android_kernel_xiaomi_sm8350/arch/xtensa/include/asm/uaccess.h
Chris Zankel 367b8112fe xtensa: move headers files to arch/xtensa/include
Move all header files for xtensa to arch/xtensa/include and platform and
variant header files to the appropriate arch/xtensa/platforms/ and
arch/xtensa/variants/ directories.

Moving the files gets also rid of all uses of symlinks in the Makefile.

This has been completed already for the majority of the architectures
and xtensa is one out of six missing.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Chris Zankel <chris@zankel.net>
2008-11-06 10:25:09 -08:00

501 lines
14 KiB
C

/*
* include/asm-xtensa/uaccess.h
*
* User space memory access functions
*
* These routines provide basic accessing functions to the user memory
* space for the kernel. This header file provides fuctions such as:
*
* 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.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*/
#ifndef _XTENSA_UACCESS_H
#define _XTENSA_UACCESS_H
#include <linux/errno.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
#ifdef __ASSEMBLY__
#include <asm/current.h>
#include <asm/asm-offsets.h>
#include <asm/processor.h>
#include <asm/types.h>
/*
* These assembly macros mirror the C macros that follow below. They
* should always have identical functionality. See
* arch/xtensa/kernel/sys.S for usage.
*/
#define KERNEL_DS 0
#define USER_DS 1
#define get_ds (KERNEL_DS)
/*
* get_fs reads current->thread.current_ds into a register.
* On Entry:
* <ad> anything
* <sp> stack
* On Exit:
* <ad> contains current->thread.current_ds
*/
.macro get_fs ad, sp
GET_CURRENT(\ad,\sp)
l32i \ad, \ad, THREAD_CURRENT_DS
.endm
/*
* set_fs sets current->thread.current_ds to some value.
* On Entry:
* <at> anything (temp register)
* <av> value to write
* <sp> stack
* On Exit:
* <at> destroyed (actually, current)
* <av> preserved, value to write
*/
.macro set_fs at, av, sp
GET_CURRENT(\at,\sp)
s32i \av, \at, THREAD_CURRENT_DS
.endm
/*
* kernel_ok determines whether we should bypass addr/size checking.
* See the equivalent C-macro version below for clarity.
* On success, kernel_ok branches to a label indicated by parameter
* <success>. This implies that the macro falls through to the next
* insruction on an error.
*
* Note that while this macro can be used independently, we designed
* in for optimal use in the access_ok macro below (i.e., we fall
* through on error).
*
* On Entry:
* <at> anything (temp register)
* <success> label to branch to on success; implies
* fall-through macro on error
* <sp> stack pointer
* On Exit:
* <at> destroyed (actually, current->thread.current_ds)
*/
#if ((KERNEL_DS != 0) || (USER_DS == 0))
# error Assembly macro kernel_ok fails
#endif
.macro kernel_ok at, sp, success
get_fs \at, \sp
beqz \at, \success
.endm
/*
* user_ok determines whether the access to user-space memory is allowed.
* See the equivalent C-macro version below for clarity.
*
* On error, user_ok branches to a label indicated by parameter
* <error>. This implies that the macro falls through to the next
* instruction on success.
*
* Note that while this macro can be used independently, we designed
* in for optimal use in the access_ok macro below (i.e., we fall
* through on success).
*
* On Entry:
* <aa> register containing memory address
* <as> register containing memory size
* <at> temp register
* <error> label to branch to on error; implies fall-through
* macro on success
* On Exit:
* <aa> preserved
* <as> preserved
* <at> destroyed (actually, (TASK_SIZE + 1 - size))
*/
.macro user_ok aa, as, at, error
movi \at, __XTENSA_UL_CONST(TASK_SIZE)
bgeu \as, \at, \error
sub \at, \at, \as
bgeu \aa, \at, \error
.endm
/*
* access_ok determines whether a memory access is allowed. See the
* equivalent C-macro version below for clarity.
*
* On error, access_ok branches to a label indicated by parameter
* <error>. This implies that the macro falls through to the next
* instruction on success.
*
* Note that we assume success is the common case, and we optimize the
* branch fall-through case on success.
*
* On Entry:
* <aa> register containing memory address
* <as> register containing memory size
* <at> temp register
* <sp>
* <error> label to branch to on error; implies fall-through
* macro on success
* On Exit:
* <aa> preserved
* <as> preserved
* <at> destroyed
*/
.macro access_ok aa, as, at, sp, error
kernel_ok \at, \sp, .Laccess_ok_\@
user_ok \aa, \as, \at, \error
.Laccess_ok_\@:
.endm
#else /* __ASSEMBLY__ not defined */
#include <linux/sched.h>
#include <asm/types.h>
/*
* 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 (Data Segment Register?), these macros are
* grossly misnamed.
