1 /*
   2 *	x86 SMP booting functions
   3 *
   4 *	(c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk>
   5 *	(c) 1998, 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
   6 *	Copyright 2001 Andi Kleen, SuSE Labs.
   7 *
   8 *	Much of the core SMP work is based on previous work by Thomas Radke, to
   9 *	whom a great many thanks are extended.
  10 *
  11 *	Thanks to Intel for making available several different Pentium,
  12 *	Pentium Pro and Pentium-II/Xeon MP machines.
  13 *	Original development of Linux SMP code supported by Caldera.
  14 *
  15 *	This code is released under the GNU General Public License version 2 or
  16 *	later.
  17 *
  18 *	Fixes
  19 *		Felix Koop	:	NR_CPUS used properly
  20 *		Jose Renau	:	Handle single CPU case.
  21 *		Alan Cox	:	By repeated request 8) - Total BogoMIPS report.
  22 *		Greg Wright	:	Fix for kernel stacks panic.
  23 *		Erich Boleyn	:	MP v1.4 and additional changes.
  24 *	Matthias Sattler	:	Changes for 2.1 kernel map.
  25 *	Michel Lespinasse	:	Changes for 2.1 kernel map.
  26 *	Michael Chastain	:	Change trampoline.S to gnu as.
  27 *		Alan Cox	:	Dumb bug: 'B' step PPro's are fine
  28 *		Ingo Molnar	:	Added APIC timers, based on code
  29 *					from Jose Renau
  30 *		Ingo Molnar	:	various cleanups and rewrites
  31 *		Tigran Aivazian	:	fixed "0.00 in /proc/uptime on SMP" bug.
  32 *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs
  33 *	Andi Kleen		:	Changed for SMP boot into long mode.
  34 *		Martin J. Bligh	: 	Added support for multi-quad systems
  35 *		Dave Jones	:	Report invalid combinations of Athlon CPUs.
  36 *		Rusty Russell	:	Hacked into shape for new "hotplug" boot process.
  37 *      Andi Kleen              :       Converted to new state machine.
  38 *	Ashok Raj		: 	CPU hotplug support
  39 *	Glauber Costa		:	i386 and x86_64 integration
  40 */
  41
  42#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  43
  44#include <linux/init.h>
  45#include <linux/smp.h>
  46#include <linux/module.h>
  47#include <linux/sched.h>
  48#include <linux/percpu.h>
  49#include <linux/bootmem.h>
  50#include <linux/err.h>
  51#include <linux/nmi.h>
  52#include <linux/tboot.h>
  53#include <linux/stackprotector.h>
  54#include <linux/gfp.h>
  55#include <linux/cpuidle.h>
  56
  57#include <asm/acpi.h>
  58#include <asm/desc.h>
  59#include <asm/nmi.h>
  60#include <asm/irq.h>
  61#include <asm/idle.h>
  62#include <asm/realmode.h>
  63#include <asm/cpu.h>
  64#include <asm/numa.h>
  65#include <asm/pgtable.h>
  66#include <asm/tlbflush.h>
  67#include <asm/mtrr.h>
  68#include <asm/mwait.h>
  69#include <asm/apic.h>
  70#include <asm/io_apic.h>
  71#include <asm/fpu/internal.h>
 
  72#include <asm/setup.h>
  73#include <asm/uv/uv.h>
  74#include <linux/mc146818rtc.h>
 
  75#include <asm/i8259.h>
  76#include <asm/realmode.h>
  77#include <asm/misc.h>
  78
 
 
 
  79/* Number of siblings per CPU package */
  80int smp_num_siblings = 1;
  81EXPORT_SYMBOL(smp_num_siblings);
  82
  83/* Last level cache ID of each logical CPU */
  84DEFINE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id) = BAD_APICID;
  85
  86/* representing HT siblings of each logical CPU */
  87DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
  88EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
  89
  90/* representing HT and core siblings of each logical CPU */
  91DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
  92EXPORT_PER_CPU_SYMBOL(cpu_core_map);
  93
  94DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);
  95
  96/* Per CPU bogomips and other parameters */
  97DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info);
  98EXPORT_PER_CPU_SYMBOL(cpu_info);
  99
 100/* Logical package management. We might want to allocate that dynamically */
 101static int *physical_to_logical_pkg __read_mostly;
 102static unsigned long *physical_package_map __read_mostly;;
 103static unsigned long *logical_package_map  __read_mostly;
 104static unsigned int max_physical_pkg_id __read_mostly;
 105unsigned int __max_logical_packages __read_mostly;
 106EXPORT_SYMBOL(__max_logical_packages);
 107
 108static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
 109{
 110	unsigned long flags;
 111
 112	spin_lock_irqsave(&rtc_lock, flags);
 113	CMOS_WRITE(0xa, 0xf);
 114	spin_unlock_irqrestore(&rtc_lock, flags);
 115	local_flush_tlb();
 116	pr_debug("1.\n");
 117	*((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_HIGH)) =
 118							start_eip >> 4;
 119	pr_debug("2.\n");
 120	*((volatile unsigned short *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) =
 121							start_eip & 0xf;
 122	pr_debug("3.\n");
 123}
 124
 125static inline void smpboot_restore_warm_reset_vector(void)
 126{
 127	unsigned long flags;
 128
 129	/*
 130	 * Install writable page 0 entry to set BIOS data area.
 131	 */
 132	local_flush_tlb();
 133
 134	/*
 135	 * Paranoid:  Set warm reset code and vector here back
 136	 * to default values.
 137	 */
 138	spin_lock_irqsave(&rtc_lock, flags);
 139	CMOS_WRITE(0, 0xf);
 140	spin_unlock_irqrestore(&rtc_lock, flags);
 141
 142	*((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0;
 143}
 144
 145/*
 146 * Report back to the Boot Processor during boot time or to the caller processor
 147 * during CPU online.
 148 */
 149static void smp_callin(void)
 150{
 151	int cpuid, phys_id;
 
 152
 153	/*
 154	 * If waken up by an INIT in an 82489DX configuration
 155	 * cpu_callout_mask guarantees we don't get here before
 156	 * an INIT_deassert IPI reaches our local APIC, so it is
 157	 * now safe to touch our local APIC.
 
