1 files changed, 154 insertions, 0 deletions

diff --git a/arch/sh/lib/clear_page.S b/arch/sh/lib/clear_page.S
new file mode 100644
index 000000000000..3539123fe517
--- /dev/null
+++ b/arch/sh/lib/clear_page.S
@@ -0,0 +1,154 @@
+/*
+ * __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>
+
+/*
+ * clear_page
+ * @to: P1 address
+ *
+ * void clear_page(void *to)
+ */
+
+/*
+ * r0 --- scratch
+ * r4 --- to
+ * r5 --- to + PAGE_SIZE
+ */
+ENTRY(clear_page)
+        mov     r4,r5
+        mov.l   .Llimit,r0
+        add     r0,r5
+        mov     #0,r0
+        !
+1:
+#if defined(CONFIG_CPU_SH3)
+        mov.l   r0,@r4
+#elif defined(CONFIG_CPU_SH4)
+        movca.l r0,@r4
+        mov     r4,r1
+#endif
+        add     #32,r4
+        mov.l   r0,@-r4
+        mov.l   r0,@-r4
+        mov.l   r0,@-r4
+        mov.l   r0,@-r4
+        mov.l   r0,@-r4
+        mov.l   r0,@-r4
+        mov.l   r0,@-r4
+#if defined(CONFIG_CPU_SH4)
+        ocbwb   @r1
+#endif
+        cmp/eq  r5,r4
+        bf/s    1b
+         add    #28,r4
+        !
+        rts
+         nop
+
+        .balign 4
+.Llimit:        .long   (PAGE_SIZE-28)
+
+ENTRY(__clear_user)
+        !
+        mov     #0, r0
+        mov     #0xe0, r1       ! 0xffffffe0
+        !
+        ! 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