/* * Cache-handling routined for MIPS 4K CPUs * * Copyright (c) 2003 Wolfgang Denk * * 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 #include #include #include #include #include /* 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_PURPLE) # define CACHE_LOCK_SIZE (CFG_DCACHE_SIZE/2) #else # define CACHE_LOCK_SIZE (CFG_DCACHE_SIZE) #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