 
 158	 */
 159	cpuid = smp_processor_id();
 
 
 
 160
 161	/*
 162	 * (This works even if the APIC is not enabled.)
 163	 */
 164	phys_id = read_apic_id();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 165
 166	/*
 167	 * the boot CPU has finished the init stage and is spinning
 168	 * on callin_map until we finish. We are free to set up this
 169	 * CPU, first the APIC. (this is probably redundant on most
 170	 * boards)
 171	 */
 172	apic_ap_setup();
 
 
 
 
 
 
 
 
 
 
 173
 174	/*
 175	 * Save our processor parameters. Note: this information
 176	 * is needed for clock calibration.
 177	 */
 178	smp_store_cpu_info(cpuid);
 179
 180	/*
 181	 * Get our bogomips.
 182	 * Update loops_per_jiffy in cpu_data. Previous call to
 183	 * smp_store_cpu_info() stored a value that is close but not as
 184	 * accurate as the value just calculated.
 185	 */
 186	calibrate_delay();
 187	cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy;
 188	pr_debug("Stack at about %p\n", &cpuid);
 189
 190	/*
 191	 * This must be done before setting cpu_online_mask
 192	 * or calling notify_cpu_starting.
 193	 */
 194	set_cpu_sibling_map(raw_smp_processor_id());
 195	wmb();
 196
 197	notify_cpu_starting(cpuid);
 198
 199	/*
 200	 * Allow the master to continue.
 201	 */
 202	cpumask_set_cpu(cpuid, cpu_callin_mask);
 203}
 204
 205static int cpu0_logical_apicid;
 206static int enable_start_cpu0;
 207/*
 208 * Activate a secondary processor.
 209 */
 210static void notrace start_secondary(void *unused)
 211{
 212	/*
 213	 * Don't put *anything* before cpu_init(), SMP booting is too
 214	 * fragile that we want to limit the things done here to the
 215	 * most necessary things.
 216	 */
 217	cpu_init();
 218	x86_cpuinit.early_percpu_clock_init();
 219	preempt_disable();
 220	smp_callin();
 221
 222	enable_start_cpu0 = 0;
 223
 224#ifdef CONFIG_X86_32
 225	/* switch away from the initial page table */
 226	load_cr3(swapper_pg_dir);
 227	__flush_tlb_all();
 228#endif
 229
 230	/* otherwise gcc will move up smp_processor_id before the cpu_init */
 231	barrier();
 232	/*
 233	 * Check TSC synchronization with the BP:
 234	 */
 235	check_tsc_sync_target();
 236
 237	/*
 238	 * Lock vector_lock and initialize the vectors on this cpu
 239	 * before setting the cpu online. We must set it online with
 240	 * vector_lock held to prevent a concurrent setup/teardown
 241	 * from seeing a half valid vector space.
 242	 */
 243	lock_vector_lock();
 244	setup_vector_irq(smp_processor_id());
 245	set_cpu_online(smp_processor_id(), true);
 246	unlock_vector_lock();
 247	cpu_set_state_online(smp_processor_id());
 248	x86_platform.nmi_init();
 249
 250	/* enable local interrupts */
 251	local_irq_enable();
 252
 253	/* to prevent fake stack check failure in clock setup */
 254	boot_init_stack_canary();
 255
 256	x86_cpuinit.setup_percpu_clockev();
 257
 258	wmb();
 259	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 260}
 261
 262int topology_update_package_map(unsigned int apicid, unsigned int cpu)
 263{
 264	unsigned int new, pkg = apicid >> boot_cpu_data.x86_coreid_bits;
 265
 266	/* Called from early boot ? */
 267	if (!physical_package_map)
 268		return 0;
 269
 270	if (pkg >= max_physical_pkg_id)
 271		return -EINVAL;
 272
 273	/* Set the logical package id */
 274	if (test_and_set_bit(pkg, physical_package_map))
 275		goto found;
 276
 277	new = find_first_zero_bit(logical_package_map, __max_logical_packages);
 278	if (new >= __max_logical_packages) {
 279		physical_to_logical_pkg[pkg] = -1;
 280		pr_warn("APIC(%x) Package %u exceeds logical package map\n",
 281			apicid, pkg);
 282		return -ENOSPC;
 283	}
 284	set_bit(new, logical_package_map);
 285	pr_info("APIC(%x) Converting physical %u to logical package %u\n",
 286		apicid, pkg, new);
 287	physical_to_logical_pkg[pkg] = new;
 288
 289found:
 290	cpu_data(cpu).logical_proc_id = physical_to_logical_pkg[pkg];
 291	return 0;
 292}
 293
 294/**
 295 * topology_phys_to_logical_pkg - Map a physical package id to a logical
 296 *
 297 * Returns logical package id or -1 if not found
 298 */
 299int topology_phys_to_logical_pkg(unsigned int phys_pkg)
 300{
 301	if (phys_pkg >= max_physical_pkg_id)
 302		return -1;
 303	return physical_to_logical_pkg[phys_pkg];
 304}
 305EXPORT_SYMBOL(topology_phys_to_logical_pkg);
 306
 307static void __init smp_init_package_map(void)
 308{
 309	unsigned int ncpus, cpu;
 310	size_t size;
 311
 312	/*
 313	 * Today neither Intel nor AMD support heterogenous systems. That
 314	 * might change in the future....
 315	 *
 316	 * While ideally we'd want '* smp_num_siblings' in the below @ncpus
 317	 * computation, this won't actually work since some Intel BIOSes
 318	 * report inconsistent HT data when they disable HT.
 319	 *
 320	 * In particular, they reduce the APIC-IDs to only include the cores,
 321	 * but leave the CPUID topology to say there are (2) siblings.
 322	 * This means we don't know how many threads there will be until
 323	 * after the APIC enumeration.
 324	 *
 325	 * By not including this we'll sometimes over-estimate the number of
 326	 * logical packages by the amount of !present siblings, but this is
 327	 * still better than MAX_LOCAL_APIC.
 328	 *
 329	 * We use total_cpus not nr_cpu_ids because nr_cpu_ids can be limited
 330	 * on the command line leading to a similar issue as the HT disable
 331	 * problem because the hyperthreads are usually enumerated after the
 332	 * primary cores.
 333	 */
 334	ncpus = boot_cpu_data.x86_max_cores;
 335	if (!ncpus) {
 336		pr_warn("x86_max_cores == zero !?!?");
 337		ncpus = 1;
 338	}
 339
 340	__max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus);
 341
 342	/*
 343	 * Possibly larger than what we need as the number of apic ids per
 344	 * package can be smaller than the actual used apic ids.
 345	 */
 346	max_physical_pkg_id = DIV_ROUND_UP(MAX_LOCAL_APIC, ncpus);
 347	size = max_physical_pkg_id * sizeof(unsigned int);
