/* * x86 SMP booting functions * * (c) 1995 Alan Cox, Building #3 * (c) 1998, 1999, 2000 Ingo Molnar * * Much of the core SMP work is based on previous work by Thomas Radke, to * whom a great many thanks are extended. * * Thanks to Intel for making available several different Pentium, * Pentium Pro and Pentium-II/Xeon MP machines. * Original development of Linux SMP code supported by Caldera. * * This code is released under the GNU General Public License version 2 or * later. * * Fixes * Felix Koop : NR_CPUS used properly * Jose Renau : Handle single CPU case. * Alan Cox : By repeated request 8) - Total BogoMIPS report. * Greg Wright : Fix for kernel stacks panic. * Erich Boleyn : MP v1.4 and additional changes. * Matthias Sattler : Changes for 2.1 kernel map. * Michel Lespinasse : Changes for 2.1 kernel map. * Michael Chastain : Change trampoline.S to gnu as. * Alan Cox : Dumb bug: 'B' step PPro's are fine * Ingo Molnar : Added APIC timers, based on code * from Jose Renau * Ingo Molnar : various cleanups and rewrites * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug. * Maciej W. Rozycki : Bits for genuine 82489DX APICs * Martin J. Bligh : Added support for multi-quad systems * Dave Jones : Report invalid combinations of Athlon CPUs. * Rusty Russell : Hacked into shape for new "hotplug" boot process. */ /* SMP boot always wants to use real time delay to allow sufficient time for * the APs to come online */ #define USE_REAL_TIME_DELAY #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Set if we find a B stepping CPU */ static int __devinitdata smp_b_stepping; /* Number of siblings per CPU package */ int smp_num_siblings = 1; EXPORT_SYMBOL(smp_num_siblings); /* Last level cache ID of each logical CPU */ int cpu_llc_id[NR_CPUS] __cpuinitdata = {[0 ... NR_CPUS-1] = BAD_APICID}; /* representing HT siblings of each logical CPU */ cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly; EXPORT_SYMBOL(cpu_sibling_map); /* representing HT and core siblings of each logical CPU */ cpumask_t cpu_core_map[NR_CPUS] __read_mostly; EXPORT_SYMBOL(cpu_core_map); /* bitmap of online cpus */ cpumask_t cpu_online_map __read_mostly; EXPORT_SYMBOL(cpu_online_map); cpumask_t cpu_callin_map; cpumask_t cpu_callout_map; EXPORT_SYMBOL(cpu_callout_map); cpumask_t cpu_possible_map; EXPORT_SYMBOL(cpu_possible_map); static cpumask_t smp_commenced_mask; /* Per CPU bogomips and other parameters */ struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned; EXPORT_SYMBOL(cpu_data); u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0xff }; EXPORT_SYMBOL(x86_cpu_to_apicid); u8 apicid_2_node[MAX_APICID]; /* * Trampoline 80x86 program as an array. */ extern unsigned char trampoline_data []; extern unsigned char trampoline_end []; static unsigned char *trampoline_base; static int trampoline_exec; static void map_cpu_to_logical_apicid(void); /* State of each CPU. */ DEFINE_PER_CPU(int, cpu_state) = { 0 }; /* * Currently trivial. Write the real->protected mode * bootstrap into the page concerned. The caller * has made sure it's suitably aligned. */ static unsigned long __devinit setup_trampoline(void) { memcpy(trampoline_base, trampoline_data, trampoline_end - trampoline_data); return virt_to_phys(trampoline_base); } /* * We are called very early to get the low memory for the * SMP bootup trampoline page. */ void __init smp_alloc_memory(void) { trampoline_base = (void *) alloc_bootmem_low_pages(PAGE_SIZE); /* * Has to be in very low memory so we can execute * real-mode AP code. */ if (__pa(trampoline_base) >= 0x9F000) BUG(); /* * Make the SMP trampoline executable: */ trampoline_exec = set_kernel_exec((unsigned long)trampoline_base, 1); } /* * The bootstrap kernel entry code has set these up. Save them for * a given CPU */ static void __cpuinit smp_store_cpu_info(int id) { struct cpuinfo_x86 *c = cpu_data + id; *c = boot_cpu_data; if (id!