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>

arch/sh/kernel/cpu/sh3/entry.S

@@ -335,7 +335,7 @@ general_exception:
 /* This code makes some assumptions to improve performance.
  * Make sure they are stil true. */
 #if PTRS_PER_PGD != PTRS_PER_PTE
-#error PDG and PTE sizes don't match
+#error PGD and PTE sizes don't match
 #endif
 
 /* gas doesn't flag impossible values for mov #immediate as an error */
@@ -547,8 +547,9 @@ ENTRY(handle_exception)
 	bt/s	1f		! It's a kernel to kernel transition.
 	 mov	r15, k0		! save original stack to k0
 	/* User space to kernel */
-	mov	#(THREAD_SIZE >> 8), k1
+	mov	#(THREAD_SIZE >> 10), k1
 	shll8	k1		! k1 := THREAD_SIZE
+	shll2	k1
 	add	current, k1
 	mov	k1, r15		! change to kernel stack
 	!

arch/sh/kernel/head.S

@@ -33,7 +33,7 @@ ENTRY(empty_zero_page)
 	.long	0x00360000	/* INITRD_START */
 	.long	0x000a0000	/* INITRD_SIZE */
 	.long	0
-	.balign 4096,0,4096
+	.balign PAGE_SIZE,0,PAGE_SIZE
 
 	.text	
 /*
@@ -70,8 +70,9 @@ ENTRY(_stext)
 	!
 	mov.l	2f, r0
 	mov	r0, r15		! Set initial r15 (stack pointer)
-	mov	#(THREAD_SIZE >> 8), r1
+	mov	#(THREAD_SIZE >> 10), r1
 	shll8	r1		! r1 = THREAD_SIZE
+	shll2	r1
 	sub	r1, r0		!
 #ifdef CONFIG_CPU_HAS_SR_RB
 	ldc	r0, r7_bank	! ... and initial thread_info

arch/sh/kernel/relocate_kernel.S

@@ -7,11 +7,9 @@
  * This source code is licensed under the GNU General Public License,
  * Version 2.  See the file COPYING for more details.
  */
-
 #include <linux/linkage.h>
-
-#define PAGE_SIZE      4096 /* must be same value as in <asm/page.h> */
-
+#include <asm/addrspace.h>
+#include <asm/page.h>
 
 		.globl relocate_new_kernel
 relocate_new_kernel:
@@ -20,8 +18,8 @@ relocate_new_kernel:
 	/* r6 = start_address      */
 	/* r7 = vbr_reg            */
 
-	mov.l	10f,r8	  /* 4096 */
-	mov.l	11f,r9    /* 0xa0000000 */
+	mov.l	10f,r8	  /* PAGE_SIZE */
+	mov.l	11f,r9    /* P2SEG */
 
 	/*  stack setting */
 	add	r8,r5
@@ -32,7 +30,7 @@ relocate_new_kernel:
 0:
 	mov.l	@r4+,r0	  /* cmd = *ind++ */
 
-1:	/* addr = (cmd | 0xa0000000) & 0xfffffff0 */
+1:	/* addr = (cmd | P2SEG) & 0xfffffff0 */
 	mov	r0,r2
 	or	r9,r2
 	mov	#-16,r1
@@ -92,7 +90,7 @@ relocate_new_kernel:
 10:
 	.long	PAGE_SIZE
 11:
-	.long	0xa0000000
+	.long	P2SEG
 
 relocate_new_kernel_end: