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>

5 files changed, 19 insertions, 22 deletions

diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
index 7e62ba071d6..ae531affccb 100644
--- a/arch/sh/mm/cache-sh4.c
+++ b/arch/sh/mm/cache-sh4.c
@@ -225,7 +225,7 @@ static inline void flush_cache_4096(unsigned long start,
 	 */
 	if ((cpu_data->flags & CPU_HAS_P2_FLUSH_BUG) ||
 	    (start < CACHE_OC_ADDRESS_ARRAY))
-	    	exec_offset = 0x20000000;
+		exec_offset = 0x20000000;
 
 	local_irq_save(flags);
 	__flush_cache_4096(start | SH_CACHE_ASSOC,
@@ -246,7 +246,7 @@ void flush_dcache_page(struct page *page)
 
 		/* Loop all the D-cache */
 		n = cpu_data->dcache.n_aliases;
-		for (i = 0; i < n; i++, addr += PAGE_SIZE)
+		for (i = 0; i < n; i++, addr += 4096)
 			flush_cache_4096(addr, phys);
 	}
 
diff --git a/arch/sh/mm/clear_page.S b/arch/sh/mm/clear_page.S
index 7b96425ae27..8a706131e52 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
 
diff --git a/arch/sh/mm/copy_page.S b/arch/sh/mm/copy_page.S
index 1addffe117c..397c94c9731 100644
--- a/arch/sh/mm/copy_page.S
+++ b/arch/sh/mm/copy_page.S
@@ -1,12 +1,12 @@
-/* $Id: copy_page.S,v 1.8 2003/08/25 17:03:10 lethal Exp $
- *
+/*
  * copy_page, __copy_user_page, __copy_user implementation of SuperH
  *
  * Copyright (C) 2001  Niibe Yutaka & Kaz Kojima
  * Copyright (C) 2002  Toshinobu Sugioka
- *
+ * Copyright (C) 2006  Paul Mundt
  */
 #include <linux/linkage.h>
+#include <asm/page.h>
 
 /*
  * copy_page_slow
@@ -18,7 +18,7 @@
 
 /*
  * r0, r1, r2, r3, r4, r5, r6, r7 --- scratch 
- * r8 --- from + 4096
+ * r8 --- from + PAGE_SIZE
  * r9 --- not used
  * r10 --- to
  * r11 --- from
@@ -30,7 +30,7 @@ ENTRY(copy_page_slow)
 	mov	r4,r10
 	mov	r5,r11
 	mov	r5,r8
-	mov.w	.L4096,r0
+	mov.l	.Lpsz,r0
 	add	r0,r8
 	!
 1:	mov.l	@r11+,r0
@@ -80,7 +80,7 @@ ENTRY(copy_page_slow)
 
 /*
  * r0, r1, r2, r3, r4, r5, r6, r7 --- scratch 
- * r8 --- from + 4096
+ * r8 --- from + PAGE_SIZE
  * r9 --- orig_to
  * r10 --- to
  * r11 --- from
@@ -94,7 +94,7 @@ ENTRY(__copy_user_page)
 	mov	r5,r11
 	mov	r6,r9
 	mov	r5,r8
-	mov.w	.L4096,r0
+	mov.l	.Lpsz,r0
 	add	r0,r8
 	!
 1:	ocbi	@r9
@@ -129,7 +129,7 @@ ENTRY(__copy_user_page)
 	rts
 	 nop
 #endif
-.L4096:	.word	4096
+.Lpsz:	.long	PAGE_SIZE
 /*
  * __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
  * Return the number of bytes NOT copied
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 462bfeac6d9..59f4cc18235 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -217,7 +217,6 @@ static struct kcore_list kcore_mem, kcore_vmalloc;
 
 void __init mem_init(void)
 {
-	extern unsigned long empty_zero_page[1024];
 	int codesize, reservedpages, datasize, initsize;
 	int tmp;
 	extern unsigned long memory_start;
diff --git a/arch/sh/mm/pg-dma.c b/arch/sh/mm/pg-dma.c
index 1406d2e348c..bb23679369d 100644
--- a/arch/sh/mm/pg-dma.c
+++ b/arch/sh/mm/pg-dma.c
@@ -39,8 +39,6 @@ static void copy_page_dma(void *to, void *from)
 
 static void clear_page_dma(void *to)
 {
-	extern unsigned long empty_zero_page[1024];
-
 	/*
 	 * We get invoked quite early on, if the DMAC hasn't been initialized
 	 * yet, fall back on the slow manual implementation.