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Diffstat (limited to 'arch/mips/kernel/cpu-probe.c')
-rw-r--r--arch/mips/kernel/cpu-probe.c111
1 files changed, 104 insertions, 7 deletions
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 94c4a0c0a577..5342674842f5 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 = &current_cpu_data;
@@ -140,7 +197,7 @@ static inline unsigned long cpu_get_fpu_id(void)
*/
static inline int __cpu_has_fpu(void)
{
- return ((cpu_get_fpu_id() & FPIR_IMP_MASK) != FPIR_IMP_NONE);
+ return (cpu_get_fpu_id() & FPIR_IMP_MASK) != FPIR_IMP_NONE;
}
static inline unsigned long cpu_get_msa_id(void)
@@ -193,6 +250,32 @@ static void set_isa(struct cpuinfo_mips *c, unsigned int isa)
static char unknown_isa[] = KERN_ERR \
"Unsupported ISA type, c0.config0: %d.";
+static unsigned int calculate_ftlb_probability(struct cpuinfo_mips *c)
+{
+
+ unsigned int probability = c->tlbsize / c->tlbsizevtlb;
+
+ /*
+ * 0 = All TLBWR instructions go to FTLB
+ * 1 = 15:1: For every 16 TBLWR instructions, 15 go to the
+ * FTLB and 1 goes to the VTLB.
+ * 2 = 7:1: As above with 7:1 ratio.
+ * 3 = 3:1: As above with 3:1 ratio.
+ *
+ * Use the linear midpoint as the probability threshold.
+ */
+ if (probability >= 12)
+ return 1;
+ else if (probability >= 6)
+ return 2;
+ else
+ /*
+ * So FTLB is less than 4 times bigger than VTLB.
+ * A 3:1 ratio can still be useful though.
+ */
+ return 3;
+}
+
static void set_ftlb_enable(struct cpuinfo_mips *c, int enable)
{
unsigned int config6;
@@ -203,9 +286,14 @@ static void set_ftlb_enable(struct cpuinfo_mips *c, int enable)
case CPU_P5600:
/* proAptiv & related cores use Config6 to enable the FTLB */
config6 = read_c0_config6();
+ /* Clear the old probability value */
+ config6 &= ~(3 << MIPS_CONF6_FTLBP_SHIFT);
if (enable)
/* Enable FTLB */
- write_c0_config6(config6 | MIPS_CONF6_FTLBEN);
+ write_c0_config6(config6 |
+ (calculate_ftlb_probability(c)
+ << MIPS_CONF6_FTLBP_SHIFT)
+ | MIPS_CONF6_FTLBEN);
else
/* Disable FTLB */
write_c0_config6(config6 & ~MIPS_CONF6_FTLBEN);
@@ -368,6 +456,8 @@ 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 +477,7 @@ 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;
}
}
@@ -401,7 +492,7 @@ static inline unsigned int decode_config5(struct cpuinfo_mips *c)
unsigned int config5;
config5 = read_c0_config5();
- config5 &= ~MIPS_CONF5_UFR;
+ config5 &= ~(MIPS_CONF5_UFR | MIPS_CONF5_UFE);
write_c0_config5(config5);
if (config5 & MIPS_CONF5_EVA)
@@ -422,8 +513,8 @@ 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! */
@@ -757,31 +848,34 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
c->cputype = CPU_LOONGSON2;
__cpu_name[cpu] = "ICT Loongson-2";
set_elf_platform(cpu, "loongson2e");
+ set_isa(c, MIPS_CPU_ISA_III);
break;
case PRID_REV_LOONGSON2F:
c->cputype = CPU_LOONGSON2;
__cpu_name[cpu] = "ICT Loongson-2";
set_elf_platform(cpu, "loongson2f");
+ set_isa(c, MIPS_CPU_ISA_III);
break;
case PRID_REV_LOONGSON3A:
c->cputype = CPU_LOONGSON3;
- c->writecombine = _CACHE_UNCACHED_ACCELERATED;
__cpu_name[cpu] = "ICT Loongson-3";
set_elf_platform(cpu, "loongson3a");
+ set_isa(c, MIPS_CPU_ISA_M64R1);
break;
case PRID_REV_LOONGSON3B_R1:
case PRID_REV_LOONGSON3B_R2:
c->cputype = CPU_LOONGSON3;
__cpu_name[cpu] = "ICT Loongson-3";
set_elf_platform(cpu, "loongson3b");
+ set_isa(c, MIPS_CPU_ISA_M64R1);
break;
}
- set_isa(c, MIPS_CPU_ISA_III);
c->options = R4K_OPTS |
MIPS_CPU_FPU | MIPS_CPU_LLSC |
MIPS_CPU_32FPR;
c->tlbsize = 64;
+ c->writecombine = _CACHE_UNCACHED_ACCELERATED;
break;
case PRID_IMP_LOONGSON_32: /* Loongson-1 */
decode_configs(c);
@@ -1024,6 +1118,7 @@ static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
break;
}
case PRID_IMP_BMIPS5000:
+ case PRID_IMP_BMIPS5200:
c->cputype = CPU_BMIPS5000;
__cpu_name[cpu] = "Broadcom BMIPS5000";
set_elf_platform(cpu, "bmips5000");
@@ -1254,6 +1349,8 @@ void cpu_probe(void)
MIPS_CPU_ISA_M64R1 | MIPS_CPU_ISA_M64R2)) {
if (c->fpu_id & MIPS_FPIR_3D)
c->ases |= MIPS_ASE_MIPS3D;
+ if (c->fpu_id & MIPS_FPIR_FREP)
+ c->options |= MIPS_CPU_FRE;
}
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.