path: root/arch/arm/mm/proc-arm940.S

/*
 *  linux/arch/arm/mm/arm940.S: utility functions for ARM940T
 *
 *  Copyright (C) 2004-2006 Hyok S. Choi (hyok.choi@samsung.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
#include <asm/hwcap.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include <asm/ptrace.h>
#include "proc-macros.S"

/* ARM940T has a 4KB DCache comprising 256 lines of 4 words */
#define CACHE_DLINESIZE	16
#define CACHE_DSEGMENTS	4
#define CACHE_DENTRIES	64

	.text
/*
 * cpu_arm940_proc_init()
 * cpu_arm940_switch_mm()
 *
 * These are not required.
 */
ENTRY(cpu_arm940_proc_init)
ENTRY(cpu_arm940_switch_mm)
	ret	lr

/*
 * cpu_arm940_proc_fin()
 */
ENTRY(cpu_arm940_proc_fin)
	mrc	p15, 0, r0, c1, c0, 0		@ ctrl register
	bic	r0, r0, #0x00001000		@ i-cache
	bic	r0, r0, #0x00000004		@ d-cache
	mcr	p15, 0, r0, c1, c0, 0		@ disable caches
	ret	lr

/*
 * cpu_arm940_reset(loc)
 * Params  : r0 = address to jump to
 * Notes   : This sets up everything for a reset
 */
	.pushsection	.idmap.text, "ax"
ENTRY(cpu_arm940_reset)
	mov	ip, #0
	mcr	p15, 0, ip, c7, c5, 0		@ flush I cache
	mcr	p15, 0, ip, c7, c6, 0		@ flush D cache
	mcr	p15, 0, ip, c7, c10, 4		@ drain WB
	mrc	p15, 0, ip, c1, c0, 0		@ ctrl register
	bic	ip, ip, #0x00000005		@ .............c.p
	bic	ip, ip, #0x00001000		@ i-cache
	mcr	p15, 0, ip, c1, c0, 0		@ ctrl register
	ret	r0
ENDPROC(cpu_arm940_reset)
	.popsection

/*
 * cpu_arm940_do_idle()
 */
	.align	5
ENTRY(cpu_arm940_do_idle)
	mcr	p15, 0, r0, c7, c0, 4		@ Wait for interrupt
	ret	lr

/*
 *	flush_icache_all()
 *
 *	Unconditionally clean and invalidate the entire icache.
 */
ENTRY(arm940_flush_icache_all)
	mov	r0, #0
	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
	ret	lr
ENDPROC(arm940_flush_icache_all)

/*
 *	flush_user_cache_all()
 */
ENTRY(arm940_flush_user_cache_all)
	/* FALLTHROUGH */

/*
 *	flush_kern_cache_all()
 *
 *	Clean and invalidate the entire cache.
 */
ENTRY(arm940_flush_kern_cache_all)
	mov	r2, #VM_EXEC
	/* FALLTHROUGH */

/*
 *	flush_user_cache_range(start, end, flags)
 *
 *	There is no efficient way to flush a range of cache entries
 *	in the specified address range. Thus, flushes all.
 *
 *	- start	- start address (inclusive)
 *	- end	- end address (exclusive)
 *	- flags	- vm_flags describing address space
 */
ENTRY(arm940_flush_user_cache_range)
	mov	ip, #0
#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
	mcr	p15, 0, ip, c7, c6, 0		@ flush D cache
#else
	mov	r1, #(CACHE_DSEGMENTS - 1) << 4	@ 4 segments
1:	orr	r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2:	mcr	p15, 0, r3, c7, c14, 2		@ clean/flush D index
	subs	r3, r3, #1 << 26
	bcs	2b				@ entries 63 to 0
	subs	r1, r1, #1 << 4
	bcs	1b				@ segments 3 to 0
#endif
	tst	r2, #VM_EXEC
	mcrne	p15, 0, ip, c7, c5, 0		@ invalidate I cache
	mcrne	p15, 0, ip, c7, c10, 4		@ drain WB
	ret	lr

/*
 *	coherent_kern_range(start, end)
 *
 *	Ensure coherency between the Icache and the Dcache in the
 *	region described by start, end.  If you have non-snooping
 *	Harvard caches, you need to implement this function.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
ENTRY(arm940_coherent_kern_range)
	/* FALLTHROUGH */

/*
 *	coherent_user_range(start, end)
 *
 *	Ensure coherency between the Icache and the Dcache in the
 *	region described by start, end.  If you have non-snooping
 *	Harvard caches, you need to implement this function.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
ENTRY(arm940_coherent_user_range)
	/* FALLTHROUGH */

/*
 *	flush_kern_dcache_area(void *addr, size_t size)
 *
 *	Ensure no D cache aliasing occurs, either with itself or
 *	the I cache
 *
 *	- addr	- kernel address
 *	- size	- region size
 */
ENTRY(arm940_flush_kern_dcache_area)
	mov	r0, #0
	mov	r1, #(CACHE_DSEGMENTS - 1) << 4	@ 4 segments
1:	orr	r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2:	mcr	p15, 0, r3, c7, c14, 2		@ clean/flush D index
	subs	r3, r3, #1 << 26
	bcs	2b				@ entries 63 to 0
	subs	r1, r1, #1 << 4
	bcs	1b				@ segments 7 to 0
	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
	mcr	p15, 0, r0, c7, c10, 4		@ drain WB
	ret	lr

/*
 *	dma_inv_range(start, end)
 *
 *	There is no efficient way to invalidate a specifid virtual
 *	address range. Thus, invalidates all.
 *
 *	- start	- virtual start address
 *	- end	- virtual end address
 */
arm940_dma_inv_range:
	mov	ip, #0
	mov	r1, #(CACHE_DSEGMENTS - 1) << 4	@ 4 segments
1:	orr	r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries
2:	mcr	p15, 0, r3, c7, c6, 2		@ flush D entry
	subs	r3, r3, #1 << 26
	bcs	2b				@ entries 63 to 0
	subs	r1, r1, #1 << 4
	bcs	1b				@ segments 7 to 0
	mcr	p15, 0, ip, c7, c10, 4		@ drain WB
	ret	lr

/*
 *	dma_clean_range(