u-boot/arch/mips/cpu/mips32/cache.S

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/*
* 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>
#ifndef CONFIG_SYS_MIPS_CACHE_MODE
#define CONFIG_SYS_MIPS_CACHE_MODE CONF_CM_CACHABLE_NONCOHERENT
#endif
#define RA t8
/*
* 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 t4, CONFIG_SYS_CACHELINE_SIZE
move t5, t4
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, t4
[MIPS] cpu/mips/cache.S: Fix build warning Some old GNU assemblers, such as v2.14 (ELDK 3.1.1), v2.16 (ELDK 4.1.0), warns illegal global symbol references by bal (and jal also) instruction. This does not happen with the latest binutils v2.18. Here's an example on gth2_config: mips_4KC-gcc -D__ASSEMBLY__ -g -Os -D__KERNEL__ -DTEXT_BASE=0x90000000 -I/home/skuribay/devel/u-boot.git/include -fno-builtin -ffreestanding -nostdinc -isy stem /opt/eldk311/usr/bin/../lib/gcc-lib/mips-linux/3.3.3/include -pipe -DCONFIG_MIPS -D__MIPS__ -G 0 -mabicalls -fpic -pipe -msoft-float -march=4kc -mtune=4k c -EB -c -o cache.o cache.S cache.S: Assembler messages: cache.S:243: Warning: Pretending global symbol used as branch target is local. cache.S:250: Warning: Pretending global symbol used as branch target is local. In principle, gas might be sensitive to global symbol references in PIC code because they should be processed through GOT (global offset table). But if `bal' instruction is used, it results in PC-based offset jump. This is the cause of this warning. In practice, we know it doesn't matter whether PC-based reference or GOT- based. As for this case, both will work before/after relocation. But let's fix the code. This patch explicitly sets up a target address, then jump there. Here's an example of disassembled code with/without this patch. 90000668: 1485ffef bne a0,a1,90000628 <mips_cache_reset+0x20> 9000066c: ac80fffc sw zero,-4(a0) 90000670: 01402821 move a1,t2 -90000674: 0411ffba bal 90000560 <mips_init_icache> -90000678: 01803021 move a2,t4 -9000067c: 01602821 move a1,t3 -90000680: 0411ffcc bal 900005b4 <mips_init_dcache> -90000684: 01a03021 move a2,t5 -90000688: 03000008 jr t8 -9000068c: 00000000 nop +90000674: 01803021 move a2,t4 +90000678: 8f8f83ec lw t7,-31764(gp) +9000067c: 01e0f809 jalr t7 +90000680: 00000000 nop +90000684: 01602821 move a1,t3 +90000688: 01a03021 move a2,t5 +9000068c: 8f8f81e0 lw t7,-32288(gp) +90000690: 01e0f809 jalr t7 +90000694: 00000000 nop +90000698: 03000008 jr t8 +9000069c: 00000000 nop Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
2008-05-06 04:22:52 +00:00
PTR_LA t7, mips_init_icache
jalr t7
/*
* then initialize D-cache.
*/
move a1, t3
move a2, t5
[MIPS] cpu/mips/cache.S: Fix build warning Some old GNU assemblers, such as v2.14 (ELDK 3.1.1), v2.16 (ELDK 4.1.0), warns illegal global symbol references by bal (and jal also) instruction. This does not happen with the latest binutils v2.18. Here's an example on gth2_config: mips_4KC-gcc -D__ASSEMBLY__ -g -Os -D__KERNEL__ -DTEXT_BASE=0x90000000 -I/home/skuribay/devel/u-boot.git/include -fno-builtin -ffreestanding -nostdinc -isy stem /opt/eldk311/usr/bin/../lib/gcc-lib/mips-linux/3.3.3/include -pipe -DCONFIG_MIPS -D__MIPS__ -G 0 -mabicalls -fpic -pipe -msoft-float -march=4kc -mtune=4k c -EB -c -o cache.o cache.S cache.S: Assembler messages: cache.S:243: Warning: Pretending global symbol used as branch target is local. cache.S:250: Warning: Pretending global symbol used as branch target is local. In principle, gas might be sensitive to global symbol references in PIC code because they should be processed through GOT (global offset table). But if `bal' instruction is used, it results in PC-based offset jump. This is the cause of this warning. In practice, we know it doesn't matter whether PC-based reference or GOT- based. As for this case, both will work before/after relocation. But let's fix the code. This patch explicitly sets up a target address, then jump there. Here's an example of disassembled code with/without this patch. 90000668: 1485ffef bne a0,a1,90000628 <mips_cache_reset+0x20> 9000066c: ac80fffc sw zero,-4(a0) 90000670: 01402821 move a1,t2 -90000674: 0411ffba bal 90000560 <mips_init_icache> -90000678: 01803021 move a2,t4 -9000067c: 01602821 move a1,t3 -90000680: 0411ffcc bal 900005b4 <mips_init_dcache> -90000684: 01a03021 move a2,t5 -90000688: 03000008 jr t8 -9000068c: 00000000 nop +90000674: 01803021 move a2,t4 +90000678: 8f8f83ec lw t7,-31764(gp) +9000067c: 01e0f809 jalr t7 +90000680: 00000000 nop +90000684: 01602821 move a1,t3 +90000688: 01a03021 move a2,t5 +9000068c: 8f8f81e0 lw t7,-32288(gp) +90000690: 01e0f809 jalr t7 +90000694: 00000000 nop +90000698: 03000008 jr t8 +9000069c: 00000000 nop Signed-off-by: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
2008-05-06 04:22:52 +00:00
PTR_LA t7, mips_init_dcache
jalr t7
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)