 348	physical_to_logical_pkg = kmalloc(size, GFP_KERNEL);
 349	memset(physical_to_logical_pkg, 0xff, size);
 350	size = BITS_TO_LONGS(max_physical_pkg_id) * sizeof(unsigned long);
 351	physical_package_map = kzalloc(size, GFP_KERNEL);
 352	size = BITS_TO_LONGS(__max_logical_packages) * sizeof(unsigned long);
 353	logical_package_map = kzalloc(size, GFP_KERNEL);
 354
 355	pr_info("Max logical packages: %u\n", __max_logical_packages);
 356
 357	for_each_present_cpu(cpu) {
 358		unsigned int apicid = apic->cpu_present_to_apicid(cpu);
 359
 360		if (apicid == BAD_APICID || !apic->apic_id_valid(apicid))
 361			continue;
 362		if (!topology_update_package_map(apicid, cpu))
 363			continue;
 364		pr_warn("CPU %u APICId %x disabled\n", cpu, apicid);
 365		per_cpu(x86_bios_cpu_apicid, cpu) = BAD_APICID;
 366		set_cpu_possible(cpu, false);
 367		set_cpu_present(cpu, false);
 368	}
 369}
 370
 371void __init smp_store_boot_cpu_info(void)
 372{
 373	int id = 0; /* CPU 0 */
 374	struct cpuinfo_x86 *c = &cpu_data(id);
 375
 376	*c = boot_cpu_data;
 377	c->cpu_index = id;
 378	smp_init_package_map();
 379}
 380
 381/*
 382 * The bootstrap kernel entry code has set these up. Save them for
 383 * a given CPU
 384 */
 385void smp_store_cpu_info(int id)
 386{
 387	struct cpuinfo_x86 *c = &cpu_data(id);
 388
 389	*c = boot_cpu_data;
 390	c->cpu_index = id;
 391	/*
 392	 * During boot time, CPU0 has this setup already. Save the info when
 393	 * bringing up AP or offlined CPU0.
 394	 */
 395	identify_secondary_cpu(c);
 396}
 397
 398static bool
 399topology_same_node(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
 400{
 401	int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
 402
 403	return (cpu_to_node(cpu1) == cpu_to_node(cpu2));
 404}
 405
 406static bool
 407topology_sane(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o, const char *name)
 408{
 409	int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
 410
 411	return !WARN_ONCE(!topology_same_node(c, o),
 412		"sched: CPU #%d's %s-sibling CPU #%d is not on the same node! "
 413		"[node: %d != %d]. Ignoring dependency.\n",
 414		cpu1, name, cpu2, cpu_to_node(cpu1), cpu_to_node(cpu2));
 415}
 416
 417#define link_mask(mfunc, c1, c2)					\
 418do {									\
 419	cpumask_set_cpu((c1), mfunc(c2));				\
 420	cpumask_set_cpu((c2), mfunc(c1));				\
 421} while (0)
 422
 423static bool match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
 424{
 425	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
 426		int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
 427
 428		if (c->phys_proc_id == o->phys_proc_id &&
 429		    per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2) &&
 430		    c->cpu_core_id == o->cpu_core_id)
 431			return topology_sane(c, o, "smt");
 432
 433	} else if (c->phys_proc_id == o->phys_proc_id &&
 434		   c->cpu_core_id == o->cpu_core_id) {
 435		return topology_sane(c, o, "smt");
 436	}
 437
 438	return false;
 439}
 440
 441static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
 442{
 443	int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
 444
 445	if (per_cpu(cpu_llc_id, cpu1) != BAD_APICID &&
 446	    per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2))
 447		return topology_sane(c, o, "llc");
 448
 449	return false;
 450}
 451
 452/*
 453 * Unlike the other levels, we do not enforce keeping a
 454 * multicore group inside a NUMA node.  If this happens, we will
 455 * discard the MC level of the topology later.
 456 */
 457static bool match_die(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
 458{
 459	if (c->phys_proc_id == o->phys_proc_id)
 460		return true;
 461	return false;
 462}
 463
 464static struct sched_domain_topology_level numa_inside_package_topology[] = {
 465#ifdef CONFIG_SCHED_SMT
 466	{ cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
 467#endif
 468#ifdef CONFIG_SCHED_MC
 469	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
 470#endif
 471	{ NULL, },
 472};
 473/*
 474 * set_sched_topology() sets the topology internal to a CPU.  The
 475 * NUMA topologies are layered on top of it to build the full
 476 * system topology.
 477 *
 478 * If NUMA nodes are observed to occur within a CPU package, this
 479 * function should be called.  It forces the sched domain code to
 480 * only use the SMT level for the CPU portion of the topology.
 481 * This essentially falls back to relying on NUMA information
 482 * from the SRAT table to describe the entire system topology
 483 * (except for hyperthreads).
 484 */
 485static void primarily_use_numa_for_topology(void)
 486{
 487	set_sched_topology(numa_inside_package_topology);
 488}
 489
 490void set_cpu_sibling_map(int cpu)
 491{
 492	bool has_smt = smp_num_siblings > 1;
 493	bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1;
 494	struct cpuinfo_x86 *c = &cpu_data(cpu);
 495	struct cpuinfo_x86 *o;
 496	int i;
 497
 498	cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
 499
 500	if (!has_mp) {
 501		cpumask_set_cpu(cpu, topology_sibling_cpumask(cpu));
 502		cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu));
 503		cpumask_set_cpu(cpu, topology_core_cpumask(cpu));
 504		c->booted_cores = 1;
 505		return;
 506	}
 507
 508	for_each_cpu(i, cpu_sibling_setup_mask) {
 509		o = &cpu_data(i);
 510
 511		if ((i == cpu) || (has_smt && match_smt(c, o)))
 512			link_mask(topology_sibling_cpumask, cpu, i);
 513
 514		if ((i == cpu) || (has_mp && match_llc(c, o)))
 515			link_mask(cpu_llc_shared_mask, cpu, i);
 516
 517	}
 518
 519	/*
 520	 * This needs a separate iteration over the cpus because we rely on all
 521	 * topology_sibling_cpumask links to be set-up.
 522	 */
 523	for_each_cpu(i, cpu_sibling_setup_mask) {
 524		o = &cpu_data(i);
 525
 526		if ((i == cpu) || (has_mp && match_die(c, o))) {
 527			link_mask(topology_core_cpumask, cpu, i);
 528
 529			/*
 530			 *  Does this new cpu bringup a new core?
 531			 */