=0) identify_cpu(c); /* * Mask B, Pentium, but not Pentium MMX */ if (c->x86_vendor == X86_VENDOR_INTEL && c->x86 == 5 && c->x86_mask >= 1 && c->x86_mask <= 4 && c->x86_model <= 3) /* * Remember we have B step Pentia with bugs */ smp_b_stepping = 1; /* * Certain Athlons might work (for various values of 'work') in SMP * but they are not certified as MP capable. */ if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) { if (num_possible_cpus() == 1) goto valid_k7; /* Athlon 660/661 is valid. */ if ((c->x86_model==6) && ((c->x86_mask==0) || (c->x86_mask==1))) goto valid_k7; /* Duron 670 is valid */ if ((c->x86_model==7) && (c->x86_mask==0)) goto valid_k7; /* * Athlon 662, Duron 671, and Athlon >model 7 have capability bit. * It's worth noting that the A5 stepping (662) of some Athlon XP's * have the MP bit set. * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for more. */ if (((c->x86_model==6) && (c->x86_mask>=2)) || ((c->x86_model==7) && (c->x86_mask>=1)) || (c->x86_model> 7)) if (cpu_has_mp) goto valid_k7; /* If we get here, it's not a certified SMP capable AMD system. */ add_taint(TAINT_UNSAFE_SMP); } valid_k7: ; } extern void calibrate_delay(void); static atomic_t init_deasserted; static void __cpuinit smp_callin(void) { int cpuid, phys_id; unsigned long timeout; /* * If waken up by an INIT in an 82489DX configuration * we may get here before an INIT-deassert IPI reaches * our local APIC. We have to wait for the IPI or we'll * lock up on an APIC access. */ wait_for_init_deassert(&init_deasserted); /* * (This works even if the APIC is not enabled.) */ phys_id = GET_APIC_ID(apic_read(APIC_ID)); cpuid = smp_processor_id(); if (cpu_isset(cpuid, cpu_callin_map)) { printk("huh, phys CPU#%d, CPU#%d already present??\n", phys_id, cpuid); BUG(); } Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id); /* * STARTUP IPIs are fragile beasts as they might sometimes * trigger some glue motherboard logic. Complete APIC bus * silence for 1 second, this overestimates the time the * boot CPU is spending to send the up to 2 STARTUP IPIs * by a factor of two. This should be enough. */ /* * Waiting 2s total for startup (udelay is not yet working) */ timeout = jiffies + 2*HZ; while (time_before(jiffies, timeout)) { /* * Has the boot CPU finished it's STARTUP sequence? */ if (cpu_isset(cpuid, cpu_callout_map)) break; rep_nop(); } if (!time_before(jiffies, timeout)) { printk("BUG: CPU%d started up but did not get a callout!\n", cpuid); BUG(); } /* * the boot CPU has finished the init stage and is spinning * on callin_map until we finish. We are free to set up this * CPU, first the APIC. (this is probably redundant on most * boards) */ Dprintk("CALLIN, before setup_local_APIC().\n"); smp_callin_clear_local_apic(); setup_local_APIC(); map_cpu_to_logical_apicid(); /* * Get our bogomips. */ calibrate_delay(); Dprintk("Stack at about %p\n",&cpuid); /* * Save our processor parameters */ smp_store_cpu_info(cpuid); disable_APIC_timer(); /* * Allow the master to continue. */ cpu_set(cpuid, cpu_callin_map); } static int cpucount; /* maps the cpu to the sched domain representing multi-core */ cpumask_t cpu_coregroup_map(int cpu) { struct cpuinfo_x86 *c = cpu_data + cpu; /* * For perf, we return last level cache shared map. * And for power savings, we return cpu_core_map */ if (sched_mc_power_savings || sched_smt_power_savings) return cpu_core_map[cpu]; else return c->llc_shared_map; } /* representing cpus for which sibling maps can be computed */ static cpumask_t cpu_sibling_setup_map; static inline void set_cpu_sibling_map(int cpu) { int i; struct cpuinfo_x86 *c = cpu_data; cpu_set(cpu, cpu_sibling_setup_map); if (smp_num_siblings > 1) { for_each_cpu_mask(i, cpu_sibling_setup_map) { if (c[cpu].phys_proc_id == c[i].phys_proc_id && c[cpu].cpu_core_id == c[i].cpu_core_id) { cpu_set(i, cpu_sibling_map[cpu]); cpu_set(cpu, cpu_sibling_map[i]); cpu_set(i, cpu_core_map[cpu]); cpu_set(cpu, cpu_core_map[i]); cpu_set(i, c[cpu].llc_shared_map); cpu_set(cpu, c[i].llc_shared_map); } } } else { cpu_set(cpu, cpu_sibling_map[cpu]); } cpu_set(cpu, c[cpu].llc_shared_map); if (current_cpu_data.x86_max_cores == 1) { cpu_core_map[cpu] = cpu_sibling_map[cpu]; c[cpu].booted_cores = 1; return; } for_each_cpu_mask(i, cpu_sibling_setup_map) { if (cpu_llc_id[cpu] != BAD_APICID && cpu_llc_id[cpu] == cpu_llc_id[i]) { cpu_set(i, c[cpu].llc_shared_map); cpu_set(cpu, c[i].llc_shared_map); } if (c[cpu].phys_proc_id == c[i].phys_proc_id) { cpu_set(i, cpu_core_map[cpu]); cpu_set(cpu, cpu_core_map[i]); /* * Does this new cpu bringup a new core? */ if (cpus_weight(cpu_sibling_map[cpu]) == 1) { /* * for each core in package, increment * the booted_cores for this new cpu */ if (first_cpu(cpu_sibling_map[i]) == i) c[cpu].booted_cores++; /* * increment the core count for all * the other cpus in this package */ if (i != cpu) c[i].booted_cores++; } else if (i != cpu && !c[cpu].booted_cores) c[cpu].booted_cores = c[i].booted_cores; } } } /* * Activate a secondary processor. */ static void __cpuinit start_secondary(void *unused) { /* * Don't put *anything* before secondary_cpu_init(), SMP * booting is too fragile that we want to limit the * things done here to the most necessary things. */ #ifdef CONFIG_VMI vmi_bringup(); #endif secondary_cpu_init(); preempt_disable(); smp_callin(); while (!cpu_isset(smp_processor_id(), smp_commenced_mask)) rep_nop(); /* * Check TSC synchronization with the BP: */ check_tsc_sync_target(); setup_secondary_clock(); if (nmi_watchdog == NMI_IO_APIC) { disable_8259A_irq(0); enable_NMI_through_LVT0(NULL); enable_8259A_irq(0); } enable_APIC_timer(); /* * low-memory mappings have been cleared, flush them from * the local TLBs too. */ local_flush_tlb(); /* This must be done before setting cpu_online_map */ set_cpu_sibling_map(raw_smp_processor_id()); wmb(); /* * We need to hold call_lock, so there is no inconsistency * between the time smp_call_function() determines number of * IPI receipients, and the time when the determination is made * for which cpus receive the IPI. Holding this * lock helps us to not include this cpu in a currently in progress * smp_call_function(). */ lock_ipi_call_lock(); cpu_set(smp_processor_id(), cpu_online_map); unlock_ipi_call_lock(); per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; /* We can take interrupts now: we're officially "up". */ local_irq_enable(); wmb(); cpu_idle(); } /* * Everything has been set up for the secondary * CPUs - they just need to reload everything * from the task structure * This function must not return. */ void __devinit initialize_secondary(void) { /* * switch to the per CPU GDT we already set up * in do_boot_cpu() */ cpu_set_gdt(current_thread_info()->cpu); /* * We don't actually need to load the full TSS, * basically just the stack pointer and the eip. */ asm volatile( "movl %0,%%esp\n\t" "jmp *%1" : :"m" (current->thread.esp),"m" (current->thread.eip)); } /* Static state in head.S used to set up a CPU */ extern struct { void * esp; unsigned short ss; } stack_start; extern struct i386_pda *start_pda; #ifdef CONFIG_NUMA /* which logical CPUs are on which nodes */ cpumask_t node_2_cpu_mask[MAX_NUMNODES] __read_mostly = { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE }; EXPORT_SYMBOL(node_2_cpu_mask); /* which node each logical CPU is on */ int cpu_2_node[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0 }; EXPORT_SYMBOL(cpu_2_node); /* set up a mapping between cpu and node. */ static inline void map_cpu_to_node(int cpu, int node) { printk("Mapping cpu %d to node %d\n", cpu, node); cpu_set(cpu, node_2_cpu_mask[node]); cpu_2_node[cpu] = node; } /* undo a mapping between cpu and node. */ static inline void unmap_cpu_to_node(int cpu) { int node; printk("Unmapping cpu %d from all nodes\n", cpu); for (node = 0; node < MAX_NUMNODES; node ++) cpu_clear(cpu, node_2_cpu_mask[node]); cpu_2_node[cpu] = 0; } #else /* !CONFIG_NUMA */ #define map_cpu_to_node(cpu, node) ({}) #define