linux/arch/i386/kernel/microcode.c
Jan Beulich ba528f2854 [PATCH] fix x86 microcode driver handling of multiple matching revisions
When multiple updates matching a given CPU are found in the update file, the
action taken by the microcode update driver was inappropriate:

- when lower revision microcode was found before matching or higher revision
  one, the driver would needlessly complain that it would not downgrade the
  CPU
- when microcode matching the currently installed revision was found before
  newer revision code, no update would actually take place

To change this behavior, the driver now concludes about possibly updates and
issues messages only when the entire input was parsed.

Additionally, this adds back (in different places, and conditionalized upon
a new module option) some messages removed by a previous patch.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Tigran Aivazian <tigran_aivazian@symantec.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:56 -07:00

525 lines
16 KiB
C

/*
* 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");
static int verbose;
module_param(verbose, int, 0644);
#define MICROCODE_VERSION "1.14a"
#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_IGNORED = 1,
MC_NOTFOUND = 2,
MC_MARKED = 3,
MC_ALLOCATED = 4,
} mc_error_code_t;
static struct ucode_cpu_info {
unsigned int sig;
unsigned int pf, orig_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);
}
uci->orig_pf = uci->pf;
}
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) {
if (uci->err == MC_NOTFOUND) {
uci->err = MC_IGNORED;
uci->cksum = mc_header->rev;
} else if (uci->err == MC_IGNORED && uci->cksum < mc_header->rev)
uci->cksum = mc_header->rev;
} else if (mc_header->rev == uci->rev) {
if (uci->err < MC_MARKED) {
/* notify the caller of success on this cpu */
uci->err = MC_SUCCESS;
}
} else if (uci->err != MC_ALLOCATED || mc_header->rev > uci->mc->hdr.rev) {
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 */
for_each_online_cpu(cpu_num) {
if (ucode_cpu_info + cpu_num != uci
&& ucode_cpu_info[cpu_num].mc == uci->mc) {
uci->mc = NULL;
break;
}
}
if (uci->mc != NULL) {
vfree(uci->mc);
uci->mc = NULL;
}
}
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 (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->orig_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 (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->orig_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) {
if (verbose) {
if (uci->err == MC_SUCCESS)
printk(KERN_INFO "microcode: CPU%d already at revision 0x%x\n",
cpu_num, uci->rev);
else
printk(KERN_INFO "microcode: No new microcode 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 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;
}
}
if (ucode_cpu_info[i].err == MC_IGNORED && verbose)
printk(KERN_WARNING "microcode: CPU%d not 'upgrading' to earlier revision"
" 0x%x (current=0x%x)\n", i, ucode_cpu_info[i].cksum, ucode_cpu_info[i].rev);
}
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 struct file_operations microcode_fops = {
.owner = THIS_MODULE,
.write = microcode_write,
.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);