 532			if (cpumask_weight(
 533			    topology_sibling_cpumask(cpu)) == 1) {
 534				/*
 535				 * for each core in package, increment
 536				 * the booted_cores for this new cpu
 537				 */
 538				if (cpumask_first(
 539				    topology_sibling_cpumask(i)) == i)
 540					c->booted_cores++;
 541				/*
 542				 * increment the core count for all
 543				 * the other cpus in this package
 544				 */
 545				if (i != cpu)
 546					cpu_data(i).booted_cores++;
 547			} else if (i != cpu && !c->booted_cores)
 548				c->booted_cores = cpu_data(i).booted_cores;
 549		}
 550		if (match_die(c, o) && !topology_same_node(c, o))
 551			primarily_use_numa_for_topology();
 552	}
 553}
 554
 555/* maps the cpu to the sched domain representing multi-core */
 556const struct cpumask *cpu_coregroup_mask(int cpu)
 557{
 558	return cpu_llc_shared_mask(cpu);
 559}
 560
 561static void impress_friends(void)
 562{
 563	int cpu;
 564	unsigned long bogosum = 0;
 565	/*
 566	 * Allow the user to impress friends.
 567	 */
 568	pr_debug("Before bogomips\n");
 569	for_each_possible_cpu(cpu)
 570		if (cpumask_test_cpu(cpu, cpu_callout_mask))
 571			bogosum += cpu_data(cpu).loops_per_jiffy;
 572	pr_info("Total of %d processors activated (%lu.%02lu BogoMIPS)\n",
 573		num_online_cpus(),
 574		bogosum/(500000/HZ),
 575		(bogosum/(5000/HZ))%100);
 576
 577	pr_debug("Before bogocount - setting activated=1\n");
 578}
 579
 580void __inquire_remote_apic(int apicid)
 581{
 582	unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
 583	const char * const names[] = { "ID", "VERSION", "SPIV" };
 584	int timeout;
 585	u32 status;
 586
 587	pr_info("Inquiring remote APIC 0x%x...\n", apicid);
 588
 589	for (i = 0; i < ARRAY_SIZE(regs); i++) {
 590		pr_info("... APIC 0x%x %s: ", apicid, names[i]);
 591
 592		/*
 593		 * Wait for idle.
 594		 */
 595		status = safe_apic_wait_icr_idle();
 596		if (status)
 597			pr_cont("a previous APIC delivery may have failed\n");
 598
 599		apic_icr_write(APIC_DM_REMRD | regs[i], apicid);
 600
 601		timeout = 0;
 602		do {
 603			udelay(100);
 604			status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
 605		} while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
 606
 607		switch (status) {
 608		case APIC_ICR_RR_VALID:
 609			status = apic_read(APIC_RRR);
 610			pr_cont("%08x\n", status);
 611			break;
 612		default:
 613			pr_cont("failed\n");
 614		}
 615	}
 616}
 617
 618/*
 619 * The Multiprocessor Specification 1.4 (1997) example code suggests
 620 * that there should be a 10ms delay between the BSP asserting INIT
 621 * and de-asserting INIT, when starting a remote processor.
 622 * But that slows boot and resume on modern processors, which include
 623 * many cores and don't require that delay.
 624 *
 625 * Cmdline "init_cpu_udelay=" is available to over-ride this delay.
 626 * Modern processor families are quirked to remove the delay entirely.
 627 */
 628#define UDELAY_10MS_DEFAULT 10000
 629
 630static unsigned int init_udelay = UINT_MAX;
 631
 632static int __init cpu_init_udelay(char *str)
 633{
 634	get_option(&str, &init_udelay);
 635
 636	return 0;
 637}
 638early_param("cpu_init_udelay", cpu_init_udelay);
 639
 640static void __init smp_quirk_init_udelay(void)
 641{
 642	/* if cmdline changed it from default, leave it alone */
 643	if (init_udelay != UINT_MAX)
 644		return;
 645
 646	/* if modern processor, use no delay */
 647	if (((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 6)) ||
 648	    ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0xF))) {
 649		init_udelay = 0;
 650		return;
 651	}
 652	/* else, use legacy delay */
 653	init_udelay = UDELAY_10MS_DEFAULT;
 654}
 655
 656/*
 657 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
 658 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
 659 * won't ... remember to clear down the APIC, etc later.
 660 */
 661int
 662wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip)
 663{
 664	unsigned long send_status, accept_status = 0;
 665	int maxlvt;
 666
 667	/* Target chip */
 668	/* Boot on the stack */
 669	/* Kick the second */
 670	apic_icr_write(APIC_DM_NMI | apic->dest_logical, apicid);
 671
 672	pr_debug("Waiting for send to finish...\n");
 673	send_status = safe_apic_wait_icr_idle();
 674
 675	/*
 676	 * Give the other CPU some time to accept the IPI.
 677	 */
 678	udelay(200);
 679	if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
 680		maxlvt = lapic_get_maxlvt();
 681		if (maxlvt > 3)			/* Due to the Pentium erratum 3AP.  */
 682			apic_write(APIC_ESR, 0);
 683		accept_status = (apic_read(APIC_ESR) & 0xEF);
 684	}
 685	pr_debug("NMI sent\n");
 686
 687	if (send_status)
 688		pr_err("APIC never delivered???\n");
 689	if (accept_status)
 690		pr_err("APIC delivery error (%lx)\n", accept_status);
 691
 692	return (send_status | accept_status);
 693}
 694
 695static int
 696wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
 697{
 698	unsigned long send_status = 0, accept_status = 0;
 699	int maxlvt, num_starts, j;
 700
 701	maxlvt = lapic_get_maxlvt();
 702
 703	/*
 704	 * Be paranoid about clearing APIC errors.
 705	 */
 706	if (APIC_INTEGRATED(apic_version[phys_apicid])) {
 707		if (maxlvt > 3)		/* Due to the Pentium erratum 3AP.  */
 708			apic_write(APIC_ESR, 0);
 709		apic_read(APIC_ESR);
 710	}
 711
 712	pr_debug("Asserting INIT\n");
 713
 714	/*
 715	 * Turn INIT on target chip
 716	 */
 717	/*
 718	 * Send IPI
 719	 */
 720	apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT,
 721		       phys_apicid);
 722
 723	pr_debug("Waiting for send to finish...\n");
 724	send_status = safe_apic_wait_icr_idle();
 725
 726	udelay(init_udelay);
 727
 728	pr_debug("Deasserting INIT\n");
 729
 730	/* Target chip */
 731	/* Send IPI */
 732	apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid);
 733
 734	pr_debug("Waiting for send to finish...\n");
 735	send_status = safe_apic_wait_icr_idle();
 736
 737	mb();
 