unmap_cpu_to_node(cpu) ({}) #endif /* CONFIG_NUMA */ u8 cpu_2_logical_apicid[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID }; static void map_cpu_to_logical_apicid(void) { int cpu = smp_processor_id(); int apicid = logical_smp_processor_id(); int node = apicid_to_node(apicid); if (!node_online(node)) node = first_online_node; cpu_2_logical_apicid[cpu] = apicid; map_cpu_to_node(cpu, node); } static void unmap_cpu_to_logical_apicid(int cpu) { cpu_2_logical_apicid[cpu] = BAD_APICID; unmap_cpu_to_node(cpu); } #if APIC_DEBUG static inline void __inquire_remote_apic(int apicid) { int i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 }; char *names[] = { "ID", "VERSION", "SPIV" }; int timeout, status; printk("Inquiring remote APIC #%d...\n", apicid); for (i = 0; i < ARRAY_SIZE(regs); i++) { printk("... APIC #%d %s: ", apicid, names[i]); /* * Wait for idle. */ apic_wait_icr_idle(); apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid)); apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]); timeout = 0; do { udelay(100); status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK; } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000); switch (status) { case APIC_ICR_RR_VALID: status = apic_read(APIC_RRR); printk("%08x\n", status); break; default: printk("failed\n"); } } } #endif #ifdef WAKE_SECONDARY_VIA_NMI /* * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this * won't ... remember to clear down the APIC, etc later. */ static int __devinit wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip) { unsigned long send_status = 0, accept_status = 0; int timeout, maxlvt; /* Target chip */ apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid)); /* Boot on the stack */ /* Kick the second */ apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL); Dprintk("Waiting for send to finish...\n"); timeout = 0; do { Dprintk("+"); udelay(100); send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY; } while (send_status && (timeout++ < 1000)); /* * Give the other CPU some time to accept the IPI. */ udelay(200); /* * Due to the Pentium erratum 3AP. */ maxlvt = get_maxlvt(); if (maxlvt > 3) { apic_read_around(APIC_SPIV); apic_write(APIC_ESR, 0); } accept_status = (apic_read(APIC_ESR) & 0xEF); Dprintk("NMI sent.\n"); if (send_status) printk("APIC never delivered???\n"); if (accept_status) printk("APIC delivery error (%lx).\n", accept_status); return (send_status | accept_status); } #endif /* WAKE_SECONDARY_VIA_NMI */ #ifdef WAKE_SECONDARY_VIA_INIT static int __devinit wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip) { unsigned long send_status = 0, accept_status = 0; int maxlvt, timeout, num_starts, j; /* * Be paranoid about clearing APIC errors. */ if (APIC_INTEGRATED(apic_version[phys_apicid])) { apic_read_around(APIC_SPIV); apic_write(APIC_ESR, 0); apic_read(APIC_ESR); } Dprintk("Asserting INIT.\n"); /* * Turn INIT on target chip */ apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* * Send IPI */ apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT); Dprintk("Waiting for send to finish...\n"); timeout = 0; do { Dprintk("+"); udelay(100); send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY; } while (send_status && (timeout++ < 1000)); mdelay(10); Dprintk("Deasserting INIT.\n"); /* Target chip */ apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* Send IPI */ apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT); Dprintk("Waiting for send to finish...\n"); timeout = 0; do { Dprintk("+"); udelay(100); send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY; } while (send_status && (timeout++ < 1000)); atomic_set(&init_deasserted, 1); /* * Should we send STARTUP IPIs ? * * Determine this based on the APIC version. * If we don't have an integrated APIC, don't send the STARTUP IPIs. */ if (APIC_INTEGRATED(apic_version[phys_apicid])) num_starts = 2; else num_starts = 0; /* * Paravirt / VMI wants a startup IPI hook here to set up the * target processor state. */ startup_ipi_hook(phys_apicid, (unsigned long) start_secondary, (unsigned long) stack_start.esp); /* * Run STARTUP IPI loop. */ Dprintk("#startup loops: %d.