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1 | /* |
2 | * Copyright 2011 IBM Corporation. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | */ | |
10 | #include <linux/types.h> | |
11 | #include <linux/threads.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/irq.h> | |
14 | #include <linux/debugfs.h> | |
15 | #include <linux/smp.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/seq_file.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/cpu.h> | |
20 | #include <linux/of.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/spinlock.h> | |
23 | ||
24 | #include <asm/prom.h> | |
25 | #include <asm/io.h> | |
26 | #include <asm/smp.h> | |
27 | #include <asm/machdep.h> | |
28 | #include <asm/irq.h> | |
29 | #include <asm/errno.h> | |
30 | #include <asm/rtas.h> | |
31 | #include <asm/xics.h> | |
32 | #include <asm/firmware.h> | |
33 | ||
34 | /* Globals common to all ICP/ICS implementations */ | |
35 | const struct icp_ops *icp_ops; | |
36 | ||
37 | unsigned int xics_default_server = 0xff; | |
38 | unsigned int xics_default_distrib_server = 0; | |
39 | unsigned int xics_interrupt_server_size = 8; | |
40 | ||
41 | DEFINE_PER_CPU(struct xics_cppr, xics_cppr); | |
42 | ||
43 | struct irq_host *xics_host; | |
44 | ||
45 | static LIST_HEAD(ics_list); | |
46 | ||
47 | void xics_update_irq_servers(void) | |
48 | { | |
49 | int i, j; | |
50 | struct device_node *np; | |
51 | u32 ilen; | |
52 | const u32 *ireg; | |
53 | u32 hcpuid; | |
54 | ||
55 | /* Find the server numbers for the boot cpu. */ | |
56 | np = of_get_cpu_node(boot_cpuid, NULL); | |
57 | BUG_ON(!np); | |
58 | ||
59 | hcpuid = get_hard_smp_processor_id(boot_cpuid); | |
f6e17f9b BH |
60 | xics_default_server = xics_default_distrib_server = hcpuid; |
61 | ||
62 | pr_devel("xics: xics_default_server = 0x%x\n", xics_default_server); | |
0b05ac6e BH |
63 | |
64 | ireg = of_get_property(np, "ibm,ppc-interrupt-gserver#s", &ilen); | |
65 | if (!ireg) { | |
66 | of_node_put(np); | |
67 | return; | |
68 | } | |
69 | ||
70 | i = ilen / sizeof(int); | |
71 | ||
72 | /* Global interrupt distribution server is specified in the last | |
73 | * entry of "ibm,ppc-interrupt-gserver#s" property. Get the last | |
74 | * entry fom this property for current boot cpu id and use it as | |
75 | * default distribution server | |
76 | */ | |
77 | for (j = 0; j < i; j += 2) { | |
78 | if (ireg[j] == hcpuid) { | |
79 | xics_default_distrib_server = ireg[j+1]; | |
f6e17f9b | 80 | break; |
0b05ac6e BH |
81 | } |
82 | } | |
f6e17f9b BH |
83 | pr_devel("xics: xics_default_distrib_server = 0x%x\n", |
84 | xics_default_distrib_server); | |
0b05ac6e BH |
85 | of_node_put(np); |
86 | } | |
87 | ||
88 | /* GIQ stuff, currently only supported on RTAS setups, will have | |
89 | * to be sorted properly for bare metal | |
90 | */ | |
91 | void xics_set_cpu_giq(unsigned int gserver, unsigned int join) | |
92 | { | |
93 | #ifdef CONFIG_PPC_RTAS | |
94 | int index; | |
95 | int status; | |
96 | ||
97 | if (!rtas_indicator_present(GLOBAL_INTERRUPT_QUEUE, NULL)) | |