 738
 739	/*
 740	 * Should we send STARTUP IPIs ?
 741	 *
 742	 * Determine this based on the APIC version.
 743	 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
 744	 */
 745	if (APIC_INTEGRATED(apic_version[phys_apicid]))
 746		num_starts = 2;
 747	else
 748		num_starts = 0;
 749
 750	/*
 
 
 
 
 
 
 
 751	 * Run STARTUP IPI loop.
 752	 */
 753	pr_debug("#startup loops: %d\n", num_starts);
 754
 755	for (j = 1; j <= num_starts; j++) {
 756		pr_debug("Sending STARTUP #%d\n", j);
 757		if (maxlvt > 3)		/* Due to the Pentium erratum 3AP.  */
 758			apic_write(APIC_ESR, 0);
 759		apic_read(APIC_ESR);
 760		pr_debug("After apic_write\n");
 761
 762		/*
 763		 * STARTUP IPI
 764		 */
 765
 766		/* Target chip */
 767		/* Boot on the stack */
 768		/* Kick the second */
 769		apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12),
 770			       phys_apicid);
 771
 772		/*
 773		 * Give the other CPU some time to accept the IPI.
 774		 */
 775		if (init_udelay == 0)
 776			udelay(10);
 777		else
 778			udelay(300);
 779
 780		pr_debug("Startup point 1\n");
 781
 782		pr_debug("Waiting for send to finish...\n");
 783		send_status = safe_apic_wait_icr_idle();
 784
 785		/*
 786		 * Give the other CPU some time to accept the IPI.
 787		 */
 788		if (init_udelay == 0)
 789			udelay(10);
 790		else
 791			udelay(200);
 792
 793		if (maxlvt > 3)		/* Due to the Pentium erratum 3AP.  */
 794			apic_write(APIC_ESR, 0);
 795		accept_status = (apic_read(APIC_ESR) & 0xEF);
 796		if (send_status || accept_status)
 797			break;
 798	}
 799	pr_debug("After Startup\n");
 800
 801	if (send_status)
 802		pr_err("APIC never delivered???\n");
 803	if (accept_status)
 804		pr_err("APIC delivery error (%lx)\n", accept_status);
 805
 806	return (send_status | accept_status);
 807}
 808
 809void smp_announce(void)
 810{
 811	int num_nodes = num_online_nodes();
 812
 813	printk(KERN_INFO "x86: Booted up %d node%s, %d CPUs\n",
 814	       num_nodes, (num_nodes > 1 ? "s" : ""), num_online_cpus());
 815}
 816
 817/* reduce the number of lines printed when booting a large cpu count system */
 818static void announce_cpu(int cpu, int apicid)
 819{
 820	static int current_node = -1;
 821	int node = early_cpu_to_node(cpu);
 822	static int width, node_width;
 823
 824	if (!width)
 825		width = num_digits(num_possible_cpus()) + 1; /* + '#' sign */
 826
 827	if (!node_width)
 828		node_width = num_digits(num_possible_nodes()) + 1; /* + '#' */
 829
 830	if (cpu == 1)
 831		printk(KERN_INFO "x86: Booting SMP configuration:\n");
 832
 833	if (system_state == SYSTEM_BOOTING) {
 834		if (node != current_node) {
 835			if (current_node > (-1))
 836				pr_cont("\n");
 837			current_node = node;
 838
 839			printk(KERN_INFO ".... node %*s#%d, CPUs:  ",
 840			       node_width - num_digits(node), " ", node);
 841		}
 842
 843		/* Add padding for the BSP */
 844		if (cpu == 1)
 845			pr_cont("%*s", width + 1, " ");
 846
 847		pr_cont("%*s#%d", width - num_digits(cpu), " ", cpu);
 848
 849	} else
 850		pr_info("Booting Node %d Processor %d APIC 0x%x\n",
 851			node, cpu, apicid);
 852}
 853
 854static int wakeup_cpu0_nmi(unsigned int cmd, struct pt_regs *regs)
 855{
 856	int cpu;
 857
 858	cpu = smp_processor_id();
 859	if (cpu == 0 && !cpu_online(cpu) && enable_start_cpu0)
 860		return NMI_HANDLED;
 861
 862	return NMI_DONE;
 863}
 864
 865/*
 866 * Wake up AP by INIT, INIT, STARTUP sequence.
 867 *
 868 * Instead of waiting for STARTUP after INITs, BSP will execute the BIOS
 869 * boot-strap code which is not a desired behavior for waking up BSP. To
 870 * void the boot-strap code, wake up CPU0 by NMI instead.
 871 *
 872 * This works to wake up soft offlined CPU0 only. If CPU0 is hard offlined
 873 * (i.e. physically hot removed and then hot added), NMI won't wake it up.
 874 * We'll change this code in the future to wake up hard offlined CPU0 if
 875 * real platform and request are available.
 876 */
 877static int
 878wakeup_cpu_via_init_nmi(int cpu, unsigned long start_ip, int apicid,
 879	       int *cpu0_nmi_registered)
 880{
 881	int id;
 882	int boot_error;
 883
 884	preempt_disable();
 885
 886	/*
 887	 * Wake up AP by INIT, INIT, STARTUP sequence.
 888	 */
 889	if (cpu) {
 890		boot_error = wakeup_secondary_cpu_via_init(apicid, start_ip);
 891		goto out;
 892	}
 893
 894	/*
 895	 * Wake up BSP by nmi.
 896	 *
 897	 * Register a NMI handler to help wake up CPU0.
 898	 */
 899	boot_error = register_nmi_handler(NMI_LOCAL,
 900					  wakeup_cpu0_nmi, 0, "wake_cpu0");
 901
 902	if (!boot_error) {
 903		enable_start_cpu0 = 1;
 904		*cpu0_nmi_registered = 1;
 905		if (apic->dest_logical == APIC_DEST_LOGICAL)
 906			id = cpu0_logical_apicid;
 907		else
 908			id = apicid;
 909		boot_error = wakeup_secondary_cpu_via_nmi(id, start_ip);
 910	}
 911
 912out:
 913	preempt_enable();
 914
 915	return boot_error;
 916}
 917
 918void common_cpu_up(unsigned int cpu, struct task_struct *idle)
 919{
 920	/* Just in case we booted with a single CPU. */
 921	alternatives_enable_smp();
 922
 923	per_cpu(current_task, cpu) = idle;
 924
 925#ifdef CONFIG_X86_32
 926	/* Stack for startup_32 can be just as for start_secondary onwards */
 927	irq_ctx_init(cpu);
 928	per_cpu(cpu_current_top_of_stack, cpu) =
 929		(unsigned long)task_stack_page(idle) + THREAD_SIZE;
 930#else
 931	clear_tsk_thread_flag(idle, TIF_FORK);
 932	initial_gs = per_cpu_offset(cpu);
 933#endif
 934}
 935
 936/*
 937 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
 938 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
 939 * Returns zero if CPU booted OK, else error code from
 940 * ->wakeup_secondary_cpu.
 941 */
 942static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
 943{
 944	volatile u32 *trampoline_status =
 945		(volatile u32 *) __va(real_mode_header->trampoline_status);
 946	/* start_ip had better be page-aligned! */
 947	unsigned long start_ip = real_mode_header->trampoline_start;
 948
 949	unsigned long boot_error = 0;
 
 950	int cpu0_nmi_registered = 0;
 951	unsigned long timeout;
 
 
 952
 953	idle->thread.sp = (unsigned long) (((struct pt_regs *)
 954			  (THREAD_SIZE +  task_stack_page(idle))) - 1);
 
 955
 
 
 
 
 
 
 
 
 
 
 956	early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
 957	initial_code = (unsigned long)start_secondary;
 958	stack_start  = idle->thread.sp;
 959
 960	/*
 961	 * Enable the espfix hack for this CPU
 962	*/
 963#ifdef CONFIG_X86_ESPFIX64
 964	init_espfix_ap(cpu);
 965#endif
 966
 967	/* So we see what's up */
 968	announce_cpu(cpu, apicid);
 969
 970	/*
 971	 * This grunge runs the startup process for
 972	 * the targeted processor.
 973	 */
 974
 
 
 975	if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
 976
 977		pr_debug("Setting warm reset code and vector.\n");
 978
 979		smpboot_setup_warm_reset_vector(start_ip);
 980		/*
 981		 * Be paranoid about clearing APIC errors.
 982		*/
 983		if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
 984			apic_write(APIC_ESR, 0);
 985			apic_read(APIC_ESR);
 986		}
 987	}
 988
 989	/*
 990	 * AP might wait on cpu_callout_mask in cpu_init() with
 991	 * cpu_initialized_mask set if previous attempt to online
 992	 * it timed-out. Clear cpu_initialized_mask so that after
 993	 * INIT/SIPI it could start with a clean state.
 994	 */
 995	cpumask_clear_cpu(cpu, cpu_initialized_mask);
 996	smp_mb();
 997
 998	/*
 999	 * Wake up a CPU in difference cases:
1000	 * - Use the method in the APIC driver if it's defined
1001	 * Otherwise,
1002	 * - Use an INIT boot APIC message for APs or NMI for BSP.
1003	 */
1004	if (apic->wakeup_secondary_cpu)
1005		boot_error = apic->wakeup_secondary_cpu(apicid, start_ip);
1006	else
1007		boot_error = wakeup_cpu_via_init_nmi(cpu, start_ip, apicid,
1008						     &cpu0_nmi_registered);
1009
1010	if (!boot_error) {
1011		/*
1012		 * Wait 10s total for first sign of life from AP
1013		 */
1014		boot_error = -1;
1015		timeout = jiffies + 10*HZ;
1016		while (time_before(jiffies, timeout)) {
1017			if (cpumask_test_cpu(cpu, cpu_initialized_mask)) {
1018				/*
1019				 * Tell AP to proceed with initialization
1020				 */
1021				cpumask_set_cpu(cpu, cpu_callout_mask);
1022				boot_error = 0;
1023				break;
1024			}
1025			schedule();
1026		}
1027	}
1028
1029	if (!boot_error) {
1030		/*
1031		 * Wait till AP completes initial initialization
1032		 */
1033		while (!cpumask_test_cpu(cpu, cpu_callin_mask)) {
 