\n", num_starts); maxlvt = get_maxlvt(); for (j = 1; j <= num_starts; j++) { Dprintk("Sending STARTUP #%d.\n",j); apic_read_around(APIC_SPIV); apic_write(APIC_ESR, 0); apic_read(APIC_ESR); Dprintk("After apic_write.\n"); /* * STARTUP IPI */ /* Target chip */ apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* Boot on the stack */ /* Kick the second */ apic_write_around(APIC_ICR, APIC_DM_STARTUP | (start_eip >> 12)); /* * Give the other CPU some time to accept the IPI. */ udelay(300); Dprintk("Startup point 1.\n"); Dprintk("Waiting for send to finish...\n"); timeout = 0; do { Dprintk("+"); udelay(100); send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY; } while (send_status && (timeout++ < 1000)); /* * Give the other CPU some time to accept the IPI. */ udelay(200); /* * Due to the Pentium erratum 3AP. */ if (maxlvt > 3) { apic_read_around(APIC_SPIV); apic_write(APIC_ESR, 0); } accept_status = (apic_read(APIC_ESR) & 0xEF); if (send_status || accept_status) break; } Dprintk("After Startup.\n"); if (send_status) printk("APIC never delivered???\n"); if (accept_status) printk("APIC delivery error (%lx).\n", accept_status); return (send_status | accept_status); } #endif /* WAKE_SECONDARY_VIA_INIT */ extern cpumask_t cpu_initialized; static inline int alloc_cpu_id(void) { cpumask_t tmp_map; int cpu; cpus_complement(tmp_map, cpu_present_map); cpu = first_cpu(tmp_map); if (cpu >= NR_CPUS) return -ENODEV; return cpu; } #ifdef CONFIG_HOTPLUG_CPU static struct task_struct * __devinitdata cpu_idle_tasks[NR_CPUS]; static inline struct task_struct * alloc_idle_task(int cpu) { struct task_struct *idle; if ((idle = cpu_idle_tasks[cpu]) != NULL) { /* initialize thread_struct. we really want to avoid destroy * idle tread */ idle->thread.esp = (unsigned long)task_pt_regs(idle); init_idle(idle, cpu); return idle; } idle = fork_idle(cpu); if (!IS_ERR(idle)) cpu_idle_tasks[cpu] = idle; return idle; } #else #define alloc_idle_task(cpu) fork_idle(cpu) #endif static int __cpuinit do_boot_cpu(int apicid, int cpu) /* * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad * (ie clustered apic addressing mode), this is a LOGICAL apic ID. * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu. */ { struct task_struct *idle; unsigned long boot_error; int timeout; unsigned long start_eip; unsigned short nmi_high = 0, nmi_low = 0; /* * We can't use kernel_thread since we must avoid to * reschedule the child. */ idle = alloc_idle_task(cpu); if (IS_ERR(idle)) panic("failed fork for CPU %d", cpu); /* Pre-allocate and initialize the CPU's GDT and PDA so it doesn't have to do any memory allocation during the delicate CPU-bringup phase. */ if (!init_gdt(cpu, idle)) { printk(KERN_INFO "Couldn't allocate GDT/PDA for CPU %d\n", cpu); return -1; /* ? */ } idle->thread.eip = (unsigned long) start_secondary; /* start_eip had better be page-aligned! */ start_eip = setup_trampoline(); ++cpucount; alternatives_smp_switch(1); /* So we see what's up */ printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip); /* Stack for startup_32 can be just as for start_secondary onwards */ stack_start.esp = (void *) idle->thread.esp; irq_ctx_init(cpu); x86_cpu_to_apicid[cpu] = apicid; /* * This grunge runs the startup process for * the targeted processor. */ atomic_set(&init_deasserted, 0); Dprintk("Setting warm reset code and vector.\n"); store_NMI_vector(&nmi_high, &nmi_low); smpboot_setup_warm_reset_vector(start_eip); /* * Starting actual IPI sequence... */ boot_error = wakeup_secondary_cpu(apicid, start_eip); if (!boot_error) { /* * allow APs to start initializing. */ Dprintk("Before Callout %d.\n", cpu); cpu_set(cpu, cpu_callout_map); Dprintk("After Callout %d.