arch/i386/kernel/microcode.c - maze/linux - Git at Google

 /*
  *	Intel CPU Microcode Update Driver for Linux
  *
  *	Copyright (C) 2000-2004 Tigran Aivazian
  *
  *	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 8.10 of Volume III, Intel Pentium 4 Manual,
  *	Order Number 245472 or free download from:
  *
  *	http://developer.intel.com/design/pentium4/manuals/245472.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/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/mutex.h>

 #include <asm/msr.h>
 #include <asm/uaccess.h>
 #include <asm/processor.h>

 MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
 MODULE_LICENSE("GPL");

 #define MICROCODE_VERSION 	"1.14"

 #define DEFAULT_UCODE_DATASIZE 	(2000) 	  /* 2000 bytes */
 #define MC_HEADER_SIZE		(sizeof (microcode_header_t))  	  /* 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) \
 	(((microcode_t *)mc)->hdr.totalsize ? \
 	 ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
 #define get_datasize(mc) \
 	(((microcode_t *)mc)->hdr.datasize ? \
 	 ((microcode_t *)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 void __user *user_buffer;	/* user area microcode data buffer */
 static unsigned int user_buffer_size;	/* it's size */

 typedef enum mc_error_code {
 	MC_SUCCESS 	= 0,
 	MC_NOTFOUND 	= 1,
 	MC_MARKED 	= 2,
 	MC_ALLOCATED 	= 3,
 } mc_error_code_t;

 static struct ucode_cpu_info {
 	unsigned int sig;
 	unsigned int pf;
 	unsigned int rev;
 	unsigned int cksum;
 	mc_error_code_t err;
 	microcode_t *mc;
 } ucode_cpu_info[NR_CPUS];

 static int microcode_open (struct inode *unused1, struct file *unused2)
 {
 	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 }

 static void collect_cpu_info (void *unused)
 {
 	int cpu_num = smp_processor_id();
 	struct cpuinfo_x86 *c = cpu_data + cpu_num;
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 	unsigned int val[2];

 	uci->sig = uci->pf = uci->rev = uci->cksum = 0;
 	uci->err = MC_NOTFOUND;
 	uci->mc = NULL;

 	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);
 		return;
 	} else {
 		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 void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

 	pr_debug("Microcode Found.\n");
 	pr_debug("   Header Revision 0x%x\n", mc_header->hdrver);
 	pr_debug("   Loader Revision 0x%x\n", mc_header->ldrver);
 	pr_debug("   Revision 0x%x \n", mc_header->rev);
 	pr_debug("   Date %x/%x/%x\n",
 		((mc_header->date >> 24 ) & 0xff),
 		((mc_header->date >> 16 ) & 0xff),
 		(mc_header->date & 0xFFFF));
 	pr_debug("   Signature 0x%x\n", sig);
 	pr_debug("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
 		((sig >> 12) & 0x3),
 		((sig >> 8) & 0xf),
 		((sig >> 4) & 0xf),
 		((sig & 0xf)));
 	pr_debug("   Processor Flags 0x%x\n", pf);
 	pr_debug("   Checksum 0x%x\n", cksum);

 	if (mc_header->rev < uci->rev) {
 		printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
 		       " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 		goto out;
 	} else if (mc_header->rev == uci->rev) {
 		/* notify the caller of success on this cpu */
 		uci->err = MC_SUCCESS;
 		goto out;
 	}

 	pr_debug("microcode: CPU%d found a matching microcode update with "
 		" revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 	uci->cksum = cksum;
 	uci->pf = pf; /* keep the original mc pf for cksum calculation */
 	uci->err = MC_MARKED; /* found the match */
 out:
 	return;
 }

 static int find_matching_ucodes (void)
 {
 	int cursor = 0;
 	int error = 0;

 	while (cursor + MC_HEADER_SIZE < user_buffer_size) {
 		microcode_header_t mc_header;
 		void *newmc = NULL;
 		int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;

