| /* |
| * SMP related functions |
| * |
| * Copyright IBM Corp. 1999, 2012 |
| * Author(s): Denis Joseph Barrow, |
| * Martin Schwidefsky <schwidefsky@de.ibm.com>, |
| * Heiko Carstens <heiko.carstens@de.ibm.com>, |
| * |
| * based on other smp stuff by |
| * (c) 1995 Alan Cox, CymruNET Ltd <alan@cymru.net> |
| * (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 <linux/workqueue.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/mm.h> |
| #include <linux/err.h> |
| #include <linux/spinlock.h> |
| #include <linux/kernel_stat.h> |
| #include <linux/delay.h> |
| #include <linux/interrupt.h> |
| #include <linux/irqflags.h> |
| #include <linux/cpu.h> |
| #include <linux/slab.h> |
| #include <linux/crash_dump.h> |
| #include <linux/memblock.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/diag.h> |
| #include <asm/switch_to.h> |
| #include <asm/facility.h> |
| #include <asm/ipl.h> |
| #include <asm/setup.h> |
| #include <asm/irq.h> |
| #include <asm/tlbflush.h> |
| #include <asm/vtimer.h> |
| #include <asm/lowcore.h> |
| #include <asm/sclp.h> |
| #include <asm/vdso.h> |
| #include <asm/debug.h> |
| #include <asm/os_info.h> |
| #include <asm/sigp.h> |
| #include <asm/idle.h> |
| #include "entry.h" |
| |
| enum { |
| ec_schedule = 0, |
| ec_call_function_single, |
| ec_stop_cpu, |
| }; |
| |
| enum { |
| CPU_STATE_STANDBY, |
| CPU_STATE_CONFIGURED, |
| }; |
| |
| static DEFINE_PER_CPU(struct cpu *, cpu_device); |
| |
| struct pcpu { |
| struct lowcore *lowcore; /* lowcore page(s) for the cpu */ |
| 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; |
| |
| 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 arreay. |
| */ |
| 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 uninitialized_var(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); |
| } |
| |
| #define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) |
| #define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) |
| |
| static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) |
| { |
| unsigned long async_stack, panic_stack; |
| struct lowcore *lc; |
| |
| if (pcpu != &pcpu_devices[0]) { |
| pcpu->lowcore = (struct lowcore *) |
| __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); |
| async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); |
| panic_stack = __get_free_page(GFP_KERNEL); |
| if (!pcpu->lowcore || !panic_stack || !async_stack) |
| goto out; |
| } else { |
| async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET; |
| panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET; |
| } |
| lc = pcpu->lowcore; |
| memcpy(lc, &S390_lowcore, 512); |
| memset((char *) lc + 512, 0, sizeof(*lc) - 512); |
| lc->async_stack = async_stack + ASYNC_FRAME_OFFSET; |
| lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET; |
| lc->cpu_nr = cpu; |
| lc->spinlock_lockval = arch_spin_lockval(cpu); |
| lc->br_r1_trampoline = 0x07f1; /* br %r1 */ |
| if (MACHINE_HAS_VX) |
| lc->vector_save_area_addr = |
| (unsigned long) &lc->vector_save_area; |
| if (vdso_alloc_per_cpu(lc)) |
| goto out; |
| lowcore_ptr[cpu] = lc; |
| pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc); |
| return 0; |
| out: |
| if (pcpu != &pcpu_devices[0]) { |
| free_page(panic_stack); |
| free_pages(async_stack, ASYNC_ORDER); |
| free_pages((unsigned long) pcpu->lowcore, LC_ORDER); |
| } |
| return -ENOMEM; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| |
| static void pcpu_free_lowcore(struct pcpu *pcpu) |
| { |
| pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); |
| lowcore_ptr[pcpu - pcpu_devices] = NULL; |
| vdso_free_per_cpu(pcpu->lowcore); |
| if (pcpu == &pcpu_devices[0]) |
| return; |
| free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET); |
| free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER); |
| free_pages((unsigned long) pcpu->lowcore, LC_ORDER); |
| } |
| |
| #endif /* CONFIG_HOTPLUG_CPU */ |
| |
| static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu) |
| { |
| struct lowcore *lc = pcpu->lowcore; |
| |
| cpumask_set_cpu(cpu, &init_mm.context.cpu_attach_mask); |
| cpumask_set_cpu(cpu, mm_cpumask(&init_mm)); |
| lc->cpu_nr = cpu; |
| lc->spinlock_lockval = arch_spin_lockval(cpu); |
| lc->percpu_offset = __per_cpu_offset[cpu]; |
| lc->kernel_asce = S390_lowcore.kernel_asce; |
| lc->machine_flags = S390_lowcore.machine_flags; |
| lc->user_timer = lc->system_timer = lc->steal_timer = 0; |
| __ctl_store(lc->cregs_save_area, 0, 15); |
| save_access_regs((unsigned int *) lc->access_regs_save_area); |
| memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list, |
| sizeof(lc->stfle_fac_list)); |
| memcpy(lc->alt_stfle_fac_list, S390_lowcore.alt_stfle_fac_list, |
| sizeof(lc->alt_stfle_fac_list)); |
| } |
| |
| static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk) |
| { |
| struct lowcore *lc = pcpu->lowcore; |
| struct thread_info *ti = task_thread_info(tsk); |
| |
| lc->kernel_stack = (unsigned long) task_stack_page(tsk) |
| + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); |
| lc->thread_info = (unsigned long) task_thread_info(tsk); |
| lc->current_task = (unsigned long) tsk; |
| lc->lpp = LPP_MAGIC; |
| lc->current_pid = tsk->pid; |
| lc->user_timer = ti->user_timer; |
| lc->system_timer = ti->system_timer; |
| lc->steal_timer = 0; |
| } |
| |
| static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) |
| { |
| struct lowcore *lc = pcpu->lowcore; |
| |
| lc->restart_stack = lc->kernel_stack; |
| lc->restart_fn = (unsigned long) func; |
| lc->restart_data = (unsigned long) data; |
| lc->restart_source = -1UL; |
| pcpu_sigp_retry(pcpu, SIGP_RESTART, 0); |
| } |
| |
| /* |
| * Call function via PSW restart on pcpu and stop the current cpu. |
| */ |
| static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), |
| void *data, unsigned long stack) |
| { |
| struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; |
| unsigned long source_cpu = stap(); |
| |
| __load_psw_mask(PSW_KERNEL_BITS); |
| if (pcpu->address == source_cpu) |
| func(data); /* should not return */ |
| /* Stop target cpu (if func returns this stops the current cpu). */ |
| pcpu_sigp_retry(pcpu, SIGP_STOP, 0); |
| /* Restart func on the target cpu and stop the current cpu. */ |
| mem_assign_absolute(lc->restart_stack, stack); |
| mem_assign_absolute(lc->restart_fn, (unsigned long) func); |
| mem_assign_absolute(lc->restart_data, (unsigned long) data); |
| mem_assign_absolute(lc->restart_source, source_cpu); |
| __bpon(); |
| 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) |
| { |
| pcpu_delegate(&pcpu_devices[0], func, data, |
| pcpu_devices->lowcore->panic_stack - |
| PANIC_FRAME_OFFSET + PAGE_SIZE); |
| } |
| |
| int smp_find_processor_id(u16 address) |
| { |
| int cpu; |
| |
| for_each_present_cpu(cpu) |
| if (pcpu_devices[cpu].address == address) |
| return cpu; |
| return -1; |
| } |
| |
| int smp_vcpu_scheduled(int cpu) |
| { |
| return pcpu_running(pcpu_devices + cpu); |
| } |
| |
| void smp_yield_cpu(int cpu) |
| { |
| if (MACHINE_HAS_DIAG9C) { |
| diag_stat_inc_norecursion(DIAG_STAT_X09C); |
| asm volatile("diag %0,0,0x9c" |
| : : "d" (pcpu_devices[cpu].address)); |
| } else if (MACHINE_HAS_DIAG44) { |
| diag_stat_inc_norecursion(DIAG_STAT_X044); |
| asm volatile("diag 0,0,0x44"); |
| } |
| } |
| |
| /* |
| * Send cpus emergency shutdown signal. This gives the cpus the |
| * opportunity to complete outstanding interrupts. |
| */ |
| static void smp_emergency_stop(cpumask_t *cpumask) |
| { |
| u64 end; |
| int cpu; |
| |
| 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(); |
| } |
| } |
| |
| /* |
| * Stop all cpus but the current one. |
| */ |
| void smp_send_stop(void) |
| { |
| cpumask_t cpumask; |
| int cpu; |
| |
| /* Disable all interrupts/machine checks */ |
| __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); |
| trace_hardirqs_off(); |
| |
| debug_set_critical(); |
| cpumask_copy(&cpumask, cpu_online_mask); |
| cpumask_clear_cpu(smp_processor_id(), &cpumask); |
| |
| if (oops_in_progress) |
| smp_emergency_stop(&cpumask); |
| |
| /* stop all processors */ |
| for_each_cpu(cpu, &cpumask) { |
| struct pcpu *pcpu = pcpu_devices + cpu; |
| pcpu_sigp_retry(pcpu, SIGP_STOP, 0); |
| while (!pcpu_stopped(pcpu)) |
| 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(); |
| } |
| |
| 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 smp_send_reschedule(int cpu) |
| { |
| pcpu_ec_call(pcpu_devices + cpu, ec_schedule); |
| } |
| |
| /* |
| * parameter area for the set/clear control bit callbacks |
| */ |
| struct ec_creg_mask_parms { |
| unsigned long orval; |
| unsigned long andval; |
| int cr; |
| }; |
| |
| /* |
| * callback for setting/clearing control bits |
| */ |
| static void smp_ctl_bit_callback(void *info) |
| { |
| struct ec_creg_mask_parms *pp = info; |
| unsigned long cregs[16]; |
| |
| __ctl_store(cregs, 0, 15); |
| cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval; |
| __ctl_load(cregs, 0, 15); |
| } |
| |
| /* |
| * Set a bit in a control register of all cpus |
| */ |
| void smp_ctl_set_bit(int cr, int bit) |
| { |
| struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr }; |
| |
| on_each_cpu(smp_ctl_bit_callback, &parms, 1); |
| } |
| EXPORT_SYMBOL(smp_ctl_set_bit); |
| |
| /* |
| * Clear a bit in a control register of all cpus |
| */ |
| void smp_ctl_clear_bit(int cr, int bit) |
| { |
| struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr }; |
| |
| on_each_cpu(smp_ctl_bit_callback, &parms, 1); |
| } |
| EXPORT_SYMBOL(smp_ctl_clear_bit); |
| |
| #ifdef CONFIG_CRASH_DUMP |
| |
| int smp_store_status(int cpu) |
| { |
| struct pcpu *pcpu = pcpu_devices + cpu; |
| unsigned long pa; |
| |
| pa = __pa(&pcpu->lowcore->floating_pt_save_area); |
| if (__pcpu_sigp_relax(pcpu->address, SIGP_STORE_STATUS_AT_ADDRESS, |
| pa) != SIGP_CC_ORDER_CODE_ACCEPTED) |
| return -EIO; |
| if (!MACHINE_HAS_VX) |
| return 0; |
| pa = __pa(pcpu->lowcore->vector_save_area_addr); |
| 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 dump |
| * condition: OLDMEM_BASE == NULL && ipl_info.type == IPL_TYPE_FCP_DUMP |
| * 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 (zfcp dump with swapped memory) |
| * condition: OLDMEM_BASE != NULL && ipl_info.type == IPL_TYPE_FCP_DUMP |
| * 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 __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr, |
| bool is_boot_cpu, unsigned long page) |
| { |
| __vector128 *vxrs = (__vector128 *) page; |
