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| /* SPDX-License-Identifier: GPL-2.0 */
| /*
| * __clear_user_page, __clear_user, clear_page implementation of SuperH
| *
| * Copyright (C) 2001 Kaz Kojima
| * Copyright (C) 2001, 2002 Niibe Yutaka
| * Copyright (C) 2006 Paul Mundt
| */
| #include <linux/linkage.h>
| #include <asm/page.h>
|
| ENTRY(__clear_user)
| !
| mov #0, r0
| mov #0xffffffe0, r1
| !
| ! r4..(r4+31)&~32 -------- not aligned [ Area 0 ]
| ! (r4+31)&~32..(r4+r5)&~32 -------- aligned [ Area 1 ]
| ! (r4+r5)&~32..r4+r5 -------- not aligned [ Area 2 ]
| !
| ! Clear area 0
| mov r4, r2
| !
| tst r1, r5 ! length < 32
| bt .Larea2 ! skip to remainder
| !
| add #31, r2
| and r1, r2
| cmp/eq r4, r2
| bt .Larea1
| mov r2, r3
| sub r4, r3
| mov r3, r7
| mov r4, r2
| !
| .L0: dt r3
| 0: mov.b r0, @r2
| bf/s .L0
| add #1, r2
| !
| sub r7, r5
| mov r2, r4
| .Larea1:
| mov r4, r3
| add r5, r3
| and r1, r3
| cmp/hi r2, r3
| bf .Larea2
| !
| ! Clear area 1
| #if defined(CONFIG_CPU_SH4)
| 1: movca.l r0, @r2
| #else
| 1: mov.l r0, @r2
| #endif
| add #4, r2
| 2: mov.l r0, @r2
| add #4, r2
| 3: mov.l r0, @r2
| add #4, r2
| 4: mov.l r0, @r2
| add #4, r2
| 5: mov.l r0, @r2
| add #4, r2
| 6: mov.l r0, @r2
| add #4, r2
| 7: mov.l r0, @r2
| add #4, r2
| 8: mov.l r0, @r2
| add #4, r2
| cmp/hi r2, r3
| bt/s 1b
| nop
| !
| ! Clear area 2
| .Larea2:
| mov r4, r3
| add r5, r3
| cmp/hs r3, r2
| bt/s .Ldone
| sub r2, r3
| .L2: dt r3
| 9: mov.b r0, @r2
| bf/s .L2
| add #1, r2
| !
| .Ldone: rts
| mov #0, r0 ! return 0 as normal return
|
| ! return the number of bytes remained
| .Lbad_clear_user:
| mov r4, r0
| add r5, r0
| rts
| sub r2, r0
|
| .section __ex_table,"a"
| .align 2
| .long 0b, .Lbad_clear_user
| .long 1b, .Lbad_clear_user
| .long 2b, .Lbad_clear_user
| .long 3b, .Lbad_clear_user
| .long 4b, .Lbad_clear_user
| .long 5b, .Lbad_clear_user
| .long 6b, .Lbad_clear_user
| .long 7b, .Lbad_clear_user
| .long 8b, .Lbad_clear_user
| .long 9b, .Lbad_clear_user
| .previous
|
|