 		if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
 			printk(KERN_ERR "microcode: error! Can not read user data\n");
 			error = -EFAULT;
 			goto out;
 		}

 		total_size = get_totalsize(&mc_header);
 		if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
 			printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 			error = -EINVAL;
 			goto out;
 		}

 		data_size = get_datasize(&mc_header);
 		if ((data_size + MC_HEADER_SIZE > total_size) || (data_size < DEFAULT_UCODE_DATASIZE)) {
 			printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 			error = -EINVAL;
 			goto out;
 		}

 		if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
 			printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
 			error = -EINVAL;
 			goto out;
 		}

 		for_each_online_cpu(cpu_num) {
 			struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 			if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 				continue;

 			if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
 				mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
 		}

 		ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
 		if (ext_table_size) {
 			struct extended_sigtable ext_header;
 			struct extended_signature ext_sig;
 			int ext_sigcount;

 			if ((ext_table_size < EXT_HEADER_SIZE)
 					|| ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
 				printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 				error = -EINVAL;
 				goto out;
 			}
 			if (copy_from_user(&ext_header, user_buffer + cursor
 					+ MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
 				printk(KERN_ERR "microcode: error! Can not read user data\n");
 				error = -EFAULT;
 				goto out;
 			}
 			if (ext_table_size != exttable_size(&ext_header)) {
 				printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 				error = -EFAULT;
 				goto out;
 			}

 			ext_sigcount = ext_header.count;

 			for (i = 0; i < ext_sigcount; i++) {
 				if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE
 						+ EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
 					printk(KERN_ERR "microcode: error! Can not read user data\n");
 					error = -EFAULT;
 					goto out;
 				}
 				for_each_online_cpu(cpu_num) {
 					struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 					if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 						continue;
 					if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
 						mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
 					}
 				}
 			}
 		}
 		/* now check if any cpu has matched */
 		allocated_flag = 0;
 		sum = 0;
 		for_each_online_cpu(cpu_num) {
 			if (ucode_cpu_info[cpu_num].err == MC_MARKED) {
 				struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 				if (!allocated_flag) {
 					allocated_flag = 1;
 					newmc = vmalloc(total_size);
 					if (!newmc) {
 						printk(KERN_ERR "microcode: error! Can not allocate memory\n");
 						error = -ENOMEM;
 						goto out;
 					}
 					if (copy_from_user(newmc + MC_HEADER_SIZE,
 								user_buffer + cursor + MC_HEADER_SIZE,
 								total_size - MC_HEADER_SIZE)) {
 						printk(KERN_ERR "microcode: error! Can not read user data\n");
 						vfree(newmc);
 						error = -EFAULT;
 						goto out;
 					}
 					memcpy(newmc, &mc_header, MC_HEADER_SIZE);
 					/* check extended table checksum */
 					if (ext_table_size) {
 						int ext_table_sum = 0;
 						int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
 						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");
 							vfree(newmc);
 							error = -EINVAL;
 							goto out;
 						}
 					}

 					/* calculate the checksum */
 					i = (MC_HEADER_SIZE + data_size) / DWSIZE;
 					while (i--) sum += ((int *)newmc)[i];
 					sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
 				}
 				ucode_cpu_info[cpu_num].mc = newmc;
 				ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
 				if (sum + uci->sig + uci->pf + uci->cksum != 0) {
 					printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
 					error = -EINVAL;
 					goto out;
 				}
 			}
 		}
 		cursor += total_size; /* goto the next update patch */
 	} /* end of while */
 out:
 	return error;
 }

 static void do_update_one (void * unused)
 {
 	unsigned long flags;
 	unsigned int val[2];
 	int cpu_num = smp_processor_id();
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

 	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]);

