patch-2.2.18 linux/arch/i386/kernel/microcode.c

• Lines: 341
• Date: Sat Oct 28 11:29:30 2000
• Orig file: v2.2.17/arch/i386/kernel/microcode.c
• Orig date: Thu Jan 1 01:00:00 1970

diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/arch/i386/kernel/microcode.c linux/arch/i386/kernel/microcode.c
@@ -0,0 +1,340 @@
+/*
+ *	CPU Microcode Update interface for Linux
+ *
+ *	Copyright (C) 2000 Tigran Aivazian
+ *
+ *	This driver allows to upgrade microcode on Intel processors
+ *	belonging to P6 family - PentiumPro, Pentium II, Pentium III etc.
+ *
+ *	Reference: Section 8.10 of Volume III, Intel Pentium III Manual, 
+ *	Order Number 243192 or download from:
+ *		
+ *	http://developer.intel.com/design/pentiumii/manuals/243192.htm
+ *
+ *	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 February 2000, Tigran Aivazian <tigran@sco.com>
+ *		Initial release.
+ *	1.01	18 February 2000, Tigran Aivazian <tigran@sco.com>
+ *		Added read() support + cleanups.
+ *	1.02	21 February 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 February 2000, Tigran Aivazian <tigran@sco.com>
+ *		Made to use devfs (/dev/cpu/microcode) + cleanups.
+ *	1.04	06 June 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 June 2000, Simon Trimmer <simon@veritas.com>
+ *		Messages for error cases (non intel & no suitable microcode).
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/smp_lock.h>
+#include <linux/miscdevice.h>
+#include <linux/smp.h>
+
+#include <asm/msr.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+
+#define MICROCODE_MINOR 184
+#define MICROCODE_IOCFREE _IO('6',0)
+struct microcode {
+	unsigned int hdrver;
+	unsigned int rev;
+	unsigned int date;
+	unsigned int sig;
+	unsigned int cksum;
+	unsigned int ldrver;
+	unsigned int pf;
+	unsigned int reserved[5];
+	unsigned int bits[500];
+};
+
+#define MICROCODE_VERSION 	"1.05"
+
+MODULE_DESCRIPTION("Intel CPU (P6) microcode update driver");
+MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
+EXPORT_NO_SYMBOLS;
+
+/* VFS interface */
+static int microcode_open(struct inode *, struct file *);
+static int microcode_release(struct inode *, struct file *);
+static ssize_t microcode_read(struct file *, char *, size_t, loff_t *);
+static ssize_t microcode_write(struct file *, const char *, size_t, loff_t *);
+static int microcode_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
+
+
+/* internal helpers to do the work */
+static int do_microcode_update(void);
+static void do_update_one(void *);
+
+/*
+ *  Bits in microcode_status. (31 bits of room for future expansion)
+ */
+#define MICROCODE_IS_OPEN	0	/* set if device is in use */
+
+static unsigned long microcode_status;
+
+/* the actual array of microcode blocks, each 2048 bytes */
+static struct microcode *microcode;
+static unsigned int microcode_num;
+static char *mc_applied; /* holds an array of applied microcode blocks */
+static unsigned int mc_fsize;
+
+static struct file_operations microcode_fops = {
+	read:		microcode_read,
+	write:		microcode_write,
+	ioctl:		microcode_ioctl,
+	open:		microcode_open,
+	release:	microcode_release,
+};
+
+static struct miscdevice microcode_dev = {
+	minor: MICROCODE_MINOR,
+	name:	"microcode",
+	fops:	&microcode_fops,
+};
+
+int __init microcode_init(void)
+{
+	int error = 0;
+
+	if (misc_register(&microcode_dev) < 0) {
+		printk(KERN_WARNING 
+			"microcode: can't misc_register on minor=%d\n",
+			MICROCODE_MINOR);
+		error = 1;
+	}
+	printk(KERN_INFO "P6 Microcode Update Driver v%s registered\n", 
+			MICROCODE_VERSION);
+	return 0;
+}
+
+#ifdef MODULE
+static void microcode_exit(void)
+{
+	misc_deregister(&microcode_dev);
+	if (mc_applied)
+		kfree(mc_applied);
+	printk(KERN_INFO "P6 Microcode Update Driver v%s unregistered\n", 
+			MICROCODE_VERSION);
+}
+
+int init_module(void)
+{
+	return microcode_init();
+}
+void cleanup_module(void)
+{
+	microcode_exit();
+}
+#endif
+
+/*
+ * We enforce only one user at a time here with open/close.
