// SPDX-License-Identifier: GPL-2.0 /* * SMP related functions * * Copyright IBM Corp. 1999, 2012 * Author(s): Denis Joseph Barrow, * Martin Schwidefsky , * * based on other smp stuff by * (c) 1995 Alan Cox, CymruNET Ltd * (c) 1998 Ingo Molnar * * The code outside of smp.c uses logical cpu numbers, only smp.c does * the translation of logical to physical cpu ids. All new code that * operates on physical cpu numbers needs to go into smp.c. */ #define KMSG_COMPONENT "cpu" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "entry.h" enum { ec_schedule = 0, ec_call_function_single, ec_stop_cpu, ec_mcck_pending, ec_irq_work, }; enum { CPU_STATE_STANDBY, CPU_STATE_CONFIGURED, }; struct pcpu { unsigned long ec_mask; /* bit mask for ec_xxx functions */ unsigned long ec_clk; /* sigp timestamp for ec_xxx */ signed char state; /* physical cpu state */ signed char polarization; /* physical polarization */ u16 address; /* physical cpu address */ }; static u8 boot_core_type; static struct pcpu pcpu_devices[NR_CPUS]; unsigned int smp_cpu_mt_shift; EXPORT_SYMBOL(smp_cpu_mt_shift); unsigned int smp_cpu_mtid; EXPORT_SYMBOL(smp_cpu_mtid); #ifdef CONFIG_CRASH_DUMP __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS]; #endif static unsigned int smp_max_threads __initdata = -1U; cpumask_t cpu_setup_mask; static int __init early_nosmt(char *s) { smp_max_threads = 1; return 0; } early_param("nosmt", early_nosmt); static int __init early_smt(char *s) { get_option(&s, &smp_max_threads); return 0; } early_param("smt", early_smt); /* * The smp_cpu_state_mutex must be held when changing the state or polarization * member of a pcpu data structure within the pcpu_devices array. */ DEFINE_MUTEX(smp_cpu_state_mutex); /* * Signal processor helper functions. */ static inline int __pcpu_sigp_relax(u16 addr, u8 order, unsigned long parm) { int cc; while (1) { cc = __pcpu_sigp(addr, order, parm, NULL); if (cc != SIGP_CC_BUSY) return cc; cpu_relax(); } } static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm) { int cc, retry; for (retry = 0; ; retry++) { cc = __pcpu_sigp(pcpu->address, order, parm, NULL); if (cc != SIGP_CC_BUSY) break; if (retry >= 3) udelay(10); } return cc; } static inline int pcpu_stopped(struct pcpu *pcpu) { u32 status; if (__pcpu_sigp(pcpu->address, SIGP_SENSE, 0, &status) != SIGP_CC_STATUS_STORED) return 0; return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED)); } static inline int pcpu_running(struct pcpu *pcpu) { if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING, 0, NULL) != SIGP_CC_STATUS_STORED) return 1; /* Status stored condition code is equivalent to cpu not running. */ return 0; } /* * Find struct pcpu by cpu address. */ static struct pcpu *pcpu_find_address(const struct cpumask *mask, u16 address) { int cpu; for_each_cpu(cpu, mask) if (pcpu_devices[cpu].address == address) return pcpu_devices + cpu; return NULL; } static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit) { int order; if (test_and_set_bit(ec_bit, &pcpu->ec_mask)) return; order = pcpu_running(pcpu) ? SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL; pcpu->ec_clk = get_tod_clock_fast(); pcpu_sigp_retry(pcpu, order, 0); } static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) { unsigned long async_stack, nodat_stack, mcck_stack; struct lowcore *lc; lc = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); nodat_stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER); async_stack = stack_alloc(); mcck_stack = stack_alloc(); if (!lc || !nodat_stack || !async_stack || !mcck_stack) goto out; memcpy(lc, get_lowcore(), 512); memset((char *) lc + 512, 0, sizeof(*lc) - 512); lc->async_stack = async_stack + STACK_INIT_OFFSET; lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET; lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET; lc->cpu_nr = cpu; lc->spinlock_lockval = arch_spin_lockval(cpu); lc->spinlock_index = 0; lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW); lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW); lc->preempt_count = PREEMPT_DISABLED; if (nmi_alloc_mcesa(&lc->mcesad)) goto out; if (abs_lowcore_map(cpu, lc, true)) goto out_mcesa; lowcore_ptr[cpu] = lc; pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, __pa(lc)); return 0; out_mcesa: nmi_free_mcesa(&lc->mcesad); out: stack_free(mcck_stack); stack_free(async_stack); free_pages(nodat_stack, THREAD_SIZE_ORDER); free_pages((unsigned long) lc, LC_ORDER); return -ENOMEM; } static void pcpu_free_lowcore(struct pcpu *pcpu) { unsigned long async_stack, nodat_stack, mcck_stack; struct lowcore *lc; int cpu; cpu = pcpu - pcpu_devices; lc = lowcore_ptr[cpu]; nodat_stack = lc->nodat_stack - STACK_INIT_OFFSET; async_stack = lc->async_stack - STACK_INIT_OFFSET; mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET; pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); lowcore_ptr[cpu] = NULL; abs_lowcore_unmap(cpu); nmi_free_mcesa(&lc->mcesad); stack_free(async_stack); stack_free(mcck_stack); free_pages(nodat_stack, THREAD_SIZE_ORDER); free_pages((unsigned long) lc, LC_ORDER); } static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) { struct lowcore *lc, *abs_lc; lc = lowcore_ptr[cpu]; cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask); cpumask_set_cpu(cpu, mm_cpumask(&init_mm)); lc->cpu_nr = cpu; lc->restart_flags = RESTART_FLAG_CTLREGS; lc->spinlock_lockval = arch_spin_lockval(cpu); lc->spinlock_index = 0; lc->percpu_offset = __per_cpu_offset[cpu]; lc->kernel_asce = get_lowcore()->kernel_asce; lc->user_asce = s390_invalid_asce; lc->machine_flags = get_lowcore()->machine_flags; lc->user_timer = lc->system_timer = lc->steal_timer = lc->avg_steal_timer = 0; abs_lc = get_abs_lowcore(); memcpy(lc->cregs_save_area, abs_lc->cregs_save_area, sizeof(lc->cregs_save_area)); put_abs_lowcore(abs_lc); lc->cregs_save_area[1] = lc->kernel_asce; lc->cregs_save_area[7] = lc->user_asce; save_access_regs((unsigned int *) lc->access_regs_save_area); arch_spin_lock_setup(cpu); } static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) { struct lowcore *lc; int cpu; cpu = pcpu - pcpu_devices; lc = lowcore_ptr[cpu]; lc->kernel_stack = (unsigned long)task_stack_page(tsk) + STACK_INIT_OFFSET; lc->current_task = (unsigned long)tsk; lc->lpp = LPP_MAGIC; lc->current_pid = tsk->pid; lc->user_timer = tsk->thread.user_timer; lc->guest_timer = tsk->thread.guest_timer; lc->system_timer = tsk->thread.system_timer; lc->hardirq_timer = tsk->thread.hardirq_timer; lc->softirq_timer = tsk->thread.softirq_timer; lc->steal_timer = 0; } static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) { struct lowcore *lc; int cpu; cpu = pcpu - pcpu_devices; lc = lowcore_ptr[cpu]; lc->restart_stack = lc->kernel_stack; lc->restart_fn = (unsigned long) func; lc->restart_data = (unsigned long) data; lc->restart_source = -1U; pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); } typedef void (pcpu_delegate_fn)(void *); /* * Call function via PSW restart on pcpu and stop the current cpu. */ static void __pcpu_delegate(pcpu_delegate_fn *func, void *data) { func(data); /* should not return */ } static void pcpu_delegate(struct pcpu *pcpu, pcpu_delegate_fn *func, void *data, unsigned long stack) { struct lowcore *lc, *abs_lc; unsigned int source_cpu; lc = lowcore_ptr[pcpu - pcpu_devices]; source_cpu = stap(); if (pcpu->address == source_cpu) { call_on_stack(2, stack, void, __pcpu_delegate, pcpu_delegate_fn *, func, void *, data); } /* Stop target cpu (if func returns this stops the current cpu). */ pcpu_sigp_retry(pcpu, SIGP_STOP, 0); pcpu_sigp_retry(pcpu, SIGP_CPU_RESET, 0); /* Restart func on the target cpu and stop the current cpu. */ if (lc) { lc->restart_stack = stack; lc->restart_fn = (unsigned long)func; lc->restart_data = (unsigned long)data; lc->restart_source = source_cpu; } else { abs_lc = get_abs_lowcore(); abs_lc->restart_stack = stack; abs_lc->restart_fn = (unsigned long)func; abs_lc->restart_data = (unsigned long)data; abs_lc->restart_source = source_cpu; put_abs_lowcore(abs_lc); } asm volatile( "0: sigp 0,%0,%2 # sigp restart to target cpu\n" " brc 2,0b # busy, try again\n" "1: sigp 0,%1,%3 # sigp stop to current cpu\n" " brc 2,1b # busy, try again\n" : : "d" (pcpu->address), "d" (source_cpu), "K" (SIGP_RESTART), "K" (SIGP_STOP) : "0", "1", "cc"); for (;;) ; } /* * Enable additional logical cpus for multi-threading. */ static int pcpu_set_smt(unsigned int mtid) { int cc; if (smp_cpu_mtid == mtid) return 0; cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL); if (cc == 0) { smp_cpu_mtid = mtid; smp_cpu_mt_shift = 0; while (smp_cpu_mtid >= (1U << smp_cpu_mt_shift)) smp_cpu_mt_shift++; pcpu_devices[0].address = stap(); } return cc; } /* * Call function on an online CPU. */ void smp_call_online_cpu(void (*func)(void *), void *data) { struct pcpu *pcpu; /* Use the current cpu if it is online. */ pcpu = pcpu_find_address(cpu_online_mask, stap()); if (!pcpu) /* Use the first online cpu. */ pcpu = pcpu_devices + cpumask_first(cpu_online_mask); pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack); } /* * Call function on the ipl CPU. */ void smp_call_ipl_cpu(void (*func)(void *), void *data) { struct lowcore *lc = lowcore_ptr[0]; if (pcpu_devices[0].address == stap()) lc = get_lowcore(); pcpu_delegate(&pcpu_devices[0], func, data, lc->nodat_stack); } int smp_find_processor_id(u16 address) { int cpu; for_each_present_cpu(cpu) if (pcpu_devices[cpu].address == address) return cpu; return -1; } void schedule_mcck_handler(void) { pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_mcck_pending); } bool notrace arch_vcpu_is_preempted(int cpu) { if (test_cpu_flag_of(CIF_ENABLED_WAIT, cpu)) return false; if (pcpu_running(pcpu_devices + cpu)) return false; return true; } EXPORT_SYMBOL(arch_vcpu_is_preempted); void notrace smp_yield_cpu(int cpu) { if (!MACHINE_HAS_DIAG9C) return; diag_stat_inc_norecursion(DIAG_STAT_X09C); asm volatile("diag %0,0,0x9c" : : "d" (pcpu_devices[cpu].address)); } EXPORT_SYMBOL_GPL(smp_yield_cpu); /* * Send cpus emergency shutdown signal. This gives the cpus the * opportunity to complete outstanding interrupts. */ void notrace smp_emergency_stop(void) { static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED; static cpumask_t cpumask; u64 end; int cpu; arch_spin_lock(&lock); cpumask_copy(&cpumask, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &cpumask); end = get_tod_clock() + (1000000UL << 12); for_each_cpu(cpu, &cpumask) { struct pcpu *pcpu = pcpu_devices + cpu; set_bit(ec_stop_cpu, &pcpu->ec_mask); while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL, 