 	/* notify the caller of success on this cpu */
 	uci->err = MC_SUCCESS;
 	spin_unlock_irqrestore(&microcode_update_lock, flags);
 	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);
 	return;
 }

 static int do_microcode_update (void)
 {
 	int i, error;

 	if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
 		printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 		error = -EIO;
 		goto out;
 	}

 	if ((error = find_matching_ucodes())) {
 		printk(KERN_ERR "microcode: Error in the microcode data\n");
 		goto out_free;
 	}

 	if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
 		printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 		error = -EIO;
 	}

 out_free:
 	for_each_online_cpu(i) {
 		if (ucode_cpu_info[i].mc) {
 			int j;
 			void *tmp = ucode_cpu_info[i].mc;
 			vfree(tmp);
 			for_each_online_cpu(j) {
 				if (ucode_cpu_info[j].mc == tmp)
 					ucode_cpu_info[j].mc = NULL;
 			}
 		}
 	}
 out:
 	return error;
 }

 static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
 {
 	ssize_t ret;

 	if (len < DEFAULT_UCODE_TOTALSIZE) {
 		printk(KERN_ERR "microcode: not enough data\n");
 		return -EINVAL;
 	}

 	if ((len >> PAGE_SHIFT) > num_physpages) {
 		printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
 		return -EINVAL;
 	}

 	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);

 	return ret;
 }

 static int microcode_ioctl (struct inode *inode, struct file *file,
 		unsigned int cmd, unsigned long arg)
 {
 	switch (cmd) {
 		/*
 		 *  XXX: will be removed after microcode_ctl
 		 *  is updated to ignore failure of this ioctl()
 		 */
 		case MICROCODE_IOCFREE:
 			return 0;
 		default:
 			return -EINVAL;
 	}
 	return -EINVAL;
 }

 static struct file_operations microcode_fops = {
 	.owner		= THIS_MODULE,
 	.write		= microcode_write,
 	.ioctl		= microcode_ioctl,
 	.open		= microcode_open,
 };

 static struct miscdevice microcode_dev = {
 	.minor		= MICROCODE_MINOR,
 	.name		= "microcode",
 	.devfs_name	= "cpu/microcode",
 	.fops		= &microcode_fops,
 };

 static int __init microcode_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;
 	}

 	printk(KERN_INFO
 		"IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
 	return 0;
 }

 static void __exit microcode_exit (void)
 {
 	misc_deregister(&microcode_dev);
 }

 module_init(microcode_init)
 module_exit(microcode_exit)
 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
	/*
	* Intel CPU Microcode Update Driver for Linux
	*
	* Copyright (C) 2000-2004 Tigran Aivazian
	*
	* 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 8.10 of Volume III, Intel Pentium 4 Manual,
	* Order Number 245472 or free download from:
	*
	* http://developer.intel.com/design/pentium4/manuals/245472.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/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/mutex.h>

	#include <asm/msr.h>
	#include <asm/uaccess.h>
	#include <asm/processor.h>

	MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
	MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
	MODULE_LICENSE("GPL");

	#define MICROCODE_VERSION "1.14"

	#define DEFAULT_UCODE_DATASIZE (2000) /* 2000 bytes */
	#define MC_HEADER_SIZE (sizeof (microcode_header_t)) /* 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) \
	(((microcode_t *)mc)->hdr.totalsize ? \
	((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
	#define get_datasize(mc) \
	(((microcode_t *)mc)->hdr.datasize ? \
	((microcode_t *)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 void __user user_buffer; / user area microcode data buffer */
	static unsigned int user_buffer_size; /* it's size */

	typedef enum mc_error_code {
	MC_SUCCESS = 0,
	MC_NOTFOUND = 1,
	MC_MARKED = 2,
	MC_ALLOCATED = 3,
	} mc_error_code_t;

	static struct ucode_cpu_info {
	unsigned int sig;
	unsigned int pf;
	unsigned int rev;
	unsigned int cksum;
	mc_error_code_t err;
	microcode_t *mc;
	} ucode_cpu_info[NR_CPUS];

	static int microcode_open (struct inode unused1, struct file unused2)
	{
	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
	}

	static void collect_cpu_info (void *unused)
	{
	int cpu_num = smp_processor_id();
	struct cpuinfo_x86 *c = cpu_data + cpu_num;
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
	unsigned int val[2];

	uci->sig = uci->pf = uci->rev = uci->cksum = 0;
	uci->err = MC_NOTFOUND;
	uci->mc = NULL;

