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Diffstat (limited to 'arch/mips/lib/cache_init.S')
| -rw-r--r-- | arch/mips/lib/cache_init.S | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/arch/mips/lib/cache_init.S b/arch/mips/lib/cache_init.S new file mode 100644 index 0000000000..137d7283ff --- /dev/null +++ b/arch/mips/lib/cache_init.S @@ -0,0 +1,241 @@ +/* + * Cache-handling routined for MIPS CPUs + * + * Copyright (c) 2003 Wolfgang Denk <wd@denx.de> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#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 INDEX_BASE CKSEG0 + + .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 + + .macro cache_loop curr, end, line_sz, op +10: cache \op, 0(\curr) + PTR_ADDU \curr, \curr, \line_sz + bne \curr, \end, 10b + .endm + + .macro l1_info sz, line_sz, off + .set push + .set noat + + mfc0 $1, CP0_CONFIG, 1 + + /* detect line size */ + srl \line_sz, $1, \off + MIPS_CONF1_DL_SHIFT - MIPS_CONF1_DA_SHIFT + andi \line_sz, \line_sz, (MIPS_CONF1_DL >> MIPS_CONF1_DL_SHIFT) + move \sz, zero + beqz \line_sz, 10f + li \sz, 2 + sllv \line_sz, \sz, \line_sz + + /* detect associativity */ + srl \sz, $1, \off + MIPS_CONF1_DA_SHIFT - MIPS_CONF1_DA_SHIFT + andi \sz, \sz, (MIPS_CONF1_DA >> MIPS_CONF1_DA_SHIFT) + addi \sz, \sz, 1 + + /* sz *= line_sz */ + mul \sz, \sz, \line_sz + + /* detect log32(sets) */ + srl $1, $1, \off + MIPS_CONF1_DS_SHIFT - MIPS_CONF1_DA_SHIFT + andi $1, $1, (MIPS_CONF1_DS >> MIPS_CONF1_DS_SHIFT) + addiu $1, $1, 1 + andi $1, $1, 0x7 + + /* sz <<= log32(sets) */ + sllv \sz, \sz, $1 + + /* sz *= 32 */ + li $1, 32 + mul \sz, \sz, $1 +10: + .set pop + .endm +/* + * 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 + * + */ +LEAF(mips_cache_reset) +#ifdef CONFIG_SYS_ICACHE_SIZE + li t2, CONFIG_SYS_ICACHE_SIZE + li t8, CONFIG_SYS_CACHELINE_SIZE +#else + l1_info t2, t8, MIPS_CONF1_IA_SHIFT +#endif + +#ifdef CONFIG_SYS_DCACHE_SIZE + li t3, CONFIG_SYS_DCACHE_SIZE + li t9, CONFIG_SYS_CACHELINE_SIZE +#else + l1_info t3, t9, MIPS_CONF1_DA_SHIFT +#endif + +#ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD + + /* Determine the largest L1 cache size */ +#if defined(CONFIG_SYS_ICACHE_SIZE) && defined(CONFIG_SYS_DCACHE_SIZE) +#if CONFIG_SYS_ICACHE_SIZE > CONFIG_SYS_DCACHE_SIZE + li v0, CONFIG_SYS_ICACHE_SIZE +#else + li v0, CONFIG_SYS_DCACHE_SIZE +#endif +#else + move v0, t2 + sltu t1, t2, t3 + movn v0, t3, t1 +#endif + /* + * 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 + +#endif /* CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD */ + + /* + * The TagLo registers used depend upon the CPU implementation, but the + * architecture requires that it is safe for software to write to both + * TagLo selects 0 & 2 covering supported cases. + */ + mtc0 zero, CP0_TAGLO + mtc0 zero, CP0_TAGLO, 2 + + /* + * The caches are probably in an indeterminate state, so we force good + * parity into them by doing an invalidate for each line. If + * CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD is set then we'll proceed to + * perform a load/fill & a further invalidate for each line, assuming + * that the bottom of RAM (having just been cleared) will generate good + * parity for the cache. + */ + + /* + * Initialize the I-cache first, + */ + blez t2, 1f + PTR_LI t0, INDEX_BASE + PTR_ADDU t1, t0, t2 + /* clear tag to invalidate */ + cache_loop t0, t1, t8, INDEX_STORE_TAG_I +#ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD + /* fill once, so data field parity is correct */ + PTR_LI t0, INDEX_BASE + cache_loop t0, t1, t8, FILL + /* invalidate again - prudent but not strictly neccessary */ + PTR_LI t0, INDEX_BASE + cache_loop t0, t1, t8, INDEX_STORE_TAG_I +#endif + + /* + * then initialize D-cache. + */ +1: blez t3, 3f + PTR_LI t0, INDEX_BASE + PTR_ADDU t1, t0, t3 + /* clear all tags */ + cache_loop t0, t1, t9, INDEX_STORE_TAG_D +#ifdef CONFIG_SYS_MIPS_CACHE_INIT_RAM_LOAD + /* load from each line (in cached space) */ + PTR_LI t0, INDEX_BASE +2: LONG_L zero, 0(t0) + PTR_ADDU t0, t9 + bne t0, t1, 2b + /* clear all tags */ + PTR_LI t0, INDEX_BASE + cache_loop t0, t1, t9, INDEX_STORE_TAG_D +#endif + +3: 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) |