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Diffstat (limited to 'arch/mips/cpu/mips64/cache.S')
| -rw-r--r-- | arch/mips/cpu/mips64/cache.S | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/arch/mips/cpu/mips64/cache.S b/arch/mips/cpu/mips64/cache.S new file mode 100644 index 0000000..036f035 --- /dev/null +++ b/arch/mips/cpu/mips64/cache.S @@ -0,0 +1,229 @@ +/* + * 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> + +#define RA t9 + +/* + * 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 t8, CONFIG_SYS_CACHELINE_SIZE + + 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, t8 + PTR_LA v1, mips_init_icache + jalr v1 + + /* + * then initialize D-cache. + */ + move a1, t3 + move a2, t8 + PTR_LA v1, mips_init_dcache + jalr v1 + + 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, CONF_CM_CACHABLE_NONCOHERENT + mtc0 t0, CP0_CONFIG + jr ra + END(dcache_enable) |