 
 
1034			/*
1035			 * Allow other tasks to run while we wait for the
1036			 * AP to come online. This also gives a chance
1037			 * for the MTRR work(triggered by the AP coming online)
1038			 * to be completed in the stop machine context.
1039			 */
1040			schedule();
1041		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1042	}
1043
1044	/* mark "stuck" area as not stuck */
1045	*trampoline_status = 0;
1046
1047	if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
1048		/*
1049		 * Cleanup possible dangling ends...
1050		 */
1051		smpboot_restore_warm_reset_vector();
1052	}
1053	/*
1054	 * Clean up the nmi handler. Do this after the callin and callout sync
1055	 * to avoid impact of possible long unregister time.
1056	 */
1057	if (cpu0_nmi_registered)
1058		unregister_nmi_handler(NMI_LOCAL, "wake_cpu0");
1059
1060	return boot_error;
1061}
1062
1063int native_cpu_up(unsigned int cpu, struct task_struct *tidle)
1064{
1065	int apicid = apic->cpu_present_to_apicid(cpu);
1066	unsigned long flags;
1067	int err;
1068
1069	WARN_ON(irqs_disabled());
1070
1071	pr_debug("++++++++++++++++++++=_---CPU UP  %u\n", cpu);
1072
1073	if (apicid == BAD_APICID ||
1074	    !physid_isset(apicid, phys_cpu_present_map) ||
1075	    !apic->apic_id_valid(apicid)) {
1076		pr_err("%s: bad cpu %d\n", __func__, cpu);
1077		return -EINVAL;
1078	}
1079
1080	/*
1081	 * Already booted CPU?
1082	 */
1083	if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
1084		pr_debug("do_boot_cpu %d Already started\n", cpu);
1085		return -ENOSYS;
1086	}
1087
1088	/*
1089	 * Save current MTRR state in case it was changed since early boot
1090	 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
1091	 */
1092	mtrr_save_state();
1093
1094	/* x86 CPUs take themselves offline, so delayed offline is OK. */
1095	err = cpu_check_up_prepare(cpu);
1096	if (err && err != -EBUSY)
1097		return err;
1098
1099	/* the FPU context is blank, nobody can own it */
1100	__cpu_disable_lazy_restore(cpu);
1101
1102	common_cpu_up(cpu, tidle);
1103
1104	/*
1105	 * We have to walk the irq descriptors to setup the vector
1106	 * space for the cpu which comes online.  Prevent irq
1107	 * alloc/free across the bringup.
1108	 */
1109	irq_lock_sparse();
1110
1111	err = do_boot_cpu(apicid, cpu, tidle);
1112
1113	if (err) {
1114		irq_unlock_sparse();
1115		pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu);
1116		return -EIO;
1117	}
1118
1119	/*
1120	 * Check TSC synchronization with the AP (keep irqs disabled
1121	 * while doing so):
1122	 */
1123	local_irq_save(flags);
1124	check_tsc_sync_source(cpu);
1125	local_irq_restore(flags);
1126
1127	while (!cpu_online(cpu)) {
1128		cpu_relax();
1129		touch_nmi_watchdog();
1130	}
1131
1132	irq_unlock_sparse();
1133
1134	return 0;
1135}
1136
1137/**
1138 * arch_disable_smp_support() - disables SMP support for x86 at runtime
1139 */
1140void arch_disable_smp_support(void)
1141{
1142	disable_ioapic_support();
1143}
1144
1145/*
1146 * Fall back to non SMP mode after errors.
1147 *
1148 * RED-PEN audit/test this more. I bet there is more state messed up here.
1149 */
1150static __init void disable_smp(void)
1151{
1152	pr_info("SMP disabled\n");
1153
1154	disable_ioapic_support();
1155
1156	init_cpu_present(cpumask_of(0));
1157	init_cpu_possible(cpumask_of(0));
 
1158
1159	if (smp_found_config)
1160		physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1161	else
1162		physid_set_mask_of_physid(0, &phys_cpu_present_map);
1163	cpumask_set_cpu(0, topology_sibling_cpumask(0));
1164	cpumask_set_cpu(0, topology_core_cpumask(0));
1165}
1166
1167enum {
1168	SMP_OK,
1169	SMP_NO_CONFIG,
1170	SMP_NO_APIC,
1171	SMP_FORCE_UP,
1172};
1173
1174/*
1175 * Various sanity checks.
1176 */
1177static int __init smp_sanity_check(unsigned max_cpus)
1178{
1179	preempt_disable();
1180
1181#if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32)
1182	if (def_to_bigsmp && nr_cpu_ids > 8) {
1183		unsigned int cpu;
1184		unsigned nr;
1185
1186		pr_warn("More than 8 CPUs detected - skipping them\n"
1187			"Use CONFIG_X86_BIGSMP\n");
1188
1189		nr = 0;
1190		for_each_present_cpu(cpu) {
1191			if (nr >= 8)
1192				set_cpu_present(cpu, false);
1193			nr++;
1194		}
1195
1196		nr = 0;
1197		for_each_possible_cpu(cpu) {
1198			if (nr >= 8)
1199				set_cpu_possible(cpu, false);
1200			nr++;
1201		}
1202
1203		nr_cpu_ids = 8;
1204	}
1205#endif
1206
1207	if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
1208		pr_warn("weird, boot CPU (#%d) not listed by the BIOS\n",
1209			hard_smp_processor_id());
1210
1211		physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1212	}
1213
1214	/*
1215	 * If we couldn't find an SMP configuration at boot time,
1216	 * get out of here now!
1217	 */
1218	if (!smp_found_config && !acpi_lapic) {
1219		preempt_enable();
1220		pr_notice("SMP motherboard not detected\n");
1221		return SMP_NO_CONFIG;
 
 
 
