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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright 2011 IBM Corporation.
4 */
5#include <linux/types.h>
6#include <linux/threads.h>
7#include <linux/kernel.h>
8#include <linux/irq.h>
9#include <linux/irqdomain.h>
10#include <linux/debugfs.h>
11#include <linux/smp.h>
12#include <linux/interrupt.h>
13#include <linux/seq_file.h>
14#include <linux/init.h>
15#include <linux/cpu.h>
16#include <linux/of.h>
17#include <linux/slab.h>
18#include <linux/spinlock.h>
19#include <linux/delay.h>
20
21#include <asm/io.h>
22#include <asm/smp.h>
23#include <asm/machdep.h>
24#include <asm/irq.h>
25#include <asm/errno.h>
26#include <asm/rtas.h>
27#include <asm/xics.h>
28#include <asm/firmware.h>
29
30/* Globals common to all ICP/ICS implementations */
31const struct icp_ops *icp_ops;
32
33unsigned int xics_default_server = 0xff;
34unsigned int xics_default_distrib_server = 0;
35unsigned int xics_interrupt_server_size = 8;
36
37DEFINE_PER_CPU(struct xics_cppr, xics_cppr);
38
39struct irq_domain *xics_host;
40
41static struct ics *xics_ics;
42
43void xics_update_irq_servers(void)
44{
45 int i, j;
46 struct device_node *np;
47 u32 ilen;
48 const __be32 *ireg;
49 u32 hcpuid;
50
51 /* Find the server numbers for the boot cpu. */
52 np = of_get_cpu_node(boot_cpuid, NULL);
53 BUG_ON(!np);
54
55 hcpuid = get_hard_smp_processor_id(boot_cpuid);
56 xics_default_server = xics_default_distrib_server = hcpuid;
57
58 pr_devel("xics: xics_default_server = 0x%x\n", xics_default_server);
59
60 ireg = of_get_property(np, "ibm,ppc-interrupt-gserver#s", &ilen);
61 if (!ireg) {
62 of_node_put(np);
63 return;
64 }
65
66 i = ilen / sizeof(int);
67
68 /* Global interrupt distribution server is specified in the last
69 * entry of "ibm,ppc-interrupt-gserver#s" property. Get the last
70 * entry fom this property for current boot cpu id and use it as
71 * default distribution server
72 */
73 for (j = 0; j < i; j += 2) {
74 if (be32_to_cpu(ireg[j]) == hcpuid) {
75 xics_default_distrib_server = be32_to_cpu(ireg[j+1]);
76 break;
77 }
78 }
79 pr_devel("xics: xics_default_distrib_server = 0x%x\n",
80 xics_default_distrib_server);
81 of_node_put(np);
82}
83
84/* GIQ stuff, currently only supported on RTAS setups, will have
85 * to be sorted properly for bare metal
86 */
87void xics_set_cpu_giq(unsigned int gserver, unsigned int join)
88{
89#ifdef CONFIG_PPC_RTAS
90 int index;
91 int status;
92
93 if (!rtas_indicator_present(GLOBAL_INTERRUPT_QUEUE, NULL))
94 return;
95
96 index = (1UL << xics_interrupt_server_size) - 1 - gserver;
97
98 status = rtas_set_indicator_fast(GLOBAL_INTERRUPT_QUEUE, index, join);
99
100 WARN(status < 0, "set-indicator(%d, %d, %u) returned %d\n",
101 GLOBAL_INTERRUPT_QUEUE, index, join, status);
102#endif
103}
104
105void xics_setup_cpu(void)
106{
107 icp_ops->set_priority(LOWEST_PRIORITY);
108
109 xics_set_cpu_giq(xics_default_distrib_server, 1);
110}
111
112void xics_mask_unknown_vec(unsigned int vec)
113{
114 pr_err("Interrupt 0x%x (real) is invalid, disabling it.\n", vec);
115
116 if (WARN_ON(!xics_ics))
117 return;
118 xics_ics->mask_unknown(xics_ics, vec);
119}
120
121
122#ifdef CONFIG_SMP
123
124static void __init xics_request_ipi(void)
125{
126 unsigned int ipi;
127
128 ipi = irq_create_mapping(xics_host, XICS_IPI);
129 BUG_ON(!ipi);
130
131 /*
132 * IPIs are marked IRQF_PERCPU. The handler was set in map.