*/
#define KERNEL_DS ((mm_segment_t) { 0 })
#define USER_DS ((mm_segment_t) { 1 })
#define get_ds() (KERNEL_DS)
#define get_fs() (current->thread.current_ds)
#define set_fs(val) (current->thread.current_ds = (val))
#define segment_eq(a,b) ((a).seg == (b).seg)
#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
#define __user_ok(addr,size) (((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size)))
#define __access_ok(addr,size) (__kernel_ok || __user_ok((addr),(size)))
#define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size))
/*
* These are the main single-value transfer routines. They
* automatically use the right size if we just have the right pointer
* type.
*
* This gets kind of ugly. We want to return _two_ values in
* "get_user()" and yet we don't want to do any pointers, because that
* is too much of a performance impact. Thus we have a few rather ugly
* macros here, and hide all the uglyness from the user.
*
* Careful to not
* (a) re-use the arguments for side effects (sizeof is ok)
* (b) require any knowledge of processes at this stage
*/
#define put_user(x,ptr) __put_user_check((x),(ptr),sizeof(*(ptr)))
#define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr)))
/*
* The "__xxx" versions of the user access functions are versions that
* do not verify the address space, that must have been done previously
* with a separate "access_ok()" call (this is used when we do multiple
* accesses to the same area of user memory).
*/
#define __put_user(x,ptr) __put_user_nocheck((x),(ptr),sizeof(*(ptr)))
#define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
extern long __put_user_bad(void);
#define __put_user_nocheck(x,ptr,size) \
({ \
long __pu_err; \
__put_user_size((x),(ptr),(size),__pu_err); \
__pu_err; \
})
#define __put_user_check(x,ptr,size) \
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) *__pu_addr = (ptr); \
if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
__put_user_size((x),__pu_addr,(size),__pu_err); \
__pu_err; \
})
#define __put_user_size(x,ptr,size,retval) \
do { \
int __cb; \
retval = 0; \
switch (size) { \
case 1: __put_user_asm(x,ptr,retval,1,"s8i",__cb); break; \
case 2: __put_user_asm(x,ptr,retval,2,"s16i",__cb); break; \
case 4: __put_user_asm(x,ptr,retval,4,"s32i",__cb); break; \
case 8: { \
__typeof__(*ptr) __v64 = x; \
retval = __copy_to_user(ptr,&__v64,8); \
break; \
} \
default: __put_user_bad(); \
} \
} while (0)
/*
* Consider a case of a user single load/store would cause both an
* unaligned exception and an MMU-related exception (unaligned
* exceptions happen first):
*
* User code passes a bad variable ptr to a system call.
* Kernel tries to access the variable.
* Unaligned exception occurs.
* Unaligned exception handler tries to make aligned accesses.
* Double exception occurs for MMU-related cause (e.g., page not mapped).
* do_page_fault() thinks the fault address belongs to the kernel, not the
* user, and panics.
*
* The kernel currently prohibits user unaligned accesses. We use the
* __check_align_* macros to check for unaligned addresses before
* accessing user space so we don't crash the kernel. Both
* __put_user_asm and __get_user_asm use these alignment macros, so
* macro-specific labels such as 0f, 1f, %0, %2, and %3 must stay in
* sync.
*/
#define __check_align_1 ""
#define __check_align_2 \
" _bbci.l %3, 0, 1f \n" \
" movi %0, %4 \n" \
" _j 2f \n"
#define __check_align_4 \
" _bbsi.l %3, 0, 0f \n" \
" _bbci.l %3, 1, 1f \n" \
"0: movi %0, %4 \n" \
" _j 2f \n"
/*
* We don't tell gcc that we are accessing memory, but this is OK
* because we do not write to any memory gcc knows about, so there
* are no aliasing issues.
*
* WARNING: If you modify this macro at all, verify that the
* __check_align_* macros still work.
*/
#define __put_user_asm(x, addr, err, align, insn, cb) \
__asm__ __volatile__( \
__check_align_##align \
"1: "insn" %2, %3, 0 \n" \
"2: \n" \
" .section .fixup,\"ax\" \n" \
" .align 4 \n" \
"4: \n" \
" .long 2b \n" \
"5: \n" \
" l32r %1, 4b \n" \
" movi %0, %4 \n" \
" jx %1 \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" .long 1b, 5b \n" \
" .previous" \
:"=r" (err), "=r" (cb) \
:"r" ((int)(x)), "r" (addr), "i" (-EFAULT), "0" (err))
#define __get_user_nocheck(x,ptr,size) \
({ \
long __gu_err, __gu_val; \
__get_user_size(__gu_val,(ptr),(size),__gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user_check(x,ptr,size) \
({ \
long __gu_err = -EFAULT, __gu_val = 0; \
const __typeof__(*(ptr)) *__gu_addr = (ptr); \
if (access_ok(VERIFY_READ,__gu_addr,size)) \
__get_user_size(__gu_val,__gu_addr,(size),__gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
extern long __get_user_bad(void);
#define __get_user_size(x,ptr,size,retval) \
do { \
int __cb; \
retval = 0; \
switch (size) { \
case 1: __get_user_asm(x,ptr,retval,1,"l8ui",__cb); break; \
case 2: __get_user_asm(x,ptr,retval,2,"l16ui",__cb); break; \
case 4: __get_user_asm(x,ptr,retval,4,"l32i",__cb); break; \
case 8: retval = __copy_from_user(&x,ptr,8); break; \
default: (x) = __get_user_bad(); \
} \
} while (0)
/*
* WARNING: If you modify this macro at all, verify that the
* __check_align_* macros still work.
