MIPS: unify cache initialization code
The mips32 & mips64 cache initialization code differs only in that the
mips32 code supports reading the cache size from coprocessor 0 registers
at runtime. Move the more developed mips32 version to a common
arch/mips/lib/cache_init.S & remove the now-redundant mips64 version in
order to reduce duplication. The temporary registers used are shuffled
slightly in order to work for both mips32 & mips64 builds. The RA
register is defined differently to suit mips32 & mips64, but will be
removed by a later commit in the series after further cleanup.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/lib/cache_init.S b/arch/mips/lib/cache_init.S
new file mode 100644
index 0000000..6c02bf9
--- /dev/null
+++ b/arch/mips/lib/cache_init.S
@@ -0,0 +1,277 @@
+/*
+ * 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
+
+#ifdef CONFIG_64BIT
+# define RA ta3
+#else
+# define RA t7
+#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
+
+/*
+ * 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 INDEX_STORE_TAG_I, 0(t0)
+ PTR_ADDU t0, a2
+ bne t0, t1, 1b
+ /* fill once, so data field parity is correct */
+ PTR_LI t0, INDEX_BASE
+2: cache FILL, 0(t0)
+ PTR_ADDU t0, a2
+ bne t0, t1, 2b
+ /* invalidate again - prudent but not strictly neccessary */
+ PTR_LI t0, INDEX_BASE
+1: cache INDEX_STORE_TAG_I, 0(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 INDEX_STORE_TAG_D, 0(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 INDEX_STORE_TAG_D, 0(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
+
+#if !defined(CONFIG_SYS_ICACHE_SIZE) || !defined(CONFIG_SYS_DCACHE_SIZE) || \
+ !defined(CONFIG_SYS_CACHELINE_SIZE)
+ /* read Config1 for use below */
+ mfc0 t5, CP0_CONFIG, 1
+#endif
+
+#ifdef CONFIG_SYS_CACHELINE_SIZE
+ li t9, CONFIG_SYS_CACHELINE_SIZE
+ li t8, CONFIG_SYS_CACHELINE_SIZE
+#else
+ /* Detect I-cache line size. */
+ srl t8, t5, MIPS_CONF1_IL_SHIFT
+ andi t8, t8, (MIPS_CONF1_IL >> MIPS_CONF1_IL_SHIFT)
+ beqz t8, 1f
+ li t6, 2
+ sllv t8, t6, t8
+
+1: /* Detect D-cache line size. */
+ srl t9, t5, MIPS_CONF1_DL_SHIFT
+ andi t9, t9, (MIPS_CONF1_DL >> MIPS_CONF1_DL_SHIFT)
+ beqz t9, 1f
+ li t6, 2
+ sllv t9, t6, t9
+1:
+#endif
+
+#ifdef CONFIG_SYS_ICACHE_SIZE
+ li t2, CONFIG_SYS_ICACHE_SIZE
+#else
+ /* Detect I-cache size. */
+ srl t6, t5, MIPS_CONF1_IS_SHIFT
+ andi t6, t6, (MIPS_CONF1_IS >> MIPS_CONF1_IS_SHIFT)
+ li t4, 32
+ xori t2, t6, 0x7
+ beqz t2, 1f
+ addi t6, t6, 1
+ sllv t4, t4, t6
+1: /* At this point t4 == I-cache sets. */
+ mul t2, t4, t8
+ srl t6, t5, MIPS_CONF1_IA_SHIFT
+ andi t6, t6, (MIPS_CONF1_IA >> MIPS_CONF1_IA_SHIFT)
+ addi t6, t6, 1
+ /* At this point t6 == I-cache ways. */
+ mul t2, t2, t6
+#endif
+
+#ifdef CONFIG_SYS_DCACHE_SIZE
+ li t3, CONFIG_SYS_DCACHE_SIZE
+#else
+ /* Detect D-cache size. */
+ srl t6, t5, MIPS_CONF1_DS_SHIFT
+ andi t6, t6, (MIPS_CONF1_DS >> MIPS_CONF1_DS_SHIFT)
+ li t4, 32
+ xori t3, t6, 0x7
+ beqz t3, 1f
+ addi t6, t6, 1
+ sllv t4, t4, t6
+1: /* At this point t4 == I-cache sets. */
+ mul t3, t4, t9
+ srl t6, t5, MIPS_CONF1_DA_SHIFT
+ andi t6, t6, (MIPS_CONF1_DA >> MIPS_CONF1_DA_SHIFT)
+ addi t6, t6, 1
+ /* At this point t6 == I-cache ways. */
+ mul t3, t3, t6
+#endif
+
+ /* 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
+
+ /*
+ * 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, t9
+ 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, CONFIG_SYS_MIPS_CACHE_MODE
+ mtc0 t0, CP0_CONFIG
+ jr ra
+ END(dcache_enable)