98 | return; | |
99 | ||
100 | index = (1UL << xics_interrupt_server_size) - 1 - gserver; | |
101 | ||
102 | status = rtas_set_indicator_fast(GLOBAL_INTERRUPT_QUEUE, index, join); | |
103 | ||
104 | WARN(status < 0, "set-indicator(%d, %d, %u) returned %d\n", | |
105 | GLOBAL_INTERRUPT_QUEUE, index, join, status); | |
106 | #endif | |
107 | } | |
108 | ||
109 | void xics_setup_cpu(void) | |
110 | { | |
111 | icp_ops->set_priority(LOWEST_PRIORITY); | |
112 | ||
113 | xics_set_cpu_giq(xics_default_distrib_server, 1); | |
114 | } | |
115 | ||
116 | void xics_mask_unknown_vec(unsigned int vec) | |
117 | { | |
118 | struct ics *ics; | |
119 | ||
f6e17f9b | 120 | pr_err("Interrupt 0x%x (real) is invalid, disabling it.\n", vec); |
0b05ac6e BH |
121 | |
122 | list_for_each_entry(ics, &ics_list, link) | |
123 | ics->mask_unknown(ics, vec); | |
124 | } | |
125 | ||
126 | ||
127 | #ifdef CONFIG_SMP | |
128 | ||
129 | DEFINE_PER_CPU_SHARED_ALIGNED(unsigned long, xics_ipi_message); | |
130 | ||
131 | irqreturn_t xics_ipi_dispatch(int cpu) | |
132 | { | |
133 | unsigned long *tgt = &per_cpu(xics_ipi_message, cpu); | |
134 | ||
135 | mb(); /* order mmio clearing qirr */ | |
136 | while (*tgt) { | |
137 | if (test_and_clear_bit(PPC_MSG_CALL_FUNCTION, tgt)) { | |
138 | smp_message_recv(PPC_MSG_CALL_FUNCTION); | |
139 | } | |
140 | if (test_and_clear_bit(PPC_MSG_RESCHEDULE, tgt)) { | |
141 | smp_message_recv(PPC_MSG_RESCHEDULE); | |
142 | } | |
143 | if (test_and_clear_bit(PPC_MSG_CALL_FUNC_SINGLE, tgt)) { | |
144 | smp_message_recv(PPC_MSG_CALL_FUNC_SINGLE); | |
145 | } | |
146 | #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC) | |
147 | if (test_and_clear_bit(PPC_MSG_DEBUGGER_BREAK, tgt)) { | |
148 | smp_message_recv(PPC_MSG_DEBUGGER_BREAK); | |
149 | } | |
150 | #endif | |
151 | } | |
152 | return IRQ_HANDLED; | |
153 | } | |
154 | ||
155 | static void xics_request_ipi(void) | |
156 | { | |
157 | unsigned int ipi; | |
158 | ||
159 | ipi = irq_create_mapping(xics_host, XICS_IPI); | |
160 | BUG_ON(ipi == NO_IRQ); | |
161 | ||
162 | /* | |
163 | * IPIs are marked IRQF_DISABLED as they must run with irqs | |
164 | * disabled | |
165 | */ | |
166 | irq_set_handler(ipi, handle_percpu_irq); | |
167 | BUG_ON(request_irq(ipi, icp_ops->ipi_action, | |
168 | IRQF_DISABLED|IRQF_PERCPU, "IPI", NULL)); | |
169 | } | |
170 | ||
171 | int __init xics_smp_probe(void) | |
172 | { | |
173 | /* Setup message_pass callback based on which ICP is used */ | |
174 | smp_ops->message_pass = icp_ops->message_pass; | |
175 | ||
176 | /* Register all the IPIs */ | |
177 | xics_request_ipi(); | |
178 | ||
179 | return cpumask_weight(cpu_possible_mask); | |
180 | } | |
181 | ||
182 | #endif /* CONFIG_SMP */ | |
183 | ||
184 | void xics_teardown_cpu(void) | |
185 | { | |
186 | struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr); | |
187 | ||
188 | /* | |
189 | * we have to reset the cppr index to 0 because we're | |
190 | * not going to return from the IPI | |
191 | */ | |
192 | os_cppr->index = 0; | |
193 | icp_ops->set_priority(0); | |
