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uaccess.h

/* Changes made by Lineo Inc.    May 2001
 *
 * Based on: include/asm-m68knommu/uaccess.h
 */

#ifndef __BLACKFIN_UACCESS_H
#define __BLACKFIN_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>

#include <asm/segment.h>
#ifdef CONFIG_ACCESS_CHECK
# include <asm/bfin-global.h>
#endif

#define get_ds()        (KERNEL_DS)
#define get_fs()        (current_thread_info()->addr_limit)

static inline void set_fs(mm_segment_t fs)
{
      current_thread_info()->addr_limit = fs;
}

#define segment_eq(a,b) ((a) == (b))

#define VERIFY_READ     0
#define VERIFY_WRITE    1

#define access_ok(type, addr, size) _access_ok((unsigned long)(addr), (size))

static inline int is_in_rom(unsigned long addr)
{
      /*
       * What we are really trying to do is determine if addr is
       * in an allocated kernel memory region. If not then assume
       * we cannot free it or otherwise de-allocate it. Ideally
       * we could restrict this to really being in a ROM or flash,
       * but that would need to be done on a board by board basis,
       * not globally.
       */
      if ((addr < _ramstart) || (addr >= _ramend))
            return (1);

      /* Default case, not in ROM */
      return (0);
}

/*
 * The fs value determines whether argument validity checking should be
 * performed or not.  If get_fs() == USER_DS, checking is performed, with
 * get_fs() == KERNEL_DS, checking is bypassed.
 */

#ifndef CONFIG_ACCESS_CHECK
static inline int _access_ok(unsigned long addr, unsigned long size) { return 1; }
#else
#ifdef CONFIG_ACCESS_OK_L1
extern int _access_ok(unsigned long addr, unsigned long size)__attribute__((l1_text));
#else
extern int _access_ok(unsigned long addr, unsigned long size);
#endif
#endif

/*
 * The exception table consists of pairs of addresses: the first is the
 * address of an instruction that is allowed to fault, and the second is
 * the address at which the program should continue.  No registers are
 * modified, so it is entirely up to the continuation code to figure out
 * what to do.
 *
 * All the routines below use bits of fixup code that are out of line
 * with the main instruction path.  This means when everything is well,
 * we don't even have to jump over them.  Further, they do not intrude
 * on our cache or tlb entries.
 */

struct exception_table_entry {
      unsigned long insn, fixup;
};

/* Returns 0 if exception not found and fixup otherwise.  */
extern unsigned long search_exception_table(unsigned long);

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 */

#define put_user(x,p)                                 \
      ({                                        \
            int _err = 0;                             \
            typeof(*(p)) _x = (x);                    \
            typeof(*(p)) *_p = (p);                   \
            if (!access_ok(VERIFY_WRITE, _p, sizeof(*(_p)))) {\
                  _err = -EFAULT;                     \
            }                                   \
            else {                                    \
            switch (sizeof (*(_p))) {                 \
            case 1:                                   \
                  __put_user_asm(_x, _p, B);          \
                  break;                              \
            case 2:                                   \
                  __put_user_asm(_x, _p, W);          \
                  break;                              \
            case 4:                                   \
                  __put_user_asm(_x, _p,  );          \
                  break;                              \
            case 8: {                           \
                  long _xl, _xh;                      \
                  _xl = ((long *)&_x)[0];             \
                  _xh = ((long *)&_x)[1];             \
                  __put_user_asm(_xl, ((long *)_p)+0, );    \
                  __put_user_asm(_xh, ((long *)_p)+1, );    \
            } break;                            \
            default:                            \
                  _err = __put_user_bad();            \
                  break;                              \
            }                                   \
            }                                   \
            _err;                               \
      })

#define __put_user(x,p) put_user(x,p)
static inline int bad_user_access_length(void)
{
      panic("bad_user_access_length");
      return -1;
}

#define __put_user_bad() (printk(KERN_INFO "put_user_bad %s:%d %s\n",\
                           __FILE__, __LINE__, __func__),\
                           bad_user_access_length(), (-EFAULT))

