diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/if.c | 443 |
1 files changed, 443 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c new file mode 100644 index 000000000..254683b50 --- /dev/null +++ b/arch/x86/kernel/cpu/mtrr/if.c @@ -0,0 +1,443 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/capability.h> +#include <linux/seq_file.h> +#include <linux/uaccess.h> +#include <linux/proc_fs.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 = kcalloc(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); + + len = min_t(size_t, len, LINE_SIZE - 1); + length = strncpy_from_user(line, buf, len); + if (length < 0) + return length; + + 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); + + i = match_string(mtrr_strings, MTRR_NUM_TYPES, ptr); + if (i < 0) + return i; + + 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; +} + +static long +mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg) +{ + int err = 0; + mtrr_type type; + unsigned long base; + unsigned long size; + struct mtrr_sentry sentry; + struct mtrr_gentry gentry; + void __user *arg = (void __user *) __arg; + + memset(&gentry, 0, sizeof(gentry)); + + 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, &base, &size, &type); + + /* Hide entries that go above 4GB */ + if (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 = 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, &base, &size, &type); + /* Hide entries that would overflow */ + if (size != (__typeof__(gentry.size))size) + gentry.base = gentry.size = gentry.type = 0; + else { + gentry.base = base; + 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; + mtrr_type type; + unsigned long base, size; + + 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 */ + 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 */ |