x86: move impress_friends and smp_check to cpus_done
[linux-2.6] / arch / x86 / kernel / smpboot.c
1 #include <linux/init.h>
2 #include <linux/smp.h>
3 #include <linux/module.h>
4 #include <linux/sched.h>
5 #include <linux/percpu.h>
6 #include <linux/bootmem.h>
7
8 #include <asm/nmi.h>
9 #include <asm/irq.h>
10 #include <asm/smp.h>
11 #include <asm/cpu.h>
12 #include <asm/numa.h>
13
14 /* Number of siblings per CPU package */
15 int smp_num_siblings = 1;
16 EXPORT_SYMBOL(smp_num_siblings);
17
18 /* Last level cache ID of each logical CPU */
19 DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
20
21 /* bitmap of online cpus */
22 cpumask_t cpu_online_map __read_mostly;
23 EXPORT_SYMBOL(cpu_online_map);
24
25 cpumask_t cpu_callin_map;
26 cpumask_t cpu_callout_map;
27 cpumask_t cpu_possible_map;
28 EXPORT_SYMBOL(cpu_possible_map);
29
30 /* representing HT siblings of each logical CPU */
31 DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
32 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
33
34 /* representing HT and core siblings of each logical CPU */
35 DEFINE_PER_CPU(cpumask_t, cpu_core_map);
36 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
37
38 /* Per CPU bogomips and other parameters */
39 DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
40 EXPORT_PER_CPU_SYMBOL(cpu_info);
41
42 /* ready for x86_64, no harm for x86, since it will overwrite after alloc */
43 unsigned char *trampoline_base = __va(SMP_TRAMPOLINE_BASE);
44
45 /* representing cpus for which sibling maps can be computed */
46 static cpumask_t cpu_sibling_setup_map;
47
48 /* Set if we find a B stepping CPU */
49 int __cpuinitdata smp_b_stepping;
50
51 static void __cpuinit smp_apply_quirks(struct cpuinfo_x86 *c)
52 {
53 #ifdef CONFIG_X86_32
54         /*
55          * Mask B, Pentium, but not Pentium MMX
56          */
57         if (c->x86_vendor == X86_VENDOR_INTEL &&
58             c->x86 == 5 &&
59             c->x86_mask >= 1 && c->x86_mask <= 4 &&
60             c->x86_model <= 3)
61                 /*
62                  * Remember we have B step Pentia with bugs
63                  */
64                 smp_b_stepping = 1;
65
66         /*
67          * Certain Athlons might work (for various values of 'work') in SMP
68          * but they are not certified as MP capable.
69          */
70         if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) {
71
72                 if (num_possible_cpus() == 1)
73                         goto valid_k7;
74
75                 /* Athlon 660/661 is valid. */
76                 if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
77                     (c->x86_mask == 1)))
78                         goto valid_k7;
79
80                 /* Duron 670 is valid */
81                 if ((c->x86_model == 7) && (c->x86_mask == 0))
82                         goto valid_k7;
83
84                 /*
85                  * Athlon 662, Duron 671, and Athlon >model 7 have capability
86                  * bit. It's worth noting that the A5 stepping (662) of some
87                  * Athlon XP's have the MP bit set.
88                  * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
89                  * more.
90                  */
91                 if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
92                     ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
93                      (c->x86_model > 7))
94                         if (cpu_has_mp)
95                                 goto valid_k7;
96
97                 /* If we get here, not a certified SMP capable AMD system. */
98                 add_taint(TAINT_UNSAFE_SMP);
99         }
100
101 valid_k7:
102         ;
103 #endif
104 }
105
106 void smp_checks(void)
107 {
108         if (smp_b_stepping)
109                 printk(KERN_WARNING "WARNING: SMP operation may be unreliable"
110                                     "with B stepping processors.\n");
111
112         /*
113          * Don't taint if we are running SMP kernel on a single non-MP
114          * approved Athlon
115          */
116         if (tainted & TAINT_UNSAFE_SMP) {
117                 if (num_online_cpus())
118                         printk(KERN_INFO "WARNING: This combination of AMD"
119                                 "processors is not suitable for SMP.\n");
120                 else
121                         tainted &= ~TAINT_UNSAFE_SMP;
122         }
123 }
124
125 /*
126  * The bootstrap kernel entry code has set these up. Save them for
127  * a given CPU
128  */
129
130 void __cpuinit smp_store_cpu_info(int id)
131 {
132         struct cpuinfo_x86 *c = &cpu_data(id);
133
134         *c = boot_cpu_data;
135         c->cpu_index = id;
136         if (id != 0)
137                 identify_secondary_cpu(c);
138         smp_apply_quirks(c);
139 }
140
141
142 void __cpuinit set_cpu_sibling_map(int cpu)
143 {
144         int i;
145         struct cpuinfo_x86 *c = &cpu_data(cpu);
146
147         cpu_set(cpu, cpu_sibling_setup_map);
148
149         if (smp_num_siblings > 1) {
150                 for_each_cpu_mask(i, cpu_sibling_setup_map) {
151                         if (c->phys_proc_id == cpu_data(i).phys_proc_id &&
152                             c->cpu_core_id == cpu_data(i).cpu_core_id) {
153                                 cpu_set(i, per_cpu(cpu_sibling_map, cpu));
154                                 cpu_set(cpu, per_cpu(cpu_sibling_map, i));
155                                 cpu_set(i, per_cpu(cpu_core_map, cpu));
156                                 cpu_set(cpu, per_cpu(cpu_core_map, i));
157                                 cpu_set(i, c->llc_shared_map);
158                                 cpu_set(cpu, cpu_data(i).llc_shared_map);