194 | icp_ops->teardown_cpu(); | |
195 | } | |
196 | ||
197 | void xics_kexec_teardown_cpu(int secondary) | |
198 | { | |
199 | xics_teardown_cpu(); | |
200 | ||
201 | icp_ops->flush_ipi(); | |
202 | ||
203 | /* | |
204 | * Some machines need to have at least one cpu in the GIQ, | |
205 | * so leave the master cpu in the group. | |
206 | */ | |
207 | if (secondary) | |
208 | xics_set_cpu_giq(xics_default_distrib_server, 0); | |
209 | } | |
210 | ||
211 | ||
212 | #ifdef CONFIG_HOTPLUG_CPU | |
213 | ||
214 | /* Interrupts are disabled. */ | |
215 | void xics_migrate_irqs_away(void) | |
216 | { | |
217 | int cpu = smp_processor_id(), hw_cpu = hard_smp_processor_id(); | |
218 | unsigned int irq, virq; | |
219 | ||
220 | /* If we used to be the default server, move to the new "boot_cpuid" */ | |
221 | if (hw_cpu == xics_default_server) | |
222 | xics_update_irq_servers(); | |
223 | ||
224 | /* Reject any interrupt that was queued to us... */ | |
225 | icp_ops->set_priority(0); | |
226 | ||
227 | /* Remove ourselves from the global interrupt queue */ | |
228 | xics_set_cpu_giq(xics_default_distrib_server, 0); | |
229 | ||
230 | /* Allow IPIs again... */ | |
231 | icp_ops->set_priority(DEFAULT_PRIORITY); | |
232 | ||
233 | for_each_irq(virq) { | |
234 | struct irq_desc *desc; | |
235 | struct irq_chip *chip; | |
236 | long server; | |
237 | unsigned long flags; | |
238 | struct ics *ics; | |
239 | ||
240 | /* We can't set affinity on ISA interrupts */ | |
241 | if (virq < NUM_ISA_INTERRUPTS) | |
242 | continue; | |
476eb491 | 243 | if (virq_to_host(virq) != xics_host) |
0b05ac6e | 244 | continue; |
476eb491 | 245 | irq = (unsigned int)virq_to_hw(virq); |
0b05ac6e BH |
246 | /* We need to get IPIs still. */ |
247 | if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS) | |
248 | continue; | |
249 | desc = irq_to_desc(virq); | |
250 | /* We only need to migrate enabled IRQS */ | |
251 | if (!desc || !desc->action) | |
252 | continue; | |
253 | chip = irq_desc_get_chip(desc); | |
254 | if (!chip || !chip->irq_set_affinity) | |
255 | continue; | |
256 | ||
257 | raw_spin_lock_irqsave(&desc->lock, flags); | |
258 | ||
259 | /* Locate interrupt server */ | |
260 | server = -1; | |
261 | ics = irq_get_chip_data(virq); | |
262 | if (ics) | |
263 | server = ics->get_server(ics, irq); | |
264 | if (server < 0) { | |
265 | printk(KERN_ERR "%s: Can't find server for irq %d\n", | |
266 | __func__, irq); | |
267 | goto unlock; | |
268 | } | |
269 | ||
270 | /* We only support delivery to all cpus or to one cpu. | |
271 | * The irq has to be migrated only in the single cpu | |
272 | * case. | |
273 | */ | |
274 | if (server != hw_cpu) | |
275 | goto unlock; | |
276 | ||
277 | /* This is expected during cpu offline. */ | |
278 | if (cpu_online(cpu)) | |
279 | pr_warning("IRQ %u affinity broken off cpu %u\n", | |
280 | virq, cpu); | |
281 | ||
282 | /* Reset affinity to all cpus */ | |
283 | raw_spin_unlock_irqrestore(&desc->lock, flags); | |
284 | irq_set_affinity(virq, cpu_all_mask); | |