133 */
134 BUG_ON(request_irq(ipi, icp_ops->ipi_action,
135 IRQF_NO_DEBUG | IRQF_PERCPU | IRQF_NO_THREAD, "IPI", NULL));
136}
137
138void __init xics_smp_probe(void)
139{
140 /* Register all the IPIs */
141 xics_request_ipi();
142
143 /* Setup cause_ipi callback based on which ICP is used */
144 smp_ops->cause_ipi = icp_ops->cause_ipi;
145}
146
147#endif /* CONFIG_SMP */
148
149noinstr void xics_teardown_cpu(void)
150{
151 struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
152
153 /*
154 * we have to reset the cppr index to 0 because we're
155 * not going to return from the IPI
156 */
157 os_cppr->index = 0;
158 icp_ops->set_priority(0);
159 icp_ops->teardown_cpu();
160}
161
162noinstr void xics_kexec_teardown_cpu(int secondary)
163{
164 xics_teardown_cpu();
165
166 icp_ops->flush_ipi();
167
168 /*
169 * Some machines need to have at least one cpu in the GIQ,
170 * so leave the master cpu in the group.
171 */
172 if (secondary)
173 xics_set_cpu_giq(xics_default_distrib_server, 0);
174}
175
176
177#ifdef CONFIG_HOTPLUG_CPU
178
179/* Interrupts are disabled. */
180void xics_migrate_irqs_away(void)
181{
182 int cpu = smp_processor_id(), hw_cpu = hard_smp_processor_id();
183 unsigned int irq, virq;
184 struct irq_desc *desc;
185
186 pr_debug("%s: CPU %u\n", __func__, cpu);
187
188 /* If we used to be the default server, move to the new "boot_cpuid" */
189 if (hw_cpu == xics_default_server)
190 xics_update_irq_servers();
191
192 /* Reject any interrupt that was queued to us... */
193 icp_ops->set_priority(0);
194
195 /* Remove ourselves from the global interrupt queue */
196 xics_set_cpu_giq(xics_default_distrib_server, 0);
197
198 for_each_irq_desc(virq, desc) {
199 struct irq_chip *chip;
200 long server;
201 unsigned long flags;
202 struct irq_data *irqd;
203
204 /* We can't set affinity on ISA interrupts */
205 if (virq < NR_IRQS_LEGACY)
206 continue;
207 /* We only need to migrate enabled IRQS */
208 if (!desc->action)
209 continue;
210 /* We need a mapping in the XICS IRQ domain */
211 irqd = irq_domain_get_irq_data(xics_host, virq);
212 if (!irqd)
213 continue;
214 irq = irqd_to_hwirq(irqd);
215 /* We need to get IPIs still. */
216 if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
217 continue;
218 chip = irq_desc_get_chip(desc);
219 if (!chip || !chip->irq_set_affinity)
220 continue;
221
222 raw_spin_lock_irqsave(&desc->lock, flags);
223
224 /* Locate interrupt server */
225 server = xics_ics->get_server(xics_ics, irq);
226 if (server < 0) {
227 pr_err("%s: Can't find server for irq %d/%x\n",
228 __func__, virq, irq);
229 goto unlock;
230 }
231
232 /* We only support delivery to all cpus or to one cpu.
233 * The irq has to be migrated only in the single cpu
234 * case.
235 */
236 if (server != hw_cpu)
237 goto unlock;
238
239 /* This is expected during cpu offline. */
240 if (cpu_online(cpu))
241 pr_warn("IRQ %u affinity broken off cpu %u\n",
242 virq, cpu);
243
244 /* Reset affinity to all cpus */
245 raw_spin_unlock_irqrestore(&desc->lock, flags);
246 irq_set_affinity(virq, cpu_all_mask);
247 continue;
248unlock:
249 raw_spin_unlock_irqrestore(&desc->lock, flags);
250 }
251
252 /* Allow "sufficient" time to drop any inflight IRQ's */
253 mdelay(5);
254
255 /*
256 * Allow IPIs again. This is done at the very end, after migrating all
257 * interrupts, the expectation is that we'll only get woken up by an IPI
258 * interrupt beyond this point, but leave externals masked just to be
259 * safe. If we're using icp-opal this may actually allow all
260 * interrupts anyway, but that should be OK.
