[PATCH] update to microcode update driver

This contains the following changes:

a) changes from Intel to support the new microcode data format
   (backward compatible of course)

b) changes from me to remove the no longer needed features of the driver,
   namely we don't need to keep a copy of applied microcode in kernel
   memory.

   This feature was hardly useful in the days of regular devfs
   /dev/cpu/microcode file and now it is completely useless so I removed
   it (after taking into account all the feedback on linux-kernel I
   received since the announcement of the intention to do this)

These are rather critical because otherwise we can't really say Linux
fully supports the very latest Intel cpus (which require microcode in
the new format).

arch/i386/kernel/microcode.c

@@ -55,10 +55,18 @@
  *		Tigran Aivazian <tigran@veritas.com>,
  *		Serialize updates as required on HT processors due to speculative
  *		nature of implementation.
- *	1.11	22 Mar 2001 Tigran Aivazian <tigran@veritas.com>
+ *	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.
  */
 
+
 #include <linux/init.h>
 #include <linux/sched.h>
 #include <linux/module.h>
@@ -72,264 +80,387 @@
 #include <asm/uaccess.h>
 #include <asm/processor.h>
 
-
-static spinlock_t microcode_update_lock = SPIN_LOCK_UNLOCKED;
-
-#define MICROCODE_VERSION 	"1.11"
-
 MODULE_DESCRIPTION("Intel CPU (IA-32) microcode update driver");
 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
 MODULE_LICENSE("GPL");
 
+#define MICROCODE_VERSION 	"1.13"
 #define MICRO_DEBUG 		0
-
 #if MICRO_DEBUG
-#define printf(x...) printk(##x)
+#define dprintk(x...) printk(KERN_INFO x)
 #else
-#define printf(x...)
+#define dprintk(x...)
 #endif
 
-/* read()/write()/ioctl() are serialized on this */
-static DECLARE_RWSEM(microcode_rwsem);
-
-static struct microcode *microcode; /* array of 2048byte microcode blocks */
-static unsigned int microcode_num;  /* number of chunks in microcode */
-static char *mc_applied;            /* array of applied microcode blocks */
-static unsigned int mc_fsize;       /* file size of /dev/cpu/microcode */
+#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)))
+#define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
+
+/* serialize access to the physical write to MSR 0x79 */
+static spinlock_t microcode_update_lock = SPIN_LOCK_UNLOCKED;
 
-static int microcode_open(struct inode *unused1, struct file *unused2)
+/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
+static DECLARE_MUTEX(microcode_sem);
+
+static void *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;
 }
 
-/*
- * update_req[cpu].err is set to 1 if update failed on 'cpu', 0 otherwise
- * if err==0, microcode[update_req[cpu].slot] points to applied block of microcode
- */
-struct update_req {
-	int err;
-	int slot;
-} update_req[NR_CPUS];
-
-static void do_update_one(void *unused)
+static void collect_cpu_info (void *unused)
 {
 	int cpu_num = smp_processor_id();
 	struct cpuinfo_x86 *c = cpu_data + cpu_num;
-	struct update_req *req = update_req + cpu_num;
-	unsigned int pf = 0, val[2], rev, sig;
-	unsigned long flags;
-	int i;
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+	unsigned int val[2];
 
