// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2013 Imagination Technologies * Author: Paul Burton */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static bool threads_disabled; static DECLARE_BITMAP(core_power, NR_CPUS); struct core_boot_config *mips_cps_core_bootcfg; static int __init setup_nothreads(char *s) { threads_disabled = true; return 0; } early_param("nothreads", setup_nothreads); static unsigned core_vpe_count(unsigned int cluster, unsigned core) { if (threads_disabled) return 1; return mips_cps_numvps(cluster, core); } static void __init cps_smp_setup(void) { unsigned int nclusters, ncores, nvpes, core_vpes; unsigned long core_entry; int cl, c, v; /* Detect & record VPE topology */ nvpes = 0; nclusters = mips_cps_numclusters(); pr_info("%s topology ", cpu_has_mips_r6 ? "VP" : "VPE"); for (cl = 0; cl < nclusters; cl++) { if (cl > 0) pr_cont(","); pr_cont("{"); ncores = mips_cps_numcores(cl); for (c = 0; c < ncores; c++) { core_vpes = core_vpe_count(cl, c); if (c > 0) pr_cont(","); pr_cont("%u", core_vpes); /* Use the number of VPEs in cluster 0 core 0 for smp_num_siblings */ if (!cl && !c) smp_num_siblings = core_vpes; for (v = 0; v < min_t(int, core_vpes, NR_CPUS - nvpes); v++) { cpu_set_cluster(&cpu_data[nvpes + v], cl); cpu_set_core(&cpu_data[nvpes + v], c); cpu_set_vpe_id(&cpu_data[nvpes + v], v); } nvpes += core_vpes; } pr_cont("}"); } pr_cont(" total %u\n", nvpes); /* Indicate present CPUs (CPU being synonymous with VPE) */ for (v = 0; v < min_t(unsigned, nvpes, NR_CPUS); v++) { set_cpu_possible(v, cpu_cluster(&cpu_data[v]) == 0); set_cpu_present(v, cpu_cluster(&cpu_data[v]) == 0); __cpu_number_map[v] = v; __cpu_logical_map[v] = v; } /* Set a coherent default CCA (CWB) */ change_c0_config(CONF_CM_CMASK, 0x5); /* Core 0 is powered up (we're running on it) */ bitmap_set(core_power, 0, 1); /* Initialise core 0 */ mips_cps_core_init(); /* Make core 0 coherent with everything */ write_gcr_cl_coherence(0xff); if (mips_cm_revision() >= CM_REV_CM3) { core_entry = CKSEG1ADDR((unsigned long)mips_cps_core_entry); write_gcr_bev_base(core_entry); } #ifdef CONFIG_MIPS_MT_FPAFF /* If we have an FPU, enroll ourselves in the FPU-full mask */ if (cpu_has_fpu) cpumask_set_cpu(0, &mt_fpu_cpumask); #endif /* CONFIG_MIPS_MT_FPAFF */ } static void __init cps_prepare_cpus(unsigned int max_cpus) { unsigned ncores, core_vpes, c, cca; bool cca_unsuitable, cores_limited; u32 *entry_code; mips_mt_set_cpuoptions(); /* Detect whether the CCA is unsuited to multi-core SMP */ cca = read_c0_config() & CONF_CM_CMASK; switch (cca) { case 0x4: /* CWBE */ case 0x5: /* CWB */ /* The CCA is coherent, multi-core is fine */ cca_unsuitable = false; break; default: /* CCA is not coherent, multi-core is not usable */ cca_unsuitable = true; } /* Warn the user if the CCA prevents multi-core */ cores_limited = false; if (cca_unsuitable || cpu_has_dc_aliases) { for_each_present_cpu(c) { if (cpus_are_siblings(smp_processor_id(), c)) continue; set_cpu_present(c, false); cores_limited = true; } } if (cores_limited) pr_warn("Using only one core due to %s%s%s\n", cca_unsuitable ? "unsuitable CCA" : "", (cca_unsuitable && cpu_has_dc_aliases) ? " & " : "", cpu_has_dc_aliases ? "dcache aliasing" : ""); /* * Patch the start of mips_cps_core_entry to provide: * * s0 = kseg0 CCA */ entry_code = (u32 *)&mips_cps_core_entry; uasm_i_addiu(&entry_code, 16, 0, cca); blast_dcache_range((unsigned long)&mips_cps_core_entry, (unsigned long)entry_code); bc_wback_inv((unsigned long)&mips_cps_core_entry, (void *)entry_code - (void *)&mips_cps_core_entry); __sync(); /* Allocate core boot configuration structs */ ncores = mips_cps_numcores(0); mips_cps_core_bootcfg = kcalloc(ncores, sizeof(*mips_cps_core_bootcfg), GFP_KERNEL); if (!mips_cps_core_bootcfg) { pr_err("Failed to allocate boot config for %u cores\n", ncores); goto err_out; } /* Allocate VPE boot configuration structs */ for (c = 0; c < ncores; c++) { core_vpes = core_vpe_count(0, c); mips_cps_core_bootcfg[c].vpe_config = kcalloc(core_vpes, sizeof(*mips_cps_core_bootcfg[c].vpe_config), GFP_KERNEL); if (!mips_cps_core_bootcfg[c].vpe_config) { pr_err("Failed to allocate %u VPE boot configs\n", core_vpes); goto err_out; } } /* Mark this CPU as booted */ atomic_set(&mips_cps_core_bootcfg[cpu_core(¤t_cpu_data)].vpe_mask, 1 << cpu_vpe_id(¤t_cpu_data)); return; err_out: /* Clean up allocations */ if (mips_cps_core_bootcfg) { for (c = 0; c < ncores; c++) kfree(mips_cps_core_bootcfg[c].vpe_config); kfree(mips_cps_core_bootcfg); mips_cps_core_bootcfg = NULL; } /* Effectively disable SMP by declaring CPUs not present */ for_each_possible_cpu(c) { if (c == 0) continue; set_cpu_present(c, false); } } static void boot_core(unsigned int core, unsigned int vpe_id) { u32 stat, seq_state; unsigned timeout; /* Select the appropriate core */ mips_cm_lock_other(0, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL); /* Set its reset vector */ write_gcr_co_reset_base(CKSEG1ADDR((unsigned long)mips_cps_core_entry)); /* Ensure its coherency is disabled */ write_gcr_co_coherence(0); /* Start it with the legacy memory map and exception base */ write_gcr_co_reset_ext_base(CM_GCR_Cx_RESET_EXT_BASE_UEB); /* Ensure the core can access the GCRs */ set_gcr_access(1 << core); if (mips_cpc_present()) { /* Reset the core */ mips_cpc_lock_other(core); if (mips_cm_revision() >= CM_REV_CM3) { /* Run only the requested VP following the reset */ write_cpc_co_vp_stop(0xf); write_cpc_co_vp_run(1 << vpe_id); /* * Ensure that the VP_RUN register is written before the * core leaves reset. */ wmb(); } write_cpc_co_cmd(CPC_Cx_CMD_RESET); timeout = 100; while (true) { stat = read_cpc_co_stat_conf(); seq_state = stat & CPC_Cx_STAT_CONF_SEQSTATE; seq_state >>= __ffs(CPC_Cx_STAT_CONF_SEQSTATE); /* U6 == coherent execution, ie. the core is up */ if (seq_state == CPC_Cx_STAT_CONF_SEQSTATE_U6) break; /* Delay a little while before we start warning */ if (timeout) { timeout--; mdelay(10); continue; } pr_warn("Waiting for core %u to start... STAT_CONF=0x%x\n", core, stat); mdelay(1000); } mips_cpc_unlock_other(); } else { /* Take the core out of reset */ write_gcr_co_reset_release(0); } mips_cm_unlock_other(); /* The core is now powered up */ bitmap_set(core_power, core, 1); } static void remote_vpe_boot(void *dummy) { unsigned core = cpu_core(¤t_cpu_data); struct core_boot_config *core_cfg = &mips_cps_core_bootcfg[core]; mips_cps_boot_vpes(core_cfg, cpu_vpe_id(¤t_cpu_data)); } static int cps_boot_secondary(int cpu, struct task_struct *idle) { unsigned core = cpu_core(&cpu_data[cpu]); unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]); struct core_boot_config *core_cfg = &mips_cps_core_bootcfg[core]; struct vpe_boot_config *vpe_cfg = &core_cfg->vpe_config[vpe_id]; unsigned long core_entry; unsigned int remote; int err; /* We don't yet support booting CPUs in other clusters */ if (cpu_cluster(&cpu_data[cpu]) != cpu_cluster(&raw_current_cpu_data)) return -ENOSYS; vpe_cfg->pc = (unsigned long)&smp_bootstrap; vpe_cfg->sp = __KSTK_TOS(idle); vpe_cfg->gp = (unsigned long)task_thread_info(idle); atomic_or(1 << cpu_vpe_id(&cpu_data[cpu]), &core_cfg->vpe_mask); preempt_disable(); if (!test_bit(core, core_power)) { /* Boot a VPE on a powered down core */ boot_core(core, vpe_id); goto out; } if (cpu_has_vp) { mips_cm_lock_other(0, core, vpe_id, CM_GCR_Cx_OTHER_BLOCK_LOCAL); core_entry = CKSEG1ADDR((unsigned