powerpc/numa: NUMA topology support for PowerNV
[linux-2.6-block.git] / arch / powerpc / sysdev / xics / xics-common.c
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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 */
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_host *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 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);
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60 xics_default_server = xics_default_distrib_server = hcpuid;
61
62 pr_devel("xics: xics_default_server = 0x%x\n", xics_default_server);
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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;
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81 }
82 }
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83 pr_devel("xics: xics_default_distrib_server = 0x%x\n",
84 xics_default_distrib_server);
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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
f6e17f9b 120 pr_err("Interrupt 0x%x (real) is invalid, disabling it.\n", vec);
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121
122 list_for_each_entry(ics, &ics_list, link)
123 ics->mask_unknown(ics, vec);
124}
125
126
127#ifdef CONFIG_SMP
128
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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_DISABLED as they must run with irqs
e085255e 138 * disabled, and PERCPU. The handler was set in map.
0b05ac6e 139 */
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140 BUG_ON(request_irq(ipi, icp_ops->ipi_action,
141 IRQF_DISABLED|IRQF_PERCPU, "IPI", NULL));
142}
143
144int __init xics_smp_probe(void)
145{
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146 /* Setup cause_ipi callback based on which ICP is used */
147 smp_ops->cause_ipi = icp_ops->cause_ipi;
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148
149 /* Register all the IPIs */
150 xics_request_ipi();
151
152 return cpumask_weight(cpu_possible_mask);
153}
154
155#endif /* CONFIG_SMP */
156
157void xics_teardown_cpu(void)
158{
159 struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
160
161 /*
162 * we have to reset the cppr index to 0 because we're
163 * not going to return from the IPI
164 */
165 os_cppr->index = 0;
166 icp_ops->set_priority(0);
167 icp_ops->teardown_cpu();
168}
169
170void xics_kexec_teardown_cpu(int secondary)
171{
172 xics_teardown_cpu();
173
174 icp_ops->flush_ipi();
175
176 /*
177 * Some machines need to have at least one cpu in the GIQ,
178 * so leave the master cpu in the group.
179 */
180 if (secondary)
181 xics_set_cpu_giq(xics_default_distrib_server, 0);
182}
183
184
185#ifdef CONFIG_HOTPLUG_CPU
186
187/* Interrupts are disabled. */
188void xics_migrate_irqs_away(void)
189{
190 int cpu = smp_processor_id(), hw_cpu = hard_smp_processor_id();
191 unsigned int irq, virq;
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(virq) {
207 struct irq_desc *desc;
208 struct irq_chip *chip;
209 long server;
210 unsigned long flags;
211 struct ics *ics;
212
213 /* We can't set affinity on ISA interrupts */
214 if (virq < NUM_ISA_INTERRUPTS)
215 continue;
3ee62d36 216 if (!virq_is_host(virq, xics_host))
0b05ac6e 217 continue;
476eb491 218 irq = (unsigned int)virq_to_hw(virq);
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219 /* We need to get IPIs still. */
220 if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
221 continue;
222 desc = irq_to_desc(virq);
223 /* We only need to migrate enabled IRQS */
224 if (!desc || !desc->action)
225 continue;
226 chip = irq_desc_get_chip(desc);
227 if (!chip || !chip->irq_set_affinity)
228 continue;
229
230 raw_spin_lock_irqsave(&desc->lock, flags);
231
232 /* Locate interrupt server */
233 server = -1;
234 ics = irq_get_chip_data(virq);
235 if (ics)
236 server = ics->get_server(ics, irq);
237 if (server < 0) {
238 printk(KERN_ERR "%s: Can't find server for irq %d\n",
239 __func__, irq);
240 goto unlock;
241 }
242
243 /* We only support delivery to all cpus or to one cpu.
244 * The irq has to be migrated only in the single cpu
245 * case.
246 */
247 if (server != hw_cpu)
248 goto unlock;
249
250 /* This is expected during cpu offline. */
251 if (cpu_online(cpu))
252 pr_warning("IRQ %u affinity broken off cpu %u\n",
253 virq, cpu);
254
255 /* Reset affinity to all cpus */
256 raw_spin_unlock_irqrestore(&desc->lock, flags);
257 irq_set_affinity(virq, cpu_all_mask);
258 continue;
259unlock:
260 raw_spin_unlock_irqrestore(&desc->lock, flags);
261 }
262}
263#endif /* CONFIG_HOTPLUG_CPU */
264
265#ifdef CONFIG_SMP
266/*
267 * For the moment we only implement delivery to all cpus or one cpu.
268 *
269 * If the requested affinity is cpu_all_mask, we set global affinity.
270 * If not we set it to the first cpu in the mask, even if multiple cpus
271 * are set. This is so things like irqbalance (which set core and package
272 * wide affinities) do the right thing.