261 */
262 icp_ops->set_priority(DEFAULT_PRIORITY);
263
264}
265#endif /* CONFIG_HOTPLUG_CPU */
266
267#ifdef CONFIG_SMP
268/*
269 * For the moment we only implement delivery to all cpus or one cpu.
270 *
271 * If the requested affinity is cpu_all_mask, we set global affinity.
272 * If not we set it to the first cpu in the mask, even if multiple cpus
273 * are set. This is so things like irqbalance (which set core and package
274 * wide affinities) do the right thing.
275 *
276 * We need to fix this to implement support for the links
277 */
278int xics_get_irq_server(unsigned int virq, const struct cpumask *cpumask,
279 unsigned int strict_check)
280{
281
282 if (!distribute_irqs)
283 return xics_default_server;
284
285 if (!cpumask_subset(cpu_possible_mask, cpumask)) {
286 int server = cpumask_first_and(cpu_online_mask, cpumask);
287
288 if (server < nr_cpu_ids)
289 return get_hard_smp_processor_id(server);
290
291 if (strict_check)
292 return -1;
293 }
294
295 /*
296 * Workaround issue with some versions of JS20 firmware that
297 * deliver interrupts to cpus which haven't been started. This
298 * happens when using the maxcpus= boot option.
299 */
300 if (cpumask_equal(cpu_online_mask, cpu_present_mask))
301 return xics_default_distrib_server;
302
303 return xics_default_server;
304}
305#endif /* CONFIG_SMP */
306
307static int xics_host_match(struct irq_domain *h, struct device_node *node,
308 enum irq_domain_bus_token bus_token)
309{
310 if (WARN_ON(!xics_ics))
311 return 0;
312 return xics_ics->host_match(xics_ics, node) ? 1 : 0;
313}
314
315/* Dummies */
316static void xics_ipi_unmask(struct irq_data *d) { }
317static void xics_ipi_mask(struct irq_data *d) { }
318
319static struct irq_chip xics_ipi_chip = {
320 .name = "XICS",
321 .irq_eoi = NULL, /* Patched at init time */
322 .irq_mask = xics_ipi_mask,
323 .irq_unmask = xics_ipi_unmask,
324};
325
326static int xics_host_map(struct irq_domain *domain, unsigned int virq,
327 irq_hw_number_t hwirq)
328{
329 pr_devel("xics: map virq %d, hwirq 0x%lx\n", virq, hwirq);
330
331 /*
332 * Mark interrupts as edge sensitive by default so that resend
333 * actually works. The device-tree parsing will turn the LSIs
334 * back to level.
335 */
336 irq_clear_status_flags(virq, IRQ_LEVEL);
337
338 /* Don't call into ICS for IPIs */
339 if (hwirq == XICS_IPI) {
340 irq_set_chip_and_handler(virq, &xics_ipi_chip,
341 handle_percpu_irq);
342 return 0;
343 }
344
345 if (WARN_ON(!xics_ics))
346 return -EINVAL;
347
348 if (xics_ics->check(xics_ics, hwirq))
349 return -EINVAL;
350
351 /* Let the ICS be the chip data for the XICS domain. For ICS native */
352 irq_domain_set_info(domain, virq, hwirq, xics_ics->chip,
353 xics_ics, handle_fasteoi_irq, NULL, NULL);
354
355 return 0;
356}
357
358static int xics_host_xlate(struct irq_domain *h, struct device_node *ct,
359 const u32 *intspec, unsigned int intsize,
360 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
361
362{
363 *out_hwirq = intspec[0];
364
365 /*
366 * If intsize is at least 2, we look for the type in the second cell,
367 * we assume the LSB indicates a level interrupt.
