ext_sigcount = ext_header->count;
+	ext_sig = (void *)ext_header + EXT_HEADER_SIZE;
+	for (i = 0; i < ext_sigcount; i++) {
+		if (microcode_update_match(cpu, mc_header,
+				ext_sig->sig, ext_sig->pf))
+			goto find;
+		ext_sig++;
+	}
+	return 0;
+find:
+	pr_debug("microcode: CPU%d found a matching microcode update with"
+		" version 0x%x (current=0x%x)\n", cpu, mc_header->rev,uci->rev);
+	new_mc = vmalloc(total_size);
+	if (!new_mc) {
+		printk(KERN_ERR "microcode: error! Can not allocate memory\n");
+		return -ENOMEM;
+	}
+
+	/* free previous update file */
+	vfree(uci->mc);
+
+	memcpy(new_mc, mc, total_size);
+	uci->mc = new_mc;
+	return 1;
+}
+
+static void apply_microcode(int cpu)
+{
+	unsigned long flags;
+	unsigned int val[2];
+	int cpu_num = raw_smp_processor_id();
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+
+	/* We should bind the task to the CPU */
+	BUG_ON(cpu_num != cpu);
+
+	if (uci->mc == NULL)
+		return;
+
+	/* serialize access to the physical write to MSR 0x79 */
+	spin_lock_irqsave(&microcode_update_lock, flags);
+
+	/* write microcode via MSR 0x79 */
+	wrmsr(MSR_IA32_UCODE_WRITE,
+		(unsigned long) uci->mc->bits,
+		(unsigned long) uci->mc->bits >> 16 >> 16);
+	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+
+	/* see notes above for revision 1.07.  Apparent chip bug */
+	sync_core();
+
+	/* get the current revision from MSR 0x8B */
+	rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
+
+	spin_unlock_irqrestore(&microcode_update_lock, flags);
+	if (val[1] != uci->mc->hdr.rev) {
+		printk(KERN_ERR "microcode: CPU%d update from revision "
+			"0x%x to 0x%x failed\n", cpu_num, uci->rev, val[1]);
+		return;
+	}
+	printk(KERN_INFO "microcode: CPU%d updated from revision "
+	       "0x%x to 0x%x, date = %08x \n",
+	       cpu_num, uci->rev, val[1], uci->mc->hdr.date);
+	uci->rev = val[1];
+}
+
+#ifdef CONFIG_MICROCODE_OLD_INTERFACE
+static void __user *user_buffer;	/* user area microcode data buffer */
+static unsigned int user_buffer_size;	/* it's size */
+
+static long get_next_ucode(void **mc, long offset)
+{
+	struct microcode_header mc_header;
+	unsigned long total_size;
+
+	/* No more data */
+	if (offset >= user_buffer_size)
+		return 0;
+	if (copy_from_user(&mc_header, user_buffer + offset, MC_HEADER_SIZE)) {
+		printk(KERN_ERR "microcode: error! Can not read user data\n");
+		return -EFAULT;
+	}
+	total_size = get_totalsize(&mc_header);
+	if (offset + total_size > user_buffer_size) {
+		printk(KERN_ERR "microcode: error! Bad total size in microcode "
+				"data file\n");
+		return -EINVAL;
+	}
+	*mc = vmalloc(total_size);
+	if (!*mc)
+		return -ENOMEM;
+	if (copy_from_user(*mc, user_buffer + offset, total_size)) {
+		printk(KERN_ERR "microcode: error! Can not read user data\n");
+		vfree(*mc);
+		return -EFAULT;
+	}
+	return offset + total_size;
+}
+
+static int do_microcode_update (void)
+{
+	long cursor = 0;
+	int error = 0;
+	void *new_mc = NULL;
+	int cpu;
+	cpumask_t old;
+	cpumask_of_cpu_ptr_declare(newmask);
+
+	old = current->cpus_allowed;
+
+	while ((cursor = get_next_ucode(&new_mc, cursor)) > 0) {
+		error = microcode_sanity_check(new_mc);
+		if (error)
+			goto out;
+		/*
+		 * It's possible the data file has multiple matching ucode,
+		 * lets keep searching till the latest version
+		 */
+		for_each_online_cpu(cpu) {
+			struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+
+			if (!uci->valid)
+				continue;
+			cpumask_of_cpu_ptr_next(newmask, cpu);
+			set_cpus_allowed_ptr(current, newmask);
