diff options
Diffstat (limited to 'arch/mips/mm/c-r4k.c')
| -rw-r--r-- | arch/mips/mm/c-r4k.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c index f092c265dc63..4c32ede464b5 100644 --- a/arch/mips/mm/c-r4k.c +++ b/arch/mips/mm/c-r4k.c @@ -786,6 +786,25 @@ static inline void rm7k_erratum31(void) } } +static inline void alias_74k_erratum(struct cpuinfo_mips *c) +{ + /* + * Early versions of the 74K do not update the cache tags on a + * vtag miss/ptag hit which can occur in the case of KSEG0/KUSEG + * aliases. In this case it is better to treat the cache as always + * having aliases. + */ + if ((c->processor_id & 0xff) <= PRID_REV_ENCODE_332(2, 4, 0)) + c->dcache.flags |= MIPS_CACHE_VTAG; + if ((c->processor_id & 0xff) == PRID_REV_ENCODE_332(2, 4, 0)) + write_c0_config6(read_c0_config6() | MIPS_CONF6_SYND); + if (((c->processor_id & 0xff00) == PRID_IMP_1074K) && + ((c->processor_id & 0xff) <= PRID_REV_ENCODE_332(1, 1, 0))) { + c->dcache.flags |= MIPS_CACHE_VTAG; + write_c0_config6(read_c0_config6() | MIPS_CONF6_SYND); + } +} + static char *way_string[] __cpuinitdata = { NULL, "direct mapped", "2-way", "3-way", "4-way", "5-way", "6-way", "7-way", "8-way" }; @@ -1056,6 +1075,8 @@ static void __cpuinit probe_pcache(void) case CPU_34K: case CPU_74K: case CPU_1004K: + if (c->cputype == CPU_74K) + alias_74k_erratum(c); if ((read_c0_config7() & (1 << 16))) { /* effectively physically indexed dcache, thus no virtual aliases. */ |