444 lines
9.8 KiB
C
444 lines
9.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/capability.h>
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#include <linux/seq_file.h>
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#include <linux/uaccess.h>
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#include <linux/proc_fs.h>
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#include <linux/ctype.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#define LINE_SIZE 80
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#include <asm/mtrr.h>
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#include "mtrr.h"
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#define FILE_FCOUNT(f) (((struct seq_file *)((f)->private_data))->private)
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static const char *const mtrr_strings[MTRR_NUM_TYPES] =
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{
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"uncachable", /* 0 */
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"write-combining", /* 1 */
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"?", /* 2 */
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"?", /* 3 */
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"write-through", /* 4 */
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"write-protect", /* 5 */
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"write-back", /* 6 */
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};
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const char *mtrr_attrib_to_str(int x)
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{
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return (x <= 6) ? mtrr_strings[x] : "?";
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}
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#ifdef CONFIG_PROC_FS
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static int
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mtrr_file_add(unsigned long base, unsigned long size,
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unsigned int type, bool increment, struct file *file, int page)
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{
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unsigned int *fcount = FILE_FCOUNT(file);
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int reg, max;
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max = num_var_ranges;
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if (fcount == NULL) {
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fcount = kcalloc(max, sizeof(*fcount), GFP_KERNEL);
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if (!fcount)
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return -ENOMEM;
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FILE_FCOUNT(file) = fcount;
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}
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if (!page) {
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if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
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return -EINVAL;
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base >>= PAGE_SHIFT;
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size >>= PAGE_SHIFT;
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}
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reg = mtrr_add_page(base, size, type, true);
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if (reg >= 0)
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++fcount[reg];
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return reg;
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}
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static int
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mtrr_file_del(unsigned long base, unsigned long size,
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struct file *file, int page)
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{
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unsigned int *fcount = FILE_FCOUNT(file);
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int reg;
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if (!page) {
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if ((base & (PAGE_SIZE - 1)) || (size & (PAGE_SIZE - 1)))
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return -EINVAL;
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base >>= PAGE_SHIFT;
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size >>= PAGE_SHIFT;
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}
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reg = mtrr_del_page(-1, base, size);
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if (reg < 0)
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return reg;
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if (fcount == NULL)
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return reg;
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if (fcount[reg] < 1)
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return -EINVAL;
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--fcount[reg];
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return reg;
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}
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/*
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* seq_file can seek but we ignore it.
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*
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* Format of control line:
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* "base=%Lx size=%Lx type=%s" or "disable=%d"
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*/
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static ssize_t
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mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
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{
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int i, err;
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unsigned long reg;
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unsigned long long base, size;
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char *ptr;
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char line[LINE_SIZE];
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int length;
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size_t linelen;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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memset(line, 0, LINE_SIZE);
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len = min_t(size_t, len, LINE_SIZE - 1);
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length = strncpy_from_user(line, buf, len);
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if (length < 0)
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return length;
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linelen = strlen(line);
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ptr = line + linelen - 1;
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if (linelen && *ptr == '\n')
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*ptr = '\0';
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if (!strncmp(line, "disable=", 8)) {
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reg = simple_strtoul(line + 8, &ptr, 0);
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err = mtrr_del_page(reg, 0, 0);
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if (err < 0)
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return err;
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return len;
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}
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if (strncmp(line, "base=", 5))
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return -EINVAL;
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base = simple_strtoull(line + 5, &ptr, 0);
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ptr = skip_spaces(ptr);
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if (strncmp(ptr, "size=", 5))
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return -EINVAL;
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size = simple_strtoull(ptr + 5, &ptr, 0);
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if ((base & 0xfff) || (size & 0xfff))
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return -EINVAL;
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ptr = skip_spaces(ptr);
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if (strncmp(ptr, "type=", 5))
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return -EINVAL;
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ptr = skip_spaces(ptr + 5);
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i = match_string(mtrr_strings, MTRR_NUM_TYPES, ptr);
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if (i < 0)
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return i;
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base >>= PAGE_SHIFT;
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size >>= PAGE_SHIFT;
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err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
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if (err < 0)
