/*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#ifndef _ASM_MICROBLAZE_UACCESS_H
#define _ASM_MICROBLAZE_UACCESS_H
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/sched.h> /* RLIMIT_FSIZE */
#include <linux/mm.h>
#include <asm/mmu.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <linux/string.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
/*
* On Microblaze the fs value is actually the top of the corresponding
* address space.
*
* 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.
*
* For historical reasons, these macros are grossly misnamed.
*
* For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
*/
# define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
# ifndef CONFIG_MMU
# define KERNEL_DS MAKE_MM_SEG(0)
# define USER_DS KERNEL_DS
# else
# define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
# define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
# endif
# define get_ds() (KERNEL_DS)
# define get_fs() (current_thread_info()->addr_limit)
# define set_fs(val) (current_thread_info()->addr_limit = (val))
# define segment_eq(a, b) ((a).seg == (b).seg)
/*
* 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);
#ifndef CONFIG_MMU
/* Check against bounds of physical memory */
static inline int ___range_ok(unsigned long addr, unsigned long size)
{
return ((addr < memory_start) ||
((addr + size) > memory_end));
}
#define __range_ok(addr, size) \
___range_ok((unsigned long)(addr), (unsigned long)(size))
#define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
#else
/*
* Address is valid if:
* - "addr", "addr + size" and "size" are all below the limit
*/
#define access_ok(type, addr, size) \
(get_fs().seg > (((unsigned long)(addr)) | \
(size) | ((unsigned long)(addr) + (size))))
/* || printk("access_ok failed for %s at 0x%08lx (size %d), seg 0x%08x\n",
type?"WRITE":"READ",addr,size,get_fs().seg)) */
#endif
#ifdef CONFIG_MMU
# define __FIXUP_SECTION ".section .fixup,\"ax\"\n"
# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
#else
# define __FIXUP_SECTION ".section .discard,\"ax\"\n"
# define __EX_TABLE_SECTION ".section .discard,\"a\"\n"
#endif
extern unsigned long __copy_tofrom_user(void __user *to,
const void __user *from, unsigned long size);
/* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */
static inline unsigned long __must_check __clear_user(void __user *to,
unsigned long n)
{
/* normal memset with two words to __ex_table */
__asm__ __volatile__ ( \
"1: sb r0, %2, r0;" \
" addik %0, %0, -1;" \
" bneid %0, 1b;" \
" addik %2, %2, 1;" \
"2: " \
__EX_TABLE_SECTION \
".word 1b,2b;" \
".previous;" \
: "=r"(n) \
: "0"(n), "r"(to)
);
return n;
}
static inline unsigned long __must_check clear_user(void __user *to,
unsigned long n)
{
might_sleep();
if (unlikely(!access_ok(VERIFY_WRITE, to, n)))
return n;
return __clear_user(to, n);
}
/* put_user and get_user macros */
extern long __user_bad(void);
#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
({ \
__asm__ __volatile__ ( \
"1:" insn " %1, %2, r0;" \
" addk %0, r0, r0;" \
"2: " \
__FIXUP_SECTION \
"3: brid 2b;" \
" addik %0, r0, %3;" \
".previous;" \
__EX_TABLE_SECTION \
".word 1b,3b;" \
".previous;" \
: "=&r"(__gu_err), "=r"(__gu_val) \
: "r"(__gu_ptr), "i"(-EFAULT) \
); \
})
/**
* get_user: - Get a simple variable from user space.
* @x: Variable to store result.
* @ptr: Source address, in user space.
*
* Context: User context only. This function may sleep.
*
* This macro copies a single simple variable from user space to kernel
* space. It supports simple types like char and int, but not larger
* data types like structures or arrays.
*
* @ptr must have pointer-to-simple-variable type, and the result of
* dereferencing @ptr must be assignable to @x without a cast.
*
* Returns zero on success, or -EFAULT on error.
* On error, the variable @x is set to zero.