0, NULL) == SIGP_CC_BUSY && get_tod_clock() < end) cpu_relax(); } while (get_tod_clock() < end) { for_each_cpu(cpu, &cpumask) if (pcpu_stopped(pcpu_devices + cpu)) cpumask_clear_cpu(cpu, &cpumask); if (cpumask_empty(&cpumask)) break; cpu_relax(); } arch_spin_unlock(&lock); } NOKPROBE_SYMBOL(smp_emergency_stop); /* * Stop all cpus but the current one. */ void smp_send_stop(void) { int cpu; /* Disable all interrupts/machine checks */ __load_psw_mask(PSW_KERNEL_BITS); trace_hardirqs_off(); debug_set_critical(); if (oops_in_progress) smp_emergency_stop(); /* stop all processors */ for_each_online_cpu(cpu) { if (cpu == smp_processor_id()) continue; pcpu_sigp_retry(pcpu_devices + cpu, SIGP_STOP, 0); while (!pcpu_stopped(pcpu_devices + cpu)) cpu_relax(); } } /* * This is the main routine where commands issued by other * cpus are handled. */ static void smp_handle_ext_call(void) { unsigned long bits; /* handle bit signal external calls */ bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0); if (test_bit(ec_stop_cpu, &bits)) smp_stop_cpu(); if (test_bit(ec_schedule, &bits)) scheduler_ipi(); if (test_bit(ec_call_function_single, &bits)) generic_smp_call_function_single_interrupt(); if (test_bit(ec_mcck_pending, &bits)) s390_handle_mcck(); if (test_bit(ec_irq_work, &bits)) irq_work_run(); } static void do_ext_call_interrupt(struct ext_code ext_code, unsigned int param32, unsigned long param64) { inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS); smp_handle_ext_call(); } void arch_send_call_function_ipi_mask(const struct cpumask *mask) { int cpu; for_each_cpu(cpu, mask) pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); } void arch_send_call_function_single_ipi(int cpu) { pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single); } /* * this function sends a 'reschedule' IPI to another CPU. * it goes straight through and wastes no time serializing * anything. Worst case is that we lose a reschedule ... */ void arch_smp_send_reschedule(int cpu) { pcpu_ec_call(pcpu_devices + cpu, ec_schedule); } #ifdef CONFIG_IRQ_WORK void arch_irq_work_raise(void) { pcpu_ec_call(pcpu_devices + smp_processor_id(), ec_irq_work); } #endif #ifdef CONFIG_CRASH_DUMP int smp_store_status(int cpu) { struct lowcore *lc; struct pcpu *pcpu; unsigned long pa; pcpu = pcpu_devices + cpu; lc = lowcore_ptr[cpu]; pa = __pa(&lc->floating_pt_save_area); if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS, pa) != SIGP_CC_ORDER_CODE_ACCEPTED) return -EIO; if (!cpu_has_vx() && !MACHINE_HAS_GS) return 0; pa = lc->mcesad & MCESA_ORIGIN_MASK; if (MACHINE_HAS_GS) pa |= lc->mcesad & MCESA_LC_MASK; if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS, pa) != SIGP_CC_ORDER_CODE_ACCEPTED) return -EIO; return 0; } /* * Collect CPU state of the previous, crashed system. * There are four cases: * 1) standard zfcp/nvme dump * condition: OLDMEM_BASE == NULL && is_ipl_type_dump() == true * The state for all CPUs except the boot CPU needs to be collected * with sigp stop-and-store-status. The boot CPU state is located in * the absolute lowcore of the memory stored in the HSA. The zcore code * will copy the boot CPU state from the HSA. * 2) stand-alone kdump for SCSI/NVMe (zfcp/nvme dump with swapped memory) * condition: OLDMEM_BASE != NULL && is_ipl_type_dump() == true * The state for all CPUs except the boot CPU needs to be collected * with sigp stop-and-store-status. The firmware or the boot-loader * stored the registers of the boot CPU in the absolute lowcore in the * memory of the old system. * 3) kdump