/*
* Cache-handling routined for MIPS 4K 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 <config.h>
#include <version.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/addrspace.h>
#include <asm/cacheops.h>
/* 16KB is the maximum size of instruction and data caches on
* MIPS 4K.
*/
#define MIPS_MAX_CACHE_SIZE 0x4000
/*
* cacheop macro to automate cache operations
* first some helpers...
*/
#define _mincache(size, maxsize) \
bltu size,maxsize,9f ; \
move size,maxsize ; \
9:
#define _align(minaddr, maxaddr, linesize) \
.set noat ; \
subu AT,linesize,1 ; \
not AT ; \
and minaddr,AT ; \
addu maxaddr,-1 ; \
and maxaddr,AT ; \
.set at
/* general operations */
#define doop1(op1) \
cache op1,0(a0)
#define doop2(op1, op2) \
cache op1,0(a0) ; \
nop ; \
cache op2,0(a0)
/* specials for cache initialisation */
#define doop1lw(op1) \
lw zero,0(a0)
#define doop1lw1(op1) \
cache op1,0(a0) ; \
lw zero,0(a0) ; \
cache op1,0(a0)
#define doop121(op1,op2) \
cache op1,0(a0) ; \
nop; \
cache op2,0(a0) ; \
nop; \
cache op1,0(a0)
#define _oploopn(minaddr, maxaddr, linesize, tag, ops) \
.set noreorder ; \
10: doop##tag##ops ; \
bne minaddr,maxaddr,10b ; \
add minaddr,linesize ; \
.set reorder
/* finally the cache operation macros */
#define vcacheopn(kva, n, cacheSize, cacheLineSize, tag, ops) \
blez n,11f ; \
addu n,kva ; \
_align(kva, n, cacheLineSize) ; \
_oploopn(kva, n, cacheLineSize, tag, ops) ; \
11:
#define icacheopn(kva, n, cacheSize, cacheLineSize, tag, ops) \
_mincache(n, cacheSize); \
blez n,11f ; \
addu n,kva ; \
_align(kva, n, cacheLineSize) ; \
_oploopn(kva, n, cacheLineSize, tag, ops) ; \
11:
#define vcacheop(kva, n, cacheSize, cacheLineSize, op) \
vcacheopn(kva, n, cacheSize, cacheLineSize, 1, (op))
#define icacheop(kva, n, cacheSize, cacheLineSize, op) \
icacheopn(kva, n, cacheSize, cacheLineSize, 1, (op))
/*******************************************************************************
*
* 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
*
*/
.globl mips_cache_reset
.ent mips_cache_reset
mips_cache_reset:
li t2, CFG_ICACHE_SIZE
li t3, CFG_DCACHE_SIZE
li t4, CFG_CACHELINE_SIZE
move t5, t4
li v0, MIPS_MAX_CACHE_SIZE
/* Now clear that much memory starting from zero.
*/
li a0, KSEG1
addu a1, a0, v0
2: sw zero, 0(a0)
sw zero, 4(a0)
sw zero, 8(a0)
sw zero, 12(a0)
sw zero, 16(a0)
sw zero, 20(a0)
sw zero, 24(a0)
sw zero, 28(a0)
addu a0, 32
bltu a0, a1, 2b
/* Set invalid tag.
*/
mtc0 zero, CP0_TAGLO
/*
* 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.
*/
li a0, K0BASE
move a2, t2 # icacheSize
move a3, t4 # icacheLineSize
move a1, a2
icacheopn(a0,a1,a2,a3,121,(Index_Store_Tag_I,Fill))
/* To support Orion/R4600, we initialise the data cache in 3 passes.
*/
/* 1: initialise dcache tags.
*/
li a0, K0BASE
move a2, t3 # dcacheSize
move a3, t5 # dcacheLineSize
move a1, a2
icacheop(a0,a1,a2,a3,Index_Store_Tag_D)
/* 2: fill dcache.
*/
li a0, K0BASE
move a2, t3 # dcacheSize
move a3, t5 # dcacheLineSize
move a1, a2
icacheopn(a0,a1,a2,a3,1lw,(dummy))
/* 3: clear dcache tags.
*/
li a0, K0BASE
move a2, t3 # dcacheSize
move a3, t5 # dcacheLineSize
move a1, a2
icacheop(a0,a1,a2,a3,Index_Store_Tag_D)
j ra
.end mips_cache_reset
/*******************************************************************************
*
* dcache_status - get cache status
*
* RETURNS: 0 - cache disabled; 1 - cache enabled
*
*/
.globl dcache_status
.ent dcache_status
dcache_status:
mfc0 v0, CP0_CONFIG
andi v0, v0, 1
j ra
.end dcache_status
/*******************************************************************************
*
* dcache_disable - disable cache
*
* RETURNS: N/A
*
*/
.globl dcache_disable
.ent dcache_disable
dcache_disable:
mfc0 t0, CP0_CONFIG
li t1, -8
and t0, t0, t1
ori t0, t0, CONF_CM_UNCACHED
mtc0 t0, CP0_CONFIG
j ra
.end dcache_disable
/*******************************************************************************
*
* mips_cache_lock - lock RAM area pointed to by a0 in cache.
*
* RETURNS: N/A
*
*/
#if defined(CONFIG_INCA_IP)
# define CACHE_LOCK_SIZE (CFG_DCACHE_SIZE)
#elif defined(CONFIG_PURPLE)
# define CACHE_LOCK_SIZE (CFG_DCACHE_SIZE/2)
#endif
.globl mips_cache_lock
.ent mips_cache_lock
mips_cache_lock:
li a1, K0BASE - CACHE_LOCK_SIZE
addu a0, a1
li a2, CACHE_LOCK_SIZE
li a3, CFG_CACHELINE_SIZE
move a1, a2
icacheop(a0,a1,a2,a3,0x1d)
j ra
.end mips_cache_lock
