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>

11 files changed, 37 insertions, 45 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:
 
diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
index 7e62ba071d64..ae531affccbd 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 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
 
diff --git a/arch/sh/mm/copy_page.S b/arch/sh/mm/copy_page.S
index 1addffe117c3..397c94c97315 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 462bfeac6d9c..59f4cc18235b 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 1406d2e348ca..bb23679369d6 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.
diff --git a/include/asm-sh/entry-macros.S b/include/asm-sh/entry-macros.S
index 099fe8189bbe..500030eae7aa 100644
--- a/include/asm-sh/entry-macros.S
+++ b/include/asm-sh/entry-macros.S
@@ -23,8 +23,9 @@
 #ifdef CONFIG_HAS_SR_RB
         stc     r7_bank, \ti
 #else
-        mov     #((THREAD_SIZE - 1)>> 8) ^ 0xff, \tmp
+        mov     #((THREAD_SIZE - 1) >> 10) ^ 0xff, \tmp
         shll8   \tmp
+        shll2   \tmp
         mov     r15, \ti
         and     \tmp, \ti
 #endif  
diff --git a/include/asm-sh/pgtable.h b/include/asm-sh/pgtable.h
index fa625245051d..f87504abb43f 100644
--- a/include/asm-sh/pgtable.h
+++ b/include/asm-sh/pgtable.h
@@ -47,8 +47,8 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
 
 /* Entries per level */
-#define PTRS_PER_PTE    (1 << PTE_BITS)
-#define PTRS_PER_PGD    (1 << PGDIR_BITS)
+#define PTRS_PER_PTE    (PAGE_SIZE / 4)
+#define PTRS_PER_PGD    (PAGE_SIZE / 4)
 
 #define USER_PTRS_PER_PGD       (TASK_SIZE/PGDIR_SIZE)
 #define FIRST_USER_ADDRESS      0
@@ -57,7 +57,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 
 /*
  * First 1MB map is used by fixed purpose.
- * Currently only 4-enty (16kB) is used (see arch/sh/mm/cache.c)
+ * Currently only 4-entry (16kB) is used (see arch/sh/mm/cache.c)
  */
 #define VMALLOC_START   (P3SEG+0x00100000)
 #define VMALLOC_END     (FIXADDR_START-2*PAGE_SIZE)
diff --git a/include/asm-sh/thread_info.h b/include/asm-sh/thread_info.h
index 3ebc3f9039eb..0c01dc550819 100644
--- a/include/asm-sh/thread_info.h
+++ b/include/asm-sh/thread_info.h
@@ -90,13 +90,7 @@ static inline struct thread_info *current_thread_info(void)
 #endif
 #define free_thread_info(ti)    kfree(ti)
 
-#else /* !__ASSEMBLY__ */
-
-/* how to get the thread information struct from ASM */
-#define GET_THREAD_INFO(reg) \
-        stc     r7_bank, reg
-
-#endif
+#endif /* __ASSEMBLY__ */
 
 /*
  * thread information flags