\n", cpu); /* * Wait 5s total for a response */ for (timeout = 0; timeout < 50000; timeout++) { if (cpu_isset(cpu, cpu_callin_map)) break; /* It has booted */ udelay(100); } if (cpu_isset(cpu, cpu_callin_map)) { /* number CPUs logically, starting from 1 (BSP is 0) */ Dprintk("OK.\n"); printk("CPU%d: ", cpu); print_cpu_info(&cpu_data[cpu]); Dprintk("CPU has booted.\n"); } else { boot_error= 1; if (*((volatile unsigned char *)trampoline_base) == 0xA5) /* trampoline started but...? */ printk("Stuck ??\n"); else /* trampoline code not run */ printk("Not responding.\n"); inquire_remote_apic(apicid); } } if (boot_error) { /* Try to put things back the way they were before ... */ unmap_cpu_to_logical_apicid(cpu); cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */ cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */ cpucount--; } else { x86_cpu_to_apicid[cpu] = apicid; cpu_set(cpu, cpu_present_map); } /* mark "stuck" area as not stuck */ *((volatile unsigned long *)trampoline_base) = 0; return boot_error; } #ifdef CONFIG_HOTPLUG_CPU void cpu_exit_clear(void) { int cpu = raw_smp_processor_id(); idle_task_exit(); cpucount --; cpu_uninit(); irq_ctx_exit(cpu); cpu_clear(cpu, cpu_callout_map); cpu_clear(cpu, cpu_callin_map); cpu_clear(cpu, smp_commenced_mask); unmap_cpu_to_logical_apicid(cpu); } struct warm_boot_cpu_info { struct completion *complete; struct work_struct task; int apicid; int cpu; }; static void __cpuinit do_warm_boot_cpu(struct work_struct *work) { struct warm_boot_cpu_info *info = container_of(work, struct warm_boot_cpu_info, task); do_boot_cpu(info->apicid, info->cpu); complete(info->complete); } static int __cpuinit __smp_prepare_cpu(int cpu) { DECLARE_COMPLETION_ONSTACK(done); struct warm_boot_cpu_info info; int apicid, ret; struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu); apicid = x86_cpu_to_apicid[cpu]; if (apicid == BAD_APICID) { ret = -ENODEV; goto exit; } /* * the CPU isn't initialized at boot time, allocate gdt table here. * cpu_init will initialize it */ if (!cpu_gdt_descr->address) { cpu_gdt_descr->address = get_zeroed_page(GFP_KERNEL); if (!cpu_gdt_descr->address) printk(KERN_CRIT "CPU%d failed to allocate GDT\n", cpu); ret = -ENOMEM; goto exit; } info.complete = &done; info.apicid = apicid; info.cpu = cpu; INIT_WORK(&info.task, do_warm_boot_cpu); /* init low mem mapping */ clone_pgd_range(swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS, min_t(unsigned long, KERNEL_PGD_PTRS, USER_PGD_PTRS)); flush_tlb_all(); schedule_work(&info.task); wait_for_completion(&done); zap_low_mappings(); ret = 0; exit: return ret; } #endif static void smp_tune_scheduling(void) { unsigned long cachesize; /* kB */ if (cpu_khz) { cachesize = boot_cpu_data.x86_cache_size; if (cachesize > 0) max_cache_size = cachesize * 1024; } } /* * Cycle through the processors sending APIC IPIs to boot each. */ static int boot_cpu_logical_apicid; /* Where the IO area was mapped on multiquad, always 0 otherwise */ void *xquad_portio; #ifdef CONFIG_X86_NUMAQ EXPORT_SYMBOL(xquad_portio); #endif static void __init smp_boot_cpus(unsigned int max_cpus) { int apicid, cpu, bit, kicked; unsigned long bogosum = 0; /* * Setup boot CPU information */ smp_store_cpu_info(0); /* Final full version of the data */ printk("CPU%d: ", 0); print_cpu_info(&cpu_data[0]); boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID)); boot_cpu_logical_apicid = logical_smp_processor_id(); x86_cpu_to_apicid[0] = boot_cpu_physical_apicid; current_thread_info()->cpu = 0; smp_tune_scheduling(); set_cpu_sibling_map(0); /* * If we couldn't find an SMP configuration at boot time, * get out of here now! */ if (!smp_found_config && !acpi_lapic) { printk(KERN_NOTICE "SMP motherboard not detected.\n"); smpboot_clear_io_apic_irqs(); phys_cpu_present_map = physid_mask_of_physid(0); if (APIC_init_uniprocessor()) printk(KERN_NOTICE "Local APIC not detected." " Using dummy APIC emulation.