| |
| if (is_boot_cpu) |
| vxrs = boot_cpu_vector_save_area; |
| else |
| __pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, page); |
| save_area_add_vxrs(sa, vxrs); |
| } |
| |
| static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr, |
| bool is_boot_cpu, unsigned long page) |
| { |
| void *regs = (void *) page; |
| |
| if (is_boot_cpu) |
| copy_oldmem_kernel(regs, (void *) __LC_FPREGS_SAVE_AREA, 512); |
| else |
| __pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, page); |
| save_area_add_regs(sa, regs); |
| } |
| |
| void __init smp_save_dump_cpus(void) |
| { |
| int addr, boot_cpu_addr, max_cpu_addr; |
| struct save_area *sa; |
| unsigned long page; |
| bool is_boot_cpu; |
| |
| if (!(OLDMEM_BASE || ipl_info.type == IPL_TYPE_FCP_DUMP)) |
| /* No previous system present, normal boot. */ |
| return; |
| /* Allocate a page as dumping area for the store status sigps */ |
| page = memblock_alloc_base(PAGE_SIZE, 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 (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) == |
| SIGP_CC_NOT_OPERATIONAL) |
| continue; |
| is_boot_cpu = (addr == boot_cpu_addr); |
| /* Allocate save area */ |
| sa = save_area_alloc(is_boot_cpu); |
| if (!sa) |
| panic("could not allocate memory for save area\n"); |
| if (MACHINE_HAS_VX) |
| /* Get the vector registers */ |
| smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page); |
| /* |
| * For a zfcp dump OLDMEM_BASE == NULL and the registers |
| * of the boot CPU are stored in the HSA. To retrieve |
| * these registers an SCLP request is required which is |
| * done by drivers/s390/char/zcore.c:init_cpu_info() |
| */ |
| if (!is_boot_cpu || OLDMEM_BASE) |
| /* Get the CPU registers */ |
| smp_save_cpu_regs(sa, addr, is_boot_cpu, page); |
| } |
| memblock_free(page, PAGE_SIZE); |
| 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; |
| } |
| |
| static struct sclp_core_info *smp_get_core_info(void) |
| { |
| static int use_sigp_detection; |
| struct sclp_core_info *info; |
| int address; |
| |
| info = kzalloc(sizeof(*info), GFP_KERNEL); |
| if (info && (use_sigp_detection || sclp_get_core_info(info))) { |
| 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; |
| } |
| return info; |
| } |
| |
| static int smp_add_present_cpu(int cpu); |
| |
| static int __smp_rescan_cpus(struct sclp_core_info *info, int sysfs_add) |
| { |
| struct pcpu *pcpu; |
| cpumask_t avail; |
| int cpu, nr, i, j; |
| u16 address; |
| |
| nr = 0; |
| cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask); |
| cpu = cpumask_first(&avail); |
| for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) { |
| if (sclp.has_core_type && info->core[i].type != boot_core_type) |
| continue; |
| address = info->core[i].core_id << smp_cpu_mt_shift; |
| for (j = 0; j <= smp_cpu_mtid; j++) { |
| if (pcpu_find_address(cpu_present_mask, address + j)) |
| continue; |
| pcpu = pcpu_devices + cpu; |
| pcpu->address = address + j; |
| pcpu->state = |
| (cpu >= info->configured*(smp_cpu_mtid + 1)) ? |
| CPU_STATE_STANDBY : CPU_STATE_CONFIGURED; |
| smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN); |
| set_cpu_present(cpu, true); |
| if (sysfs_add && smp_add_present_cpu(cpu) != 0) |
| set_cpu_present(cpu, false); |
| else |
| nr++; |
| cpu = cpumask_next(cpu, &avail); |
| if (cpu >= nr_cpu_ids) |
| break; |
| } |
| } |
| return nr; |
| } |
| |
| static 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 = smp_get_core_info(); |
