kernel-fxtec-pro1x/arch/i386/kernel/cpu/mtrr/if.c
Jan Beulich 365bff806e [PATCH] i386: fix MTRR code
Until not so long ago, there were system log messages pointing to
inconsistent MTRR setup of the video frame buffer caused by the way vesafb
and X worked. While vesafb was fixed meanwhile, I believe fixing it there
only hides a shortcoming in the MTRR code itself, in that that code is not
symmetric with respect to the ordering of attempts to set up two (or more)
regions where one contains the other. In the current shape, it permits
only setting up sub-regions of pre-exisiting ones. The patch below makes
this symmetric.

While working on that I noticed a few more inconsistencies in that code,
namely
- use of 'unsigned int' for sizes in many, but not all places (the patch
  is converting this to use 'unsigned long' everywhere, which specifically
  might be necessary for x86-64 once a processor supporting more than 44
  physical address bits would become available)
- the code to correct inconsistent settings during secondary processor
  startup tried (if necessary) to correct, among other things, the value
  in IA32_MTRR_DEF_TYPE, however the newly computed value would never get
  used (i.e. stored in the respective MSR)
- the generic range validation code checked that the end of the
  to-be-added range would be above 1MB; the value checked should have been
  the start of the range
- when contained regions are detected, previously this was allowed only
  when the old region was uncacheable; this can be symmetric (i.e. the new
  region can also be uncacheable) and even further as per Intel's
  documentation write-trough and write-back for either region is also
  compatible with the respective opposite in the other

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-12-07 02:14:09 +01:00

410 lines
9.6 KiB
C

#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/capability.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <asm/uaccess.h>
#define LINE_SIZE 80
#include <asm/mtrr.h>
#include "mtrr.h"
/* RED-PEN: this is accessed without any locking */
extern unsigned int *usage_table;
#define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
static const char *const mtrr_strings[MTRR_NUM_TYPES] =
{
"uncachable", /* 0 */
"write-combining", /* 1 */
"?", /* 2 */
"?", /* 3 */
"write-through", /* 4 */
"write-protect", /* 5 */
"write-back", /* 6 */
};
const char *mtrr_attrib_to_str(int x)
{
return (x <= 6) ? mtrr_strings[x] : "?";
}
#ifdef CONFIG_PROC_FS
static int
mtrr_file_add(unsigned long base, unsigned long size,
unsigned int type, char increment, struct file *file, int page)
{
int reg, max;
unsigned int *fcount = FILE_FCOUNT(file);
max = num_var_ranges;
if (fcount == NULL) {
fcount = kmalloc(max * sizeof *fcount, GFP_KERNEL);
if (!fcount)
return -ENOMEM;
memset(fcount, 0, max * sizeof *fcount);
FILE_FCOUNT(file) = fcount;
}
if (!page) {
if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
return -EINVAL;
base >>= PAGE_SHIFT;
size >>= PAGE_SHIFT;
}
reg = mtrr_add_page(base, size, type, 1);
if (reg >= 0)
++fcount[reg];
return reg;
}
static int
mtrr_file_del(unsigned long base, unsigned long size,
struct file *file, int page)
{
int reg;
unsigned int *fcount = FILE_FCOUNT(file);
if (!page) {
if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
return -EINVAL;
base >>= PAGE_SHIFT;
size >>= PAGE_SHIFT;
}
reg = mtrr_del_page(-1, base, size);
if (reg < 0)
return reg;
if (fcount == NULL)
return reg;
if (fcount[reg] < 1)
return -EINVAL;
--fcount[reg];
return reg;
}
/* RED-PEN: seq_file can seek now. this is ignored. */
static ssize_t
mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
/* Format of control line:
"base=%Lx size=%Lx type=%s" OR:
"disable=%d"
*/
{
int i, err;
unsigned long reg;
unsigned long long base, size;
char *ptr;
char line[LINE_SIZE];
size_t linelen;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (!len)
return -EINVAL;
memset(line, 0, LINE_SIZE);
if (len > LINE_SIZE)
len = LINE_SIZE;
if (copy_from_user(line, buf, len - 1))
return -EFAULT;
linelen = strlen(line);
ptr = line + linelen - 1;
if (linelen && *ptr == '\n')
*ptr = '\0';
if (!strncmp(line, "disable=", 8)) {
reg = simple_strtoul(line + 8, &ptr, 0);
err = mtrr_del_page(reg, 0, 0);
if (err < 0)
return err;
return len;
}
if (strncmp(line, "base=", 5))
return -EINVAL;
base = simple_strtoull(line + 5, &ptr, 0);
for (; isspace(*ptr); ++ptr) ;
if (strncmp(ptr, "size=", 5))
return -EINVAL;
size = simple_strtoull(ptr + 5, &ptr, 0);
if ((base & 0xfff) || (size & 0xfff))
return -EINVAL;
for (; isspace(*ptr); ++ptr) ;
if (strncmp(ptr, "type=", 5))
return -EINVAL;
ptr += 5;
for (; isspace(*ptr); ++ptr) ;
for (i = 0; i < MTRR_NUM_TYPES; ++i) {
if (strcmp(ptr, mtrr_strings[i]))
continue;
base >>= PAGE_SHIFT;
size >>= PAGE_SHIFT;
err =
mtrr_add_page((unsigned long) base, (unsigned long) size, i,
1);
if (err < 0)
return err;
return len;
}
return -EINVAL;
}
static long
mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
{
int err = 0;
mtrr_type type;
unsigned long size;
struct mtrr_sentry sentry;
struct mtrr_gentry gentry;
void __user *arg = (void __user *) __arg;
switch (cmd) {
case MTRRIOC_ADD_ENTRY:
case MTRRIOC_SET_ENTRY:
case MTRRIOC_DEL_ENTRY:
case MTRRIOC_KILL_ENTRY:
case MTRRIOC_ADD_PAGE_ENTRY:
case MTRRIOC_SET_PAGE_ENTRY:
case MTRRIOC_DEL_PAGE_ENTRY:
case MTRRIOC_KILL_PAGE_ENTRY:
if (copy_from_user(&sentry, arg, sizeof sentry))
return -EFAULT;
break;
case MTRRIOC_GET_ENTRY:
case MTRRIOC_GET_PAGE_ENTRY:
if (copy_from_user(&gentry, arg, sizeof gentry))
return -EFAULT;
break;
#ifdef CONFIG_COMPAT
case MTRRIOC32_ADD_ENTRY:
case MTRRIOC32_SET_ENTRY:
case MTRRIOC32_DEL_ENTRY:
case MTRRIOC32_KILL_ENTRY:
case MTRRIOC32_ADD_PAGE_ENTRY:
case MTRRIOC32_SET_PAGE_ENTRY:
case MTRRIOC32_DEL_PAGE_ENTRY:
case MTRRIOC32_KILL_PAGE_ENTRY: {
struct mtrr_sentry32 __user *s32 = (struct mtrr_sentry32 __user *)__arg;
err = get_user(sentry.base, &s32->base);
err |= get_user(sentry.size, &s32->size);
err |= get_user(sentry.type, &s32->type);
if (err)
return err;
break;
}
case MTRRIOC32_GET_ENTRY:
case MTRRIOC32_GET_PAGE_ENTRY: {
struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
err = get_user(gentry.regnum, &g32->regnum);
err |= get_user(gentry.base, &g32->base);
err |= get_user(gentry.size, &g32->size);
err |= get_user(gentry.type, &g32->type);
if (err)
return err;
break;
}
#endif
}
switch (cmd) {
default:
return -ENOTTY;
case MTRRIOC_ADD_ENTRY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err =
mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
file, 0);
break;
case MTRRIOC_SET_ENTRY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_add(sentry.base, sentry.size, sentry.type, 0);
break;
case MTRRIOC_DEL_ENTRY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_file_del(sentry.base, sentry.size, file, 0);
break;
case MTRRIOC_KILL_ENTRY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_del(-1, sentry.base, sentry.size);
break;
case MTRRIOC_GET_ENTRY:
if (gentry.regnum >= num_var_ranges)
return -EINVAL;
mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
/* Hide entries that go above 4GB */
if (gentry.base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
|| size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