*/
#define __get_user_asm(x, addr, err, align, insn, cb) \
__asm__ __volatile__( \
__check_align_##align \
"1: "insn" %2, %3, 0 \n" \
"2: \n" \
" .section .fixup,\"ax\" \n" \
" .align 4 \n" \
"4: \n" \
" .long 2b \n" \
"5: \n" \
" l32r %1, 4b \n" \
" movi %2, 0 \n" \
" movi %0, %4 \n" \
" jx %1 \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" .long 1b, 5b \n" \
" .previous" \
:"=r" (err), "=r" (cb), "=r" (x) \
:"r" (addr), "i" (-EFAULT), "0" (err))
/*
* Copy to/from user space
*/
/*
* We use a generic, arbitrary-sized copy subroutine. The Xtensa
* architecture would cause heavy code bloat if we tried to inline
* these functions and provide __constant_copy_* equivalents like the
* i386 versions. __xtensa_copy_user is quite efficient. See the
* .fixup section of __xtensa_copy_user for a discussion on the
* X_zeroing equivalents for Xtensa.
*/
extern unsigned __xtensa_copy_user(void *to, const void *from, unsigned n);
#define __copy_user(to,from,size) __xtensa_copy_user(to,from,size)
static inline unsigned long
__generic_copy_from_user_nocheck(void *to, const void *from, unsigned long n)
{
return __copy_user(to,from,n);
}
static inline unsigned long
__generic_copy_to_user_nocheck(void *to, const void *from, unsigned long n)
{
return __copy_user(to,from,n);
}
static inline unsigned long
__generic_copy_to_user(void *to, const void *from, unsigned long n)
{
prefetch(from);
if (access_ok(VERIFY_WRITE, to, n))
return __copy_user(to,from,n);
return n;
}
static inline unsigned long
__generic_copy_from_user(void *to, const void *from, unsigned long n)
{
prefetchw(to);
if (access_ok(VERIFY_READ, from, n))
return __copy_user(to,from,n);
else
memset(to, 0, n);
return n;
}
#define copy_to_user(to,from,n) __generic_copy_to_user((to),(from),(n))
#define copy_from_user(to,from,n) __generic_copy_from_user((to),(from),(n))
#define __copy_to_user(to,from,n) __generic_copy_to_user_nocheck((to),(from),(n))
#define __copy_from_user(to,from,n) __generic_copy_from_user_nocheck((to),(from),(n))
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
/*
* We need to return the number of bytes not cleared. Our memset()
* returns zero if a problem occurs while accessing user-space memory.
* In that event, return no memory cleared. Otherwise, zero for
* success.
*/
static inline unsigned long
__xtensa_clear_user(void *addr, unsigned long size)
{
if ( ! memset(addr, 0, size) )
return size;
return 0;
}
static inline unsigned long
clear_user(void *addr, unsigned long size)
{
if (access_ok(VERIFY_WRITE, addr, size))
return __xtensa_clear_user(addr, size);
return size ? -EFAULT : 0;
}
#define __clear_user __xtensa_clear_user
extern long __strncpy_user(char *, const char *, long);
#define __strncpy_from_user __strncpy_user
static inline long
strncpy_from_user(char *dst, const char *src, long count)
{
if (access_ok(VERIFY_READ, src, 1))
return __strncpy_from_user(dst, src, count);
return -EFAULT;
}
#define strlen_user(str) strnlen_user((str), TASK_SIZE - 1)
/*
* Return the size of a string (including the ending 0!)
*/
extern long __strnlen_user(const char *, long);
static inline long strnlen_user(const char *str, long len)
{
unsigned long top = __kernel_ok ? ~0UL : TASK_SIZE - 1;
if ((unsigned long)str > top)
return 0;
return __strnlen_user(str, len);
}
struct exception_table_entry
{
unsigned long insn, fixup;
};
/* Returns 0 if exception not found and fixup.unit otherwise. */
extern unsigned long search_exception_table(unsigned long addr);
extern void sort_exception_table(void);
/* Returns the new pc */
#define fixup_exception(map_reg, fixup_unit, pc) \
({ \
fixup_unit; \
})
#endif /* __ASSEMBLY__ */
#endif /* _XTENSA_UACCESS_H */