Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
69a80d3f | 2 | * SMP support for pSeries machines. |
1da177e4 LT |
3 | * |
4 | * Dave Engebretsen, Peter Bergner, and | |
5 | * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com | |
6 | * | |
7 | * Plus various changes from other IBM teams... | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | */ | |
14 | ||
15 | #undef DEBUG | |
16 | ||
17 | #include <linux/config.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/sched.h> | |
21 | #include <linux/smp.h> | |
22 | #include <linux/interrupt.h> | |
23 | #include <linux/delay.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/spinlock.h> | |
26 | #include <linux/cache.h> | |
27 | #include <linux/err.h> | |
28 | #include <linux/sysdev.h> | |
29 | #include <linux/cpu.h> | |
30 | ||
31 | #include <asm/ptrace.h> | |
32 | #include <asm/atomic.h> | |
33 | #include <asm/irq.h> | |
34 | #include <asm/page.h> | |
35 | #include <asm/pgtable.h> | |
36 | #include <asm/io.h> | |
37 | #include <asm/prom.h> | |
38 | #include <asm/smp.h> | |
39 | #include <asm/paca.h> | |
40 | #include <asm/time.h> | |
41 | #include <asm/machdep.h> | |
007e8f51 | 42 | #include "xics.h" |
1da177e4 | 43 | #include <asm/cputable.h> |
1ababe11 | 44 | #include <asm/firmware.h> |
1da177e4 LT |
45 | #include <asm/system.h> |
46 | #include <asm/rtas.h> | |
1da177e4 | 47 | #include <asm/pSeries_reconfig.h> |
bbeb3f4c | 48 | #include <asm/mpic.h> |
271c3f35 | 49 | #include <asm/vdso_datapage.h> |
1da177e4 | 50 | |
a1218720 ME |
51 | #include "plpar_wrappers.h" |
52 | ||
1da177e4 | 53 | #ifdef DEBUG |
f9e4ec57 | 54 | #include <asm/udbg.h> |
1da177e4 LT |
55 | #define DBG(fmt...) udbg_printf(fmt) |
56 | #else | |
57 | #define DBG(fmt...) | |
58 | #endif | |
59 | ||
60 | /* | |
61 | * The primary thread of each non-boot processor is recorded here before | |
62 | * smp init. | |
63 | */ | |
64 | static cpumask_t of_spin_map; | |
65 | ||
66 | extern void pSeries_secondary_smp_init(unsigned long); | |
67 | ||
68 | #ifdef CONFIG_HOTPLUG_CPU | |
69 | ||
70 | /* Get state of physical CPU. | |
71 | * Return codes: | |
72 | * 0 - The processor is in the RTAS stopped state | |
73 | * 1 - stop-self is in progress | |
74 | * 2 - The processor is not in the RTAS stopped state | |
75 | * -1 - Hardware Error | |
76 | * -2 - Hardware Busy, Try again later. | |
77 | */ | |
78 | static int query_cpu_stopped(unsigned int pcpu) | |
79 | { | |
80 | int cpu_status; | |
81 | int status, qcss_tok; | |
82 | ||
83 | qcss_tok = rtas_token("query-cpu-stopped-state"); | |
84 | if (qcss_tok == RTAS_UNKNOWN_SERVICE) | |
85 | return -1; | |
86 | status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); | |
87 | if (status != 0) { | |
88 | printk(KERN_ERR | |
89 | "RTAS query-cpu-stopped-state failed: %i\n", status); | |
90 | return status; | |
91 | } | |
92 | ||
93 | return cpu_status; | |
94 | } | |
95 | ||
8446196a | 96 | static int pSeries_cpu_disable(void) |
1da177e4 | 97 | { |
f3705136 ZM |
98 | int cpu = smp_processor_id(); |
99 | ||
100 | cpu_clear(cpu, cpu_online_map); | |
271c3f35 | 101 | vdso_data->processorCount--; |