+			error = get_maching_microcode(new_mc, cpu);
+			if (error < 0)
+				goto out;
+			if (error == 1)
+				apply_microcode(cpu);
+		}
+		vfree(new_mc);
+	}
+out:
+	if (cursor > 0)
+		vfree(new_mc);
+	if (cursor < 0)
+		error = cursor;
+	set_cpus_allowed_ptr(current, &old);
+	return error;
+}
+
+static int microcode_open (struct inode *unused1, struct file *unused2)
+{
+	cycle_kernel_lock();
+	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
+}
+
+static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
+{
+	ssize_t ret;
+
+	if ((len >> PAGE_SHIFT) > num_physpages) {
+		printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
+		return -EINVAL;
+	}
+
+	get_online_cpus();
+	mutex_lock(&microcode_mutex);
+
+	user_buffer = (void __user *) buf;
+	user_buffer_size = (int) len;
+
+	ret = do_microcode_update();
+	if (!ret)
+		ret = (ssize_t)len;
+
+	mutex_unlock(&microcode_mutex);
+	put_online_cpus();
+
+	return ret;
+}
+
+static const struct file_operations microcode_fops = {
+	.owner		= THIS_MODULE,
+	.write		= microcode_write,
+	.open		= microcode_open,
+};
+
+static struct miscdevice microcode_dev = {
+	.minor		= MICROCODE_MINOR,
+	.name		= "microcode",
+	.fops		= &microcode_fops,
+};
+
+static int __init microcode_dev_init (void)
+{
+	int error;
+
+	error = misc_register(&microcode_dev);
+	if (error) {
+		printk(KERN_ERR
+			"microcode: can't misc_register on minor=%d\n",
+			MICROCODE_MINOR);
+		return error;
+	}
+
+	return 0;
+}
+
+static void microcode_dev_exit (void)
+{
+	misc_deregister(&microcode_dev);
+}
+
+MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
+#else
+#define microcode_dev_init() 0
+#define microcode_dev_exit() do { } while(0)
+#endif
+
+static long get_next_ucode_from_buffer(void **mc, const u8 *buf,
+	unsigned long size, long offset)
+{
+	struct microcode_header *mc_header;
+	unsigned long total_size;
+
+	/* No more data */
+	if (offset >= size)
+		return 0;
+	mc_header = (struct microcode_header *)(buf + offset);
+	total_size = get_totalsize(mc_header);
+
+	if (offset + total_size > size) {
+		printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
+		return -EINVAL;
+	}
+
+	*mc = vmalloc(total_size);
+	if (!*mc) {
+		printk(KERN_ERR "microcode: error! Can not allocate memory\n");
+		return -ENOMEM;
+	}
+	memcpy(*mc, buf + offset, total_size);
+	return offset + total_size;
+}
+
+/* fake device for request_firmware */
+static struct platform_device *microcode_pdev;
+
+static int cpu_request_microcode(int cpu)
+{
+	char name[30];
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+	const struct firmware *firmware;
+	const u8 *buf;
+	unsigned long size;
+	long offset = 0;
+	int error;
+	void *mc;
+
+	/* We should bind the task to the CPU */
+	BUG_ON(cpu != raw_smp_processor_id());
+	sprintf(name,"intel-ucode/%02x-%02x-%02x",
+		c->x86, c->x86_model, c->x86_mask);
+	error = request_firmware(&firmware, name, &microcode_pdev->dev);
+	if (error) {
+		pr_debug("microcode: data file %s load failed\n", name);
+		return error;
+	}
+	buf = firmware->data;
+	size = firmware->size;
+	while ((offset = get_next_ucode_from_buffer(&mc, buf, size, offset))
+			> 0) {
+		error = microcode_sanity_check(mc);
+		if (error)
+			break;
+		error = get_maching_microcode(mc, cpu);
+		if (error < 0)
+			break;
+		/*
+		 * It's possible the data file has multiple matching ucode,
+		 * lets keep searching till the latest version
+		 */
+		if (error == 1) {
+			apply_microcode(cpu);
+			error = 0;
+		}
+		vfree(mc);
+	}