long)mips_cps_core_entry); write_gcr_co_reset_base(core_entry); mips_cm_unlock_other(); } if (!cpus_are_siblings(cpu, smp_processor_id())) { /* Boot a VPE on another powered up core */ for (remote = 0; remote < NR_CPUS; remote++) { if (!cpus_are_siblings(cpu, remote)) continue; if (cpu_online(remote)) break; } if (remote >= NR_CPUS) { pr_crit("No online CPU in core %u to start CPU%d\n", core, cpu); goto out; } err = smp_call_function_single(remote, remote_vpe_boot, NULL, 1); if (err) panic("Failed to call remote CPU\n"); goto out; } BUG_ON(!cpu_has_mipsmt && !cpu_has_vp); /* Boot a VPE on this core */ mips_cps_boot_vpes(core_cfg, vpe_id); out: preempt_enable(); return 0; } static void cps_init_secondary(void) { /* Disable MT - we only want to run 1 TC per VPE */ if (cpu_has_mipsmt) dmt(); if (mips_cm_revision() >= CM_REV_CM3) { unsigned int ident = read_gic_vl_ident(); /* * Ensure that our calculation of the VP ID matches up with * what the GIC reports, otherwise we'll have configured * interrupts incorrectly. */ BUG_ON(ident != mips_cm_vp_id(smp_processor_id())); } if (cpu_has_veic) clear_c0_status(ST0_IM); else change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 | STATUSF_IP4 | STATUSF_IP5 | STATUSF_IP6 | STATUSF_IP7); } static void cps_smp_finish(void) { write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ)); #ifdef CONFIG_MIPS_MT_FPAFF /* If we have an FPU, enroll ourselves in the FPU-full mask */ if (cpu_has_fpu) cpumask_set_cpu(smp_processor_id(), &mt_fpu_cpumask); #endif /* CONFIG_MIPS_MT_FPAFF */ local_irq_enable(); } #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_KEXEC) enum cpu_death { CPU_DEATH_HALT, CPU_DEATH_POWER, }; static void cps_shutdown_this_cpu(enum cpu_death death) { unsigned int cpu, core, vpe_id; cpu = smp_processor_id(); core = cpu_core(&cpu_data[cpu]); if (death == CPU_DEATH_HALT) { vpe_id = cpu_vpe_id(&cpu_data[cpu]); pr_debug("Halting core %d VP%d\n", core, vpe_id); if (cpu_has_mipsmt) { /* Halt this TC */ write_c0_tchalt(TCHALT_H); instruction_hazard(); } else if (cpu_has_vp) { write_cpc_cl_vp_stop(1 << vpe_id); /* Ensure that the VP_STOP register is written */ wmb(); } } else { if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) { pr_debug("Gating power to core %d\n", core); /* Power down the core */ cps_pm_enter_state(CPS_PM_POWER_GATED); } } } #ifdef CONFIG_KEXEC static void cps_kexec_nonboot_cpu(void) { if (cpu_has_mipsmt || cpu_has_vp) cps_shutdown_this_cpu(CPU_DEATH_HALT); else cps_shutdown_this_cpu(CPU_DEATH_POWER); } #endif /* CONFIG_KEXEC */ #endif /* CONFIG_HOTPLUG_CPU || CONFIG_KEXEC */ #ifdef CONFIG_HOTPLUG_CPU static int cps_cpu_disable(void) { unsigned cpu = smp_processor_id(); struct core_boot_config *core_cfg; if (!cps_pm_support_state(CPS_PM_POWER_GATED)) return -EINVAL; core_cfg = &mips_cps_core_bootcfg[cpu_core(¤t_cpu_data)]; atomic_sub(1 << cpu_vpe_id(¤t_cpu_data), &core_cfg->vpe_mask); smp_mb__after_atomic(); set_cpu_online(cpu, false); calculate_cpu_foreign_map(); irq_migrate_all_off_this_cpu(); return 0; } static unsigned cpu_death_sibling; static enum cpu_death cpu_death; void play_dead(void) { unsigned int cpu; local_irq_disable(); idle_task_exit(); cpu = smp_processor_id(); cpu_death = CPU_DEATH_POWER; pr_debug("CPU%d going offline\n", cpu); if (cpu_has_mipsmt || cpu_has_vp) { /* Look for another online VPE within the core */ for_each_online_cpu(cpu_death_sibling) { if (!cpus_are_siblings(cpu, cpu_death_sibling)) continue; /* * There is an online VPE within the core. Just halt * this TC and leave the core alone. */ cpu_death = CPU_DEATH_HALT; break; } } /* This CPU has chosen its way out */ (void)cpu_report_death(); cps_shutdown_this_cpu(cpu_death); /* This should never be reached */ panic("Failed to offline CPU %u", cpu); } static void wait_for_sibling_halt(void *ptr_cpu) { unsigned cpu = (unsigned long)ptr_cpu; unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]); unsigned halted; unsigned long flags; do { local_irq_save(flags); settc(vpe_id); halted = read_tc_c0_tchalt(); local_irq_restore(flags); } while (!