1da177e4 LT |
102 | |
103 | /*fix boot_cpuid here*/ | |
f3705136 | 104 | if (cpu == boot_cpuid) |
1da177e4 LT |
105 | boot_cpuid = any_online_cpu(cpu_online_map); |
106 | ||
107 | /* FIXME: abstract this to not be platform specific later on */ | |
108 | xics_migrate_irqs_away(); | |
109 | return 0; | |
110 | } | |
111 | ||
8446196a | 112 | static void pSeries_cpu_die(unsigned int cpu) |
1da177e4 LT |
113 | { |
114 | int tries; | |
115 | int cpu_status; | |
116 | unsigned int pcpu = get_hard_smp_processor_id(cpu); | |
117 | ||
118 | for (tries = 0; tries < 25; tries++) { | |
119 | cpu_status = query_cpu_stopped(pcpu); | |
120 | if (cpu_status == 0 || cpu_status == -1) | |
121 | break; | |
122 | msleep(200); | |
123 | } | |
124 | if (cpu_status != 0) { | |
125 | printk("Querying DEAD? cpu %i (%i) shows %i\n", | |
126 | cpu, pcpu, cpu_status); | |
127 | } | |
128 | ||
129 | /* Isolation and deallocation are definatly done by | |
130 | * drslot_chrp_cpu. If they were not they would be | |
131 | * done here. Change isolate state to Isolate and | |
132 | * change allocation-state to Unusable. | |
133 | */ | |
134 | paca[cpu].cpu_start = 0; | |
135 | } | |
136 | ||
137 | /* | |
138 | * Update cpu_present_map and paca(s) for a new cpu node. The wrinkle | |
139 | * here is that a cpu device node may represent up to two logical cpus | |
140 | * in the SMT case. We must honor the assumption in other code that | |
141 | * the logical ids for sibling SMT threads x and y are adjacent, such | |
142 | * that x^1 == y and y^1 == x. | |
143 | */ | |
144 | static int pSeries_add_processor(struct device_node *np) | |
145 | { | |
146 | unsigned int cpu; | |
147 | cpumask_t candidate_map, tmp = CPU_MASK_NONE; | |
148 | int err = -ENOSPC, len, nthreads, i; | |
149 | u32 *intserv; | |
150 | ||
151 | intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s", &len); | |
152 | if (!intserv) | |
153 | return 0; | |
154 | ||
155 | nthreads = len / sizeof(u32); | |
156 | for (i = 0; i < nthreads; i++) | |
157 | cpu_set(i, tmp); | |
158 | ||
159 | lock_cpu_hotplug(); | |
160 | ||
161 | BUG_ON(!cpus_subset(cpu_present_map, cpu_possible_map)); | |
162 | ||
163 | /* Get a bitmap of unoccupied slots. */ | |
164 | cpus_xor(candidate_map, cpu_possible_map, cpu_present_map); | |
165 | if (cpus_empty(candidate_map)) { | |
166 | /* If we get here, it most likely means that NR_CPUS is | |
167 | * less than the partition's max processors setting. | |
168 | */ | |
169 | printk(KERN_ERR "Cannot add cpu %s; this system configuration" | |
170 | " supports %d logical cpus.\n", np->full_name, | |
171 | cpus_weight(cpu_possible_map)); | |
172 | goto out_unlock; | |
173 | } | |
174 | ||
175 | while (!cpus_empty(tmp)) | |
176 | if (cpus_subset(tmp, candidate_map)) | |
177 | /* Found a range where we can insert the new cpu(s) */ | |
178 | break; | |
179 | else | |
180 | cpus_shift_left(tmp, tmp, nthreads); | |
181 | ||
182 | if (cpus_empty(tmp)) { | |
183 | printk(KERN_ERR "Unable to find space in cpu_present_map for" | |
184 | " processor %s with %d thread(s)\n", np->name, | |
185 | nthreads); | |