and the old kernel did not store the CPU state, * or stand-alone kdump for DASD * condition: OLDMEM_BASE != NULL && !is_kdump_kernel() * The state for all CPUs except the boot CPU needs to be collected * with sigp stop-and-store-status. The kexec code or the boot-loader * stored the registers of the boot CPU in the memory of the old system. * 4) kdump and the old kernel stored the CPU state * condition: OLDMEM_BASE != NULL && is_kdump_kernel() * This case does not exist for s390 anymore, setup_arch explicitly * deactivates the elfcorehdr= kernel parameter */ static bool dump_available(void) { return oldmem_data.start || is_ipl_type_dump(); } void __init smp_save_dump_ipl_cpu(void) { struct save_area *sa; void *regs; if (!dump_available()) return; sa = save_area_alloc(true); regs = memblock_alloc(512, 8); if (!sa || !regs) panic("could not allocate memory for boot CPU save area\n"); copy_oldmem_kernel(regs, __LC_FPREGS_SAVE_AREA, 512); save_area_add_regs(sa, regs); memblock_free(regs, 512); if (cpu_has_vx()) save_area_add_vxrs(sa, boot_cpu_vector_save_area); } void __init smp_save_dump_secondary_cpus(void) { int addr, boot_cpu_addr, max_cpu_addr; struct save_area *sa; void *page; if (!dump_available()) return; /* Allocate a page as dumping area for the store status sigps */ page = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); if (!page) panic("ERROR: Failed to allocate %lx bytes below %lx\n", PAGE_SIZE, 1UL << 31); /* Set multi-threading state to the previous system. */ pcpu_set_smt(sclp.mtid_prev); boot_cpu_addr = stap(); max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev; for (addr = 0; addr <= max_cpu_addr; addr++) { if (addr == boot_cpu_addr) continue; if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) == SIGP_CC_NOT_OPERATIONAL) continue; sa = save_area_alloc(false); if (!sa) panic("could not allocate memory for save area\n"); __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(page)); save_area_add_regs(sa, page); if (cpu_has_vx()) { __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, __pa(page)); save_area_add_vxrs(sa, page); } } memblock_free(page, PAGE_SIZE); diag_amode31_ops.diag308_reset(); pcpu_set_smt(0); } #endif /* CONFIG_CRASH_DUMP */ void smp_cpu_set_polarization(int cpu, int val) { pcpu_devices[cpu].polarization = val; } int smp_cpu_get_polarization(int cpu) { return pcpu_devices[cpu].polarization; } int smp_cpu_get_cpu_address(int cpu) { return pcpu_devices[cpu].address; } static void __ref smp_get_core_info(struct sclp_core_info *info, int early) { static int use_sigp_detection; int address; if (use_sigp_detection || sclp_get_core_info(info, early)) { use_sigp_detection = 1; for (address = 0; address < (SCLP_MAX_CORES << smp_cpu_mt_shift); address += (1U << smp_cpu_mt_shift)) { if (__pcpu_sigp_relax(address, SIGP_SENSE, 0) == SIGP_CC_NOT_OPERATIONAL) continue; info->core[info->configured].core_id = address >> smp_cpu_mt_shift; info->configured++; } info->combined = info->configured; } } static int smp_add_core(struct sclp_core_entry *core, cpumask_t *avail, bool configured, bool early) { struct pcpu *pcpu; int cpu, nr, i; u16 address; nr = 0; if (sclp.has_core_type && core->type != boot_core_type) return nr; cpu = cpumask_first(avail); address = core->core_id << smp_cpu_mt_shift; for (i = 0; (i <= smp_cpu_mtid) && (cpu < nr_cpu_ids); i++) { if (pcpu_find_address(cpu_present_mask, address + i)) continue; pcpu = pcpu_devices + cpu; pcpu->address = address + i; if (configured) pcpu->state = CPU_STATE_CONFIGURED; else