gentry.base = gentry.size = gentry.type = 0;
else {
gentry.base <<= PAGE_SHIFT;
gentry.size = size << PAGE_SHIFT;
gentry.type = type;
}
break;
case MTRRIOC_ADD_PAGE_ENTRY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err =
mtrr_file_add(sentry.base, sentry.size, sentry.type, 1,
file, 1);
break;
case MTRRIOC_SET_PAGE_ENTRY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_add_page(sentry.base, sentry.size, sentry.type, 0);
break;
case MTRRIOC_DEL_PAGE_ENTRY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_file_del(sentry.base, sentry.size, file, 1);
break;
case MTRRIOC_KILL_PAGE_ENTRY:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_del_page(-1, sentry.base, sentry.size);
break;
case MTRRIOC_GET_PAGE_ENTRY:
if (gentry.regnum >= num_var_ranges)
return -EINVAL;
mtrr_if->get(gentry.regnum, &gentry.base, &size, &type);
/* Hide entries that would overflow */
if (size != (__typeof__(gentry.size))size)
gentry.base = gentry.size = gentry.type = 0;
else {
gentry.size = size;
gentry.type = type;
}
break;
}
if (err)
return err;
switch(cmd) {
case MTRRIOC_GET_ENTRY:
case MTRRIOC_GET_PAGE_ENTRY:
if (copy_to_user(arg, &gentry, sizeof gentry))
err = -EFAULT;
break;
#ifdef CONFIG_COMPAT
case MTRRIOC32_GET_ENTRY:
case MTRRIOC32_GET_PAGE_ENTRY: {
struct mtrr_gentry32 __user *g32 = (struct mtrr_gentry32 __user *)__arg;
err = put_user(gentry.base, &g32->base);
err |= put_user(gentry.size, &g32->size);
err |= put_user(gentry.regnum, &g32->regnum);
err |= put_user(gentry.type, &g32->type);
break;
}
#endif
}
return err;
}
static int
mtrr_close(struct inode *ino, struct file *file)
{
int i, max;
unsigned int *fcount = FILE_FCOUNT(file);
if (fcount != NULL) {
max = num_var_ranges;
for (i = 0; i < max; ++i) {
while (fcount[i] > 0) {
mtrr_del(i, 0, 0);
--fcount[i];
}
}
kfree(fcount);
FILE_FCOUNT(file) = NULL;
}
return single_release(ino, file);
}
static int mtrr_seq_show(struct seq_file *seq, void *offset);
static int mtrr_open(struct inode *inode, struct file *file)
{
if (!mtrr_if)
return -EIO;
if (!mtrr_if->get)
return -ENXIO;
return single_open(file, mtrr_seq_show, NULL);
}
static struct file_operations mtrr_fops = {
.owner = THIS_MODULE,
.open = mtrr_open,
.read = seq_read,
.llseek = seq_lseek,
.write = mtrr_write,
.unlocked_ioctl = mtrr_ioctl,
.compat_ioctl = mtrr_ioctl,
.release = mtrr_close,
};
static struct proc_dir_entry *proc_root_mtrr;
static int mtrr_seq_show(struct seq_file *seq, void *offset)
{
char factor;
int i, max, len;
mtrr_type type;
unsigned long base, size;
len = 0;
max = num_var_ranges;
for (i = 0; i < max; i++) {
mtrr_if->get(i, &base, &size, &type);
if (size == 0)
usage_table[i] = 0;
else {
if (size < (0x100000 >> PAGE_SHIFT)) {
/* less than 1MB */
factor = 'K';
size <<= PAGE_SHIFT - 10;
} else {
factor = 'M';
size >>= 20 - PAGE_SHIFT;
}
/* RED-PEN: base can be > 32bit */
len += seq_printf(seq,
"reg%02i: base=0x%05lx000 (%4luMB), size=%4lu%cB: %s, count=%d\n",
i, base, base >> (20 - PAGE_SHIFT), size, factor,
mtrr_attrib_to_str(type), usage_table[i]);
}
}
return 0;
}
static int __init mtrr_if_init(void)
{
struct cpuinfo_x86 *c = &boot_cpu_data;
if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
(!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
(!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
(!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
return -ENODEV;
proc_root_mtrr =
create_proc_entry("mtrr", S_IWUSR | S_IRUGO, &proc_root);
if (proc_root_mtrr) {
proc_root_mtrr->owner = THIS_MODULE;
proc_root_mtrr->proc_fops = &mtrr_fops;
}
return 0;
}
arch_initcall(mtrr_if_init);
#endif /* CONFIG_PROC_FS */