From 6ad816e77ed77538fe729050cf6631328c6113f7 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Wed, 11 May 2016 15:50:30 +0100 Subject: MIPS: Add probing & defs for VZ & guest features Add a few new cpu-features.h definitions for VZ sub-features, namely the existence of the CP0_GuestCtl0Ext, CP0_GuestCtl1, and CP0_GuestCtl2 registers, and support for GuestID to dialias TLB entries belonging to different guests. Also add certain features present in the guest, with the naming scheme cpu_guest_has_*. These are added separately to the main options bitfield since they generally parallel similar features in the root context. A few of these (FPU, MSA, watchpoints, perf counters, CP0_[X]ContextConfig registers, MAAR registers, and probably others in future) can be dynamically configured in the guest context, for which the cpu_guest_has_dyn_* macros are added. [ralf@linux-mips.org: Resolve merge conflict.] Signed-off-by: James Hogan Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13231/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/cpu-probe.c | 232 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 232 insertions(+) (limited to 'arch/mips/kernel/cpu-probe.c') diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index 31c2757..5ac5c3e 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -915,6 +915,235 @@ static void decode_configs(struct cpuinfo_mips *c) #endif } +/* + * Probe for certain guest capabilities by writing config bits and reading back. + * Finally write back the original value. + */ +#define probe_gc0_config(name, maxconf, bits) \ +do { \ + unsigned int tmp; \ + tmp = read_gc0_##name(); \ + write_gc0_##name(tmp | (bits)); \ + back_to_back_c0_hazard(); \ + maxconf = read_gc0_##name(); \ + write_gc0_##name(tmp); \ +} while (0) + +/* + * Probe for dynamic guest capabilities by changing certain config bits and + * reading back to see if they change. Finally write back the original value. + */ +#define probe_gc0_config_dyn(name, maxconf, dynconf, bits) \ +do { \ + maxconf = read_gc0_##name(); \ + write_gc0_##name(maxconf ^ (bits)); \ + back_to_back_c0_hazard(); \ + dynconf = maxconf ^ read_gc0_##name(); \ + write_gc0_##name(maxconf); \ + maxconf |= dynconf; \ +} while (0) + +static inline unsigned int decode_guest_config0(struct cpuinfo_mips *c) +{ + unsigned int config0; + + probe_gc0_config(config, config0, MIPS_CONF_M); + + if (config0 & MIPS_CONF_M) + c->guest.conf |= BIT(1); + return config0 & MIPS_CONF_M; +} + +static inline unsigned int decode_guest_config1(struct cpuinfo_mips *c) +{ + unsigned int config1, config1_dyn; + + probe_gc0_config_dyn(config1, config1, config1_dyn, + MIPS_CONF_M | MIPS_CONF1_PC | MIPS_CONF1_WR | + MIPS_CONF1_FP); + + if (config1 & MIPS_CONF1_FP) + c->guest.options |= MIPS_CPU_FPU; + if (config1_dyn & MIPS_CONF1_FP) + c->guest.options_dyn |= MIPS_CPU_FPU; + + if (config1 & MIPS_CONF1_WR) + c->guest.options |= MIPS_CPU_WATCH; + if (config1_dyn & MIPS_CONF1_WR) + c->guest.options_dyn |= MIPS_CPU_WATCH; + + if (config1 & MIPS_CONF1_PC) + c->guest.options |= MIPS_CPU_PERF; + if (config1_dyn & MIPS_CONF1_PC) + c->guest.options_dyn |= MIPS_CPU_PERF; + + if (config1 & MIPS_CONF_M) + c->guest.conf |= BIT(2); + return config1 & MIPS_CONF_M; +} + +static inline unsigned int decode_guest_config2(struct cpuinfo_mips *c) +{ + unsigned int config2; + + probe_gc0_config(config2, config2, MIPS_CONF_M); + + if (config2 & MIPS_CONF_M) + c->guest.conf |= BIT(3); + return config2 & MIPS_CONF_M; +} + +static inline unsigned int decode_guest_config3(struct cpuinfo_mips *c) +{ + unsigned int config3, config3_dyn; + + probe_gc0_config_dyn(config3, config3, config3_dyn, + MIPS_CONF_M | MIPS_CONF3_MSA | MIPS_CONF3_CTXTC); + + if (config3 & MIPS_CONF3_CTXTC) + c->guest.options |= MIPS_CPU_CTXTC; + if (config3_dyn & MIPS_CONF3_CTXTC) + c->guest.options_dyn |= MIPS_CPU_CTXTC; + + if (config3 & MIPS_CONF3_PW) + c->guest.options |= MIPS_CPU_HTW; + + if (config3 & MIPS_CONF3_SC) + c->guest.options |= MIPS_CPU_SEGMENTS; + + if (config3 & MIPS_CONF3_BI) + c->guest.options |= MIPS_CPU_BADINSTR; + if (config3 & MIPS_CONF3_BP) + c->guest.options |= MIPS_CPU_BADINSTRP; + + if (config3 & MIPS_CONF3_MSA) + c->guest.ases |= MIPS_ASE_MSA; + if (config3_dyn & MIPS_CONF3_MSA) + c->guest.ases_dyn |= MIPS_ASE_MSA; + + if (config3 & MIPS_CONF_M) + c->guest.conf |= BIT(4); + return config3 & MIPS_CONF_M; +} + +static inline unsigned int decode_guest_config4(struct cpuinfo_mips *c) +{ + unsigned int config4; + + probe_gc0_config(config4, config4, + MIPS_CONF_M | MIPS_CONF4_KSCREXIST); + + c->guest.kscratch_mask = (config4 & MIPS_CONF4_KSCREXIST) + >> MIPS_CONF4_KSCREXIST_SHIFT; + + if (config4 & MIPS_CONF_M) + c->guest.conf |= BIT(5); + return config4 & MIPS_CONF_M; +} + +static inline unsigned int decode_guest_config5(struct cpuinfo_mips *c) +{ + unsigned int config5, config5_dyn; + + probe_gc0_config_dyn(config5, config5, config5_dyn, + MIPS_CONF_M | MIPS_CONF5_MRP); + + if (config5 & MIPS_CONF5_MRP) + c->guest.options |= MIPS_CPU_MAAR; + if (config5_dyn & MIPS_CONF5_MRP) + c->guest.options_dyn |= MIPS_CPU_MAAR; + + if (config5 & MIPS_CONF5_LLB) + c->guest.options |= MIPS_CPU_RW_LLB; + + if (config5 & MIPS_CONF_M) + c->guest.conf |= BIT(6); + return config5 & MIPS_CONF_M; +} + +static inline void decode_guest_configs(struct cpuinfo_mips *c) +{ + unsigned int ok; + + ok = decode_guest_config0(c); + if (ok) + ok = decode_guest_config1(c); + if (ok) + ok = decode_guest_config2(c); + if (ok) + ok = decode_guest_config3(c); + if (ok) + ok = decode_guest_config4(c); + if (ok) + decode_guest_config5(c); +} + +static inline void cpu_probe_guestctl0(struct cpuinfo_mips *c) +{ + unsigned int guestctl0, temp; + + guestctl0 = read_c0_guestctl0(); + + if (guestctl0 & MIPS_GCTL0_G0E) + c->options |= MIPS_CPU_GUESTCTL0EXT; + if (guestctl0 & MIPS_GCTL0_G1) + c->options |= MIPS_CPU_GUESTCTL1; + if (guestctl0 & MIPS_GCTL0_G2) + c->options |= MIPS_CPU_GUESTCTL2; + if (!(guestctl0 & MIPS_GCTL0_RAD)) { + c->options |= MIPS_CPU_GUESTID; + + /* + * Probe for Direct Root to Guest (DRG). Set GuestCtl1.RID = 0 + * first, otherwise all data accesses will be fully virtualised + * as if they were performed by guest mode. + */ + write_c0_guestctl1(0); + tlbw_use_hazard(); + + write_c0_guestctl0(guestctl0 | MIPS_GCTL0_DRG); + back_to_back_c0_hazard(); + temp = read_c0_guestctl0(); + + if (temp & MIPS_GCTL0_DRG) { + write_c0_guestctl0(guestctl0); + c->options |= MIPS_CPU_DRG; + } + } +} + +static inline void cpu_probe_guestctl1(struct cpuinfo_mips *c) +{ + if (cpu_has_guestid) { + /* determine the number of bits of GuestID available */ + write_c0_guestctl1(MIPS_GCTL1_ID); + back_to_back_c0_hazard(); + c->guestid_mask = (read_c0_guestctl1() & MIPS_GCTL1_ID) + >> MIPS_GCTL1_ID_SHIFT; + write_c0_guestctl1(0); + } +} + +static inline void cpu_probe_gtoffset(struct cpuinfo_mips *c) +{ + /* determine the number of bits of GTOffset available */ + write_c0_gtoffset(0xffffffff); + back_to_back_c0_hazard(); + c->gtoffset_mask = read_c0_gtoffset(); + write_c0_gtoffset(0); +} + +static inline void cpu_probe_vz(struct cpuinfo_mips *c) +{ + cpu_probe_guestctl0(c); + if (cpu_has_guestctl1) + cpu_probe_guestctl1(c); + + cpu_probe_gtoffset(c); + + decode_guest_configs(c); +} + #define R4K_OPTS (MIPS_CPU_TLB | MIPS_CPU_4KEX | MIPS_CPU_4K_CACHE \ | MIPS_CPU_COUNTER) @@ -1817,6 +2046,9 @@ void cpu_probe(void) elf_hwcap |= HWCAP_MIPS_MSA; } + if (cpu_has_vz) + cpu_probe_vz(c); + cpu_probe_vmbits(c); #ifdef CONFIG_64BIT -- cgit v1.1