pcpu->state = CPU_STATE_STANDBY; smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); set_cpu_present(cpu, true); if (!early && arch_register_cpu(cpu)) set_cpu_present(cpu, false); else nr++; cpumask_clear_cpu(cpu, avail); cpu = cpumask_next(cpu, avail); } return nr; } static int __smp_rescan_cpus(struct sclp_core_info *info, bool early) { struct sclp_core_entry *core; static cpumask_t avail; bool configured; u16 core_id; int nr, i; cpus_read_lock(); mutex_lock(&smp_cpu_state_mutex); nr = 0; cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); /* * Add IPL core first (which got logical CPU number 0) to make sure * that all SMT threads get subsequent logical CPU numbers. */ if (early) { core_id = pcpu_devices[0].address >> smp_cpu_mt_shift; for (i = 0; i < info->configured; i++) { core = &info->core[i]; if (core->core_id == core_id) { nr += smp_add_core(core, &avail, true, early); break; } } } for (i = 0; i < info->combined; i++) { configured = i < info->configured; nr += smp_add_core(&info->core[i], &avail, configured, early); } mutex_unlock(&smp_cpu_state_mutex); cpus_read_unlock(); return nr; } void __init smp_detect_cpus(void) { unsigned int cpu, mtid, c_cpus, s_cpus; struct sclp_core_info *info; u16 address; /* Get CPU information */ info = memblock_alloc(sizeof(*info), 8); if (!info) panic("%s: Failed to allocate %zu bytes align=0x%x\n", __func__, sizeof(*info), 8); smp_get_core_info(info, 1); /* Find boot CPU type */ if (sclp.has_core_type) { address = stap(); for (cpu = 0; cpu < info->combined; cpu++) if (info->core[cpu].core_id == address) { /* The boot cpu dictates the cpu type. */ boot_core_type = info->core[cpu].type; break; } if (cpu >= info->combined) panic("Could not find boot CPU type"); } /* Set multi-threading state for the current system */ mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp; mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1; pcpu_set_smt(mtid); /* Print number of CPUs */ c_cpus = s_cpus = 0; for (cpu = 0; cpu < info->combined; cpu++) { if (sclp.has_core_type && info->core[cpu].type != boot_core_type) continue; if (cpu < info->configured) c_cpus += smp_cpu_mtid + 1; else s_cpus += smp_cpu_mtid + 1; } pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus); memblock_free(info, sizeof(*info)); } /* * Activate a secondary processor. */ static void smp_start_secondary(void *cpuvoid) { struct lowcore *lc = get_lowcore(); int cpu = raw_smp_processor_id(); lc->last_update_clock = get_tod_clock(); lc->restart_stack = (unsigned long)restart_stack; lc->restart_fn = (unsigned long)do_restart; lc->restart_data = 0; lc->restart_source = -1U; lc->restart_flags = 0; restore_access_regs(lc->access_regs_save_area); cpu_init(); rcutree_report_cpu_starting(cpu); init_cpu_timer(); vtime_init(); vdso_getcpu_init(); pfault_init(); cpumask_set_cpu(cpu, &cpu_setup_mask); update_cpu_masks(); notify_cpu_starting(cpu); if (topology_cpu_dedicated(cpu)) set_cpu_flag(CIF_DEDICATED_CPU); else clear_cpu_flag(CIF_DEDICATED_CPU); set_cpu_online(cpu, true); inc_irq_stat(CPU_RST); local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } /* Upping and downing of CPUs */ int __cpu_up(unsigned int cpu, struct task_struct *tidle) { struct pcpu *pcpu = pcpu_devices + cpu; int rc; if (pcpu->state != CPU_STATE_CONFIGURED) return -EIO; if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) != SIGP_CC_ORDER_CODE_ACCEPTED) return -EIO; rc = pcpu_alloc_lowcore(pcpu, cpu); if (rc) return rc; /* * Make sure global control register contents do not change * until new CPU has initialized control registers. */ system_ctlreg_lock(); pcpu_prepare_secondary(pcpu, cpu); pcpu_attach_task(pcpu, tidle); pcpu_start_fn(pcpu, smp_start_secondary, NULL); /* Wait until cpu puts itself in the online & active maps */ while (!cpu_online(cpu)) cpu_relax(); system_ctlreg_unlock(); return 0; } static unsigned int setup_possible_cpus __initdata; static int __init _setup_possible_cpus(char *s) { get_option(&s, &setup_possible_cpus); return 0; } early_param("possible_cpus", _setup_possible_cpus); int __cpu_disable(void) { struct ctlreg cregs[16]; int cpu; /* Handle possible pending IPIs */ smp_handle_ext_call(); cpu = smp_processor_id(); set_cpu_online(cpu, false); cpumask_clear_cpu(cpu, &cpu_setup_mask); update_cpu_masks(); /* Disable pseudo page faults on this cpu. */ pfault_fini(); /* Disable interrupt sources via control register. */ __local_ctl_store(0, 15, cregs); cregs[0].val &= ~0x0000ee70UL; /* disable all external interrupts */ cregs[6].val &= ~0xff000000UL; /* disable all I/O interrupts */ cregs[14].val &= ~0x1f000000UL; /* disable most machine checks */ __local_ctl_load(0, 15, cregs); clear_cpu_flag(CIF_NOHZ_DELAY); return 0; } void __cpu_die(unsigned int cpu) { struct pcpu *pcpu; /* Wait until target cpu is down */ pcpu = pcpu_devices + cpu; while (!pcpu_stopped(pcpu)) cpu_relax(); pcpu_free_lowcore(pcpu); cpumask_clear_cpu(cpu, mm_cpumask(&init_mm)); cpumask_clear_cpu(cpu, &init_mm.context.cpu_attach_mask); } void __noreturn cpu_die(void) { idle_task_exit(); pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); for (;;) ; } void __init smp_fill_possible_mask(void) { unsigned int possible, sclp_max, cpu; sclp_max = max(sclp.mtid, sclp.mtid_cp) + 1; sclp_max = min(smp_max_threads, sclp_max); sclp_max = (sclp.max_cores * sclp_max) ?: nr_cpu_ids; possible = setup_possible_cpus ?: nr_cpu_ids; possible = min(possible, sclp_max); for (cpu = 0; cpu < possible && cpu < nr_cpu_ids; cpu++) set_cpu_possible(cpu, true); } void __init smp_prepare_cpus(unsigned int max_cpus) { if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt)) panic("Couldn't request external interrupt 0x1201"); system_ctl_set_bit(0, 14); if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt)) panic("Couldn't request external interrupt 0x1202"); system_ctl_set_bit(0, 13); smp_rescan_cpus(true); } void __init smp_prepare_boot_cpu(void) { struct pcpu *pcpu = pcpu_devices; WARN_ON(!cpu_present(0) || !cpu_online(0)); pcpu->state = CPU_STATE_CONFIGURED; get_lowcore()->percpu_offset = __per_cpu_offset[0]; smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN); } void __init smp_setup_processor_id(void) { struct lowcore *lc = get_lowcore(); pcpu_devices[0].address = stap(); lc->cpu_nr = 0; lc->spinlock_lockval = arch_spin_lockval(0); lc->spinlock_index = 0; } /* * the frequency of the profiling timer can be changed * by writing a multiplier value into /proc/profile. * * usually you want to run this on all CPUs ;) */ int setup_profiling_timer(unsigned int multiplier) { return 0; } static ssize_t cpu_configure_show(struct device *dev, struct device_attribute *attr, char *buf) { ssize_t count; mutex_lock(&smp_cpu_state_mutex); count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state); mutex_unlock(&smp_cpu_state_mutex); return count; } static ssize_t cpu_configure_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct pcpu *pcpu; int cpu, val, rc, i; char delim; if (sscanf(buf, "%d %c", &val, &delim) != 1) return -EINVAL; if (val != 0 && val != 1) return -EINVAL; cpus_read_lock(); mutex_lock(&smp_cpu_state_mutex); rc = -EBUSY; /* disallow configuration changes of online cpus */ cpu = dev->id; cpu = smp_get_base_cpu(cpu); for (i = 0; i <= smp_cpu_mtid; i++) if (cpu_online(cpu + i)) goto out; pcpu = pcpu_devices + cpu; rc = 0; switch (val) { case 0: if (pcpu->state != CPU_STATE_CONFIGURED) break; rc = sclp_core_deconfigure(pcpu->address >> smp_cpu_mt_shift); if (rc) break; for (i = 0; i <= smp_cpu_mtid; i++) { if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i)) continue; pcpu[i].state = CPU_STATE_STANDBY; smp_cpu_set_polarization(cpu + i, POLARIZATION_UNKNOWN); } topology_expect_change(); break; case 1: if (pcpu->state != CPU_STATE_STANDBY) break; rc = sclp_core_configure(pcpu->address >> smp_cpu_mt_shift); if (rc) break; for (i = 0; i <= smp_cpu_mtid; i++) { if (cpu + i >= nr_cpu_ids || !cpu_present(cpu + i)) continue; pcpu[i].state = CPU_STATE_CONFIGURED; smp_cpu_set_polarization(cpu + i, POLARIZATION_UNKNOWN); } topology_expect_change(); break; default: break; } out: mutex_unlock(&smp_cpu_state_mutex); cpus_read_unlock(); return rc ? rc : count; } static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); static ssize_t show_cpu_address(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "%d\n", pcpu_devices[dev->id].address); } static DEVICE_ATTR(address, 0444, show_cpu_address, NULL); static struct attribute *cpu_common_attrs[] = { &dev_attr_configure.attr, &dev_attr_address.attr, NULL, }; static struct attribute_group cpu_common_attr_group = { .attrs = cpu_common_attrs, }; static struct attribute *cpu_online_attrs[] = { &dev_attr_idle_count.attr, &dev_attr_idle_time_us.attr, NULL, }; static struct attribute_group cpu_online_attr_group = { .attrs = cpu_online_attrs, }; static int smp_cpu_online(unsigned int cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); return sysfs_create_group(&c->dev.kobj, &cpu_online_attr_group); } static int smp_cpu_pre_down(unsigned int cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); sysfs_remove_group(&c->dev.kobj, &cpu_online_attr_group); return 0; } bool arch_cpu_is_hotpluggable(int cpu) { return !!cpu; } int arch_register_cpu(int cpu) { struct cpu *c = &per_cpu(cpu_devices, cpu); int rc; c->hotpluggable = arch_cpu_is_hotpluggable(cpu); rc = register_cpu(c, cpu); if (rc) goto out; rc = sysfs_create_group(&c->dev.kobj, &cpu_common_attr_group); if (rc) goto out_cpu; rc = topology_cpu_init(c); if (rc) goto out_topology; return 0; out_topology: sysfs_remove_group(&c->dev.kobj, &cpu_common_attr_group); out_cpu: unregister_cpu(c); out: return rc; } int __ref smp_rescan_cpus(bool early) { struct sclp_core_info *info; int nr; info = kzalloc(sizeof(*info), GFP_KERNEL); if (!info) return -ENOMEM; smp_get_core_info(info, 0); nr = __smp_rescan_cpus(info, early); kfree(info); if (nr) topology_schedule_update(); return 0; } static ssize_t __ref rescan_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int rc; rc = lock_device_hotplug_sysfs(); if (rc) return rc; rc = smp_rescan_cpus(false); unlock_device_hotplug(); return rc ? rc : count; } static DEVICE_ATTR_WO(rescan); static int __init s390_smp_init(void) { struct device *dev_root; int rc; dev_root = bus_get_dev_root(&cpu_subsys); if (dev_root) { rc = device_create_file(dev_root, &dev_attr_rescan); put_device(dev_root); if (rc) return rc; } rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "s390/smp:online", smp_cpu_online, smp_cpu_pre_down); rc = rc <= 0 ? rc : 0; return rc; } subsys_initcall(s390_smp_init);