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/*
* Copyright 2004-2009 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*
* 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>
#include <asm/sections.h>
#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))
/*
* 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
extern int _access_ok(unsigned long addr, unsigned long size);
#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;
};
/*
* 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)) __user *_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 = ((__force long *)&_x)[0]; \
_xh = ((__force long *)&_x)[1]; \
__put_user_asm(_xl, ((__force long __user *)_p)+0, );\
__put_user_asm(_xh, ((__force long __user *)_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 __force *)(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, ptr) \
({ \
int _err = 0; \
unsigned long _val = 0; \
const typeof(*(ptr)) __user *_p = (ptr); \
const size_t ptr_size = sizeof(*(_p)); \
if (likely(access_ok(VERIFY_READ, _p, ptr_size))) { \
BUILD_BUG_ON(ptr_size >= 8); \
switch (ptr_size) { \
case 1: \
__get_user_asm(_val, _p, B, (Z)); \
break; \
case 2: \
__get_user_asm(_val, _p, W, (Z)); \
break; \
case 4: \
__get_user_asm(_val, _p, , ); \
break; \
} \
} else \
_err = -EFAULT; \
x = (__force typeof(*(ptr)))_val; \
_err; \
})
#define __get_user(x, p) get_user(x, p)
#define __get_user_bad() (bad_user_access_length(), (-EFAULT))
#define __get_user_asm(x, ptr, bhw, option) \
({ \
__asm__ __volatile__ ( \
"%0 =" #bhw "[%1]" #option ";" \
: "=d" (x) \
: "a" (__ptr(ptr))); \
})
#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 unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (likely(access_ok(VERIFY_READ, from, n))) {
memcpy(to, (const void __force *)from, n);
return 0;
}
memset(to, 0, n);
return n;
}
static inline unsigned long __must_check
copy_to_user(void __user *to, const void *from, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
memcpy((void __force *)to, from, n);
else
return n;
SSYNC();
return 0;
}
/*
* Copy a null terminated string from userspace.
*/
static inline long __must_check
strncpy_from_user(char *dst, const char __user *src, long count)
{
char *tmp;
if (!access_ok(VERIFY_READ, src, 1))
return -EFAULT;
strncpy(dst, (const char __force *)src, count);
for (tmp = dst; *tmp && count > 0; tmp++, count--) ;
return (tmp - dst);
}
/*
* Get the size of a string in user space.
* src: The string to measure
* n: The maximum valid length
*
* Get the size of a NUL-terminated string in user space.
*
* Returns the size of the string INCLUDING the terminating NUL.
* On exception, returns 0.
* If the string is too long, returns a value greater than n.
*/
static inline long __must_check strnlen_user(const char __user *src, long n)
{
if (!access_ok(VERIFY_READ, src, 1))
return 0;
return strnlen((const char __force *)src, n) + 1;
}
static inline long __must_check strlen_user(const char __user *src)
{
if (!access_ok(VERIFY_READ, src, 1))
return 0;
return strlen((const char __force *)src) + 1;
}
/*
* Zero Userspace
*/
static inline unsigned long __must_check
__clear_user(void __user *to, unsigned long n)
{
if (!access_ok(VERIFY_WRITE, to, n))
return n;
memset((void __force *)to, 0, n);
return 0;
}
#define clear_user(to, n) __clear_user(to, n)
/* How to interpret these return values:
* CORE: can be accessed by core load or dma memcpy
* CORE_ONLY: can only be accessed by core load
* DMA: can only be accessed by dma memcpy
* IDMA: can only be accessed by interprocessor dma memcpy (BF561)
* ITEST: can be accessed by isram memcpy or dma memcpy
*/
enum {
BFIN_MEM_ACCESS_CORE = 0,
BFIN_MEM_ACCESS_CORE_ONLY,
BFIN_MEM_ACCESS_DMA,
BFIN_MEM_ACCESS_IDMA,
BFIN_MEM_ACCESS_ITEST,
};
/**
* bfin_mem_access_type() - what kind of memory access is required
* @addr: the address to check
* @size: number of bytes needed
* @return: <0 is error, >=0 is BFIN_MEM_ACCESS_xxx enum (see above)
*/
int bfin_mem_access_type(unsigned long addr, unsigned long size);
#endif /* _BLACKFIN_UACCESS_H */
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