368 */
369 if (intsize > 1) {
370 if (intspec[1] & 1)
371 *out_flags = IRQ_TYPE_LEVEL_LOW;
372 else
373 *out_flags = IRQ_TYPE_EDGE_RISING;
374 } else
375 *out_flags = IRQ_TYPE_LEVEL_LOW;
376
377 return 0;
378}
379
380int xics_set_irq_type(struct irq_data *d, unsigned int flow_type)
381{
382 /*
383 * We only support these. This has really no effect other than setting
384 * the corresponding descriptor bits mind you but those will in turn
385 * affect the resend function when re-enabling an edge interrupt.
386 *
387 * Set set the default to edge as explained in map().
388 */
389 if (flow_type == IRQ_TYPE_DEFAULT || flow_type == IRQ_TYPE_NONE)
390 flow_type = IRQ_TYPE_EDGE_RISING;
391
392 if (flow_type != IRQ_TYPE_EDGE_RISING &&
393 flow_type != IRQ_TYPE_LEVEL_LOW)
394 return -EINVAL;
395
396 irqd_set_trigger_type(d, flow_type);
397
398 return IRQ_SET_MASK_OK_NOCOPY;
399}
400
401int xics_retrigger(struct irq_data *data)
402{
403 /*
404 * We need to push a dummy CPPR when retriggering, since the subsequent
405 * EOI will try to pop it. Passing 0 works, as the function hard codes
406 * the priority value anyway.
407 */
408 xics_push_cppr(0);
409
410 /* Tell the core to do a soft retrigger */
411 return 0;
412}
413
414#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
415static int xics_host_domain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
416 unsigned long *hwirq, unsigned int *type)
417{
418 return xics_host_xlate(d, to_of_node(fwspec->fwnode), fwspec->param,
419 fwspec->param_count, hwirq, type);
420}
421
422static int xics_host_domain_alloc(struct irq_domain *domain, unsigned int virq,
423 unsigned int nr_irqs, void *arg)
424{
425 struct irq_fwspec *fwspec = arg;
426 irq_hw_number_t hwirq;
427 unsigned int type = IRQ_TYPE_NONE;
428 int i, rc;
429
430 rc = xics_host_domain_translate(domain, fwspec, &hwirq, &type);
431 if (rc)
432 return rc;
433
434 pr_debug("%s %d/%lx #%d\n", __func__, virq, hwirq, nr_irqs);
435
436 for (i = 0; i < nr_irqs; i++)
437 irq_domain_set_info(domain, virq + i, hwirq + i, xics_ics->chip,
438 xics_ics, handle_fasteoi_irq, NULL, NULL);
439
440 return 0;
441}
442
443static void xics_host_domain_free(struct irq_domain *domain,
444 unsigned int virq, unsigned int nr_irqs)
445{
446 pr_debug("%s %d #%d\n", __func__, virq, nr_irqs);
447}
448#endif
449
450static const struct irq_domain_ops xics_host_ops = {
451#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
452 .alloc = xics_host_domain_alloc,
453 .free = xics_host_domain_free,
454 .translate = xics_host_domain_translate,
455#endif
456 .match = xics_host_match,
457 .map = xics_host_map,
458 .xlate = xics_host_xlate,
459};
460
461static int __init xics_allocate_domain(void)
462{
463 struct fwnode_handle *fn;
464
465 fn = irq_domain_alloc_named_fwnode("XICS");
466 if (!fn)
467 return -ENOMEM;
468
469 xics_host = irq_domain_create_tree(fn, &xics_host_ops, NULL);
470 if (!xics_host) {
471 irq_domain_free_fwnode(fn);
472 return -ENOMEM;
473 }
474
475 irq_set_default_host(xics_host);
476 return 0;
477}
478
479void __init xics_register_ics(struct ics *ics)
480{
481 if (WARN_ONCE(xics_ics, "XICS: Source Controller is already defined !"))
482 return;
483 xics_ics = ics;
484}
485
486static void __init xics_get_server_size(void)
487{
488 struct device_node *np;
489 const __be32 *isize;
490
491 /* We fetch the interrupt server size from the first ICS node
492 * we find if any
493 */
494 np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xics");
495 if (!np)
496 return;
497
498 isize = of_get_property(np, "ibm,interrupt-server#-size", NULL);
499 if (isize)
500 xics_interrupt_server_size = be32_to_cpu(*isize);
501
502 of_node_put(np);
503}
504
505void __init xics_init(void)
506{
507 int rc = -1;
508
509 /* Fist locate ICP */
510 if (firmware_has_feature(FW_FEATURE_LPAR))
511 rc = icp_hv_init();
512 if (rc < 0) {
513 rc = icp_native_init();
514 if (rc == -ENODEV)
515 rc = icp_opal_init();
516 }
517 if (rc < 0) {
518 pr_warn("XICS: Cannot find a Presentation Controller !\n");
519 return;
520 }
521
522 /* Copy get_irq callback over to ppc_md */
523 ppc_md.get_irq = icp_ops->get_irq;
524
525 /* Patch up IPI chip EOI */
526 xics_ipi_chip.irq_eoi = icp_ops->eoi;
527
528 /* Now locate ICS */
529 rc = ics_rtas_init();
530 if (rc < 0)
531 rc = ics_opal_init();
532 if (rc < 0)
533 rc = ics_native_init();
534 if (rc < 0)
535 pr_warn("XICS: Cannot find a Source Controller !\n");
536
537 /* Initialize common bits */
538 xics_get_server_size();
539 xics_update_irq_servers();
540 rc = xics_allocate_domain();
541 if (rc < 0)
542 pr_err("XICS: Failed to create IRQ domain");
543 xics_setup_cpu();
544}
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 */
35const struct icp_ops *icp_ops;
36
37unsigned int xics_default_server = 0xff;
38unsigned int xics_default_distrib_server = 0;
39unsigned int xics_interrupt_server_size = 8;
40
41DEFINE_PER_CPU(struct xics_cppr, xics_cppr);
42
43struct irq_domain *xics_host;
44
45static LIST_HEAD(ics_list);
46
47void xics_update_irq_servers(void)
48{
49 int i, j;
50 struct device_node *np;
51 u32 ilen;
52 const __be32 *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);
60 xics_default_server = xics_default_distrib_server = hcpuid;
61
62 pr_devel("xics: xics_default_server = 0x%x\n", xics_default_server);
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 (be32_to_cpu(ireg[j]) == hcpuid) {
79 xics_default_distrib_server = be32_to_cpu(ireg[j+1]);
80 break;
81 }
82 }
83 pr_devel("xics: xics_default_distrib_server = 0x%x\n",
84 xics_default_distrib_server);
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 */
91void 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
109void 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
116void xics_mask_unknown_vec(unsigned int vec)
117{
118 struct ics *ics;
119
120 pr_err("Interrupt 0x%x (real) is invalid, disabling it.\n", vec);
121
122 list_for_each_entry(ics, &ics_list, link)
123 ics->mask_unknown(ics, vec);
124}
125
126
127#ifdef CONFIG_SMP
128
129static void xics_request_ipi(void)
130{
131 unsigned int ipi;
132
133 ipi = irq_create_mapping(xics_host, XICS_IPI);
134 BUG_ON(ipi == NO_IRQ);
135
136 /*
137 * IPIs are marked IRQF_PERCPU. The handler was set in map.
138 */
139 BUG_ON(request_irq(ipi, icp_ops->ipi_action,
140 IRQF_PERCPU | IRQF_NO_THREAD, "IPI", NULL));
141}
142
143int __init xics_smp_probe(void)
144{
145 /* Setup cause_ipi callback based on which ICP is used */
146 smp_ops->cause_ipi = icp_ops->cause_ipi;
147
148 /* Register all the IPIs */
149 xics_request_ipi();
150
151 return cpumask_weight(cpu_possible_mask);
152}
153
154#endif /* CONFIG_SMP */
155
156void xics_teardown_cpu(void)
157{
158 struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
159
160 /*
161 * we have to reset the cppr index to 0 because we're
162 * not going to return from the IPI
163 */
164 os_cppr->index = 0;
165 icp_ops->set_priority(0);
166 icp_ops->teardown_cpu();
167}
168
169void xics_kexec_teardown_cpu(int secondary)
170{
171 xics_teardown_cpu();
172
173 icp_ops->flush_ipi();
174
175 /*
176 * Some machines need to have at least one cpu in the GIQ,
177 * so leave the master cpu in the group.