1222	}
1223
1224	/*
1225	 * Should not be necessary because the MP table should list the boot
1226	 * CPU too, but we do it for the sake of robustness anyway.
1227	 */
1228	if (!apic->check_phys_apicid_present(boot_cpu_physical_apicid)) {
1229		pr_notice("weird, boot CPU (#%d) not listed by the BIOS\n",
1230			  boot_cpu_physical_apicid);
1231		physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1232	}
1233	preempt_enable();
1234
1235	/*
1236	 * If we couldn't find a local APIC, then get out of here now!
1237	 */
1238	if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
1239	    !cpu_has_apic) {
1240		if (!disable_apic) {
1241			pr_err("BIOS bug, local APIC #%d not detected!...\n",
1242				boot_cpu_physical_apicid);
1243			pr_err("... forcing use of dummy APIC emulation (tell your hw vendor)\n");
1244		}
1245		return SMP_NO_APIC;
 
 
1246	}
1247
 
 
1248	/*
1249	 * If SMP should be disabled, then really disable it!
1250	 */
1251	if (!max_cpus) {
1252		pr_info("SMP mode deactivated\n");
1253		return SMP_FORCE_UP;
 
 
 
 
 
1254	}
1255
1256	return SMP_OK;
1257}
1258
1259static void __init smp_cpu_index_default(void)
1260{
1261	int i;
1262	struct cpuinfo_x86 *c;
1263
1264	for_each_possible_cpu(i) {
1265		c = &cpu_data(i);
1266		/* mark all to hotplug */
1267		c->cpu_index = nr_cpu_ids;
1268	}
1269}
1270
1271/*
1272 * Prepare for SMP bootup.  The MP table or ACPI has been read
1273 * earlier.  Just do some sanity checking here and enable APIC mode.
1274 */
1275void __init native_smp_prepare_cpus(unsigned int max_cpus)
1276{
1277	unsigned int i;
1278
 
1279	smp_cpu_index_default();
1280
1281	/*
1282	 * Setup boot CPU information
1283	 */
1284	smp_store_boot_cpu_info(); /* Final full version of the data */
1285	cpumask_copy(cpu_callin_mask, cpumask_of(0));
1286	mb();
1287
1288	current_thread_info()->cpu = 0;  /* needed? */
1289	for_each_possible_cpu(i) {
1290		zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
1291		zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
1292		zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
1293	}
1294	set_cpu_sibling_map(0);
1295
1296	switch (smp_sanity_check(max_cpus)) {
1297	case SMP_NO_CONFIG:
1298		disable_smp();
1299		if (APIC_init_uniprocessor())
1300			pr_notice("Local APIC not detected. Using dummy APIC emulation.\n");
1301		return;
1302	case SMP_NO_APIC:
1303		disable_smp();
1304		return;
1305	case SMP_FORCE_UP:
1306		disable_smp();
1307		apic_bsp_setup(false);
1308		return;
1309	case SMP_OK:
1310		break;
1311	}
1312
1313	default_setup_apic_routing();
1314
 
1315	if (read_apic_id() != boot_cpu_physical_apicid) {
1316		panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1317		     read_apic_id(), boot_cpu_physical_apicid);
1318		/* Or can we switch back to PIC here? */
1319	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1320
1321	cpu0_logical_apicid = apic_bsp_setup(false);
 
 
 
 
 
 
 
 
1322
1323	pr_info("CPU%d: ", 0);
1324	print_cpu_info(&cpu_data(0));
 
1325
1326	if (is_uv_system())
1327		uv_system_init();
1328
1329	set_mtrr_aps_delayed_init();
1330
1331	smp_quirk_init_udelay();
1332}
1333
1334void arch_enable_nonboot_cpus_begin(void)
1335{
1336	set_mtrr_aps_delayed_init();
1337}
1338
1339void arch_enable_nonboot_cpus_end(void)
1340{
1341	mtrr_aps_init();
1342}
1343
1344/*
1345 * Early setup to make printk work.
1346 */
1347void __init native_smp_prepare_boot_cpu(void)
1348{
1349	int me = smp_processor_id();
1350	switch_to_new_gdt(me);
1351	/* already set me in cpu_online_mask in boot_cpu_init() */
1352	cpumask_set_cpu(me, cpu_callout_mask);
1353	cpu_set_state_online(me);
1354}
1355
1356void __init native_smp_cpus_done(unsigned int max_cpus)
1357{
1358	pr_debug("Boot done\n");
1359
1360	nmi_selftest();
1361	impress_friends();
 
1362	setup_ioapic_dest();
 
1363	mtrr_aps_init();
1364}
1365
1366static int __initdata setup_possible_cpus = -1;
1367static int __init _setup_possible_cpus(char *str)
1368{
1369	get_option(&str, &setup_possible_cpus);
1370	return 0;
1371}
1372early_param("possible_cpus", _setup_possible_cpus);
1373
1374
1375/*
1376 * cpu_possible_mask should be static, it cannot change as cpu's
1377 * are onlined, or offlined. The reason is per-cpu data-structures
1378 * are allocated by some modules at init time, and dont expect to
1379 * do this dynamically on cpu arrival/departure.
1380 * cpu_present_mask on the other hand can change dynamically.
1381 * In case when cpu_hotplug is not compiled, then we resort to current
1382 * behaviour, which is cpu_possible == cpu_present.
1383 * - Ashok Raj
1384 *
1385 * Three ways to find out the number of additional hotplug CPUs:
1386 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1387 * - The user can overwrite it with possible_cpus=NUM
1388 * - Otherwise don't reserve additional CPUs.
1389 * We do this because additional CPUs waste a lot of memory.
1390 * -AK
1391 */
1392__init void prefill_possible_map(void)
1393{
1394	int i, possible;
1395
1396	/* no processor from mptable or madt */
1397	if (!num_processors)
1398		num_processors = 1;
1399
1400	i = setup_max_cpus ?: 1;
1401	if (setup_possible_cpus == -1) {
1402		possible = num_processors;
1403#ifdef CONFIG_HOTPLUG_CPU
1404		if (setup_max_cpus)
1405			possible += disabled_cpus;
1406#else
1407		if (possible > i)
1408			possible = i;
1409#endif
1410	} else
1411		possible = setup_possible_cpus;
1412
1413	total_cpus = max_t(int, possible, num_processors + disabled_cpus);
1414
1415	/* nr_cpu_ids could be reduced via nr_cpus= */
1416	if (possible > nr_cpu_ids) {
1417		pr_warn("%d Processors exceeds NR_CPUS limit of %d\n",
1418			possible, nr_cpu_ids);
1419		possible = nr_cpu_ids;
1420	}
1421
1422#ifdef CONFIG_HOTPLUG_CPU
1423	if (!setup_max_cpus)
1424#endif
1425	if (possible > i) {
1426		pr_warn("%d Processors exceeds max_cpus limit of %u\n",
1427			possible, setup_max_cpus);
1428		possible = i;
1429	}
1430
1431	pr_info("Allowing %d CPUs, %d hotplug CPUs\n",
1432		possible, max_t(int, possible - num_processors, 0));
1433
1434	for (i = 0; i < possible; i++)
1435		set_cpu_possible(i, true);
1436	for (; i < NR_CPUS; i++)
1437		set_cpu_possible(i, false);
1438
1439	nr_cpu_ids = possible;
1440}
1441
1442#ifdef CONFIG_HOTPLUG_CPU
1443
1444static void remove_siblinginfo(int cpu)
1445{
1446	int sibling;
1447	struct cpuinfo_x86 *c = &cpu_data(cpu);
1448
1449	for_each_cpu(sibling, topology_core_cpumask(cpu)) {
1450		cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
1451		/*/
1452		 * last thread sibling in this cpu core going down
1453		 */
1454		if (cpumask_weight(topology_sibling_cpumask(cpu)) == 1)
1455			cpu_data(sibling).booted_cores--;
1456	}
1457
1458	for_each_cpu(sibling, topology_sibling_cpumask(cpu))
1459		cpumask_clear_cpu(cpu, topology_sibling_cpumask(sibling));
1460	for_each_cpu(sibling, cpu_llc_shared_mask(cpu))
1461		cpumask_clear_cpu(cpu, cpu_llc_shared_mask(sibling));
1462	cpumask_clear(cpu_llc_shared_mask(cpu));
1463	cpumask_clear(topology_sibling_cpumask(cpu));
1464	cpumask_clear(topology_core_cpumask(cpu));
1465	c->phys_proc_id = 0;
1466	c->cpu_core_id = 0;
1467	cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
1468}
1469
1470static void remove_cpu_from_maps(int cpu)
1471{
1472	set_cpu_online(cpu, false);
1473	cpumask_clear_cpu(cpu, cpu_callout_mask);
1474	cpumask_clear_cpu(cpu, cpu_callin_mask);
1475	/* was set by cpu_init() */
1476	cpumask_clear_cpu(cpu, cpu_initialized_mask);
1477	numa_remove_cpu(cpu);
1478}
1479
1480void cpu_disable_common(void)
1481{
1482	int cpu = smp_processor_id();
1483
1484	remove_siblinginfo(cpu);
1485
1486	/* It's now safe to remove this processor from the online map */
1487	lock_vector_lock();
1488	remove_cpu_from_maps(cpu);
1489	unlock_vector_lock();
1490	fixup_irqs();
1491}
1492
1493int native_cpu_disable(void)
1494{
1495	int ret;
1496
1497	ret = check_irq_vectors_for_cpu_disable();
1498	if (ret)
1499		return ret;
1500
1501	clear_local_APIC();
1502	cpu_disable_common();
1503
 