159                         }
160                 }
161         } else {
162                 cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
163         }
164
165         cpu_set(cpu, c->llc_shared_map);
166
167         if (current_cpu_data.x86_max_cores == 1) {
168                 per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
169                 c->booted_cores = 1;
170                 return;
171         }
172
173         for_each_cpu_mask(i, cpu_sibling_setup_map) {
174                 if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
175                     per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
176                         cpu_set(i, c->llc_shared_map);
177                         cpu_set(cpu, cpu_data(i).llc_shared_map);
178                 }
179                 if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
180                         cpu_set(i, per_cpu(cpu_core_map, cpu));
181                         cpu_set(cpu, per_cpu(cpu_core_map, i));
182                         /*
183                          *  Does this new cpu bringup a new core?
184                          */
185                         if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) {
186                                 /*
187                                  * for each core in package, increment
188                                  * the booted_cores for this new cpu
189                                  */
190                                 if (first_cpu(per_cpu(cpu_sibling_map, i)) == i)
191                                         c->booted_cores++;
192                                 /*
193                                  * increment the core count for all
194                                  * the other cpus in this package
195                                  */
196                                 if (i != cpu)
197                                         cpu_data(i).booted_cores++;
198                         } else if (i != cpu && !c->booted_cores)
199                                 c->booted_cores = cpu_data(i).booted_cores;
200                 }
201         }
202 }
203
204 /* maps the cpu to the sched domain representing multi-core */
205 cpumask_t cpu_coregroup_map(int cpu)
206 {
207         struct cpuinfo_x86 *c = &cpu_data(cpu);
208         /*
209          * For perf, we return last level cache shared map.
210          * And for power savings, we return cpu_core_map
211          */
212         if (sched_mc_power_savings || sched_smt_power_savings)
213                 return per_cpu(cpu_core_map, cpu);
214         else
215                 return c->llc_shared_map;
216 }
217
218 /*
219  * Currently trivial. Write the real->protected mode
220  * bootstrap into the page concerned. The caller
221  * has made sure it's suitably aligned.
222  */
223
224 unsigned long __cpuinit setup_trampoline(void)
225 {
226         memcpy(trampoline_base, trampoline_data,
227                trampoline_end - trampoline_data);
228         return virt_to_phys(trampoline_base);
229 }
230
231 #ifdef CONFIG_X86_32
232 /*
233  * We are called very early to get the low memory for the
234  * SMP bootup trampoline page.
235  */
236 void __init smp_alloc_memory(void)
237 {
238         trampoline_base = alloc_bootmem_low_pages(PAGE_SIZE);
239         /*
240          * Has to be in very low memory so we can execute
241          * real-mode AP code.
242          */
243         if (__pa(trampoline_base) >= 0x9F000)
244                 BUG();
245 }
246 #endif
247
248 void impress_friends(void)
249 {
250         int cpu;
251         unsigned long bogosum = 0;
252         /*
253          * Allow the user to impress friends.
254          */
255         Dprintk("Before bogomips.\n");
256         for_each_possible_cpu(cpu)
257                 if (cpu_isset(cpu, cpu_callout_map))
258                         bogosum += cpu_data(cpu).loops_per_jiffy;
259         printk(KERN_INFO
260                 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
261                 num_online_cpus(),
262                 bogosum/(500000/HZ),
263                 (bogosum/(5000/HZ))%100);
264
265         Dprintk("Before bogocount - setting activated=1.\n");
266 }
267
268 #ifdef CONFIG_HOTPLUG_CPU
269 void remove_siblinginfo(int cpu)
270 {
271         int sibling;
272         struct cpuinfo_x86 *c = &cpu_data(cpu);
273
274         for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) {
275                 cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
276                 /*/
277                  * last thread sibling in this cpu core going down
278                  */
279                 if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1)
280                         cpu_data(sibling).booted_cores--;
281         }
282
283         for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu))
284                 cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling));
285         cpus_clear(per_cpu(cpu_sibling_map, cpu));
286         cpus_clear(per_cpu(cpu_core_map, cpu));
287         c->phys_proc_id = 0;
288         c->cpu_core_id = 0;
289         cpu_clear(cpu, cpu_sibling_setup_map);
290 }
291
292 int additional_cpus __initdata = -1;
293
294 static __init int setup_additional_cpus(char *s)
295 {
296         return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL;
297 }
298 early_param("additional_cpus", setup_additional_cpus);
299
300 /*
301  * cpu_possible_map should be static, it cannot change as cpu's
302  * are onlined, or offlined. The reason is per-cpu data-structures
303  * are allocated by some modules at init time, and dont expect to
304  * do this dynamically on cpu arrival/departure.
