android_kernel_motorola_sm6225/arch/blackfin/include/asm/uaccess.h
Mike Frysinger e56e03b0cf Blackfin: unify memory region checks between kgdb and traps
The kgdb (in multiple places) and traps code developed pretty much
identical checks for how to access different regions of the Blackfin
memory map, but each wasn't 100%, so unify them to avoid duplication,
bitrot, and bugs with edge cases.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2009-06-22 21:15:34 -04:00

290 lines
7.4 KiB
C

/* 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
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)) *_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, 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 = (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 (access_ok(VERIFY_READ, from, n))
memcpy(to, from, n);
else
return n;
return 0;
}
static inline unsigned long __must_check
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 __must_check
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);
}
/*
* 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 *src, long n)
{
if (!access_ok(VERIFY_READ, src, 1))
return 0;
return strnlen(src, n) + 1;
}
static inline long __must_check strlen_user(const char *src)
{
if (!access_ok(VERIFY_READ, src, 1))
return 0;
return strlen(src) + 1;
}
/*
* Zero Userspace
*/
static inline unsigned long __must_check
__clear_user(void *to, unsigned long n)
{
if (!access_ok(VERIFY_WRITE, to, n))
return n;
memset(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 */