285 | continue; | |
286 | unlock: | |
287 | raw_spin_unlock_irqrestore(&desc->lock, flags); | |
288 | } | |
289 | } | |
290 | #endif /* CONFIG_HOTPLUG_CPU */ | |
291 | ||
292 | #ifdef CONFIG_SMP | |
293 | /* | |
294 | * For the moment we only implement delivery to all cpus or one cpu. | |
295 | * | |
296 | * If the requested affinity is cpu_all_mask, we set global affinity. | |
297 | * If not we set it to the first cpu in the mask, even if multiple cpus | |
298 | * are set. This is so things like irqbalance (which set core and package | |
299 | * wide affinities) do the right thing. | |
f6e17f9b BH |
300 | * |
301 | * We need to fix this to implement support for the links | |
0b05ac6e BH |
302 | */ |
303 | int xics_get_irq_server(unsigned int virq, const struct cpumask *cpumask, | |
304 | unsigned int strict_check) | |
305 | { | |
306 | ||
307 | if (!distribute_irqs) | |
308 | return xics_default_server; | |
309 | ||
310 | if (!cpumask_subset(cpu_possible_mask, cpumask)) { | |
311 | int server = cpumask_first_and(cpu_online_mask, cpumask); | |
312 | ||
313 | if (server < nr_cpu_ids) | |
314 | return get_hard_smp_processor_id(server); | |
315 | ||
316 | if (strict_check) | |
317 | return -1; | |
318 | } | |
319 | ||
320 | /* | |
321 | * Workaround issue with some versions of JS20 firmware that | |
322 | * deliver interrupts to cpus which haven't been started. This | |
323 | * happens when using the maxcpus= boot option. | |
324 | */ | |
325 | if (cpumask_equal(cpu_online_mask, cpu_present_mask)) | |
326 | return xics_default_distrib_server; | |
327 | ||
328 | return xics_default_server; | |
329 | } | |
330 | #endif /* CONFIG_SMP */ | |
331 | ||
332 | static int xics_host_match(struct irq_host *h, struct device_node *node) | |
333 | { | |
5ca12376 ME |
334 | struct ics *ics; |
335 | ||
336 | list_for_each_entry(ics, &ics_list, link) | |
337 | if (ics->host_match(ics, node)) | |
338 | return 1; | |
339 | ||
340 | return 0; | |
0b05ac6e BH |
341 | } |
342 | ||
343 | /* Dummies */ | |
344 | static void xics_ipi_unmask(struct irq_data *d) { } | |
345 | static void xics_ipi_mask(struct irq_data *d) { } | |
346 | ||
347 | static struct irq_chip xics_ipi_chip = { | |
348 | .name = "XICS", | |
349 | .irq_eoi = NULL, /* Patched at init time */ | |
350 | .irq_mask = xics_ipi_mask, | |
351 | .irq_unmask = xics_ipi_unmask, | |
352 | }; | |
353 | ||
354 | static int xics_host_map(struct irq_host *h, unsigned int virq, | |
355 | irq_hw_number_t hw) | |
356 | { | |
357 | struct ics *ics; | |
358 | ||
359 | pr_devel("xics: map virq %d, hwirq 0x%lx\n", virq, hw); | |
360 | ||
361 | /* Insert the interrupt mapping into the radix tree for fast lookup */ | |
362 | irq_radix_revmap_insert(xics_host, virq, hw); | |
363 | ||
364 | /* They aren't all level sensitive but we just don't really know */ | |
365 | irq_set_status_flags(virq, IRQ_LEVEL); | |
366 | ||
367 | /* Don't call into ICS for IPIs */ | |
368 | if (hw == XICS_IPI) { | |
369 | irq_set_chip_and_handler(virq, &xics_ipi_chip, | |
370 | handle_fasteoi_irq); | |
