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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2008-2009 Michal Simek <[email protected]>
* Copyright (C) 2008-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*/
#ifndef _ASM_MICROBLAZE_UACCESS_H
#define _ASM_MICROBLAZE_UACCESS_H
#include <linux/kernel.h>
#include <asm/mmu.h>
#include <asm/page.h>
#include <linux/pgtable.h>
#include <asm/extable.h>
#include <linux/string.h>
/*
* 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) })
# define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
# define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
# define get_fs() (current_thread_info()->addr_limit)
# define set_fs(val) (current_thread_info()->addr_limit = (val))
# define user_addr_max() get_fs().seg
# define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
static inline int __access_ok(unsigned long addr, unsigned long size)
{
unsigned long limit = user_addr_max();
return (size <= limit) && (addr <= (limit - size));
}
#define access_ok(addr, size) __access_ok((unsigned long)addr, size)
# define __FIXUP_SECTION ".section .fixup,\"ax\"\n"
# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
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, %1, r0;" \
" addik %0, %0, -1;" \
" bneid %0, 1b;" \
" addik %1, %1, 1;" \
"2: " \
__EX_TABLE_SECTION \
".word 1b,2b;" \
".previous;" \
: "=r"(n), "=r"(to) \
: "0"(n), "1"(to)
);
return n;
}
static inline unsigned long __must_check clear_user(void __user *to,
unsigned long n)
{
might_fault();
if (unlikely(!access_ok(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 if pagefaults are
* enabled.
*
* 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) ({ \
const typeof(*(ptr)) __user *__gu_ptr = (ptr); \
access_ok(__gu_ptr, sizeof(*__gu_ptr)) ? \
__get_user(x, __gu_ptr) : -EFAULT; \
})
#define __get_user(x, ptr) \
({ \
long __gu_err; \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_asm("lbu", (ptr), x, __gu_err); \
break; \
case 2: \
__get_user_asm("lhu", (ptr), x, __gu_err); \
break; \
case 4: \
__get_user_asm("lw", (ptr), x, __gu_err); \
break; \
case 8: { \
__u64 __x = 0; \
__gu_err = raw_copy_from_user(&__x, ptr, 8) ? \
-EFAULT : 0; \
(x) = (typeof(x))(typeof((x) - (x)))__x; \
break; \
} \
default: \
/* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
} \
__gu_err; \
})
#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 if pagefaults are
* enabled.
*
* 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) \
__put_user_check((x), (ptr), sizeof(*(ptr)))
#define __put_user_check(x, ptr, size) \
({ \
typeof(*(ptr)) volatile __pu_val = x; \
typeof(*(ptr)) __user *__pu_addr = (ptr); \
int __pu_err = 0; \
\
if (access_ok(__pu_addr, size)) { \
switch (size) { \
case 1: \
__put_user_asm("sb", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 2: \
__put_user_asm("sh", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 4: \
__put_user_asm("sw", __pu_addr, __pu_val, \
__pu_err); \
break; \
case 8: \
__put_user_asm_8(__pu_addr, __pu_val, __pu_err);\
break; \
default: \
__pu_err = __user_bad(); \
break; \
} \
} else { \
__pu_err = -EFAULT; \
} \
__pu_err; \
})
#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; \
})
static inline unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
return __copy_tofrom_user((__force void __user *)to, from, n);
}
static inline unsigned long
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
return __copy_tofrom_user(to, (__force const void __user *)from, n);
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
/*
* Copy a null terminated string from userspace.
*/
__must_check long strncpy_from_user(char *dst, const char __user *src,
long count);
/*
* Return the size of a string (including the ending 0)
*
* Return 0 on exception, a value greater than N if too long
*/
__must_check long strnlen_user(const char __user *sstr, long len);
#endif /* _ASM_MICROBLAZE_UACCESS_H */
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