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Commit 510c72ad authored by Paul Mundt's avatar Paul Mundt
Browse files

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: default avatarPaul Mundt <lethal@linux-sh.org>
parent 1dc41e58

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

+3 −2
Original line number Diff line number Diff line
@@ -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

+3 −2
Original line number Diff line number Diff line
@@ -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

+6 −8
Original line number Diff line number Diff line
@@ -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:

arch/sh/mm/cache-sh4.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

	}

arch/sh/mm/clear_page.S

+9 −9
Original line number Diff line number Diff line 
/* $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