+	if (offset > 0)
+		vfree(mc);
+	if (offset < 0)
+		error = offset;
+	release_firmware(firmware);
+
+	return error;
+}
+
+static int apply_microcode_check_cpu(int cpu)
+{
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+	cpumask_t old;
+	cpumask_of_cpu_ptr(newmask, cpu);
+	unsigned int val[2];
+	int err = 0;
+
+	/* Check if the microcode is available */
+	if (!uci->mc)
+		return 0;
+
+	old = current->cpus_allowed;
+	set_cpus_allowed_ptr(current, newmask);
+
+	/* Check if the microcode we have in memory matches the CPU */
+	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
+	    cpu_has(c, X86_FEATURE_IA64) || uci->sig != cpuid_eax(0x00000001))
+		err = -EINVAL;
+
+	if (!err && ((c->x86_model >= 5) || (c->x86 > 6))) {
+		/* get processor flags from MSR 0x17 */
+		rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
+		if (uci->pf != (1 << ((val[1] >> 18) & 7)))
+			err = -EINVAL;
+	}
+
+	if (!err) {
+		wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+		/* see notes above for revision 1.07.  Apparent chip bug */
+		sync_core();
+		/* get the current revision from MSR 0x8B */
+		rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
+		if (uci->rev != val[1])
+			err = -EINVAL;
+	}
+
+	if (!err)
+		apply_microcode(cpu);
+	else
+		printk(KERN_ERR "microcode: Could not apply microcode to CPU%d:"
+			" sig=0x%x, pf=0x%x, rev=0x%x\n",
+			cpu, uci->sig, uci->pf, uci->rev);
+
+	set_cpus_allowed_ptr(current, &old);
+	return err;
+}
+
+static void microcode_init_cpu(int cpu, int resume)
+{
+	cpumask_t old;
+	cpumask_of_cpu_ptr(newmask, cpu);
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+
+	old = current->cpus_allowed;
+
+	set_cpus_allowed_ptr(current, newmask);
+	mutex_lock(&microcode_mutex);
+	collect_cpu_info(cpu);
+	if (uci->valid && system_state == SYSTEM_RUNNING && !resume)
+		cpu_request_microcode(cpu);
+	mutex_unlock(&microcode_mutex);
+	set_cpus_allowed_ptr(current, &old);
+}
+
+static void microcode_fini_cpu(int cpu)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+
+	mutex_lock(&microcode_mutex);
+	uci->valid = 0;
+	vfree(uci->mc);
+	uci->mc = NULL;
+	mutex_unlock(&microcode_mutex);
+}
+
+static ssize_t reload_store(struct sys_device *dev,
+			    struct sysdev_attribute *attr,
+			    const char *buf, size_t sz)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
+	char *end;
+	unsigned long val = simple_strtoul(buf, &end, 0);
+	int err = 0;
+	int cpu = dev->id;
+
+	if (end == buf)
+		return -EINVAL;
+	if (val == 1) {
+		cpumask_t old;
+		cpumask_of_cpu_ptr(newmask, cpu);
+
+		old = current->cpus_allowed;
+
+		get_online_cpus();
+		set_cpus_allowed_ptr(current, newmask);
+
+		mutex_lock(&microcode_mutex);
+		if (uci->valid)
+			err = cpu_request_microcode(cpu);
+		mutex_unlock(&microcode_mutex);
+		put_online_cpus();
+		set_cpus_allowed_ptr(current, &old);
+	}
+	if (err)
+		return err;
+	return sz;
+}
+
+static ssize_t version_show(struct sys_device *dev,
+			struct sysdev_attribute *attr, char *buf)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
+
+	return sprintf(buf, "0x%x\n", uci->rev);
+}
+
+static ssize_t pf_show(struct sys_device *dev,
+			struct sysdev_attribute *attr, char *buf)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
+
+	return sprintf(buf, "0x%x\n", uci->pf);
+}
+
+static SYSDEV_ATTR(reload, 0200, NULL, reload_store);
+static SYSDEV_ATTR(version, 0400, version_show, NULL);
+static SYSDEV_ATTR(processor_flags, 0400, pf_show, NULL);
+
+static struct attribute *mc_default_attrs[] = {