178 */
179 if (secondary)
180 xics_set_cpu_giq(xics_default_distrib_server, 0);
181}
182
183
184#ifdef CONFIG_HOTPLUG_CPU
185
186/* Interrupts are disabled. */
187void xics_migrate_irqs_away(void)
188{
189 int cpu = smp_processor_id(), hw_cpu = hard_smp_processor_id();
190 unsigned int irq, virq;
191 struct irq_desc *desc;
192
193 /* If we used to be the default server, move to the new "boot_cpuid" */
194 if (hw_cpu == xics_default_server)
195 xics_update_irq_servers();
196
197 /* Reject any interrupt that was queued to us... */
198 icp_ops->set_priority(0);
199
200 /* Remove ourselves from the global interrupt queue */
201 xics_set_cpu_giq(xics_default_distrib_server, 0);
202
203 /* Allow IPIs again... */
204 icp_ops->set_priority(DEFAULT_PRIORITY);
205
206 for_each_irq_desc(virq, desc) {
207 struct irq_chip *chip;
208 long server;
209 unsigned long flags;
210 struct ics *ics;
211
212 /* We can't set affinity on ISA interrupts */
213 if (virq < NUM_ISA_INTERRUPTS)
214 continue;
215 /* We only need to migrate enabled IRQS */
216 if (!desc->action)
217 continue;
218 if (desc->irq_data.domain != xics_host)
219 continue;
220 irq = desc->irq_data.hwirq;
221 /* We need to get IPIs still. */
222 if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
223 continue;
224 chip = irq_desc_get_chip(desc);
225 if (!chip || !chip->irq_set_affinity)
226 continue;
227
228 raw_spin_lock_irqsave(&desc->lock, flags);
229
230 /* Locate interrupt server */
231 server = -1;
232 ics = irq_get_chip_data(virq);
233 if (ics)
234 server = ics->get_server(ics, irq);
235 if (server < 0) {
236 printk(KERN_ERR "%s: Can't find server for irq %d\n",
237 __func__, irq);
238 goto unlock;
239 }
240
241 /* We only support delivery to all cpus or to one cpu.
242 * The irq has to be migrated only in the single cpu
243 * case.
244 */
245 if (server != hw_cpu)
246 goto unlock;
247
248 /* This is expected during cpu offline. */
249 if (cpu_online(cpu))
250 pr_warning("IRQ %u affinity broken off cpu %u\n",
251 virq, cpu);
252
253 /* Reset affinity to all cpus */
254 raw_spin_unlock_irqrestore(&desc->lock, flags);
255 irq_set_affinity(virq, cpu_all_mask);
256 continue;
257unlock:
258 raw_spin_unlock_irqrestore(&desc->lock, flags);
259 }
260}
261#endif /* CONFIG_HOTPLUG_CPU */
262
263#ifdef CONFIG_SMP
264/*
265 * For the moment we only implement delivery to all cpus or one cpu.
266 *
267 * If the requested affinity is cpu_all_mask, we set global affinity.
268 * If not we set it to the first cpu in the mask, even if multiple cpus
269 * are set. This is so things like irqbalance (which set core and package
270 * wide affinities) do the right thing.
271 *
272 * We need to fix this to implement support for the links
273 */
274int xics_get_irq_server(unsigned int virq, const struct cpumask *cpumask,
275 unsigned int strict_check)
276{
277
278 if (!distribute_irqs)
279 return xics_default_server;
280
281 if (!cpumask_subset(cpu_possible_mask, cpumask)) {
282 int server = cpumask_first_and(cpu_online_mask, cpumask);
283
284 if (server < nr_cpu_ids)
285 return get_hard_smp_processor_id(server);
286
287 if (strict_check)
288 return -1;
289 }
290
291 /*
292 * Workaround issue with some versions of JS20 firmware that
293 * deliver interrupts to cpus which haven't been started. This
294 * happens when using the maxcpus= boot option.
