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if.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 = 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, 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:
#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, 1,
                          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, 0);
            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, 1,
                          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, 0);
            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 = (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 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 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  */

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