+	&attr_reload.attr,
+	&attr_version.attr,
+	&attr_processor_flags.attr,
+	NULL
+};
+
+static struct attribute_group mc_attr_group = {
+	.attrs = mc_default_attrs,
+	.name = "microcode",
+};
+
+static int __mc_sysdev_add(struct sys_device *sys_dev, int resume)
+{
+	int err, cpu = sys_dev->id;
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+
+	if (!cpu_online(cpu))
+		return 0;
+
+	pr_debug("microcode: CPU%d added\n", cpu);
+	memset(uci, 0, sizeof(*uci));
+
+	err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
+	if (err)
+		return err;
+
+	microcode_init_cpu(cpu, resume);
+
+	return 0;
+}
+
+static int mc_sysdev_add(struct sys_device *sys_dev)
+{
+	return __mc_sysdev_add(sys_dev, 0);
+}
+
+static int mc_sysdev_remove(struct sys_device *sys_dev)
+{
+	int cpu = sys_dev->id;
+
+	if (!cpu_online(cpu))
+		return 0;
+
+	pr_debug("microcode: CPU%d removed\n", cpu);
+	microcode_fini_cpu(cpu);
+	sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
+	return 0;
+}
+
+static int mc_sysdev_resume(struct sys_device *dev)
+{
+	int cpu = dev->id;
+
+	if (!cpu_online(cpu))
+		return 0;
+	pr_debug("microcode: CPU%d resumed\n", cpu);
+	/* only CPU 0 will apply ucode here */
+	apply_microcode(0);
+	return 0;
+}
+
+static struct sysdev_driver mc_sysdev_driver = {
+	.add = mc_sysdev_add,
+	.remove = mc_sysdev_remove,
+	.resume = mc_sysdev_resume,
+};
+
+static __cpuinit int
+mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (unsigned long)hcpu;
+	struct sys_device *sys_dev;
+
+	sys_dev = get_cpu_sysdev(cpu);
+	switch (action) {
+	case CPU_UP_CANCELED_FROZEN:
+		/* The CPU refused to come up during a system resume */
+		microcode_fini_cpu(cpu);
+		break;
+	case CPU_ONLINE:
+	case CPU_DOWN_FAILED:
+		mc_sysdev_add(sys_dev);
+		break;
+	case CPU_ONLINE_FROZEN:
+		/* System-wide resume is in progress, try to apply microcode */
+		if (apply_microcode_check_cpu(cpu)) {
+			/* The application of microcode failed */
+			microcode_fini_cpu(cpu);
+			__mc_sysdev_add(sys_dev, 1);
+			break;
+		}
+	case CPU_DOWN_FAILED_FROZEN:
+		if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
+			printk(KERN_ERR "microcode: Failed to create the sysfs "
+				"group for CPU%d\n", cpu);
+		break;
+	case CPU_DOWN_PREPARE:
+		mc_sysdev_remove(sys_dev);
+		break;
+	case CPU_DOWN_PREPARE_FROZEN:
+		/* Suspend is in progress, only remove the interface */
+		sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block __refdata mc_cpu_notifier = {
+	.notifier_call = mc_cpu_callback,
+};
+
+static int __init microcode_init (void)
+{
+	int error;
+
+	printk(KERN_INFO
+		"IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@aivazian.fsnet.co.uk>\n");
+
+	error = microcode_dev_init();
+	if (error)
+		return error;
+	microcode_pdev = platform_device_register_simple("microcode", -1,
+							 NULL, 0);
+	if (IS_ERR(microcode_pdev)) {
+		microcode_dev_exit();
+		return PTR_ERR(microcode_pdev);
+	}
+
+	get_online_cpus();
+	error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
+	put_online_cpus();
+	if (error) {
+		microcode_dev_exit();
+		platform_device_unregister(microcode_pdev);
+		return error;
+	}
+
+	register_hotcpu_notifier(&mc_cpu_notifier);
+	return 0;
+}
+
+static void __exit microcode_exit (void)
+{
+	microcode_dev_exit();
+
+	unregister_hotcpu_notifier(&mc_cpu_notifier);
+
+	get_online_cpus();
+	sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
+	put_online_cpus();
+
+	platform_device_unregister(microcode_pdev);
+}
+
+module_init(microcode_init)
+module_exit(microcode_exit)