| if (!info) |
| panic("smp_detect_cpus failed to allocate memory\n"); |
| |
| /* 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); |
| |
| /* Add CPUs present at boot */ |
| get_online_cpus(); |
| __smp_rescan_cpus(info, 0); |
| put_online_cpus(); |
| kfree(info); |
| } |
| |
| /* |
| * Activate a secondary processor. |
| */ |
| static void smp_start_secondary(void *cpuvoid) |
| { |
| S390_lowcore.last_update_clock = get_tod_clock(); |
| S390_lowcore.restart_stack = (unsigned long) restart_stack; |
| S390_lowcore.restart_fn = (unsigned long) do_restart; |
| S390_lowcore.restart_data = 0; |
| S390_lowcore.restart_source = -1UL; |
| restore_access_regs(S390_lowcore.access_regs_save_area); |
| __ctl_load(S390_lowcore.cregs_save_area, 0, 15); |
| __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); |
| cpu_init(); |
| preempt_disable(); |
| init_cpu_timer(); |
| vtime_init(); |
| pfault_init(); |
| notify_cpu_starting(smp_processor_id()); |
| set_cpu_online(smp_processor_id(), 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; |
| int base, i, rc; |
| |
| pcpu = pcpu_devices + cpu; |
| if (pcpu->state != CPU_STATE_CONFIGURED) |
| return -EIO; |
| base = cpu - (cpu % (smp_cpu_mtid + 1)); |
| for (i = 0; i <= smp_cpu_mtid; i++) { |
| if (base + i < nr_cpu_ids) |
| if (cpu_online(base + i)) |
| break; |
| } |
| /* |
| * If this is the first CPU of the core to get online |
| * do an initial CPU reset. |
| */ |
| if (i > smp_cpu_mtid && |
| pcpu_sigp_retry(pcpu_devices + base, SIGP_INITIAL_CPU_RESET, 0) != |
| SIGP_CC_ORDER_CODE_ACCEPTED) |
| return -EIO; |
| |
| rc = pcpu_alloc_lowcore(pcpu, cpu); |
| if (rc) |
| return rc; |
| 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(); |
| 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); |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| |
| int __cpu_disable(void) |
| { |
| unsigned long cregs[16]; |
| |
| /* Handle possible pending IPIs */ |
| smp_handle_ext_call(); |
| set_cpu_online(smp_processor_id(), false); |
| /* Disable pseudo page faults on this cpu. */ |
| pfault_fini(); |
| /* Disable interrupt sources via control register. */ |
| __ctl_store(cregs, 0, 15); |
| cregs[0] &= ~0x0000ee70UL; /* disable all external interrupts */ |
| cregs[6] &= ~0xff000000UL; /* disable all I/O interrupts */ |
| cregs[14] &= ~0x1f000000UL; /* disable most machine checks */ |
| __ctl_load(cregs, 0, 15); |
| 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(); |
| __bpon(); |
| pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0); |
| for (;;) ; |
| } |
| |
| #endif /* CONFIG_HOTPLUG_CPU */ |
| |
| 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) |
| { |
| /* request the 0x1201 emergency signal external interrupt */ |
| if (register_external_irq(EXT_IRQ_EMERGENCY_SIG, do_ext_call_interrupt)) |
| panic("Couldn't request external interrupt 0x1201"); |
| /* request the 0x1202 external call external interrupt */ |
| if (register_external_irq(EXT_IRQ_EXTERNAL_CALL, do_ext_call_interrupt)) |
| panic("Couldn't request external interrupt 0x1202"); |
| smp_detect_cpus(); |
| } |
| |
| void __init smp_prepare_boot_cpu(void) |
| { |
| struct pcpu *pcpu = pcpu_devices; |
| |
| pcpu->state = CPU_STATE_CONFIGURED; |
| pcpu->address = stap(); |
| pcpu->lowcore = (struct lowcore *)(unsigned long) store_prefix(); |
| S390_lowcore.percpu_offset = __per_cpu_offset[0]; |
| smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN); |
| set_cpu_present(0, true); |