295 */
296 if (cpumask_equal(cpu_online_mask, cpu_present_mask))
297 return xics_default_distrib_server;
298
299 return xics_default_server;
300}
301#endif /* CONFIG_SMP */
302
303static int xics_host_match(struct irq_domain *h, struct device_node *node)
304{
305 struct ics *ics;
306
307 list_for_each_entry(ics, &ics_list, link)
308 if (ics->host_match(ics, node))
309 return 1;
310
311 return 0;
312}
313
314/* Dummies */
315static void xics_ipi_unmask(struct irq_data *d) { }
316static void xics_ipi_mask(struct irq_data *d) { }
317
318static struct irq_chip xics_ipi_chip = {
319 .name = "XICS",
320 .irq_eoi = NULL, /* Patched at init time */
321 .irq_mask = xics_ipi_mask,
322 .irq_unmask = xics_ipi_unmask,
323};
324
325static int xics_host_map(struct irq_domain *h, unsigned int virq,
326 irq_hw_number_t hw)
327{
328 struct ics *ics;
329
330 pr_devel("xics: map virq %d, hwirq 0x%lx\n", virq, hw);
331
332 /* They aren't all level sensitive but we just don't really know */
333 irq_set_status_flags(virq, IRQ_LEVEL);
334
335 /* Don't call into ICS for IPIs */
336 if (hw == XICS_IPI) {
337 irq_set_chip_and_handler(virq, &xics_ipi_chip,
338 handle_percpu_irq);
339 return 0;
340 }
341
342 /* Let the ICS setup the chip data */
343 list_for_each_entry(ics, &ics_list, link)
344 if (ics->map(ics, virq) == 0)
345 return 0;
346
347 return -EINVAL;
348}
349
350static int xics_host_xlate(struct irq_domain *h, struct device_node *ct,
351 const u32 *intspec, unsigned int intsize,
352 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
353
354{
355 /* Current xics implementation translates everything
356 * to level. It is not technically right for MSIs but this
357 * is irrelevant at this point. We might get smarter in the future
358 */
359 *out_hwirq = intspec[0];
360 *out_flags = IRQ_TYPE_LEVEL_LOW;
361
362 return 0;
363}
364
365static struct irq_domain_ops xics_host_ops = {
366 .match = xics_host_match,
367 .map = xics_host_map,
368 .xlate = xics_host_xlate,
369};
370
371static void __init xics_init_host(void)
372{
373 xics_host = irq_domain_add_tree(NULL, &xics_host_ops, NULL);
374 BUG_ON(xics_host == NULL);
375 irq_set_default_host(xics_host);
376}
377
378void __init xics_register_ics(struct ics *ics)
379{
380 list_add(&ics->link, &ics_list);
381}
382
383static void __init xics_get_server_size(void)
384{
385 struct device_node *np;
386 const __be32 *isize;
387
388 /* We fetch the interrupt server size from the first ICS node
389 * we find if any
390 */
391 np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xics");
392 if (!np)
393 return;
394 isize = of_get_property(np, "ibm,interrupt-server#-size", NULL);
395 if (!isize)
396 return;
397 xics_interrupt_server_size = be32_to_cpu(*isize);
398 of_node_put(np);
399}
400
401void __init xics_init(void)
402{
403 int rc = -1;
404
405 /* Fist locate ICP */
406 if (firmware_has_feature(FW_FEATURE_LPAR))
407 rc = icp_hv_init();
408 if (rc < 0)
409 rc = icp_native_init();
410 if (rc < 0) {
411 pr_warning("XICS: Cannot find a Presentation Controller !\n");
412 return;
413 }
414
415 /* Copy get_irq callback over to ppc_md */
416 ppc_md.get_irq = icp_ops->get_irq;
417
418 /* Patch up IPI chip EOI */
419 xics_ipi_chip.irq_eoi = icp_ops->eoi;
420
421 /* Now locate ICS */
422 rc = ics_rtas_init();
423 if (rc < 0)
424 rc = ics_opal_init();
425 if (rc < 0)
426 pr_warning("XICS: Cannot find a Source Controller !\n");
427
428 /* Initialize common bits */
429 xics_get_server_size();
430 xics_update_irq_servers();
431 xics_init_host();
432 xics_setup_cpu();
433}