/* * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int _foo; #define set_kernel_exec(x,y) (_foo=0) #define alloc_bootmem_low_pages(x) __va(0x90000) /* trampoline address */ int tainted; #define TAINT_UNSAFE_SMP 0 /* Set if we find a B stepping CPU */ static int __initdata smp_b_stepping; /* Number of siblings per CPU package */ int smp_num_siblings = 1; int phys_proc_id[NR_CPUS]; /* Package ID of each logical CPU */ EXPORT_SYMBOL(phys_proc_id); int cpu_core_id[NR_CPUS]; /* Core ID of each logical CPU */ EXPORT_SYMBOL(cpu_core_id); /* bitmap of online cpus */ cpumask_t cpu_online_map; cpumask_t cpu_callin_map; cpumask_t cpu_callout_map; static cpumask_t smp_commenced_mask; /* Per CPU bogomips and other parameters */ struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned; u8 x86_cpu_to_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = 0xff }; EXPORT_SYMBOL(x86_cpu_to_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; /* * Currently trivial. Write the real->protected mode * bootstrap into the page concerned. The caller * has made sure it's suitably aligned. */ static unsigned long __init setup_trampoline(void) { memcpy(trampoline_base, trampoline_data, trampoline_end - trampoline_data); return virt_to_maddr(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 __init 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)) { /* 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 M
//-----------------------------------------------------
// This is simple parity Program
// Design Name : parity
// File Name   : parity.v
// Function    : This program shows how a verilog
//               primitive/module port connection are done
// Coder       : Deepak
//-----------------------------------------------------
module parity (
a      , // First input
b      , // Second input 
c      , // Third Input
d      , // Fourth Input
y        // Parity  output
);

// Input Declaration
input       a       ;
input       b       ;
input       c       ;
input       d       ;
// Ouput Declaration
output      y      ;
// port data types
wire        a        ;
wire        b        ;
wire        c        ;
wire        d        ;
wire        y        ;
// Internal variables
wire        out_0 ;
wire        out_1 ;

// Code starts Here
xor u0 (out_0,a,b);

xor u1 (out_1,c,d);

xor u2 (y,out_0,out_1);