186 | goto out_unlock; | |
187 | } | |
188 | ||
189 | for_each_cpu_mask(cpu, tmp) { | |
190 | BUG_ON(cpu_isset(cpu, cpu_present_map)); | |
191 | cpu_set(cpu, cpu_present_map); | |
192 | set_hard_smp_processor_id(cpu, *intserv++); | |
193 | } | |
194 | err = 0; | |
195 | out_unlock: | |
196 | unlock_cpu_hotplug(); | |
197 | return err; | |
198 | } | |
199 | ||
200 | /* | |
201 | * Update the present map for a cpu node which is going away, and set | |
202 | * the hard id in the paca(s) to -1 to be consistent with boot time | |
203 | * convention for non-present cpus. | |
204 | */ | |
205 | static void pSeries_remove_processor(struct device_node *np) | |
206 | { | |
207 | unsigned int cpu; | |
208 | int len, nthreads, i; | |
209 | u32 *intserv; | |
210 | ||
211 | intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s", &len); | |
212 | if (!intserv) | |
213 | return; | |
214 | ||
215 | nthreads = len / sizeof(u32); | |
216 | ||
217 | lock_cpu_hotplug(); | |
218 | for (i = 0; i < nthreads; i++) { | |
219 | for_each_present_cpu(cpu) { | |
220 | if (get_hard_smp_processor_id(cpu) != intserv[i]) | |
221 | continue; | |
222 | BUG_ON(cpu_online(cpu)); | |
223 | cpu_clear(cpu, cpu_present_map); | |
224 | set_hard_smp_processor_id(cpu, -1); | |
225 | break; | |
226 | } | |
227 | if (cpu == NR_CPUS) | |
228 | printk(KERN_WARNING "Could not find cpu to remove " | |
229 | "with physical id 0x%x\n", intserv[i]); | |
230 | } | |
231 | unlock_cpu_hotplug(); | |
232 | } | |
233 | ||
234 | static int pSeries_smp_notifier(struct notifier_block *nb, unsigned long action, void *node) | |
235 | { | |
236 | int err = NOTIFY_OK; | |
237 | ||
238 | switch (action) { | |
239 | case PSERIES_RECONFIG_ADD: | |
240 | if (pSeries_add_processor(node)) | |
241 | err = NOTIFY_BAD; | |
242 | break; | |
243 | case PSERIES_RECONFIG_REMOVE: | |
244 | pSeries_remove_processor(node); | |
245 | break; | |
246 | default: | |
247 | err = NOTIFY_DONE; | |
248 | break; | |
249 | } | |
250 | return err; | |
251 | } | |
252 | ||
253 | static struct notifier_block pSeries_smp_nb = { | |
254 | .notifier_call = pSeries_smp_notifier, | |
255 | }; | |
256 | ||
257 | #endif /* CONFIG_HOTPLUG_CPU */ | |
258 | ||
259 | /** | |
260 | * smp_startup_cpu() - start the given cpu | |
261 | * | |
262 | * At boot time, there is nothing to do for primary threads which were | |
263 | * started from Open Firmware. For anything else, call RTAS with the | |
264 | * appropriate start location. | |
265 | * | |
266 | * Returns: | |
267 | * 0 - failure | |
268 | * 1 - success | |
269 | */ | |
270 | static inline int __devinit smp_startup_cpu(unsigned int lcpu) | |
271 | { | |
272 | int status; | |
273 | unsigned long start_here = __pa((u32)*((unsigned long *) | |
274 | pSeries_secondary_smp_init)); | |
275 | unsigned int pcpu; | |
1ed2fd2d | 276 | int start_cpu; |
1da177e4 LT |
277 | |
278 | if (cpu_isset(lcpu, of_spin_map)) | |
279 | /* Already started by OF and sitting in spin loop */ | |
280 | return 1; | |
281 | ||
282 | pcpu = get_hard_smp_processor_id(lcpu); | |
283 | ||
284 | /* Fixup atomic count: it exited inside IRQ handler. */ | |