-	req->err = 1; /* assume update will fail on this cpu */
+	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;
-	}
-
-	sig = c->x86_mask + (c->x86_model<<4) + (c->x86<<8);
+	} 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]);
-		pf = 1 << ((val[1] >> 18) & 7);
-	}
-
-	for (i=0; i<microcode_num; i++)
-		if (microcode[i].sig == sig && microcode[i].pf == pf &&
-		    microcode[i].ldrver == 1 && microcode[i].hdrver == 1) {
-			int sum = 0;
-			struct microcode *m = &microcode[i];
-			unsigned int *sump = (unsigned int *)(m+1);
-
-			printf("Microcode\n");
-			printf("   Header Revision %d\n",microcode[i].hdrver);
-			printf("   Date %x/%x/%x\n",
-				((microcode[i].date >> 24 ) & 0xff),
-				((microcode[i].date >> 16 ) & 0xff),
-				(microcode[i].date & 0xFFFF));
-			printf("   Type %x Family %x Model %x Stepping %x\n",
-				((microcode[i].sig >> 12) & 0x3),
-				((microcode[i].sig >> 8) & 0xf),
-				((microcode[i].sig >> 4) & 0xf),
-				((microcode[i].sig & 0xf)));
-			printf("   Checksum %x\n",microcode[i].cksum);
-			printf("   Loader Revision %x\n",microcode[i].ldrver);
-			printf("   Processor Flags %x\n\n",microcode[i].pf);
-
-			req->slot = i;
-
-			/* serialize access to update decision */
-			spin_lock_irqsave(&microcode_update_lock, flags);          
+			uci->pf = 1 << ((val[1] >> 18) & 7);
+		}
+	}
 
-			/* trick, to work even if there was no prior update by the BIOS */
 	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 	__asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
+	/* get the current revision from MSR 0x8B */
+	rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
+	dprintk("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n", 
+			uci->sig, uci->pf, uci->rev);
+}
 
-			/* get current (on-cpu) revision into rev (ignore val[0]) */
-			rdmsr(MSR_IA32_UCODE_REV, val[0], rev);
-			
-			if (microcode[i].rev < rev) {
-				spin_unlock_irqrestore(&microcode_update_lock, flags);
-				printk(KERN_INFO
-				       "microcode: CPU%d not 'upgrading' to earlier revision"
-				       " %d (current=%d)\n", cpu_num, microcode[i].rev, rev);
-				return;
-			} else if (microcode[i].rev == 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;
+
+	dprintk("Microcode Found.\n");
+	dprintk("   Header Revision 0x%x\n", mc_header->hdrver);
+	dprintk("   Loader Revision 0x%x\n", mc_header->ldrver);
+	dprintk("   Revision 0x%x \n", mc_header->rev);
+	dprintk("   Date %x/%x/%x\n",
+		((mc_header->date >> 24 ) & 0xff),
+		((mc_header->date >> 16 ) & 0xff),
+		(mc_header->date & 0xFFFF));
+	dprintk("   Signature 0x%x\n", sig);
+	dprintk("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
+		((sig >> 12) & 0x3),
+		((sig >> 8) & 0xf),
+		((sig >> 4) & 0xf),
+		((sig & 0xf)));
+	dprintk("   Processor Flags 0x%x\n", pf);
+	dprintk("   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 */
-				req->err = 0;
-				spin_unlock_irqrestore(&microcode_update_lock, flags);
-				printk(KERN_INFO
-					"microcode: CPU%d already at revision"
-					" %d (current=%d)\n", cpu_num, microcode[i].rev, rev);
+		uci->err = MC_SUCCESS;
+		printk(KERN_ERR "microcode: CPU%d already at revision"
+			" 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
+		goto out;
+	}
+
+	dprintk("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;
 		}
 
-			/* Verify the checksum */
-			while (--sump >= (unsigned int *)m)
-				sum += *sump;
-			if (sum != 0) {
-				req->err = 1;
-				spin_unlock_irqrestore(&microcode_update_lock, flags);
-				printk(KERN_ERR "microcode: CPU%d aborting, "
-				       "bad checksum\n", cpu_num);
+		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 (cpu_num = 0; cpu_num < num_online_cpus(); 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 (cpu_num = 0; cpu_num < num_online_cpus(); 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 */
+		for (cpu_num = 0, allocated_flag = 0, sum = 0; cpu_num < num_online_cpus(); 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;
+						i = ext_table_size / DWSIZE;
+						int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
+						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) {
+		printk(KERN_INFO "microcode: No suitable data for cpu %d\n", cpu_num);
 		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 int)(m->bits), 0);
+	wrmsr(MSR_IA32_UCODE_WRITE, (unsigned int)(uci->mc->bits), 0);
+	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 
-			/* serialize */
 	__asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
-
 	/* get the current revision from MSR 0x8B */
 	rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
 