+ */
+static int microcode_open(struct inode *inode, struct file *file)
+{
+	if (!capable(CAP_SYS_RAWIO))
+		return -EPERM;
+
+	/* one at a time, please */
+	if (test_and_set_bit(MICROCODE_IS_OPEN, &microcode_status))
+		return -EBUSY;
+
+	return 0;
+}
+
+static int microcode_release(struct inode *inode, struct file *file)
+{
+	clear_bit(MICROCODE_IS_OPEN, &microcode_status);
+	return 0;
+}
+
+/* a pointer to 'struct update_req' is passed to the IPI handler = do_update_one()
+ * 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 int do_microcode_update(void)
+{
+	int i, error = 0, err;
+	struct microcode *m;
+
+	if (smp_call_function(do_update_one, (void *)update_req, 1, 1) != 0)
+		panic("do_microcode_update(): timed out waiting for other CPUs\n");
+
+	do_update_one((void *)update_req);
+
+	for (i=0; i<smp_num_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));
+		}
+	}
+	return error;
+}
+
+static void do_update_one(void *arg)
+{
+	int cpu_num = smp_processor_id();
+	struct cpuinfo_x86 *c = cpu_data + cpu_num;
+	struct update_req *req = (struct update_req *)arg + cpu_num;
+	unsigned int pf = 0, val[2], rev, sig;
+	int i,found=0;
+
+	req->err = 1; /* be pessimistic */
+
+	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6){
+		printk(KERN_ERR "microcode: CPU%d not an Intel P6\n", cpu_num );
+		return;
+	}
+
+	sig = c->x86_mask + (c->x86_model<<4) + (c->x86<<8);
+
+	if (c->x86_model >= 5) {
+		/* get processor flags from BBL_CR_OVRD MSR (0x17) */
+		rdmsr(0x17, 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) {
+
+			found=1;
+
+			rdmsr(0x8B, val[0], rev);
+			if (microcode[i].rev < rev) {
+				printk(KERN_ERR 
+					"microcode: CPU%d not 'upgrading' to earlier revision"
+					" %d (current=%d)\n", cpu_num, microcode[i].rev, rev);
+			} else if (microcode[i].rev == rev) {
+				printk(KERN_ERR
+					"microcode: CPU%d already up-to-date (revision %d)\n",
+						cpu_num, rev);
+			} else {
+				int sum = 0;
+				struct microcode *m = &microcode[i];
+				unsigned int *sump = (unsigned int *)(m+1);
+
+				while (--sump >= (unsigned int *)m)
+					sum += *sump;
+				if (sum != 0) {
+					printk(KERN_ERR "microcode: CPU%d aborting, "
+							"bad checksum\n", cpu_num);
+					break;
+				}
+
+				wrmsr(0x79, (unsigned int)(m->bits), 0);
+				__asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
+				rdmsr(0x8B, val[0], val[1]);
+
+				req->err = 0;
+				req->slot = i;
+				printk(KERN_ERR "microcode: CPU%d updated from revision "
+						"%d to %d, date=%08x\n", 
+						cpu_num, rev, val[1], m->date);
+			}
+			break;
+		}
+
+	if(!found)
+		printk(KERN_ERR "microcode: found no data for CPU%d (sig=%x, pflags=%d)\n", cpu_num, sig, pf);
+}
+
+static ssize_t microcode_read(struct file *file, char *buf, size_t len, loff_t *ppos)
+{
+	if (*ppos >= mc_fsize)
+		return 0;
+	if (*ppos + len > mc_fsize)
+		len = mc_fsize - *ppos;
+	if (copy_to_user(buf, mc_applied + *ppos, len))
+		return -EFAULT;
+	*ppos += len;
+	return len;
+}
+
+static ssize_t microcode_write(struct file *file, const char *buf, size_t len, loff_t *ppos)
+{
+	ssize_t ret;
+
+	if (len % sizeof(struct microcode) != 0) {
+		printk(KERN_ERR "microcode: can only write in N*%d bytes units\n", 
+			sizeof(struct microcode));
+		return -EINVAL;
+	}
+	if (!mc_applied) {
+		mc_applied = kmalloc(smp_num_cpus*sizeof(struct microcode),
+				GFP_KERNEL);
+		if (!mc_applied) {
+			printk(KERN_ERR "microcode: out of memory for saved microcode\n");
+			return -ENOMEM;
+		}
+		memset(mc_applied, 0, mc_fsize);
+	}
+	
+	lock_kernel();
+	microcode_num = len/sizeof(struct microcode);
+	microcode = vmalloc(len);
+	if (!microcode) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
+	if (copy_from_user(microcode, buf, len)) {
+		ret = -EFAULT;
+		goto out_fsize;
+	}
+	if(do_microcode_update()) {
+		ret = -EIO;
+		goto out_fsize;
+	} else {
+		mc_fsize = smp_num_cpus * sizeof(struct microcode);
+		ret = (ssize_t)len;
+	}
+out_fsize:
+	vfree(microcode);
+out_unlock:
+	unlock_kernel();
+	return ret;
+}
+
+static int microcode_ioctl(struct inode *inode, struct file *file, 
+		unsigned int cmd, unsigned long arg)
+{
+	switch(cmd) {
+		case MICROCODE_IOCFREE:
+			if (mc_applied) {
+				memset(mc_applied, 0, mc_fsize);
+				kfree(mc_applied);
+				mc_applied = NULL;
+				printk(KERN_WARNING 
+					"microcode: freed %d bytes\n", mc_fsize);
+				mc_fsize = 0;
+				return 0;
+			}
+			return -ENODATA;
+
+		default:
+			printk(KERN_ERR "microcode: unknown ioctl cmd=%d\n",
+					cmd);
+			return -EINVAL;
+	}
+	/* NOT REACHED */
+	return -EINVAL;
+}