diff options
| -rw-r--r-- | arch/mips/include/asm/cpu-features.h | 4 | ||||
| -rw-r--r-- | arch/mips/include/asm/cpu.h | 1 | ||||
| -rw-r--r-- | arch/mips/include/asm/mipsregs.h | 3 | ||||
| -rw-r--r-- | arch/mips/kernel/cpu-probe.c | 35 |
4 files changed, 43 insertions, 0 deletions
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h index bff73c5..676a37b 100644 --- a/arch/mips/include/asm/cpu-features.h +++ b/arch/mips/include/asm/cpu-features.h @@ -438,4 +438,8 @@ #define cpu_has_nan_2008 (cpu_data[0].options & MIPS_CPU_NAN_2008) #endif +#ifndef cpu_has_ebase_wg +# define cpu_has_ebase_wg (cpu_data[0].options & MIPS_CPU_EBASE_WG) +#endif + #endif /* __ASM_CPU_FEATURES_H */ diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h index f6cecc5..3108d9b 100644 --- a/arch/mips/include/asm/cpu.h +++ b/arch/mips/include/asm/cpu.h @@ -404,6 +404,7 @@ enum cpu_type_enum { #define MIPS_CPU_VP MBIT_ULL(40) /* MIPSr6 Virtual Processors (multi-threading) */ #define MIPS_CPU_LDPTE MBIT_ULL(41) /* CPU has ldpte/lddir instructions */ #define MIPS_CPU_MVH MBIT_ULL(42) /* CPU supports MFHC0/MTHC0 */ +#define MIPS_CPU_EBASE_WG MBIT_ULL(43) /* CPU has EBase.WG */ /* * CPU ASE encodings diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h index 57d72f2..4e8ad9d 100644 --- a/arch/mips/include/asm/mipsregs.h +++ b/arch/mips/include/asm/mipsregs.h @@ -1458,6 +1458,9 @@ do { \ #define read_c0_ebase() __read_32bit_c0_register($15, 1) #define write_c0_ebase(val) __write_32bit_c0_register($15, 1, val) +#define read_c0_ebase_64() __read_64bit_c0_register($15, 1) +#define write_c0_ebase_64(val) __write_64bit_c0_register($15, 1, val) + #define read_c0_cdmmbase() __read_ulong_c0_register($15, 2) #define write_c0_cdmmbase(val) __write_ulong_c0_register($15, 2, val) diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 46a2472..6a1a7da 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -860,6 +860,41 @@ static void decode_configs(struct cpuinfo_mips *c) if (ok) ok = decode_config5(c); + /* Probe the EBase.WG bit */ + if (cpu_has_mips_r2_r6) { + u64 ebase; + unsigned int status; + + /* {read,write}_c0_ebase_64() may be UNDEFINED prior to r6 */ + ebase = cpu_has_mips64r6 ? read_c0_ebase_64() + : (s32)read_c0_ebase(); + if (ebase & MIPS_EBASE_WG) { + /* WG bit already set, we can avoid the clumsy probe */ + c->options |= MIPS_CPU_EBASE_WG; + } else { + /* Its UNDEFINED to change EBase while BEV=0 */ + status = read_c0_status(); + write_c0_status(status | ST0_BEV); + irq_enable_hazard(); + /* + * On pre-r6 cores, this may well clobber the upper bits + * of EBase. This is hard to avoid without potentially + * hitting UNDEFINED dm*c0 behaviour if EBase is 32-bit. + */ + if (cpu_has_mips64r6) + write_c0_ebase_64(ebase | MIPS_EBASE_WG); + else + write_c0_ebase(ebase | MIPS_EBASE_WG); + back_to_back_c0_hazard(); + /* Restore BEV */ + write_c0_status(status); + if (read_c0_ebase() & MIPS_EBASE_WG) { + c->options |= MIPS_CPU_EBASE_WG; + write_c0_ebase(ebase); + } + } + } + mips_probe_watch_registers(c); #ifndef CONFIG_MIPS_CPS |