1504	return 0;
1505}
1506
1507int common_cpu_die(unsigned int cpu)
1508{
1509	int ret = 0;
1510
1511	/* We don't do anything here: idle task is faking death itself. */
 
1512
1513	/* They ack this in play_dead() by setting CPU_DEAD */
1514	if (cpu_wait_death(cpu, 5)) {
1515		if (system_state == SYSTEM_RUNNING)
1516			pr_info("CPU %u is now offline\n", cpu);
1517	} else {
1518		pr_err("CPU %u didn't die...\n", cpu);
1519		ret = -1;
 
1520	}
1521
1522	return ret;
1523}
1524
1525void native_cpu_die(unsigned int cpu)
1526{
1527	common_cpu_die(cpu);
1528}
1529
1530void play_dead_common(void)
1531{
1532	idle_task_exit();
1533	reset_lazy_tlbstate();
1534	amd_e400_remove_cpu(raw_smp_processor_id());
1535
 
1536	/* Ack it */
1537	(void)cpu_report_death();
1538
1539	/*
1540	 * With physical CPU hotplug, we should halt the cpu
1541	 */
1542	local_irq_disable();
1543}
1544
1545static bool wakeup_cpu0(void)
1546{
1547	if (smp_processor_id() == 0 && enable_start_cpu0)
1548		return true;
1549
1550	return false;
1551}
1552
1553/*
1554 * We need to flush the caches before going to sleep, lest we have
1555 * dirty data in our caches when we come back up.
1556 */
1557static inline void mwait_play_dead(void)
1558{
1559	unsigned int eax, ebx, ecx, edx;
1560	unsigned int highest_cstate = 0;
1561	unsigned int highest_subcstate = 0;
1562	void *mwait_ptr;
1563	int i;
1564
1565	if (!this_cpu_has(X86_FEATURE_MWAIT))
1566		return;
1567	if (!this_cpu_has(X86_FEATURE_CLFLUSH))
1568		return;
1569	if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF)
1570		return;
1571
1572	eax = CPUID_MWAIT_LEAF;
1573	ecx = 0;
1574	native_cpuid(&eax, &ebx, &ecx, &edx);
1575
1576	/*
1577	 * eax will be 0 if EDX enumeration is not valid.
1578	 * Initialized below to cstate, sub_cstate value when EDX is valid.
1579	 */
1580	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) {
1581		eax = 0;
1582	} else {
1583		edx >>= MWAIT_SUBSTATE_SIZE;
1584		for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
1585			if (edx & MWAIT_SUBSTATE_MASK) {
1586				highest_cstate = i;
1587				highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
1588			}
1589		}
1590		eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
1591			(highest_subcstate - 1);
1592	}
1593
1594	/*
1595	 * This should be a memory location in a cache line which is
1596	 * unlikely to be touched by other processors.  The actual
1597	 * content is immaterial as it is not actually modified in any way.
1598	 */
1599	mwait_ptr = &current_thread_info()->flags;
1600
1601	wbinvd();
1602
1603	while (1) {
1604		/*
1605		 * The CLFLUSH is a workaround for erratum AAI65 for
1606		 * the Xeon 7400 series.  It's not clear it is actually
1607		 * needed, but it should be harmless in either case.
1608		 * The WBINVD is insufficient due to the spurious-wakeup
1609		 * case where we return around the loop.
1610		 */
1611		mb();
1612		clflush(mwait_ptr);
1613		mb();
1614		__monitor(mwait_ptr, 0, 0);
1615		mb();
1616		__mwait(eax, 0);
1617		/*
1618		 * If NMI wants to wake up CPU0, start CPU0.
1619		 */
1620		if (wakeup_cpu0())
1621			start_cpu0();
1622	}
1623}
1624
1625static inline void hlt_play_dead(void)
1626{
1627	if (__this_cpu_read(cpu_info.x86) >= 4)
1628		wbinvd();
1629
1630	while (1) {
1631		native_halt();
1632		/*
1633		 * If NMI wants to wake up CPU0, start CPU0.
1634		 */
1635		if (wakeup_cpu0())
1636			start_cpu0();
1637	}
1638}
1639
1640void native_play_dead(void)
1641{
1642	play_dead_common();
1643	tboot_shutdown(TB_SHUTDOWN_WFS);
1644
1645	mwait_play_dead();	/* Only returns on failure */
1646	if (cpuidle_play_dead())
1647		hlt_play_dead();
1648}
1649
1650#else /* ... !CONFIG_HOTPLUG_CPU */
1651int native_cpu_disable(void)
1652{
1653	return -ENOSYS;
1654}
1655
1656void native_cpu_die(unsigned int cpu)
1657{
1658	/* We said "no" in __cpu_disable */
1659	BUG();
1660}
1661
1662void native_play_dead(void)
1663{
1664	BUG();
1665}
1666
1667#endif