u-boot/arch/mips/lib/cache_init.S
Paul Burton 9f8ac82452 MIPS: Use unchecked immediate addition/subtraction
In MIPS assembly there have historically been 2 variants of immediate
addition - the standard "addi" which traps if an overflow occurs, and
the unchecked "addiu" which does not trap on overflow. In release 6 of
the MIPS architecture the trapping variants of immediate addition &
subtraction have been removed. In preparation for supporting MIPSr6,
stop using the trapping instructions from assembly & switch to their
unchecked variants.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
2016-05-21 01:36:39 +02:00

241 lines
5.7 KiB
ArmAsm

/*
* 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_SHF - MIPS_CONF1_DA_SHF
andi \line_sz, \line_sz, (MIPS_CONF1_DL >> MIPS_CONF1_DL_SHF)
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_SHF - MIPS_CONF1_DA_SHF
andi \sz, \sz, (MIPS_CONF1_DA >> MIPS_CONF1_DA_SHF)
addiu \sz, \sz, 1
/* sz *= line_sz */
mul \sz, \sz, \line_sz
/* detect log32(sets) */
srl $1, $1, \off + MIPS_CONF1_DS_SHF - MIPS_CONF1_DA_SHF
andi $1, $1, (MIPS_CONF1_DS >> MIPS_CONF1_DS_SHF)
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_SHF
#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_SHF
#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)