| set_cpu_online(0, true); |
| } |
| |
| void __init smp_cpus_done(unsigned int max_cpus) |
| { |
| } |
| |
| void __init smp_setup_processor_id(void) |
| { |
| S390_lowcore.cpu_nr = 0; |
| S390_lowcore.spinlock_lockval = arch_spin_lockval(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; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| 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; |
| get_online_cpus(); |
| mutex_lock(&smp_cpu_state_mutex); |
| rc = -EBUSY; |
| /* disallow configuration changes of online cpus and cpu 0 */ |
| cpu = dev->id; |
| cpu -= cpu % (smp_cpu_mtid + 1); |
| if (cpu == 0) |
| goto out; |
| 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); |
| put_online_cpus(); |
| return rc ? rc : count; |
| } |
| static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); |
| #endif /* CONFIG_HOTPLUG_CPU */ |
| |
| 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[] = { |
| #ifdef CONFIG_HOTPLUG_CPU |
| &dev_attr_configure.attr, |
| #endif |
| &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_notify(struct notifier_block *self, unsigned long action, |
| void *hcpu) |
| { |
| unsigned int cpu = (unsigned int)(long)hcpu; |
| struct device *s = &per_cpu(cpu_device, cpu)->dev; |
| int err = 0; |
| |
| switch (action & ~CPU_TASKS_FROZEN) { |
| case CPU_ONLINE: |
| err = sysfs_create_group(&s->kobj, &cpu_online_attr_group); |
| break; |
| case CPU_DEAD: |
| sysfs_remove_group(&s->kobj, &cpu_online_attr_group); |
| break; |
| } |
| return notifier_from_errno(err); |
| } |
| |
| static int smp_add_present_cpu(int cpu) |
| { |
| struct device *s; |
| struct cpu *c; |
| int rc; |
| |
| c = kzalloc(sizeof(*c), GFP_KERNEL); |
| if (!c) |
| return -ENOMEM; |
| per_cpu(cpu_device, cpu) = c; |
| s = &c->dev; |
| c->hotpluggable = 1; |
| rc = register_cpu(c, cpu); |
| if (rc) |
| goto out; |
| rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group); |
| if (rc) |
| goto out_cpu; |
| if (cpu_online(cpu)) { |
| rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group); |
| if (rc) |
| goto out_online; |
| } |
| rc = topology_cpu_init(c); |
| if (rc) |
| goto out_topology; |
| return 0; |
| |
| out_topology: |
| if (cpu_online(cpu)) |
| sysfs_remove_group(&s->kobj, &cpu_online_attr_group); |
| out_online: |
| sysfs_remove_group(&s->kobj, &cpu_common_attr_group); |
| out_cpu: |
| #ifdef CONFIG_HOTPLUG_CPU |
| unregister_cpu(c); |
| #endif |
| out: |
| return rc; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| |
| int __ref smp_rescan_cpus(void) |
| { |
| struct sclp_core_info *info; |
| int nr; |
| |
| info = smp_get_core_info(); |
| if (!info) |
| return -ENOMEM; |
| get_online_cpus(); |
| mutex_lock(&smp_cpu_state_mutex); |
| nr = __smp_rescan_cpus(info, 1); |
| mutex_unlock(&smp_cpu_state_mutex); |
| put_online_cpus(); |
| 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 = smp_rescan_cpus(); |
| return rc ? rc : count; |
| } |
| static DEVICE_ATTR(rescan, 0200, NULL, rescan_store); |
| #endif /* CONFIG_HOTPLUG_CPU */ |
| |
| static int __init s390_smp_init(void) |
| { |
| int cpu, rc = 0; |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan); |
| if (rc) |
| return rc; |
| #endif |
| cpu_notifier_register_begin(); |
| for_each_present_cpu(cpu) { |
| rc = smp_add_present_cpu(cpu); |
| if (rc) |
| goto out; |
| } |
| |
| __hotcpu_notifier(smp_cpu_notify, 0); |
| |
| out: |
| cpu_notifier_register_done(); |
| return rc; |
| } |
| subsys_initcall(s390_smp_init); |