/*
 * Tell gcc we read from memory instead of writing: this is because
 * we do not write to any memory gcc knows about, so there are no
 * aliasing issues.
 */

#define __ptr(x) ((unsigned long *)(x))

#define __put_user_asm(x,p,bhw)                       \
      __asm__ (#bhw"[%1] = %0;\n\t"             \
             : /* no outputs */                 \
             :"d" (x),"a" (__ptr(p)) : "memory")

#define get_user(x,p)                                       \
      ({                                              \
            int _err = 0;                                   \
            typeof(*(p)) *_p = (p);                         \
            if (!access_ok(VERIFY_READ, _p, sizeof(*(_p)))) {     \
                  _err = -EFAULT;                           \
            }                                         \
            else {                                          \
            switch (sizeof(*(_p))) {                        \
            case 1:                                         \
                  __get_user_asm(x, _p, B,(Z));             \
                  break;                                    \
            case 2:                                         \
                  __get_user_asm(x, _p, W,(Z));             \
                  break;                                    \
            case 4:                                         \
                  __get_user_asm(x, _p,  , );               \
                  break;                                    \
            case 8: {                                 \
                  unsigned long _xl, _xh;                   \
                  __get_user_asm(_xl, ((unsigned long *)_p)+0,  , ); \
                  __get_user_asm(_xh, ((unsigned long *)_p)+1,  , ); \
                  ((unsigned long *)&x)[0] = _xl;                 \
                  ((unsigned long *)&x)[1] = _xh;                 \
            } break;                                  \
            default:                                  \
                  x = 0;                                    \
                  printk(KERN_INFO "get_user_bad: %s:%d %s\n",    \
                         __FILE__, __LINE__, __func__);     \
                  _err = __get_user_bad();                  \
                  break;                                    \
            }                                         \
            }                                         \
            _err;                                     \
      })

#define __get_user(x,p) get_user(x,p)

#define __get_user_bad() (bad_user_access_length(), (-EFAULT))

#define __get_user_asm(x,p,bhw,option)                      \
      {                                         \
            unsigned long _tmp;                       \
            __asm__ ("%0 =" #bhw "[%1]"#option";\n\t" \
                   : "=d" (_tmp)                      \
                   : "a" (__ptr(p)));                 \
            (x) = (__typeof__(*(p))) _tmp;                  \
      }

#define __copy_from_user(to, from, n) copy_from_user(to, from, n)
#define __copy_to_user(to, from, n) copy_to_user(to, from, n)
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

#define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n))\
                                         return retval; })

#define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n))\
                                                   return retval; })

static inline long copy_from_user(void *to,
                          const void __user * from, unsigned long n)
{
      if (access_ok(VERIFY_READ, from, n))
            memcpy(to, from, n);
      else
            return n;
      return 0;
}

static inline long copy_to_user(void *to,
                        const void __user * from, unsigned long n)
{
      if (access_ok(VERIFY_WRITE, to, n))
            memcpy(to, from, n);
      else
            return n;
      return 0;
}

/*
 * Copy a null terminated string from userspace.
 */

static inline long strncpy_from_user(char *dst,
                                     const char *src, long count)
{
      char *tmp;
      if (!access_ok(VERIFY_READ, src, 1))
            return -EFAULT;
      strncpy(dst, src, count);
      for (tmp = dst; *tmp && count > 0; tmp++, count--) ;
      return (tmp - dst);
}

/*
 * Return the size of a string (including the ending 0)
 *
 * Return 0 on exception, a value greater than N if too long
 */
static inline long strnlen_user(const char *src, long n)
{
      return (strlen(src) + 1);
}

#define strlen_user(str) strnlen_user(str, 32767)

/*
 * Zero Userspace
 */

static inline unsigned long __clear_user(void *to, unsigned long n)
{
      memset(to, 0, n);
      return 0;
}

#define clear_user(to, n) __clear_user(to, n)

#endif                        /* _BLACKFIN_UACCESS_H */

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