(halted & TCHALT_H)); } static void cps_cpu_die(unsigned int cpu) { unsigned core = cpu_core(&cpu_data[cpu]); unsigned int vpe_id = cpu_vpe_id(&cpu_data[cpu]); ktime_t fail_time; unsigned stat; int err; /* Wait for the cpu to choose its way out */ if (!cpu_wait_death(cpu, 5)) { pr_err("CPU%u: didn't offline\n", cpu); return; } /* * Now wait for the CPU to actually offline. Without doing this that * offlining may race with one or more of: * * - Onlining the CPU again. * - Powering down the core if another VPE within it is offlined. * - A sibling VPE entering a non-coherent state. * * In the non-MT halt case (ie. infinite loop) the CPU is doing nothing * with which we could race, so do nothing. */ if (cpu_death == CPU_DEATH_POWER) { /* * Wait for the core to enter a powered down or clock gated * state, the latter happening when a JTAG probe is connected * in which case the CPC will refuse to power down the core. */ fail_time = ktime_add_ms(ktime_get(), 2000); do { mips_cm_lock_other(0, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL); mips_cpc_lock_other(core); stat = read_cpc_co_stat_conf(); stat &= CPC_Cx_STAT_CONF_SEQSTATE; stat >>= __ffs(CPC_Cx_STAT_CONF_SEQSTATE); mips_cpc_unlock_other(); mips_cm_unlock_other(); if (stat == CPC_Cx_STAT_CONF_SEQSTATE_D0 || stat == CPC_Cx_STAT_CONF_SEQSTATE_D2 || stat == CPC_Cx_STAT_CONF_SEQSTATE_U2) break; /* * The core ought to have powered down, but didn't & * now we don't really know what state it's in. It's * likely that its _pwr_up pin has been wired to logic * 1 & it powered back up as soon as we powered it * down... * * The best we can do is warn the user & continue in * the hope that the core is doing nothing harmful & * might behave properly if we online it later. */ if (WARN(ktime_after(ktime_get(), fail_time), "CPU%u hasn't powered down, seq. state %u\n", cpu, stat)) break; } while (1); /* Indicate the core is powered off */ bitmap_clear(core_power, core, 1); } else if (cpu_has_mipsmt) { /* * Have a CPU with access to the offlined CPUs registers wait * for its TC to halt. */ err = smp_call_function_single(cpu_death_sibling, wait_for_sibling_halt, (void *)(unsigned long)cpu, 1); if (err) panic("Failed to call remote sibling CPU\n"); } else if (cpu_has_vp) { do { mips_cm_lock_other(0, core, vpe_id, CM_GCR_Cx_OTHER_BLOCK_LOCAL); stat = read_cpc_co_vp_running(); mips_cm_unlock_other(); } while (stat & (1 << vpe_id)); } } #endif /* CONFIG_HOTPLUG_CPU */ static const struct plat_smp_ops cps_smp_ops = { .smp_setup = cps_smp_setup, .prepare_cpus = cps_prepare_cpus, .boot_secondary = cps_boot_secondary, .init_secondary = cps_init_secondary, .smp_finish = cps_smp_finish, .send_ipi_single = mips_smp_send_ipi_single, .send_ipi_mask = mips_smp_send_ipi_mask, #ifdef CONFIG_HOTPLUG_CPU .cpu_disable = cps_cpu_disable, .cpu_die = cps_cpu_die, #endif #ifdef CONFIG_KEXEC .kexec_nonboot_cpu = cps_kexec_nonboot_cpu, #endif }; bool mips_cps_smp_in_use(void) { extern const struct plat_smp_ops *mp_ops; return mp_ops == &cps_smp_ops; } int register_cps_smp_ops(void) { if (!mips_cm_present()) { pr_warn("MIPS CPS SMP unable to proceed without a CM\n"); return -ENODEV; } /* check we have a GIC - we need one for IPIs */ if (!(read_gcr_gic_status() & CM_GCR_GIC_STATUS_EX)) { pr_warn("MIPS CPS SMP unable to proceed without a GIC\n"); return -ENODEV; } register_smp_ops(&cps_smp_ops); return 0; }