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/*
* Cache-handling routined for MIPS CPUs
*
* Copyright (c) 2003 Wolfgang Denk <wd@denx.de>
*
* 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
*/
#include <asm-offsets.h>
#include <config.h>
#include <asm/asm.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/addrspace.h>
#include <asm/cacheops.h>
#ifndef CONFIG_SYS_MIPS_CACHE_MODE
#define CONFIG_SYS_MIPS_CACHE_MODE CONF_CM_CACHABLE_NONCOHERENT
#endif
#define RA t8
/*
* 16kB is the maximum size of instruction and data caches on MIPS 4K,
* 64kB is on 4KE, 24K, 5K, etc. Set bigger size for convenience.
*
* Note that the above size is the maximum size of primary cache. U-Boot
* doesn't have L2 cache support for now.
*/
#define MIPS_MAX_CACHE_SIZE 0x10000
#define INDEX_BASE CKSEG0
.macro cache_op op addr
.set push
.set noreorder
.set mips3
cache \op, 0(\addr)
.set pop
.endm
.macro f_fill64 dst, offset, val
LONG_S \val, (\offset + 0 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 1 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 2 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 3 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 4 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 5 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 6 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 7 * LONGSIZE)(\dst)
#if LONGSIZE == 4
LONG_S \val, (\offset + 8 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 9 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 10 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 11 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 12 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 13 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 14 * LONGSIZE)(\dst)
LONG_S \val, (\offset + 15 * LONGSIZE)(\dst)
#endif
.endm
/*
* mips_init_icache(uint PRId, ulong icache_size, unchar icache_linesz)
*/
LEAF(mips_init_icache)
blez a1, 9f
mtc0 zero, CP0_TAGLO
/* clear tag to invalidate */
PTR_LI t0, INDEX_BASE
PTR_ADDU t1, t0, a1
1: cache_op INDEX_STORE_TAG_I t0
PTR_ADDU t0, a2
bne t0, t1, 1b
/* fill once, so data field parity is correct */
PTR_LI t0, INDEX_BASE
2: cache_op FILL t0
PTR_ADDU t0, a2
bne t0, t1, 2b
/* invalidate again - prudent but not strictly neccessary */
PTR_LI t0, INDEX_BASE
1: cache_op INDEX_STORE_TAG_I t0
PTR_ADDU t0, a2
bne t0, t1, 1b
9: jr ra
END(mips_init_icache)
/*
* mips_init_dcache(uint PRId, ulong dcache_size, unchar dcache_linesz)
*/
LEAF(mips_init_dcache)
blez a1, 9f
mtc0 zero, CP0_TAGLO
/* clear all tags */
PTR_LI t0, INDEX_BASE
PTR_ADDU t1, t0, a1
1: cache_op INDEX_STORE_TAG_D t0
PTR_ADDU t0, a2
bne t0, t1, 1b
/* load from each line (in cached space) */
PTR_LI t0, INDEX_BASE
2: LONG_L zero, 0(t0)
PTR_ADDU t0, a2
bne t0, t1, 2b
/* clear all tags */
PTR_LI t0, INDEX_BASE
1: cache_op INDEX_STORE_TAG_D t0
PTR_ADDU t0, a2
bne t0, t1, 1b
9: jr ra
END(mips_init_dcache)
/*
* mips_cache_reset - low level initialisation of the primary caches
*
* This routine initialises the primary caches to ensure that they have good
* parity. It must be called by the ROM before any cached locations are used
* to prevent the possibility of data with bad parity being written to memory.
*
* To initialise the instruction cache it is essential that a source of data
* with good parity is available. This routine will initialise an area of
* memory starting at location zero to be used as a source of parity.
*
* RETURNS: N/A
*
*/
NESTED(mips_cache_reset, 0, ra)
move RA, ra
li t2, CONFIG_SYS_ICACHE_SIZE
li t3, CONFIG_SYS_DCACHE_SIZE
li t4, CONFIG_SYS_CACHELINE_SIZE
move t5, t4
li v0, MIPS_MAX_CACHE_SIZE
/*
* Now clear that much memory starting from zero.
*/
PTR_LI a0, CKSEG1
PTR_ADDU a1, a0, v0
2: PTR_ADDIU a0, 64
f_fill64 a0, -64, zero
bne a0, a1, 2b
/*
* The caches are probably in an indeterminate state,
* so we force good parity into them by doing an
* invalidate, load/fill, invalidate for each line.
*/
/*
* Assume bottom of RAM will generate good parity for the cache.
*/
/*
* Initialize the I-cache first,
*/
move a1, t2
move a2, t4
PTR_LA t7, mips_init_icache
jalr t7
/*
* then initialize D-cache.
*/
move a1, t3
move a2, t5
PTR_LA t7, mips_init_dcache
jalr t7
jr RA
END(mips_cache_reset)
/*
* dcache_status - get cache status
*
* RETURNS: 0 - cache disabled; 1 - cache enabled
*
*/
LEAF(dcache_status)
mfc0 t0, CP0_CONFIG
li t1, CONF_CM_UNCACHED
andi t0, t0, CONF_CM_CMASK
move v0, zero
beq t0, t1, 2f
li v0, 1
2: jr ra
END(dcache_status)
/*
* dcache_disable - disable cache
*
* RETURNS: N/A
*
*/
LEAF(dcache_disable)
mfc0 t0, CP0_CONFIG
li t1, -8
and t0, t0, t1
ori t0, t0, CONF_CM_UNCACHED
mtc0 t0, CP0_CONFIG
jr ra
END(dcache_disable)
/*
* dcache_enable - enable cache
*
* RETURNS: N/A
*
*/
LEAF(dcache_enable)
mfc0 t0, CP0_CONFIG
ori t0, CONF_CM_CMASK
xori t0, CONF_CM_CMASK
ori t0, CONFIG_SYS_MIPS_CACHE_MODE
mtc0 t0, CP0_CONFIG
jr ra
END(dcache_enable)