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return err;
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return len;
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}
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static long
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mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
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{
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int err = 0;
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mtrr_type type;
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unsigned long base;
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unsigned long size;
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struct mtrr_sentry sentry;
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struct mtrr_gentry gentry;
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void __user *arg = (void __user *) __arg;
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memset(&gentry, 0, sizeof(gentry));
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switch (cmd) {
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case MTRRIOC_ADD_ENTRY:
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case MTRRIOC_SET_ENTRY:
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case MTRRIOC_DEL_ENTRY:
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case MTRRIOC_KILL_ENTRY:
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case MTRRIOC_ADD_PAGE_ENTRY:
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case MTRRIOC_SET_PAGE_ENTRY:
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case MTRRIOC_DEL_PAGE_ENTRY:
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case MTRRIOC_KILL_PAGE_ENTRY:
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if (copy_from_user(&sentry, arg, sizeof(sentry)))
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return -EFAULT;
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break;
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case MTRRIOC_GET_ENTRY:
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case MTRRIOC_GET_PAGE_ENTRY:
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if (copy_from_user(&gentry, arg, sizeof(gentry)))
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return -EFAULT;
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break;
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_ADD_ENTRY:
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case MTRRIOC32_SET_ENTRY:
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case MTRRIOC32_DEL_ENTRY:
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case MTRRIOC32_KILL_ENTRY:
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case MTRRIOC32_ADD_PAGE_ENTRY:
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case MTRRIOC32_SET_PAGE_ENTRY:
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case MTRRIOC32_DEL_PAGE_ENTRY:
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case MTRRIOC32_KILL_PAGE_ENTRY: {
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struct mtrr_sentry32 __user *s32;
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s32 = (struct mtrr_sentry32 __user *)__arg;
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err = get_user(sentry.base, &s32->base);
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err |= get_user(sentry.size, &s32->size);
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err |= get_user(sentry.type, &s32->type);
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if (err)
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return err;
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break;
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}
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case MTRRIOC32_GET_ENTRY:
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case MTRRIOC32_GET_PAGE_ENTRY: {
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struct mtrr_gentry32 __user *g32;
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g32 = (struct mtrr_gentry32 __user *)__arg;
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err = get_user(gentry.regnum, &g32->regnum);
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err |= get_user(gentry.base, &g32->base);
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err |= get_user(gentry.size, &g32->size);
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err |= get_user(gentry.type, &g32->type);
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if (err)
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return err;
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break;
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}
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#endif
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}
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switch (cmd) {
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default:
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return -ENOTTY;
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case MTRRIOC_ADD_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_ADD_ENTRY:
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#endif
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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err =
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mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
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file, 0);
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break;
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case MTRRIOC_SET_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_SET_ENTRY:
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#endif
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
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break;
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case MTRRIOC_DEL_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_DEL_ENTRY:
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#endif
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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err = mtrr_file_del(sentry.base, sentry.size, file, 0);
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break;
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case MTRRIOC_KILL_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_KILL_ENTRY:
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#endif
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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err = mtrr_del(-1, sentry.base, sentry.size);
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break;
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case MTRRIOC_GET_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_GET_ENTRY:
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#endif
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if (gentry.regnum >= num_var_ranges)
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return -EINVAL;
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mtrr_if->get(gentry.regnum, &base, &size, &type);
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/* Hide entries that go above 4GB */
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if (base + size - 1 >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT))
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|| size >= (1UL << (8 * sizeof(gentry.size) - PAGE_SHIFT)))
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gentry.base = gentry.size = gentry.type = 0;
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else {
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gentry.base = base << PAGE_SHIFT;
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gentry.size = size << PAGE_SHIFT;
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gentry.type = type;
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}
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break;
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case MTRRIOC_ADD_PAGE_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_ADD_PAGE_ENTRY:
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#endif
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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err =
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mtrr_file_add(sentry.base, sentry.size, sentry.type, true,
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file, 1);
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break;
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case MTRRIOC_SET_PAGE_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_SET_PAGE_ENTRY:
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#endif
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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err =
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mtrr_add_page(sentry.base, sentry.size, sentry.type, false);
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break;
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case MTRRIOC_DEL_PAGE_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_DEL_PAGE_ENTRY:
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#endif
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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err = mtrr_file_del(sentry.base, sentry.size, file, 1);
