if.c
#include <linux/capability.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/init.h>
#define LINE_SIZE 80
#include <asm/mtrr.h>
#include "mtrr.h"
#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, bool increment, struct file *file, int page)
{
unsigned int *fcount = FILE_FCOUNT(file);
int reg, max;
max = num_var_ranges;
if (fcount == NULL) {
fcount = kzalloc(max * sizeof *fcount, GFP_KERNEL);
if (!fcount)
return -ENOMEM;
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, true);
if (reg >= 0)
++fcount[reg];
return reg;
}
static int
mtrr_file_del(unsigned long base, unsigned long size,
struct file *file, int page)
{
unsigned int *fcount = FILE_FCOUNT(file);
int reg;
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;
}
/*
* seq_file can seek but we ignore it.
*
* Format of control line:
* "base=%Lx size=%Lx type=%s" or "disable=%d"
*/
static ssize_t
mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
{
int i, err;
unsigned long reg;
unsigned long long base, size;
char *ptr;
char line[LINE_SIZE];
int length;
size_t linelen;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
memset(line, 0, LINE_SIZE);
length = len;
length--;
if (length > LINE_SIZE - 1)
length = LINE_SIZE - 1;
if (length < 0)
return -EINVAL;
if (copy_from_user(line, buf, length))
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);
ptr = skip_spaces(ptr);
if (strncmp(ptr, "size=", 5))
return -EINVAL;
size = simple_strtoull(ptr + 5, &ptr, 0);
if ((base & 0xfff) || (size & 0xfff))
return -EINVAL;
ptr = skip_spaces(ptr);
if (strncmp(ptr, "type=", 5))
return -EINVAL;
ptr = skip_spaces(ptr + 5);
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, true);
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;
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;
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:
#ifdef CONFIG_COMPAT
case MTRRIOC32_ADD_ENTRY:
#endif
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err =
mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
file, 0);
break;
case MTRRIOC_SET_ENTRY:
#ifdef CONFIG_COMPAT
case MTRRIOC32_SET_ENTRY:
#endif
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
break;
case MTRRIOC_DEL_ENTRY:
#ifdef CONFIG_COMPAT
case MTRRIOC32_DEL_ENTRY:
#endif
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_file_del(sentry.base, sentry.size, file, 0);
break;
case MTRRIOC_KILL_ENTRY:
#ifdef CONFIG_COMPAT
case MTRRIOC32_KILL_ENTRY:
#endif
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_del(-1, sentry.base, sentry.size);
break;
case MTRRIOC_GET_ENTRY:
#ifdef CONFIG_COMPAT
case MTRRIOC32_GET_ENTRY:
#endif
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:
#ifdef CONFIG_COMPAT
case MTRRIOC32_ADD_PAGE_ENTRY:
#endif
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err =
mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
file, 1);
break;
case MTRRIOC_SET_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
case MTRRIOC32_SET_PAGE_ENTRY:
#endif
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err =
mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
break;
case MTRRIOC_DEL_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
case MTRRIOC32_DEL_PAGE_ENTRY:
#endif
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_file_del(sentry.base, sentry.size, file, 1);
break;
case MTRRIOC_KILL_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
case MTRRIOC32_KILL_PAGE_ENTRY:
#endif
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
err = mtrr_del_page(-1, sentry.base, sentry.size);
break;
case MTRRIOC_GET_PAGE_ENTRY:
#ifdef CONFIG_COMPAT
case MTRRIOC32_GET_PAGE_ENTRY:
#endif
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;
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)
{
unsigned int *fcount = FILE_FCOUNT(file);
int i, max;
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 const 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 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) {
mtrr_usage_table[i] = 0;
continue;
}
if (size < (0x100000 >> PAGE_SHIFT)) {
/* less than 1MB */
factor = 'K';
size <<= PAGE_SHIFT - 10;
} else {
factor = 'M';
size >>= 20 - PAGE_SHIFT;
}
/* Base can be > 32bit */
len += seq_printf(seq, "reg%02i: base=0x%06lx000 "
"(%5luMB), size=%5lu%cB, count=%d: %s\n",
i, base, base >> (20 - PAGE_SHIFT), size,
factor, mtrr_usage_table[i],
mtrr_attrib_to_str(type));
}
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_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
return 0;
}
arch_initcall(mtrr_if_init);
#endif /* CONFIG_PROC_FS */