 	/* notify the caller of success on this cpu */
-			req->err = 0;
+	uci->err = MC_SUCCESS;
 	spin_unlock_irqrestore(&microcode_update_lock, flags);
 	printk(KERN_INFO "microcode: CPU%d updated from revision "
-			       "%d to %d, date=%08x\n", 
-			       cpu_num, rev, val[1], microcode[i].date);
+	       "0x%x to 0x%x, date = %08x \n", 
+	       cpu_num, uci->rev, val[1], uci->mc->hdr.date);
 	return;
-		}
-	
-	printk(KERN_ERR
-	       "microcode: CPU%d no microcode found! (sig=%x, pflags=%d)\n", 
-	       cpu_num, sig, pf);
 }
 
-
-static int do_microcode_update(void)
+static int do_microcode_update (void)
 {
-	int i, error = 0, err;
-	struct microcode *m;
+	int i, error;
 
-	if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
-		printk(KERN_ERR "microcode: IPI timeout, giving up\n");
-		return -EIO;
+	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;
 	}
 
-	for (i=0; i<NR_CPUS; i++) {
-		err = update_req[i].err;
-		error += err;
-		if (!err) {
-			m = (struct microcode *)mc_applied + i;
-			memcpy(m, &microcode[update_req[i].slot], sizeof(struct microcode));
-		}
+	if ((error = find_matching_ucodes())) {
+		printk(KERN_ERR "microcode: Error in the microcode data\n");
+		goto out_free;
 	}
-	return error;
-}
 
-static ssize_t microcode_read(struct file *file, char __user *buf, size_t len, loff_t *ppos)
-{
-	ssize_t ret = 0;
+	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;
+	}
 
-	down_read(&microcode_rwsem);
-	if (*ppos >= mc_fsize)
-		goto out;
-	if (*ppos + len > mc_fsize)
-		len = mc_fsize - *ppos;
-	ret = -EFAULT;
-	if (copy_to_user(buf, mc_applied + *ppos, len))
-		goto out;
-	*ppos += len;
-	ret = len;
+out_free:
+	for (i = 0; i < num_online_cpus(); i++) {
+		if (ucode_cpu_info[i].mc) {
+			int j;
+			void *tmp = ucode_cpu_info[i].mc;
+			vfree(tmp);
+			for (j = i; j < num_online_cpus(); j++) {
+				if (ucode_cpu_info[j].mc == tmp)
+					ucode_cpu_info[j].mc = NULL;
+			}
+		}
+	}
 out:
-	up_read(&microcode_rwsem);
-	return ret;
+	return error;
 }
 
-static ssize_t microcode_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos)
+static ssize_t microcode_write (struct file *file, const char *buf, size_t len, loff_t *ppos)
 {
 	ssize_t ret;
 
-	if (!len || len % sizeof(struct microcode) != 0) {
-		printk(KERN_ERR "microcode: can only write in N*%d bytes units\n", 
-			sizeof(struct microcode));
+	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;
 	}
-	down_write(&microcode_rwsem);
-	if (!mc_applied) {
-		mc_applied = kmalloc(NR_CPUS*sizeof(struct microcode),
-				     GFP_KERNEL);
-		if (!mc_applied) {
-			up_write(&microcode_rwsem);
-			printk(KERN_ERR "microcode: out of memory for saved microcode\n");
-			return -ENOMEM;
-		}
-	}
 
-	microcode_num = len/sizeof(struct microcode);
-	microcode = vmalloc(len);
-	if (!microcode) {
-		ret = -ENOMEM;
-		goto out_unlock;
-	}
+	down(&microcode_sem);
 
-	if (copy_from_user(microcode, buf, len)) {
-		ret = -EFAULT;
-		goto out_fsize;
-	}
+	user_buffer = (void *) buf;
+	user_buffer_size = (int) len;
 
-	if(do_microcode_update()) {
-		ret = -EIO;
-		goto out_fsize;
-	} else {
-		mc_fsize = NR_CPUS * sizeof(struct microcode);
+	ret = do_microcode_update();
+	if (!ret)
 		ret = (ssize_t)len;
-	}
-out_fsize:
-	vfree(microcode);
-out_unlock:
-	up_write(&microcode_rwsem);
+
+	up(&microcode_sem);
+
 	return ret;
 }
 