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273 *
274 * We need to fix this to implement support for the links
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275 */
276int xics_get_irq_server(unsigned int virq, const struct cpumask *cpumask,
277 unsigned int strict_check)
278{
279
280 if (!distribute_irqs)
281 return xics_default_server;
282
283 if (!cpumask_subset(cpu_possible_mask, cpumask)) {
284 int server = cpumask_first_and(cpu_online_mask, cpumask);
285
286 if (server < nr_cpu_ids)
287 return get_hard_smp_processor_id(server);
288
289 if (strict_check)
290 return -1;
291 }
292
293 /*
294 * Workaround issue with some versions of JS20 firmware that
295 * deliver interrupts to cpus which haven't been started. This
296 * happens when using the maxcpus= boot option.
297 */
298 if (cpumask_equal(cpu_online_mask, cpu_present_mask))
299 return xics_default_distrib_server;
300
301 return xics_default_server;
302}
303#endif /* CONFIG_SMP */
304
305static int xics_host_match(struct irq_host *h, struct device_node *node)
306{
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307 struct ics *ics;
308
309 list_for_each_entry(ics, &ics_list, link)
310 if (ics->host_match(ics, node))
311 return 1;
312
313 return 0;
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314}
315
316/* Dummies */
317static void xics_ipi_unmask(struct irq_data *d) { }
318static void xics_ipi_mask(struct irq_data *d) { }
319
320static struct irq_chip xics_ipi_chip = {
321 .name = "XICS",
322 .irq_eoi = NULL, /* Patched at init time */
323 .irq_mask = xics_ipi_mask,
324 .irq_unmask = xics_ipi_unmask,
325};
326
327static int xics_host_map(struct irq_host *h, unsigned int virq,
328 irq_hw_number_t hw)
329{
330 struct ics *ics;
331
332 pr_devel("xics: map virq %d, hwirq 0x%lx\n", virq, hw);
333
334 /* Insert the interrupt mapping into the radix tree for fast lookup */
335 irq_radix_revmap_insert(xics_host, virq, hw);
336
337 /* They aren't all level sensitive but we just don't really know */
338 irq_set_status_flags(virq, IRQ_LEVEL);
339
340 /* Don't call into ICS for IPIs */
341 if (hw == XICS_IPI) {
342 irq_set_chip_and_handler(virq, &xics_ipi_chip,
e085255e 343 handle_percpu_irq);
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344 return 0;
345 }
346
347 /* Let the ICS setup the chip data */
348 list_for_each_entry(ics, &ics_list, link)
349 if (ics->map(ics, virq) == 0)
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350 return 0;
351
352 return -EINVAL;
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353}
354
355static int xics_host_xlate(struct irq_host *h, struct device_node *ct,
356 const u32 *intspec, unsigned int intsize,
357 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
358
359{
360 /* Current xics implementation translates everything
361 * to level. It is not technically right for MSIs but this
362 * is irrelevant at this point. We might get smarter in the future
363 */
364 *out_hwirq = intspec[0];
365 *out_flags = IRQ_TYPE_LEVEL_LOW;
366
367 return 0;
368}
369
370static struct irq_host_ops xics_host_ops = {
371 .match = xics_host_match,
372 .map = xics_host_map,
373 .xlate = xics_host_xlate,
374};
375
376static void __init xics_init_host(void)
377{
378 xics_host = irq_alloc_host(NULL, IRQ_HOST_MAP_TREE, 0, &xics_host_ops,
379 XICS_IRQ_SPURIOUS);
380 BUG_ON(xics_host == NULL);
381 irq_set_default_host(xics_host);
382}
383
384void __init xics_register_ics(struct ics *ics)
385{
386 list_add(&ics->link, &ics_list);
387}
388
389static void __init xics_get_server_size(void)
390{
391 struct device_node *np;
392 const u32 *isize;
393
394 /* We fetch the interrupt server size from the first ICS node
395 * we find if any
396 */
397 np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xics");
398 if (!np)
399 return;
400 isize = of_get_property(np, "ibm,interrupt-server#-size", NULL);
401 if (!isize)
402 return;
403 xics_interrupt_server_size = *isize;
404 of_node_put(np);
405}
406
407void __init xics_init(void)
408{
409 int rc = -1;
410
411 /* Fist locate ICP */
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412 if (firmware_has_feature(FW_FEATURE_LPAR))
413 rc = icp_hv_init();
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414 if (rc < 0)
415 rc = icp_native_init();
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416 if (rc < 0) {
417 pr_warning("XICS: Cannot find a Presentation Controller !\n");
418 return;
419 }
420
421 /* Copy get_irq callback over to ppc_md */
422 ppc_md.get_irq = icp_ops->get_irq;
423
424 /* Patch up IPI chip EOI */
425 xics_ipi_chip.irq_eoi = icp_ops->eoi;
426
427 /* Now locate ICS */
0b05ac6e 428 rc = ics_rtas_init();
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429 if (rc < 0)
430 rc = ics_opal_init();
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431 if (rc < 0)
432 pr_warning("XICS: Cannot find a Source Controller !\n");
433
434 /* Initialize common bits */
435 xics_get_server_size();
436 xics_update_irq_servers();
437 xics_init_host();
438 xics_setup_cpu();
439}