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break;
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case MTRRIOC_KILL_PAGE_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_KILL_PAGE_ENTRY:
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#endif
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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err = mtrr_del_page(-1, sentry.base, sentry.size);
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break;
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case MTRRIOC_GET_PAGE_ENTRY:
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_GET_PAGE_ENTRY:
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#endif
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if (gentry.regnum >= num_var_ranges)
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return -EINVAL;
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mtrr_if->get(gentry.regnum, &base, &size, &type);
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/* Hide entries that would overflow */
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if (size != (__typeof__(gentry.size))size)
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gentry.base = gentry.size = gentry.type = 0;
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else {
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gentry.base = base;
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gentry.size = size;
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gentry.type = type;
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}
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break;
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}
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if (err)
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return err;
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switch (cmd) {
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case MTRRIOC_GET_ENTRY:
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case MTRRIOC_GET_PAGE_ENTRY:
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if (copy_to_user(arg, &gentry, sizeof(gentry)))
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err = -EFAULT;
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break;
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#ifdef CONFIG_COMPAT
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case MTRRIOC32_GET_ENTRY:
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case MTRRIOC32_GET_PAGE_ENTRY: {
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struct mtrr_gentry32 __user *g32;
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g32 = (struct mtrr_gentry32 __user *)__arg;
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err = put_user(gentry.base, &g32->base);
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err |= put_user(gentry.size, &g32->size);
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err |= put_user(gentry.regnum, &g32->regnum);
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err |= put_user(gentry.type, &g32->type);
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break;
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}
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#endif
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}
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return err;
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}
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static int mtrr_close(struct inode *ino, struct file *file)
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{
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unsigned int *fcount = FILE_FCOUNT(file);
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int i, max;
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if (fcount != NULL) {
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max = num_var_ranges;
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for (i = 0; i < max; ++i) {
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while (fcount[i] > 0) {
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mtrr_del(i, 0, 0);
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--fcount[i];
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}
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}
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kfree(fcount);
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FILE_FCOUNT(file) = NULL;
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}
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return single_release(ino, file);
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}
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static int mtrr_seq_show(struct seq_file *seq, void *offset);
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static int mtrr_open(struct inode *inode, struct file *file)
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{
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if (!mtrr_if)
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return -EIO;
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if (!mtrr_if->get)
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return -ENXIO;
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return single_open(file, mtrr_seq_show, NULL);
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}
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static const struct file_operations mtrr_fops = {
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.owner = THIS_MODULE,
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.open = mtrr_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.write = mtrr_write,
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.unlocked_ioctl = mtrr_ioctl,
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.compat_ioctl = mtrr_ioctl,
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.release = mtrr_close,
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};
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static int mtrr_seq_show(struct seq_file *seq, void *offset)
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{
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char factor;
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int i, max;
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mtrr_type type;
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unsigned long base, size;
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max = num_var_ranges;
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for (i = 0; i < max; i++) {
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mtrr_if->get(i, &base, &size, &type);
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if (size == 0) {
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mtrr_usage_table[i] = 0;
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continue;
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}
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if (size < (0x100000 >> PAGE_SHIFT)) {
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/* less than 1MB */
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factor = 'K';
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size <<= PAGE_SHIFT - 10;
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} else {
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factor = 'M';
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size >>= 20 - PAGE_SHIFT;
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}
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/* Base can be > 32bit */
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seq_printf(seq, "reg%02i: base=0x%06lx000 (%5luMB), size=%5lu%cB, count=%d: %s\n",
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i, base, base >> (20 - PAGE_SHIFT),
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size, factor,
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mtrr_usage_table[i], mtrr_attrib_to_str(type));
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}
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return 0;
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}
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static int __init mtrr_if_init(void)
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{
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struct cpuinfo_x86 *c = &boot_cpu_data;
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if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
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(!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
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(!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
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(!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
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return -ENODEV;
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proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops);
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return 0;
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}
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arch_initcall(mtrr_if_init);
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#endif /* CONFIG_PROC_FS */
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