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-rw-r--r--arch/mips/lib/cache_init.S241
1 files changed, 241 insertions, 0 deletions
diff --git a/arch/mips/lib/cache_init.S b/arch/mips/lib/cache_init.S
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+++ b/arch/mips/lib/cache_init.S
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+/*
+ * 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)