sh: Fixup various PAGE_SIZE == 4096 assumptions.

There were a number of places that made evil PAGE_SIZE == 4k
assumptions that ended up breaking when trying to play with
8k and 64k page sizes, this fixes those up.

The most significant change is the way we load THREAD_SIZE,
previously this was done via:

	mov	#(THREAD_SIZE >> 8), reg
	shll8	reg

to avoid a memory access and allow the immediate load. With
a 64k PAGE_SIZE, we're out of range for the immediate load
size without resorting to special instructions available in
later ISAs (movi20s and so on). The "workaround" for this is
to bump up the shift to 10 and insert a shll2, which gives a
bit more flexibility while still being much cheaper than a
memory access.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 9 insertions, 9 deletions

diff --git a/arch/sh/mm/clear_page.S b/arch/sh/mm/clear_page.S
index 7b96425ae270..8a706131e521 100644
--- a/arch/sh/mm/clear_page.S
+++ b/arch/sh/mm/clear_page.S
@@ -1,12 +1,12 @@
-/* $Id: clear_page.S,v 1.13 2003/08/25 17:03:10 lethal Exp $
- *
+/*
  * __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_slow
@@ -18,11 +18,11 @@
 /*
  * r0 --- scratch
  * r4 --- to
- * r5 --- to + 4096
+ * r5 --- to + PAGE_SIZE
  */
 ENTRY(clear_page_slow)
         mov     r4,r5
-        mov.w   .Llimit,r0
+        mov.l   .Llimit,r0
         add     r0,r5
         mov     #0,r0
         !
@@ -50,7 +50,7 @@ ENTRY(clear_page_slow)
         !
         rts
          nop
-.Llimit:        .word   (4096-28)
+.Llimit:        .long   (PAGE_SIZE-28)
 
 ENTRY(__clear_user)
         !
@@ -164,10 +164,10 @@ ENTRY(__clear_user)
  * r0 --- scratch 
  * r4 --- to
  * r5 --- orig_to
- * r6 --- to + 4096
+ * r6 --- to + PAGE_SIZE
  */
 ENTRY(__clear_user_page)
-        mov.w   .L4096,r0
+        mov.l   .Lpsz,r0
         mov     r4,r6
         add     r0,r6
         mov     #0,r0
@@ -191,7 +191,7 @@ ENTRY(__clear_user_page)
         !
         rts
          nop
-.L4096: .word   4096
+.Lpsz:  .long   PAGE_SIZE
 
 #endif