endmodule // End Of Module parity
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-24 00:17:34 +0000
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 __init 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 __init 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; /* * 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 int __init do_boot_cpu(int apicid) /* * 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 vcpu *v; unsigned long boot_error; int timeout, cpu; unsigned long start_eip; unsigned short nmi_high = 0, nmi_low = 0; cpu = ++cpucount; v = idle_vcpu[cpu] = alloc_vcpu(idle_vcpu[0]->domain, cpu, cpu); BUG_ON(v == NULL); v->arch.monitor_table = mk_pagetable(__pa(idle_pg_table)); /* start_eip had better be page-aligned! */ start_eip = setup_trampoline(); /* So we see what's up */ printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip); stack_start.esp = alloc_xenheap_pages(STACK_ORDER); /* Debug build: detect stack overflow by setting up a guard page. */ memguard_guard_stack(stack_start.esp); /* * 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); CMOS_WRITE(0xa, 0xf); local_flush_tlb(); Dprintk("1.\n"); *((volatile unsigned short *) TRAMPOLINE_HIGH) = start_eip >> 4; Dprintk("2.\n"); *((volatile unsigned short *) TRAMPOLINE_LOW) = start_eip & 0xf; Dprintk("3.\n"); /* * 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); } } x86_cpu_to_apicid[cpu] = 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--; } /* mark "stuck" area as not stuck */ *((volatile unsigned long *)trampoline_base) = 0; return boot_error; } #if 0 cycles_t cacheflush_time; unsigned long cache_decay_ticks; static void smp_tune_scheduling (void) { unsigned long cachesize; /* kB */ unsigned long bandwidth = 350; /* MB/s */ /* * Rough estimation for SMP scheduling, this is the number of * cycles it takes for a fully memory-limited process to flush * the SMP-local cache. * * (For a P5 this pretty much means we will choose another idle * CPU almost always at wakeup time (this is due to the small * L1 cache), on PIIs it's around 50-100 usecs, depending on * the cache size) */ if (!cpu_khz) { /* * this basically disables processor-affinity * scheduling on SMP without a TSC. */ cacheflush_time = 0; return; } else { cachesize = boot_cpu_data.x86_cache_size; if (cachesize == -1) { cachesize = 16; /* Pentiums, 2x8kB cache */ bandwidth = 100; } cacheflush_time = (cpu_khz>>10) * (cachesize<<10) / bandwidth; } cache_decay_ticks = (long)cacheflush_time/cpu_khz + 1; printk("per-CPU timeslice cutoff: %ld.%02ld usecs.\n", (long)cacheflush_time/(cpu_khz/1000), ((long)cacheflush_time*100/(cpu_khz/1000)) % 100); printk("task migration cache decay timeout: %ld msecs.\n", cache_decay_ticks); } #else #define smp_tune_scheduling() ((void)0) #endif /* * 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; cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned; cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned; EXPORT_SYMBOL(cpu_core_map); static void __init smp_boot_cpus(unsigned int max_cpus) { int apicid, cpu, bit, kicked; #ifdef BOGOMIPS unsigned long bogosum = 0; #endif /* * 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(); cpus_clear(cpu_sibling_map[0]); cpu_set(0, cpu_sibling_map[0]); cpus_clear(cpu_core_map[0]); cpu_set(0, cpu_core_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"); init_uniprocessor: 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); goto init_uniprocessor; } verify_local_APIC(); /* * If SMP should be disabled, then really disable it! */ if (!max_cpus) goto init_uniprocessor; 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 (do_boot_cpu(apicid)) printk("CPU #%d not responding - cannot use it.\n", apicid); else ++kicked; } /* * Install writable page 0 entry to set BIOS data area. */ local_flush_tlb(); /* * Paranoid: Set warm reset code and vector here back * to default values. */ CMOS_WRITE(0, 0xf); *((volatile long *) maddr_to_virt(0x467)) = 0; #ifdef BOGOMIPS /* * 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); #else printk("Total of %d processors activated.\n", cpucount+1); #endif 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]); } for (cpu = 0; cpu < NR_CPUS; cpu++) { struct cpuinfo_x86 *c = cpu_data + cpu; int siblings = 0; int i; if (!cpu_isset(cpu, cpu_callout_map)) continue; if (smp_num_siblings > 1) { for (i = 0; i < NR_CPUS; i++) { if (!cpu_isset(i, cpu_callout_map)) continue; if (cpu_core_id[cpu] == cpu_core_id[i]) { siblings++; cpu_set(i, cpu_sibling_map[cpu]); } } } else { siblings++; cpu_set(cpu, cpu_sibling_map[cpu]); } if (siblings != smp_num_siblings) { printk(KERN_WARNING "WARNING: %d siblings found for CPU%d, should be %d\n", siblings, cpu, smp_num_siblings); smp_num_siblings = siblings; } if (c->x86_num_cores > 1) { for (i = 0; i < NR_CPUS; i++) { if (!cpu_isset(i, cpu_callout_map)) continue; if (phys_proc_id[cpu] == phys_proc_id[i]) { cpu_set(i, cpu_core_map[cpu]); } } } else { cpu_core_map[cpu] = cpu_sibling_map[cpu]; } } if (nmi_watchdog == NMI_LOCAL_APIC) check_nmi_watchdog(); /* * Here we can be sure that there is an IO-APIC in the system. Let's * go and set it up: */ if (!skip_ioapic_setup && nr_ioapics) setup_IO_APIC(); setup_boot_APIC_clock(); /* * Synchronize the TSC with the AP */ if (cpu_has_tsc && cpucount && cpu_khz) synchronize_tsc_bp(); calibrate_tsc_bp(); } /* 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_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); } int __devinit __cpu_up(unsigned int cpu) { /* This only works at boot for x86. See "rewrite" above. */ if (cpu_isset(cpu, smp_commenced_mask)) return -ENOSYS; /* In case one didn't come up */ if (!cpu_isset(cpu, cpu_callin_map)) return -EIO; /* Unleash the CPU! */ cpu_set(cpu, smp_commenced_mask); while (!cpu_isset(cpu, cpu_online_map)) { mb(); if (softirq_pending(0)) do_softirq(); } return 0; } void __init smp_cpus_done(unsigned int max_cpus) { #ifdef CONFIG_X86_IO_APIC setup_ioapic_dest(); #endif #ifdef CONFIG_X86_64 zap_low_mappings(); #endif /* * Disable executability of the SMP trampoline: */ set_kernel_exec((unsigned long)trampoline_base, trampoline_exec); } #if 0 void __init smp_intr_init(void) { /* * 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); } #endif