-static int microcode_ioctl(struct inode *inode, struct file *file, 
+static int microcode_ioctl (struct inode *inode, struct file *file, 
 		unsigned int cmd, unsigned long arg)
 {
-	switch(cmd) {
+	switch (cmd) {
+		/* 
+		 *  XXX: will be removed after microcode_ctl 
+		 *  is updated to ignore failure of this ioctl()
+		 */
 		case MICROCODE_IOCFREE:
-			down_write(&microcode_rwsem);
-			if (mc_applied) {
-				int bytes = NR_CPUS * sizeof(struct microcode);
-
-				kfree(mc_applied);
-				mc_applied = NULL;
-				printk(KERN_INFO "microcode: freed %d bytes\n", bytes);
-				mc_fsize = 0;
-				up_write(&microcode_rwsem);
 			return 0;
-			}
-			up_write(&microcode_rwsem);
-			return -ENODATA;
-
 		default:
 			return -EINVAL;
 	}
@@ -338,7 +469,6 @@ static int microcode_ioctl(struct inode *inode, struct file *file,
 
 static struct file_operations microcode_fops = {
 	.owner		= THIS_MODULE,
-	.read		= microcode_read,
 	.write		= microcode_write,
 	.ioctl		= microcode_ioctl,
 	.open		= microcode_open,
@@ -347,17 +477,20 @@ static struct file_operations microcode_fops = {
 static struct miscdevice microcode_dev = {
 	.minor		= MICROCODE_MINOR,
 	.name		= "microcode",
-	.devfs_name	= "cpu/microcode",
 	.fops		= &microcode_fops,
 };
 
-static int __init microcode_init(void)
+static int __init microcode_init (void)
 {
 	int error;
 
 	error = misc_register(&microcode_dev);
-	if (error)
+	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%s <tigran@veritas.com>\n", 
@@ -365,14 +498,12 @@ static int __init microcode_init(void)
 	return 0;
 }
 
-static void __exit microcode_exit(void)
+static void __exit microcode_exit (void)
 {
 	misc_deregister(&microcode_dev);
-	kfree(mc_applied);
 	printk(KERN_INFO "IA-32 Microcode Update Driver v%s unregistered\n", 
 			MICROCODE_VERSION);
 }
 
 module_init(microcode_init)
 module_exit(microcode_exit)
-

include/asm-i386/processor.h

@@ -498,7 +498,7 @@ unsigned long get_wchan(struct task_struct *p);
 #define KSTK_EIP(tsk)	(((unsigned long *)(4096+(unsigned long)(tsk)->thread_info))[1019])
 #define KSTK_ESP(tsk)	(((unsigned long *)(4096+(unsigned long)(tsk)->thread_info))[1022])
 
-struct microcode {
+struct microcode_header {
 	unsigned int hdrver;
 	unsigned int rev;
 	unsigned int date;
@@ -506,10 +506,32 @@ struct microcode {
 	unsigned int cksum;
 	unsigned int ldrver;
 	unsigned int pf;
-	unsigned int reserved[5];
-	unsigned int bits[500];
+	unsigned int datasize;
+	unsigned int totalsize;
+	unsigned int reserved[3];
+};
+
+struct microcode {
+	struct microcode_header hdr;
+	unsigned int bits[0];
+};
+
+typedef struct microcode microcode_t;
+typedef struct microcode_header microcode_header_t;
+
+/* microcode format is extended from prescott processors */
+struct extended_signature {
+	unsigned int sig;
+	unsigned int pf;
+	unsigned int cksum;
 };
 
+struct extended_sigtable {
+	unsigned int count;
+	unsigned int cksum;
+	unsigned int reserved[3];
+	struct extended_signature sigs[0];
+};
 /* '6' because it used to be for P6 only (but now covers Pentium 4 as well) */
 #define MICROCODE_IOCFREE	_IO('6',0)