patch-2.3.46 linux/arch/i386/kernel/microcode.c

• Lines: 206
• Date: Wed Feb 16 14:39:53 2000
• Orig file: v2.3.45/linux/arch/i386/kernel/microcode.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.45/linux/arch/i386/kernel/microcode.c linux/arch/i386/kernel/microcode.c
@@ -0,0 +1,205 @@
+/*
+ *	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.
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/smp_lock.h>
+#include <linux/proc_fs.h>
+
+#include <asm/msr.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+
+#define MICROCODE_VERSION 	"1.0"
+
+MODULE_DESCRIPTION("CPU (P6) microcode update driver");
+MODULE_AUTHOR("Tigran Aivazian <tigran@ocston.org>");
+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_write(struct file *, const char *, size_t, loff_t *);
+
+
+/* internal helpers to do the work */
+static void 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 /dev/microcode is in use */
+static unsigned long microcode_status = 0;
+
+/* the actual array of microcode blocks, each 2048 bytes */
+static struct microcode * microcode = NULL;
+static unsigned int microcode_num = 0;
+
+static struct file_operations microcode_fops = {
+	write:		microcode_write,
+	open:		microcode_open,
+	release:	microcode_release,
+};
+
+static struct inode_operations microcode_inops = {
+	default_file_ops:	&microcode_fops,
+};
+
+static struct proc_dir_entry *proc_microcode;
+
+static int __init microcode_init(void)
+{
+	/* write-only /proc/driver/microcode file, one day may become read-write.. */
+	proc_microcode = create_proc_entry("microcode", S_IWUSR, proc_root_driver);
+	if (!proc_microcode) {
+		printk(KERN_ERR "microcode: can't create /proc/driver/microcode entry\n");
+		return -ENOMEM;
+	}
+	proc_microcode->ops = &microcode_inops;
+	printk(KERN_ERR "P6 Microcode Update Driver v%s registered\n", MICROCODE_VERSION);
+	return 0;
+}
+
+static void __exit microcode_exit(void)
+{
+	remove_proc_entry("microcode", proc_root_driver);
+	printk(KERN_ERR "P6 Microcode Update Driver v%s unregistered\n", MICROCODE_VERSION);
+}
+
+module_init(microcode_init);
+module_exit(microcode_exit);
+
+/*
+ * 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;
+
+	MOD_INC_USE_COUNT;
+
+	return 0;
+}
+
+static int microcode_release(struct inode *inode, struct file *file)
+{
+	MOD_DEC_USE_COUNT;
+
+	clear_bit(MICROCODE_IS_OPEN, &microcode_status);
+	return 0;
+}
+
+
+static void do_microcode_update(void)
+{
+	if (smp_call_function(do_update_one, NULL, 1, 0) != 0)
+		panic("do_microcode_update(): timed out waiting for other CPUs\n");
+	do_update_one(NULL);
+}
+
+static void do_update_one(void *unused)
+{
+	struct cpuinfo_x86 * c;
+	unsigned int pf = 0, val[2], rev, sig;
+	int i, id;
+
+	id = smp_processor_id();
+	c = cpu_data + id;
+
+
+	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6)
+		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) {
+
+			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", id, microcode[i].rev, 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", id);
+					break;
+				}
+				wrmsr(0x79, (unsigned int)(m->bits), 0);
+				__asm__ __volatile__ ("cpuid");
+				rdmsr(0x8B, val[0], val[1]);
+				printk(KERN_ERR "microcode: CPU%d microcode updated "
+						"from revision %d to %d\n", id, rev, val[1]);
+			}
+			break;
+		}
+}
+
+static ssize_t microcode_write(struct file *file, const char *buf, size_t len, loff_t *ppos)
+{
+	if (len % sizeof(struct microcode) != 0) {
+		printk(KERN_ERR "microcode: can only write in N*%d bytes units\n", 
+			sizeof(struct microcode));
+		return -EINVAL;
+		return -EINVAL;
+	}
+	if (!capable(CAP_SYS_RAWIO))
+		return -EPERM;
+	lock_kernel();
+	microcode_num = len/sizeof(struct microcode);
+	microcode = vmalloc(len);
+	if (!microcode) {
+		unlock_kernel();
+		return -ENOMEM;
+	}
+	if (copy_from_user(microcode, buf, len)) {
+		vfree(microcode);
+		unlock_kernel();
+		return -EFAULT;
+	}
+	do_microcode_update();
+	vfree(microcode);
+	unlock_kernel();
+	return len;
+}