	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);
	return;
	} else {
	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 void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
	{
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

	pr_debug("Microcode Found.\n");
	pr_debug(" Header Revision 0x%x\n", mc_header->hdrver);
	pr_debug(" Loader Revision 0x%x\n", mc_header->ldrver);
	pr_debug(" Revision 0x%x \n", mc_header->rev);
	pr_debug(" Date %x/%x/%x\n",
	((mc_header->date >> 24 ) & 0xff),
	((mc_header->date >> 16 ) & 0xff),
	(mc_header->date & 0xFFFF));
	pr_debug(" Signature 0x%x\n", sig);
	pr_debug(" Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
	((sig >> 12) & 0x3),
	((sig >> 8) & 0xf),
	((sig >> 4) & 0xf),
	((sig & 0xf)));
	pr_debug(" Processor Flags 0x%x\n", pf);
	pr_debug(" Checksum 0x%x\n", cksum);

	if (mc_header->rev < uci->rev) {
	printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
	" 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
	goto out;
	} else if (mc_header->rev == uci->rev) {
	/* notify the caller of success on this cpu */
	uci->err = MC_SUCCESS;
	goto out;
	}

	pr_debug("microcode: CPU%d found a matching microcode update with "
	" revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
	uci->cksum = cksum;
	uci->pf = pf; /* keep the original mc pf for cksum calculation */
	uci->err = MC_MARKED; /* found the match */
	out:
	return;
	}

	static int find_matching_ucodes (void)
	{
	int cursor = 0;
	int error = 0;

	while (cursor + MC_HEADER_SIZE < user_buffer_size) {
	microcode_header_t mc_header;
	void *newmc = NULL;
	int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;

	if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
	printk(KERN_ERR "microcode: error! Can not read user data\n");
	error = -EFAULT;
	goto out;
	}

	total_size = get_totalsize(&mc_header);
	if ((cursor + total_size > user_buffer_size) \|\| (total_size < DEFAULT_UCODE_TOTALSIZE)) {
	printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
	error = -EINVAL;
	goto out;
	}

	data_size = get_datasize(&mc_header);
	if ((data_size + MC_HEADER_SIZE > total_size) \|\| (data_size < DEFAULT_UCODE_DATASIZE)) {
	printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
	error = -EINVAL;
	goto out;
	}

	if (mc_header.ldrver != 1 \|\| mc_header.hdrver != 1) {
	printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
	error = -EINVAL;
	goto out;
	}

	for_each_online_cpu(cpu_num) {
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
	if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
	continue;

	if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
	mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
	}

	ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
	if (ext_table_size) {
	struct extended_sigtable ext_header;
	struct extended_signature ext_sig;
	int ext_sigcount;

	if ((ext_table_size < EXT_HEADER_SIZE)
	\|\| ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
	printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
	error = -EINVAL;
	goto out;
	}
	if (copy_from_user(&ext_header, user_buffer + cursor
	+ MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
	printk(KERN_ERR "microcode: error! Can not read user data\n");
	error = -EFAULT;
	goto out;
	}
	if (ext_table_size != exttable_size(&ext_header)) {
	printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
	error = -EFAULT;
	goto out;
	}

	ext_sigcount = ext_header.count;

