linux/arch/m68k/lib/uaccess.c
Greg Ungerer e08d703cc2 m68k: modify user space access functions to support ColdFire CPUs
Modify the user space access functions to support the ColdFire V4e cores
running with MMU enabled.

The ColdFire processors do not support the "moves" instruction used by
the traditional 680x0 processors for moving data into and out of another
address space. They only support the notion of a single address space,
and you use the usual "move" instruction to access that.

Create a new config symbol (CONFIG_CPU_HAS_ADDRESS_SPACES) to mark the
CPU types that support separate address spaces, and thus also support
the sfc/dfc registers and the "moves" instruction that go along with that.

The code is almost identical for user space access, so lets just use a
define to choose either the "move" or "moves" in the assembler code.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Matt Waddel <mwaddel@yahoo.com>
Acked-by: Kurt Mahan <kmahan@xmission.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2011-12-30 10:20:21 +10:00

223 lines
4.2 KiB
C

/*
* 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.
*/
#include <linux/module.h>
#include <asm/uaccess.h>
unsigned long __generic_copy_from_user(void *to, const void __user *from,
unsigned long n)
{
unsigned long tmp, res;
asm volatile ("\n"
" tst.l %0\n"
" jeq 2f\n"
"1: "MOVES".l (%1)+,%3\n"
" move.l %3,(%2)+\n"
" subq.l #1,%0\n"
" jne 1b\n"
"2: btst #1,%5\n"
" jeq 4f\n"
"3: "MOVES".w (%1)+,%3\n"
" move.w %3,(%2)+\n"
"4: btst #0,%5\n"
" jeq 6f\n"
"5: "MOVES".b (%1)+,%3\n"
" move.b %3,(%2)+\n"
"6:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"10: move.l %0,%3\n"
"7: clr.l (%2)+\n"
" subq.l #1,%3\n"
" jne 7b\n"
" lsl.l #2,%0\n"
" btst #1,%5\n"
" jeq 8f\n"
"30: clr.w (%2)+\n"
" addq.l #2,%0\n"
"8: btst #0,%5\n"
" jeq 6b\n"
"50: clr.b (%2)+\n"
" addq.l #1,%0\n"
" jra 6b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,10b\n"
" .long 3b,30b\n"
" .long 5b,50b\n"
" .previous"
: "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
: "0" (n / 4), "d" (n & 3));
return res;
}
EXPORT_SYMBOL(__generic_copy_from_user);
unsigned long __generic_copy_to_user(void __user *to, const void *from,
unsigned long n)
{
unsigned long tmp, res;
asm volatile ("\n"
" tst.l %0\n"
" jeq 4f\n"
"1: move.l (%1)+,%3\n"
"2: "MOVES".l %3,(%2)+\n"
"3: subq.l #1,%0\n"
" jne 1b\n"
"4: btst #1,%5\n"
" jeq 6f\n"
" move.w (%1)+,%3\n"
"5: "MOVES".w %3,(%2)+\n"
"6: btst #0,%5\n"
" jeq 8f\n"
" move.b (%1)+,%3\n"
"7: "MOVES".b %3,(%2)+\n"
"8:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"20: lsl.l #2,%0\n"
"50: add.l %5,%0\n"
" jra 8b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 2b,20b\n"
" .long 3b,20b\n"
" .long 5b,50b\n"
" .long 6b,50b\n"
" .long 7b,50b\n"
" .long 8b,50b\n"
" .previous"
: "=d" (res), "+a" (from), "+a" (to), "=&r" (tmp)
: "0" (n / 4), "d" (n & 3));
return res;
}
EXPORT_SYMBOL(__generic_copy_to_user);
/*
* Copy a null terminated string from userspace.
*/
long strncpy_from_user(char *dst, const char __user *src, long count)
{
long res;
char c;
if (count <= 0)
return count;
asm volatile ("\n"
"1: "MOVES".b (%2)+,%4\n"
" move.b %4,(%1)+\n"
" jeq 2f\n"
" subq.l #1,%3\n"
" jne 1b\n"
"2: sub.l %3,%0\n"
"3:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"10: move.l %5,%0\n"
" jra 3b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,10b\n"
" .previous"
: "=d" (res), "+a" (dst), "+a" (src), "+r" (count), "=&d" (c)
: "i" (-EFAULT), "0" (count));
return res;
}
EXPORT_SYMBOL(strncpy_from_user);
/*
* Return the size of a string (including the ending 0)
*
* Return 0 on exception, a value greater than N if too long
*/
long strnlen_user(const char __user *src, long n)
{
char c;
long res;
asm volatile ("\n"
"1: subq.l #1,%1\n"
" jmi 3f\n"
"2: "MOVES".b (%0)+,%2\n"
" tst.b %2\n"
" jne 1b\n"
" jra 4f\n"
"\n"
"3: addq.l #1,%0\n"
"4: sub.l %4,%0\n"
"5:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"20: sub.l %0,%0\n"
" jra 5b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 2b,20b\n"
" .previous\n"
: "=&a" (res), "+d" (n), "=&d" (c)
: "0" (src), "r" (src));
return res;
}
EXPORT_SYMBOL(strnlen_user);
/*
* Zero Userspace
*/
unsigned long __clear_user(void __user *to, unsigned long n)
{
unsigned long res;
asm volatile ("\n"
" tst.l %0\n"
" jeq 3f\n"
"1: "MOVES".l %2,(%1)+\n"
"2: subq.l #1,%0\n"
" jne 1b\n"
"3: btst #1,%4\n"
" jeq 5f\n"
"4: "MOVES".w %2,(%1)+\n"
"5: btst #0,%4\n"
" jeq 7f\n"
"6: "MOVES".b %2,(%1)\n"
"7:\n"
" .section .fixup,\"ax\"\n"
" .even\n"
"10: lsl.l #2,%0\n"
"40: add.l %4,%0\n"
" jra 7b\n"
" .previous\n"
"\n"
" .section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,10b\n"
" .long 2b,10b\n"
" .long 4b,40b\n"
" .long 5b,40b\n"
" .long 6b,40b\n"
" .long 7b,40b\n"
" .previous"
: "=d" (res), "+a" (to)
: "r" (0), "0" (n / 4), "d" (n & 3));
return res;
}
EXPORT_SYMBOL(__clear_user);