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>

3 files changed, 12 insertions, 12 deletions

diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S
index 5de99b498738..7ba3dcbe7504 100644
--- a/arch/sh/kernel/cpu/sh3/entry.S
+++ b/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
         !
diff --git a/arch/sh/kernel/head.S b/arch/sh/kernel/head.S
index b5ff23264617..6aca4bc6ec5d 100644
--- a/arch/sh/kernel/head.S
+++ b/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
diff --git a/arch/sh/kernel/relocate_kernel.S b/arch/sh/kernel/relocate_kernel.S
index 8221b37c9773..c66cb3209db5 100644
--- a/arch/sh/kernel/relocate_kernel.S
+++ b/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: