diff options
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/kernel/cpu-probe.c | 64 |
1 files changed, 62 insertions, 2 deletions
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 793c86beffa2..b27e7ffd1112 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -69,6 +69,63 @@ static int __init htw_disable(char *s) __setup("nohtw", htw_disable); +static int mips_ftlb_disabled; +static int mips_has_ftlb_configured; + +static void set_ftlb_enable(struct cpuinfo_mips *c, int enable); + +static int __init ftlb_disable(char *s) +{ + unsigned int config4, mmuextdef; + + /* + * If the core hasn't done any FTLB configuration, there is nothing + * for us to do here. + */ + if (!mips_has_ftlb_configured) + return 1; + + /* Disable it in the boot cpu */ + set_ftlb_enable(&cpu_data[0], 0); + + back_to_back_c0_hazard(); + + config4 = read_c0_config4(); + + /* Check that FTLB has been disabled */ + mmuextdef = config4 & MIPS_CONF4_MMUEXTDEF; + /* MMUSIZEEXT == VTLB ON, FTLB OFF */ + if (mmuextdef == MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT) { + /* This should never happen */ + pr_warn("FTLB could not be disabled!\n"); + return 1; + } + + mips_ftlb_disabled = 1; + mips_has_ftlb_configured = 0; + + /* + * noftlb is mainly used for debug purposes so print + * an informative message instead of using pr_debug() + */ + pr_info("FTLB has been disabled\n"); + + /* + * Some of these bits are duplicated in the decode_config4. + * MIPS_CONF4_MMUEXTDEF_MMUSIZEEXT is the only possible case + * once FTLB has been disabled so undo what decode_config4 did. + */ + cpu_data[0].tlbsize -= cpu_data[0].tlbsizeftlbways * + cpu_data[0].tlbsizeftlbsets; + cpu_data[0].tlbsizeftlbsets = 0; + cpu_data[0].tlbsizeftlbways = 0; + + return 1; +} + +__setup("noftlb", ftlb_disable); + + static inline void check_errata(void) { struct cpuinfo_mips *c = ¤t_cpu_data; @@ -368,6 +425,8 @@ static inline unsigned int decode_config4(struct cpuinfo_mips *c) ftlb_page = MIPS_CONF4_VFTLBPAGESIZE; /* fall through */ case MIPS_CONF4_MMUEXTDEF_FTLBSIZEEXT: + if (mips_ftlb_disabled) + break; newcf4 = (config4 & ~ftlb_page) | (page_size_ftlb(mmuextdef) << MIPS_CONF4_FTLBPAGESIZE_SHIFT); @@ -387,6 +446,7 @@ static inline unsigned int decode_config4(struct cpuinfo_mips *c) c->tlbsizeftlbways = ((config4 & MIPS_CONF4_FTLBWAYS) >> MIPS_CONF4_FTLBWAYS_SHIFT) + 2; c->tlbsize += c->tlbsizeftlbways * c->tlbsizeftlbsets; + mips_has_ftlb_configured = 1; break; } } @@ -422,8 +482,8 @@ static void decode_configs(struct cpuinfo_mips *c) c->scache.flags = MIPS_CACHE_NOT_PRESENT; - /* Enable FTLB if present */ - set_ftlb_enable(c, 1); + /* Enable FTLB if present and not disabled */ + set_ftlb_enable(c, !mips_ftlb_disabled); ok = decode_config0(c); /* Read Config registers. */ BUG_ON(!ok); /* Arch spec violation! */ |