b5e2fc1c | 285 | task_thread_info(paca[lcpu].__current)->preempt_count = 0; |
1da177e4 | 286 | |
1ed2fd2d AB |
287 | /* |
288 | * If the RTAS start-cpu token does not exist then presume the | |
289 | * cpu is already spinning. | |
290 | */ | |
291 | start_cpu = rtas_token("start-cpu"); | |
292 | if (start_cpu == RTAS_UNKNOWN_SERVICE) | |
293 | return 1; | |
294 | ||
496b7a51 | 295 | status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu); |
1da177e4 LT |
296 | if (status != 0) { |
297 | printk(KERN_ERR "start-cpu failed: %i\n", status); | |
298 | return 0; | |
299 | } | |
1ed2fd2d | 300 | |
1da177e4 LT |
301 | return 1; |
302 | } | |
303 | ||
cebf589c | 304 | #ifdef CONFIG_XICS |
1da177e4 LT |
305 | static inline void smp_xics_do_message(int cpu, int msg) |
306 | { | |
307 | set_bit(msg, &xics_ipi_message[cpu].value); | |
308 | mb(); | |
309 | xics_cause_IPI(cpu); | |
310 | } | |
311 | ||
312 | static void smp_xics_message_pass(int target, int msg) | |
313 | { | |
314 | unsigned int i; | |
315 | ||
316 | if (target < NR_CPUS) { | |
317 | smp_xics_do_message(target, msg); | |
318 | } else { | |
319 | for_each_online_cpu(i) { | |
320 | if (target == MSG_ALL_BUT_SELF | |
321 | && i == smp_processor_id()) | |
322 | continue; | |
323 | smp_xics_do_message(i, msg); | |
324 | } | |
325 | } | |
326 | } | |
327 | ||
328 | static int __init smp_xics_probe(void) | |
329 | { | |
330 | xics_request_IPIs(); | |
331 | ||
332 | return cpus_weight(cpu_possible_map); | |
333 | } | |
334 | ||
335 | static void __devinit smp_xics_setup_cpu(int cpu) | |
336 | { | |
337 | if (cpu != boot_cpuid) | |
338 | xics_setup_cpu(); | |
339 | ||
1ababe11 | 340 | if (firmware_has_feature(FW_FEATURE_SPLPAR)) |
1da177e4 LT |
341 | vpa_init(cpu); |
342 | ||
343 | cpu_clear(cpu, of_spin_map); | |
344 | ||
1da177e4 | 345 | } |
cebf589c | 346 | #endif /* CONFIG_XICS */ |
1da177e4 LT |
347 | |
348 | static DEFINE_SPINLOCK(timebase_lock); | |
349 | static unsigned long timebase = 0; | |
350 | ||
351 | static void __devinit pSeries_give_timebase(void) | |
352 | { | |
353 | spin_lock(&timebase_lock); | |
354 | rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); | |
355 | timebase = get_tb(); | |
356 | spin_unlock(&timebase_lock); | |
357 | ||
358 | while (timebase) | |
359 | barrier(); | |
360 | rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); | |
361 | } | |
362 | ||
363 | static void __devinit pSeries_take_timebase(void) | |
364 | { | |
365 | while (!timebase) | |
366 | barrier(); | |
367 | spin_lock(&timebase_lock); | |
368 | set_tb(timebase >> 32, timebase & 0xffffffff); | |
369 | timebase = 0; | |
370 | spin_unlock(&timebase_lock); | |
371 | } | |
372 | ||
373 | static void __devinit smp_pSeries_kick_cpu(int nr) | |
374 | { | |
375 | BUG_ON(nr < 0 || nr >= NR_CPUS); | |
376 | ||
377 | if (!smp_startup_cpu(nr)) | |
378 | return; | |
379 | ||
380 | /* | |
381 | * The processor is currently spinning, waiting for the | |
382 | * cpu_start field to become non-zero After we set cpu_start, | |
383 | * the processor will continue on to secondary_start | |
384 | */ | |
