2 * x86 SMP booting functions
4 * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
5 * (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
6 * Copyright 2001 Andi Kleen, SuSE Labs.
8 * Much of the core SMP work is based on previous work by Thomas Radke, to
9 * whom a great many thanks are extended.
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.
15 * This code is released under the GNU General Public License version 2
18 * Felix Koop : NR_CPUS used properly
19 * Jose Renau : Handle single CPU case.
20 * Alan Cox : By repeated request 8) - Total BogoMIP report.
21 * Greg Wright : Fix for kernel stacks panic.
22 * Erich Boleyn : MP v1.4 and additional changes.
23 * Matthias Sattler : Changes for 2.1 kernel map.
24 * Michel Lespinasse : Changes for 2.1 kernel map.
25 * Michael Chastain : Change trampoline.S to gnu as.
26 * Alan Cox : Dumb bug: 'B' step PPro's are fine
27 * Ingo Molnar : Added APIC timers, based on code
29 * Ingo Molnar : various cleanups and rewrites
30 * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug.
31 * Maciej W. Rozycki : Bits for genuine 82489DX APICs
32 * Andi Kleen : Changed for SMP boot into long mode.
33 * Rusty Russell : Hacked into shape for new "hotplug" boot process.
34 * Andi Kleen : Converted to new state machine.
36 * Probably mostly hotplug CPU ready now.
37 * Ashok Raj : CPU hotplug support
41 #include <linux/init.h>
44 #include <linux/kernel_stat.h>
45 #include <linux/bootmem.h>
46 #include <linux/thread_info.h>
47 #include <linux/module.h>
48 #include <linux/delay.h>
49 #include <linux/mc146818rtc.h>
50 #include <linux/smp.h>
51 #include <linux/kdebug.h>
54 #include <asm/pgalloc.h>
56 #include <asm/tlbflush.h>
57 #include <asm/proto.h>
60 #include <asm/hw_irq.h>
63 #include <mach_wakecpu.h>
64 #include <mach_apic.h>
65 #include <smpboot_hooks.h>
66 #include <mach_apic.h>
68 /* Set when the idlers are all forked */
69 int smp_threads_ready;
71 /* State of each CPU */
72 DEFINE_PER_CPU(int, cpu_state) = { 0 };
74 extern void smp_callin(void);
76 * Setup code on secondary processor (after comming out of the trampoline)
78 void __cpuinit start_secondary(void)
81 * Dont put anything before smp_callin(), SMP
82 * booting is too fragile that we want to limit the
83 * things done here to the most necessary things.
89 /* otherwise gcc will move up the smp_processor_id before the cpu_init */
93 * Check TSC sync first:
95 check_tsc_sync_target();
97 if (nmi_watchdog == NMI_IO_APIC) {
99 enable_NMI_through_LVT0();
104 * The sibling maps must be set before turing the online map on for
107 set_cpu_sibling_map(smp_processor_id());
110 * We need to hold call_lock, so there is no inconsistency
111 * between the time smp_call_function() determines number of
112 * IPI recipients, and the time when the determination is made
113 * for which cpus receive the IPI in genapic_flat.c. Holding this
114 * lock helps us to not include this cpu in a currently in progress
115 * smp_call_function().
117 lock_ipi_call_lock();
118 spin_lock(&vector_lock);
120 /* Setup the per cpu irq handling data structures */
121 __setup_vector_irq(smp_processor_id());
123 * Allow the master to continue.
125 spin_unlock(&vector_lock);
126 cpu_set(smp_processor_id(), cpu_online_map);
127 unlock_ipi_call_lock();
129 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
131 setup_secondary_clock();
137 cycles_t cacheflush_time;
138 unsigned long cache_decay_ticks;
141 * Fall back to non SMP mode after errors.
143 * RED-PEN audit/test this more. I bet there is more state messed up here.
145 static __init void disable_smp(void)
147 cpu_present_map = cpumask_of_cpu(0);
148 cpu_possible_map = cpumask_of_cpu(0);
149 if (smp_found_config)
150 phys_cpu_present_map =
151 physid_mask_of_physid(boot_cpu_physical_apicid);
153 phys_cpu_present_map = physid_mask_of_physid(0);
154 cpu_set(0, per_cpu(cpu_sibling_map, 0));
155 cpu_set(0, per_cpu(cpu_core_map, 0));
159 * Various sanity checks.
161 static int __init smp_sanity_check(unsigned max_cpus)
163 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
164 printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
165 hard_smp_processor_id());
166 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
170 * If we couldn't find an SMP configuration at boot time,
171 * get out of here now!
173 if (!smp_found_config) {
174 printk(KERN_NOTICE "SMP motherboard not detected.\n");
176 if (APIC_init_uniprocessor())
177 printk(KERN_NOTICE "Local APIC not detected."
178 " Using dummy APIC emulation.\n");
183 * Should not be necessary because the MP table should list the boot
184 * CPU too, but we do it for the sake of robustness anyway.
186 if (!physid_isset(boot_cpu_physical_apicid, phys_cpu_present_map)) {
188 "weird, boot CPU (#%d) not listed by the BIOS.\n",
189 boot_cpu_physical_apicid);
190 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
194 * If we couldn't find a local APIC, then get out of here now!
197 printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
198 boot_cpu_physical_apicid);
199 printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
205 * If SMP should be disabled, then really disable it!
208 printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
216 static void __init smp_cpu_index_default(void)
219 struct cpuinfo_x86 *c;
221 for_each_cpu_mask(i, cpu_possible_map) {
223 /* mark all to hotplug */
224 c->cpu_index = NR_CPUS;
229 * Prepare for SMP bootup. The MP table or ACPI has been read
230 * earlier. Just do some sanity checking here and enable APIC mode.
232 void __init native_smp_prepare_cpus(unsigned int max_cpus)
234 nmi_watchdog_default();
235 smp_cpu_index_default();
236 current_cpu_data = boot_cpu_data;
237 current_thread_info()->cpu = 0; /* needed? */
238 set_cpu_sibling_map(0);
240 if (smp_sanity_check(max_cpus) < 0) {
241 printk(KERN_INFO "SMP disabled\n");
248 * Switch from PIC to APIC mode.
253 * Enable IO APIC before setting up error vector
255 if (!skip_ioapic_setup && nr_ioapics)
257 end_local_APIC_setup();
259 if (GET_APIC_ID(apic_read(APIC_ID)) != boot_cpu_physical_apicid) {
260 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
261 GET_APIC_ID(apic_read(APIC_ID)), boot_cpu_physical_apicid);
262 /* Or can we switch back to PIC here? */
266 * Now start the IO-APICs
268 if (!skip_ioapic_setup && nr_ioapics)
274 * Set up local APIC timer on boot CPU.
278 printk(KERN_INFO "CPU%d: ", 0);
279 print_cpu_info(&cpu_data(0));
283 * Early setup to make printk work.
285 void __init native_smp_prepare_boot_cpu(void)
287 int me = smp_processor_id();
288 /* already set me in cpu_online_map in boot_cpu_init() */
289 cpu_set(me, cpu_callout_map);
290 per_cpu(cpu_state, me) = CPU_ONLINE;
293 extern void impress_friends(void);
294 extern void smp_checks(void);
297 * Finish the SMP boot.
299 void __init native_smp_cpus_done(unsigned int max_cpus)
301 smpboot_restore_warm_reset_vector();
303 Dprintk("Boot done.\n");
308 check_nmi_watchdog();