371 | return 0; | |
372 | } | |
373 | ||
374 | /* Let the ICS setup the chip data */ | |
375 | list_for_each_entry(ics, &ics_list, link) | |
376 | if (ics->map(ics, virq) == 0) | |
377 | break; | |
378 | return 0; | |
379 | } | |
380 | ||
381 | static int xics_host_xlate(struct irq_host *h, struct device_node *ct, | |
382 | const u32 *intspec, unsigned int intsize, | |
383 | irq_hw_number_t *out_hwirq, unsigned int *out_flags) | |
384 | ||
385 | { | |
386 | /* Current xics implementation translates everything | |
387 | * to level. It is not technically right for MSIs but this | |
388 | * is irrelevant at this point. We might get smarter in the future | |
389 | */ | |
390 | *out_hwirq = intspec[0]; | |
391 | *out_flags = IRQ_TYPE_LEVEL_LOW; | |
392 | ||
393 | return 0; | |
394 | } | |
395 | ||
396 | static struct irq_host_ops xics_host_ops = { | |
397 | .match = xics_host_match, | |
398 | .map = xics_host_map, | |
399 | .xlate = xics_host_xlate, | |
400 | }; | |
401 | ||
402 | static void __init xics_init_host(void) | |
403 | { | |
404 | xics_host = irq_alloc_host(NULL, IRQ_HOST_MAP_TREE, 0, &xics_host_ops, | |
405 | XICS_IRQ_SPURIOUS); | |
406 | BUG_ON(xics_host == NULL); | |
407 | irq_set_default_host(xics_host); | |
408 | } | |
409 | ||
410 | void __init xics_register_ics(struct ics *ics) | |
411 | { | |
412 | list_add(&ics->link, &ics_list); | |
413 | } | |
414 | ||
415 | static void __init xics_get_server_size(void) | |
416 | { | |
417 | struct device_node *np; | |
418 | const u32 *isize; | |
419 | ||
420 | /* We fetch the interrupt server size from the first ICS node | |
421 | * we find if any | |
422 | */ | |
423 | np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xics"); | |
424 | if (!np) | |
425 | return; | |
426 | isize = of_get_property(np, "ibm,interrupt-server#-size", NULL); | |
427 | if (!isize) | |
428 | return; | |
429 | xics_interrupt_server_size = *isize; | |
430 | of_node_put(np); | |
431 | } | |
432 | ||
433 | void __init xics_init(void) | |
434 | { | |
435 | int rc = -1; | |
436 | ||
437 | /* Fist locate ICP */ | |
438 | #ifdef CONFIG_PPC_ICP_HV | |
439 | if (firmware_has_feature(FW_FEATURE_LPAR)) | |
440 | rc = icp_hv_init(); | |
441 | #endif | |
442 | #ifdef CONFIG_PPC_ICP_NATIVE | |
443 | if (rc < 0) | |
444 | rc = icp_native_init(); | |
445 | #endif | |
446 | if (rc < 0) { | |
447 | pr_warning("XICS: Cannot find a Presentation Controller !\n"); | |
448 | return; | |
449 | } | |
450 | ||
451 | /* Copy get_irq callback over to ppc_md */ | |
452 | ppc_md.get_irq = icp_ops->get_irq; | |
453 | ||
454 | /* Patch up IPI chip EOI */ | |
455 | xics_ipi_chip.irq_eoi = icp_ops->eoi; | |
456 | ||
457 | /* Now locate ICS */ | |
458 | #ifdef CONFIG_PPC_ICS_RTAS | |
459 | rc = ics_rtas_init(); | |
460 | #endif | |
461 | if (rc < 0) | |
462 | pr_warning("XICS: Cannot find a Source Controller !\n"); | |
463 | ||
464 | /* Initialize common bits */ | |
465 | xics_get_server_size(); | |
466 | xics_update_irq_servers(); | |
467 | xics_init_host(); | |
468 | xics_setup_cpu(); | |
469 | } |