berlin_tools/bootloader/cache.S

/*
 * Copyright (C) 2009 Samsung Electronics
 * Minkyu Kang <mk7.kang@samsung.com>
 *
 * based on arch/arm/cpu/armv7/omap3/cache.S
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */



.align 5
.global invalidate_dcache
.global invalidate_dcache_range
.global l2_cache_enable
.global l2_cache_disable
.global flush_dcache_range
.global flush_all_dcache

/*
 * cache_line_size - get the cache line size from the CSIDR register
 * (available on ARMv7+). It assumes that the CSSR register was configured
 * to access the L1 data cache CSIDR.
 */
.macro  dcache_line_size, reg, tmp
	mrc     p15, 1, \tmp, c0, c0, 0         @ read CSIDR
	and     \tmp, \tmp, #7                  @ cache line size encoding
	mov     \reg, #16                       @ size offset
	mov     \reg, \reg, lsl \tmp            @ actual cache line size
.endm

/*
 *      flush_dcache_range(start,end)
 *      - start   - virtual start address of region
 *      - end     - virtual end address of region
 */
flush_dcache_range:
	stmfd	sp!, {r0 - r3, lr}
	dcache_line_size r2, r3
	sub     r3, r2, #1
	bic     r0, r0, r3
1:
	mcr     p15, 0, r0, c7, c14, 1          @ clean & invalidate D / U line
	add     r0, r0, r2
	cmp     r0, r1
	blo     1b
	mov	r0, #0
	mcr     p15, 0, r0, c7, c10, 4          @ dsb
	ldmfd	sp!, {r0 - r3, lr}
	bx	lr

/*
 * flush_all_dcache()
 * Clean & Invalidate the whole D-cache.
 *
 * Corrupted registers: r0-r5, r7, r9-r11
 */
flush_all_dcache:
	stmfd	r13!, {r0, lr}
	mov	r0, #1
	bl	__invalidate_dcache
	ldmfd	r13!, {r0, lr}
	bx	lr

/*
 *      invalidate_dcache_range(start,end)
 *      - start   - virtual start address of region
 *      - end     - virtual end address of region
 */
invalidate_dcache_range:
	stmfd	sp!, {r0 - r3, lr}
	dcache_line_size r2, r3
	sub     r3, r2, #1
	bic     r0, r0, r3
1:
	mcr     p15, 0, r0, c7, c6, 1          @ invalidate D / U line
	add     r0, r0, r2
	cmp     r0, r1
	blo     1b
	mov	r0, #0
	mcr     p15, 0, r0, c7, c10, 4          @ dsb
	ldmfd	sp!, {r0 - r3, lr}
	bx	lr

/*
 * invalidate_dcache()
 * Invalidate the whole D-cache.
 *
 * Corrupted registers: r0-r5, r7, r9-r11
 */
invalidate_dcache:
	stmfd	r13!, {r0, lr}
	mov	r0, #0
	bl	__invalidate_dcache
	ldmfd	r13!, {r0, lr}
	bx	lr

/*
 * __invalidate_dcache()
 * Flush or Invalidate the whole D-cache.
 *
 * Corrupted registers: r0-r5, r7, r9-r11
 */

__invalidate_dcache:
	stmfd	r13!, {r0 - r7, r9 - r12, lr}
	mov	r6, r0
	mov	r0, #0
	mcr     p15, 0, r0, c7, c10, 5          @ dmb
	mrc	p15, 1, r0, c0, c0, 1		@ read clidr
	ands	r3, r0, #0x7000000		@ extract loc from clidr
	mov	r3, r3, lsr #23			@ left align loc bit field
	beq	finished_inval			@ if loc is 0, then no need to clean
	mov	r10, #0				@ start clean at cache level 0
inval_loop1:
	add	r2, r10, r10, lsr #1		@ work out 3x current cache level
	mov	r1, r0, lsr r2			@ extract cache type bits from clidr
	and	r1, r1, #7			@ mask of the bits for current cache only
	cmp	r1, #2				@ see what cache we have at this level
	blt	skip_inval			@ skip if no cache, or just i-cache
	mcr	p15, 2, r10, c0, c0, 0		@ select current cache level in cssr
	mov	r2, #0				@ operand for mcr SBZ
	mcr	p15, 0, r2, c7, c5, 4		@ isb
	mrc	p15, 1, r1, c0, c0, 0		@ read the new csidr
	and	r2, r1, #7			@ extract the length of the cache lines
	add	r2, r2, #4			@ add 4 (line length offset)
	ldr	r4, =0x3ff
	ands	r4, r4, r1, lsr #3		@ find maximum number on the way size
	clz	r5, r4				@ find bit position of way size increment
	ldr	r7, =0x7fff
	ands	r7, r7, r1, lsr #13		@ extract max number of the index size
inval_loop2:
	mov	r9, r4				@ create working copy of max way size
inval_loop3:
	orr	r11, r10, r9, lsl r5		@ factor way and cache number into r11
	orr	r11, r11, r7, lsl r2		@ factor index number into r11
	cmp	r6, #0
	mcreq	p15, 0, r11, c7, c6, 2		@ invalidate by set/way
	mcrne	p15, 0, r11, c7, c14, 2		@ clean & invalidate by set/way
	subs	r9, r9, #1			@ decrement the way
	bge	inval_loop3
	subs	r7, r7, #1			@ decrement the index
	bge	inval_loop2
skip_inval:
	add	r10, r10, #2			@ increment cache number
	cmp	r3, r10
	bgt	inval_loop1
finished_inval:
	mov	r10, #0				@ swith back to cache level 0
	mcr	p15, 2, r10, c0, c0, 0		@ select current cache level in cssr
	mcr     p15, 0, r10, c7, c10, 4         @ dsb
	mcr	p15, 0, r10, c7, c5, 4		@ isb
	ldmfd	r13!, {r0 - r7, r9 - r12, lr}
	bx	lr

l2_cache_enable:
	push	{r0, r1, r2, lr}
	mrc	15, 0, r3, cr1, cr0, 1
	orr	r3, r3, #2
	mcr	15, 0, r3, cr1, cr0, 1
	pop	{r1, r2, r3, lr}
	bx	lr

l2_cache_disable:
	push	{r0, r1, r2, lr}
	mrc	15, 0, r3, cr1, cr0, 1
	bic	r3, r3, #2
	mcr	15, 0, r3, cr1, cr0, 1
	pop	{r1, r2, r3, lr}
	bx	lr