	for (i = 0; i < ext_sigcount; i++) {
	if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE
	+ EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
	printk(KERN_ERR "microcode: error! Can not read user data\n");
	error = -EFAULT;
	goto out;
	}
	for_each_online_cpu(cpu_num) {
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
	if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
	continue;
	if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
	mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
	}
	}
	}
	}
	/* now check if any cpu has matched */
	allocated_flag = 0;
	sum = 0;
	for_each_online_cpu(cpu_num) {
	if (ucode_cpu_info[cpu_num].err == MC_MARKED) {
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
	if (!allocated_flag) {
	allocated_flag = 1;
	newmc = vmalloc(total_size);
	if (!newmc) {
	printk(KERN_ERR "microcode: error! Can not allocate memory\n");
	error = -ENOMEM;
	goto out;
	}
	if (copy_from_user(newmc + MC_HEADER_SIZE,
	user_buffer + cursor + MC_HEADER_SIZE,
	total_size - MC_HEADER_SIZE)) {
	printk(KERN_ERR "microcode: error! Can not read user data\n");
	vfree(newmc);
	error = -EFAULT;
	goto out;
	}
	memcpy(newmc, &mc_header, MC_HEADER_SIZE);
	/* check extended table checksum */
	if (ext_table_size) {
	int ext_table_sum = 0;
	int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
	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");
	vfree(newmc);
	error = -EINVAL;
	goto out;
	}
	}

	/* calculate the checksum */
	i = (MC_HEADER_SIZE + data_size) / DWSIZE;
	while (i--) sum += ((int *)newmc)[i];
	sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
	}
	ucode_cpu_info[cpu_num].mc = newmc;
	ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
	if (sum + uci->sig + uci->pf + uci->cksum != 0) {
	printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
	error = -EINVAL;
	goto out;
	}
	}
	}
	cursor += total_size; /* goto the next update patch */
	} /* end of while */
	out:
	return error;
	}

	static void do_update_one (void * unused)
	{
	unsigned long flags;
	unsigned int val[2];
	int cpu_num = smp_processor_id();
	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;

	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]);

	/* notify the caller of success on this cpu */
	uci->err = MC_SUCCESS;
	spin_unlock_irqrestore(&microcode_update_lock, flags);
	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);
	return;
	}

	static int do_microcode_update (void)
	{
	int i, error;

	if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
	printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
	error = -EIO;
	goto out;
	}

	if ((error = find_matching_ucodes())) {
	printk(KERN_ERR "microcode: Error in the microcode data\n");
	goto out_free;
	}

	if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
	printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
	error = -EIO;
	}

	out_free:
	for_each_online_cpu(i) {
	if (ucode_cpu_info[i].mc) {
	int j;
	void *tmp = ucode_cpu_info[i].mc;
	vfree(tmp);
	for_each_online_cpu(j) {
	if (ucode_cpu_info[j].mc == tmp)
	ucode_cpu_info[j].mc = NULL;
	}
	}
	}
	out:
	return error;
	}

	static ssize_t microcode_write (struct file file, const char __user buf, size_t len, loff_t *ppos)
	{
	ssize_t ret;

	if (len < DEFAULT_UCODE_TOTALSIZE) {
	printk(KERN_ERR "microcode: not enough data\n");
	return -EINVAL;
	}

	if ((len >> PAGE_SHIFT) > num_physpages) {
	printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
	return -EINVAL;
	}

	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);

	return ret;
	}

	static int microcode_ioctl (struct inode inode, struct file file,
	unsigned int cmd, unsigned long arg)
	{
	switch (cmd) {
	/*
	* XXX: will be removed after microcode_ctl
	* is updated to ignore failure of this ioctl()
	*/
	case MICROCODE_IOCFREE:
	return 0;
	default:
	return -EINVAL;
	}
	return -EINVAL;
	}

	static struct file_operations microcode_fops = {
	.owner = THIS_MODULE,
	.write = microcode_write,
	.ioctl = microcode_ioctl,
	.open = microcode_open,
	};

	static struct miscdevice microcode_dev = {
	.minor = MICROCODE_MINOR,
	.name = "microcode",
	.devfs_name = "cpu/microcode",
	.fops = &microcode_fops,
	};

	static int __init microcode_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;
	}

	printk(KERN_INFO
	"IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
	return 0;
	}

	static void __exit microcode_exit (void)
	{
	misc_deregister(&microcode_dev);
	}

	module_init(microcode_init)
	module_exit(microcode_exit)
	MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);