385 | paca[nr].cpu_start = 1; | |
386 | } | |
387 | ||
388 | static int smp_pSeries_cpu_bootable(unsigned int nr) | |
389 | { | |
390 | /* Special case - we inhibit secondary thread startup | |
391 | * during boot if the user requests it. Odd-numbered | |
392 | * cpus are assumed to be secondary threads. | |
393 | */ | |
394 | if (system_state < SYSTEM_RUNNING && | |
0231c290 | 395 | cpu_has_feature(CPU_FTR_SMT) && |
1da177e4 LT |
396 | !smt_enabled_at_boot && nr % 2 != 0) |
397 | return 0; | |
398 | ||
399 | return 1; | |
400 | } | |
cebf589c | 401 | #ifdef CONFIG_MPIC |
1da177e4 LT |
402 | static struct smp_ops_t pSeries_mpic_smp_ops = { |
403 | .message_pass = smp_mpic_message_pass, | |
404 | .probe = smp_mpic_probe, | |
405 | .kick_cpu = smp_pSeries_kick_cpu, | |
406 | .setup_cpu = smp_mpic_setup_cpu, | |
407 | }; | |
cebf589c AB |
408 | #endif |
409 | #ifdef CONFIG_XICS | |
1da177e4 LT |
410 | static struct smp_ops_t pSeries_xics_smp_ops = { |
411 | .message_pass = smp_xics_message_pass, | |
412 | .probe = smp_xics_probe, | |
413 | .kick_cpu = smp_pSeries_kick_cpu, | |
414 | .setup_cpu = smp_xics_setup_cpu, | |
415 | .cpu_bootable = smp_pSeries_cpu_bootable, | |
416 | }; | |
cebf589c | 417 | #endif |
1da177e4 LT |
418 | |
419 | /* This is called very early */ | |
420 | void __init smp_init_pSeries(void) | |
421 | { | |
422 | int i; | |
423 | ||
424 | DBG(" -> smp_init_pSeries()\n"); | |
425 | ||
cebf589c AB |
426 | switch (ppc64_interrupt_controller) { |
427 | #ifdef CONFIG_MPIC | |
428 | case IC_OPEN_PIC: | |
1da177e4 | 429 | smp_ops = &pSeries_mpic_smp_ops; |
cebf589c AB |
430 | break; |
431 | #endif | |
432 | #ifdef CONFIG_XICS | |
433 | case IC_PPC_XIC: | |
1da177e4 | 434 | smp_ops = &pSeries_xics_smp_ops; |
cebf589c | 435 | break; |
cebf589c AB |
436 | #endif |
437 | default: | |
438 | panic("Invalid interrupt controller"); | |
439 | } | |
1da177e4 LT |
440 | |
441 | #ifdef CONFIG_HOTPLUG_CPU | |
442 | smp_ops->cpu_disable = pSeries_cpu_disable; | |
443 | smp_ops->cpu_die = pSeries_cpu_die; | |
444 | ||
445 | /* Processors can be added/removed only on LPAR */ | |
57cfb814 | 446 | if (firmware_has_feature(FW_FEATURE_LPAR)) |
1da177e4 LT |
447 | pSeries_reconfig_notifier_register(&pSeries_smp_nb); |
448 | #endif | |
449 | ||
450 | /* Mark threads which are still spinning in hold loops. */ | |
0231c290 AB |
451 | if (cpu_has_feature(CPU_FTR_SMT)) { |
452 | for_each_present_cpu(i) { | |
1da177e4 LT |
453 | if (i % 2 == 0) |
454 | /* | |
455 | * Even-numbered logical cpus correspond to | |
456 | * primary threads. | |
457 | */ | |
458 | cpu_set(i, of_spin_map); | |
459 | } | |
0231c290 | 460 | } else { |
1da177e4 | 461 | of_spin_map = cpu_present_map; |
0231c290 | 462 | } |
1da177e4 LT |
463 | |
464 | cpu_clear(boot_cpuid, of_spin_map); | |
465 | ||
466 | /* Non-lpar has additional take/give timebase */ | |
467 | if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { | |
468 | smp_ops->give_timebase = pSeries_give_timebase; | |
469 | smp_ops->take_timebase = pSeries_take_timebase; | |
470 | } | |
471 | ||
472 | DBG(" <- smp_init_pSeries()\n"); | |
473 | } | |
474 |