305  * cpu_present_map on the other hand can change dynamically.
306  * In case when cpu_hotplug is not compiled, then we resort to current
307  * behaviour, which is cpu_possible == cpu_present.
308  * - Ashok Raj
309  *
310  * Three ways to find out the number of additional hotplug CPUs:
311  * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
312  * - The user can overwrite it with additional_cpus=NUM
313  * - Otherwise don't reserve additional CPUs.
314  * We do this because additional CPUs waste a lot of memory.
315  * -AK
316  */
317 __init void prefill_possible_map(void)
318 {
319         int i;
320         int possible;
321
322         if (additional_cpus == -1) {
323                 if (disabled_cpus > 0)
324                         additional_cpus = disabled_cpus;
325                 else
326                         additional_cpus = 0;
327         }
328         possible = num_processors + additional_cpus;
329         if (possible > NR_CPUS)
330                 possible = NR_CPUS;
331
332         printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
333                 possible, max_t(int, possible - num_processors, 0));
334
335         for (i = 0; i < possible; i++)
336                 cpu_set(i, cpu_possible_map);
337 }
338
339 static void __ref remove_cpu_from_maps(int cpu)
340 {
341         cpu_clear(cpu, cpu_online_map);
342 #ifdef CONFIG_X86_64
343         cpu_clear(cpu, cpu_callout_map);
344         cpu_clear(cpu, cpu_callin_map);
345         /* was set by cpu_init() */
346         clear_bit(cpu, (unsigned long *)&cpu_initialized);
347         clear_node_cpumask(cpu);
348 #endif
349 }
350
351 int __cpu_disable(void)
352 {
353         int cpu = smp_processor_id();
354
355         /*
356          * Perhaps use cpufreq to drop frequency, but that could go
357          * into generic code.
358          *
359          * We won't take down the boot processor on i386 due to some
360          * interrupts only being able to be serviced by the BSP.
361          * Especially so if we're not using an IOAPIC   -zwane
362          */
363         if (cpu == 0)
364                 return -EBUSY;
365
366         if (nmi_watchdog == NMI_LOCAL_APIC)
367                 stop_apic_nmi_watchdog(NULL);
368         clear_local_APIC();
369
370         /*
371          * HACK:
372          * Allow any queued timer interrupts to get serviced
373          * This is only a temporary solution until we cleanup
374          * fixup_irqs as we do for IA64.
375          */
376         local_irq_enable();
377         mdelay(1);
378
379         local_irq_disable();
380         remove_siblinginfo(cpu);
381
382         /* It's now safe to remove this processor from the online map */
383         remove_cpu_from_maps(cpu);
384         fixup_irqs(cpu_online_map);
385         return 0;
386 }
387
388 void __cpu_die(unsigned int cpu)
389 {
390         /* We don't do anything here: idle task is faking death itself. */
391         unsigned int i;
392
393         for (i = 0; i < 10; i++) {
394                 /* They ack this in play_dead by setting CPU_DEAD */
395                 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
396                         printk(KERN_INFO "CPU %d is now offline\n", cpu);
397                         if (1 == num_online_cpus())
398                                 alternatives_smp_switch(0);
399                         return;
400                 }
401                 msleep(100);
402         }
403         printk(KERN_ERR "CPU %u didn't die...\n", cpu);
404 }
405 #else /* ... !CONFIG_HOTPLUG_CPU */
406 int __cpu_disable(void)
407 {
408         return -ENOSYS;
409 }
410
411 void __cpu_die(unsigned int cpu)
412 {
413         /* We said "no" in __cpu_disable */
414         BUG();
415 }
416 #endif
417
418 /*
419  * If the BIOS enumerates physical processors before logical,
420  * maxcpus=N at enumeration-time can be used to disable HT.
421  */
422 static int __init parse_maxcpus(char *arg)
423 {
424         extern unsigned int maxcpus;
425
426         maxcpus = simple_strtoul(arg, NULL, 0);
427         return 0;
428 }
429 early_param("maxcpus", parse_maxcpus);