\n"); map_cpu_to_logical_apicid(); cpu_set(0, cpu_sibling_map[0]); cpu_set(0, cpu_core_map[0]); return; } /* * Should not be necessary because the MP table should list the boot * CPU too, but we do it for the sake of robustness anyway. * Makes no sense to do this check in clustered apic mode, so skip it */ if (!check_phys_apicid_present(boot_cpu_physical_apicid)) { printk("weird, boot CPU (#%d) not listed by the BIOS.\n", boot_cpu_physical_apicid); physid_set(hard_smp_processor_id(), phys_cpu_present_map); } /* * If we couldn't find a local APIC, then get out of here now! */ if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) && !cpu_has_apic) { printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n", boot_cpu_physical_apicid); printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n"); smpboot_clear_io_apic_irqs(); phys_cpu_present_map = physid_mask_of_physid(0); cpu_set(0, cpu_sibling_map[0]); cpu_set(0, cpu_core_map[0]); return; } verify_local_APIC(); /* * If SMP should be disabled, then really disable it! */ if (!max_cpus) { smp_found_config = 0; printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n"); smpboot_clear_io_apic_irqs(); phys_cpu_present_map = physid_mask_of_physid(0); cpu_set(0, cpu_sibling_map[0]); cpu_set(0, cpu_core_map[0]); return; } connect_bsp_APIC(); setup_local_APIC(); map_cpu_to_logical_apicid(); setup_portio_remap(); /* * Scan the CPU present map and fire up the other CPUs via do_boot_cpu * * In clustered apic mode, phys_cpu_present_map is a constructed thus: * bits 0-3 are quad0, 4-7 are quad1, etc. A perverse twist on the * clustered apic ID. */ Dprintk("CPU present map: %lx\n", physids_coerce(phys_cpu_present_map)); kicked = 1; for (bit = 0; kicked < NR_CPUS && bit < MAX_APICS; bit++) { apicid = cpu_present_to_apicid(bit); /* * Don't even attempt to start the boot CPU! */ if ((apicid == boot_cpu_apicid) || (apicid == BAD_APICID)) continue; if (!check_apicid_present(bit)) continue; if (max_cpus <= cpucount+1) continue; if (((cpu = alloc_cpu_id()) <= 0) || do_boot_cpu(apicid, cpu)) printk("CPU #%d not responding - cannot use it.\n", apicid); else ++kicked; } /* * Cleanup possible dangling ends... */ smpboot_restore_warm_reset_vector(); /* * Allow the user to impress friends. */ Dprintk("Before bogomips.\n"); for (cpu = 0; cpu < NR_CPUS; cpu++) if (cpu_isset(cpu, cpu_callout_map)) bogosum += cpu_data[cpu].loops_per_jiffy; printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n", cpucount+1, bogosum/(500000/HZ), (bogosum/(5000/HZ))%100); Dprintk("Before bogocount - setting activated=1.\n"); if (smp_b_stepping) printk(KERN_WARNING "WARNING: SMP operation may be unreliable with B stepping processors.\n"); /* * Don't taint if we are running SMP kernel on a single non-MP * approved Athlon */ if (tainted & TAINT_UNSAFE_SMP) { if (cpucount) printk (KERN_INFO "WARNING: This combination of AMD processors is not suitable for SMP.\n"); else tainted &= ~TAINT_UNSAFE_SMP; } Dprintk("Boot done.\n"); /* * construct cpu_sibling_map[], so that we can tell sibling CPUs * efficiently. */ for (cpu = 0; cpu < NR_CPUS; cpu++) { cpus_clear(cpu_sibling_map[cpu]); cpus_clear(cpu_core_map[cpu]); } cpu_set(0, cpu_sibling_map[0]); cpu_set(0, cpu_core_map[0]); smpboot_setup_io_apic(); setup_boot_clock(); } /* These are wrappers to interface to the new boot process. Someone who understands all this stuff should rewrite it properly. --RR 15/Jul/02 */ void __init smp_prepare_cpus(unsigned int max_cpus) { smp_commenced_mask = cpumask_of_cpu(0); cpu_callin_map = cpumask_of_cpu(0); mb(); smp_boot_cpus(max_cpus); } void __devinit smp_prepare_boot_cpu(void) { cpu_set(smp_processor_id(), cpu_online_map); cpu_set(smp_processor_id(), cpu_callout_map); cpu_set(smp_processor_id(), cpu_present_map); cpu_set(smp_processor_id(), cpu_possible_map); per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; } #ifdef CONFIG_HOTPLUG_CPU static void remove_siblinginfo(int cpu) { int sibling; struct cpuinfo_x86 *c = cpu_data; for_each_cpu_mask(sibling, cpu_core_map[cpu]) { cpu_clear(cpu, cpu_core_map[sibling]); /* * last thread sibling in this cpu core going down */ if (cpus_weight(cpu_sibling_map[cpu]) == 1) c[sibling].booted_cores--; } for_each_cpu_mask(sibling, cpu_sibling_map[cpu]) cpu_clear(cpu, cpu_sibling_map[sibling]); cpus_clear(cpu_sibling_map[cpu]); cpus_clear(cpu_core_map[cpu]); c[cpu].phys_proc_id = 0; c[cpu].cpu_core_id = 0; cpu_clear(cpu, cpu_sibling_setup_map); } int __cpu_disable(void) { cpumask_t map = cpu_online_map; int cpu = smp_processor_id(); /* * Perhaps use cpufreq to drop frequency, but that could go * into generic code. * * We won't take down the boot processor on i386 due to some * interrupts only being able to be serviced by the BSP. * Especially so if we're not using an IOAPIC -zwane */ if (cpu == 0) return -EBUSY; if (nmi_watchdog == NMI_LOCAL_APIC) stop_apic_nmi_watchdog(NULL); clear_local_APIC(); /* Allow any queued timer interrupts to get serviced */ local_irq_enable(); mdelay(1); local_irq_disable(); remove_siblinginfo(cpu); cpu_clear(cpu, map); fixup_irqs(map); /* It's now safe to remove this processor from the online map */ cpu_clear(cpu, cpu_online_map); return 0; } void __cpu_die(unsigned int cpu) { /* We don't do anything here: idle task is faking death itself. */ unsigned int i; for (i = 0; i < 10; i++) { /* They ack this in play_dead by setting CPU_DEAD */ if (per_cpu(cpu_state, cpu) == CPU_DEAD) { printk ("CPU %d is now offline\n", cpu); if (1 == num_online_cpus()) alternatives_smp_switch(0); return; } msleep(100); } printk(KERN_ERR "CPU %u didn't die...\n", cpu); } #else /* ... !CONFIG_HOTPLUG_CPU */ int __cpu_disable(void) { return -ENOSYS; } void __cpu_die(unsigned int cpu) { /* We said "no" in __cpu_disable */ BUG(); } #endif /* CONFIG_HOTPLUG_CPU */ int __cpuinit __cpu_up(unsigned int cpu) { #ifdef CONFIG_HOTPLUG_CPU int ret=0; /* * We do warm boot only on cpus that had booted earlier * Otherwise cold boot is all handled from smp_boot_cpus(). * cpu_callin_map is set during AP kickstart process. Its reset * when a cpu is taken offline from cpu_exit_clear(). */ if (!cpu_isset(cpu, cpu_callin_map)) ret = __smp_prepare_cpu(cpu); if (ret) return -EIO; #endif /* In case one didn't come up */ if (!cpu_isset(cpu, cpu_callin_map)) { printk(KERN_DEBUG "skipping cpu%d, didn't come online\n", cpu); local_irq_enable(); return -EIO; } local_irq_enable(); per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; /* Unleash the CPU! */ cpu_set(cpu, smp_commenced_mask); /* * Check TSC synchronization with the AP: */ check_tsc_sync_source(cpu); while (!cpu_isset(cpu, cpu_online_map)) cpu_relax(); #ifdef CONFIG_X86_GENERICARCH if (num_online_cpus() > 8 && genapic == &apic_default) panic("Default flat APIC routing can't be used with > 8 cpus\n"); #endif return 0; } void __init smp_cpus_done(unsigned int max_cpus) { #ifdef CONFIG_X86_IO_APIC setup_ioapic_dest(); #endif zap_low_mappings(); #ifndef CONFIG_HOTPLUG_CPU /* * Disable executability of the SMP trampoline: */ set_kernel_exec((unsigned long)trampoline_base, trampoline_exec); #endif } void __init smp_intr_init(void) { /* * IRQ0 must be given a fixed assignment and initialized, * because it's used before the IO-APIC is set up. */ set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]); /* * The reschedule interrupt is a CPU-to-CPU reschedule-helper * IPI, driven by wakeup. */ set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt); /* IPI for invalidation */ set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt); /* IPI for generic function call */ set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt); } /* * If the BIOS enumerates physical processors before logical, * maxcpus=N at enumeration-time can be used to disable HT. */ static int __init parse_maxcpus(char *arg) { extern unsigned int maxcpus; maxcpus = simple_strtoul(arg, NULL, 0); return 0; } early_param("maxcpus", parse_maxcpus);