*/
#define __get_user(x, ptr) \
({ \
unsigned long __gu_val; \
/*unsigned long __gu_ptr = (unsigned long)(ptr);*/ \
long __gu_err; \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_asm("lbu", (ptr), __gu_val, __gu_err); \
break; \
case 2: \
__get_user_asm("lhu", (ptr), __gu_val, __gu_err); \
break; \
case 4: \
__get_user_asm("lw", (ptr), __gu_val, __gu_err); \
break; \
default: \
/* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
} \
x = (__typeof__(*(ptr))) __gu_val; \
__gu_err; \
})
#define get_user(x, ptr) \
({ \
access_ok(VERIFY_READ, (ptr), sizeof(*(ptr))) \
? __get_user((x), (ptr)) : -EFAULT; \
})
#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
({ \
__asm__ __volatile__ ( \
"1:" insn " %1, %2, r0;" \
" addk %0, r0, r0;" \
"2: " \
__FIXUP_SECTION \
"3: brid 2b;" \
" addik %0, r0, %3;" \
".previous;" \
__EX_TABLE_SECTION \
".word 1b,3b;" \
".previous;" \
: "=&r"(__gu_err) \
: "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \
); \
})
#define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \
({ \
__asm__ __volatile__ (" lwi %0, %1, 0;" \
"1: swi %0, %2, 0;" \
" lwi %0, %1, 4;" \
"2: swi %0, %2, 4;" \
" addk %0, r0, r0;" \
"3: " \
__FIXUP_SECTION \
"4: brid 3b;" \
" addik %0, r0, %3;" \
".previous;" \
__EX_TABLE_SECTION \
".word 1b,4b,2b,4b;" \
".previous;" \
: "=&r"(__gu_err) \
: "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \
); \
})
/**
* put_user: - Write a simple value into user space.
* @x: Value to copy to user space.
* @ptr: Destination address, in user space.
*
* Context: User context only. This function may sleep.
*
* This macro copies a single simple value from kernel space to user
* space. It supports simple types like char and int, but not larger
* data types like structures or arrays.
*
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
* to the result of dereferencing @ptr.
*
* Returns zero on success, or -EFAULT on error.
*/
#define __put_user(x, ptr) \
({ \
__typeof__(*(ptr)) volatile __gu_val = (x); \
long __gu_err = 0; \
switch (sizeof(__gu_val)) { \
case 1: \
__put_user_asm("sb", (ptr), __gu_val, __gu_err); \
break; \
case 2: \
__put_user_asm("sh", (ptr), __gu_val, __gu_err); \
break; \
case 4: \
__put_user_asm("sw", (ptr), __gu_val, __gu_err); \
break; \
case 8: \
__put_user_asm_8((ptr), __gu_val, __gu_err); \
break; \
default: \
/*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \
} \
__gu_err; \
})
#ifndef CONFIG_MMU
#define put_user(x, ptr) __put_user((x), (ptr))
#else /* CONFIG_MMU */
#define put_user(x, ptr) \
({ \
access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) \
? __put_user((x), (ptr)) : -EFAULT; \
})
#endif /* CONFIG_MMU */
/* copy_to_from_user */
#define __copy_from_user(to, from, n) \
__copy_tofrom_user((__force void __user *)(to), \
(void __user *)(from), (n))
#define __copy_from_user_inatomic(to, from, n) \
copy_from_user((to), (from), (n))
static inline long copy_from_user(void *to,
const void __user *from, unsigned long n)
{
might_sleep();
if (access_ok(VERIFY_READ, from, n))
return __copy_from_user(to, from, n);
return n;
}
#define __copy_to_user(to, from, n) \
__copy_tofrom_user((void __user *)(to), \
(__force const void __user *)(from), (n))
#define __copy_to_user_inatomic(to, from, n) copy_to_user((to), (from), (n))
static inline long copy_to_user(void __user *to,
const void *from, unsigned long n)
{
might_sleep();
if (access_ok(VERIFY_WRITE, to, n))
return __copy_to_user(to, from, n);
return n;
}
/*
* Copy a null terminated string from userspace.
*/
extern int __strncpy_user(char *to, const char __user *from, int len);
#define __strncpy_from_user __strncpy_user
static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
if (!access_ok(VERIFY_READ, src, 1))
return -EFAULT;
return __strncpy_from_user(dst, src, count);
}
/*
* Return the size of a string (including the ending 0)
*
* Return 0 on exception, a value greater than N if too long
*/
extern int __strnlen_user(const char __user *sstr, int len);
static inline long strnlen_user(const char __user *src, long n)
{
if (!access_ok(VERIFY_READ, src, 1))
return 0;
return __strnlen_user(src, n);
}
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_MICROBLAZE_UACCESS_H */
