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-rw-r--r--arch/x86/kernel/cpu/mtrr/if.c425
1 files changed, 425 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..a5c506f6d
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -0,0 +1,425 @@
+// 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;
+
+ 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
+ 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
+ err = mtrr_add(sentry.base, sentry.size, sentry.type, false);
+ break;
+ case MTRRIOC_DEL_ENTRY:
+#ifdef CONFIG_COMPAT
+ case MTRRIOC32_DEL_ENTRY:
+#endif
+ err = mtrr_file_del(sentry.base, sentry.size, file, 0);
+ break;
+ case MTRRIOC_KILL_ENTRY:
+#ifdef CONFIG_COMPAT
+ case MTRRIOC32_KILL_ENTRY:
+#endif
+ 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
+ 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
+ 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
+ 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
+ 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)
+{
+ 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 mtrr_open(struct inode *inode, struct file *file)
+{
+ if (!mtrr_if)
+ return -EIO;
+ if (!mtrr_if->get)
+ return -ENXIO;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ return single_open(file, mtrr_seq_show, NULL);
+}
+
+static const struct proc_ops mtrr_proc_ops = {
+ .proc_open = mtrr_open,
+ .proc_read = seq_read,
+ .proc_lseek = seq_lseek,
+ .proc_write = mtrr_write,
+ .proc_ioctl = mtrr_ioctl,
+#ifdef CONFIG_COMPAT
+ .proc_compat_ioctl = mtrr_ioctl,
+#endif
+ .proc_release = mtrr_close,
+};
+
+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_proc_ops);
+ return 0;
+}
+arch_initcall(mtrr_if_init);
+#endif /* CONFIG_PROC_FS */