1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2016,2017 IBM Corporation.
4 */
5
6 #define pr_fmt(fmt) "xive: " fmt
7
8 #include <linux/types.h>
9 #include <linux/irq.h>
10 #include <linux/smp.h>
11 #include <linux/interrupt.h>
12 #include <linux/init.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_fdt.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
18 #include <linux/bitmap.h>
19 #include <linux/cpumask.h>
20 #include <linux/mm.h>
21 #include <linux/delay.h>
22 #include <linux/libfdt.h>
23
24 #include <asm/machdep.h>
25 #include <asm/prom.h>
26 #include <asm/io.h>
27 #include <asm/smp.h>
28 #include <asm/irq.h>
29 #include <asm/errno.h>
30 #include <asm/xive.h>
31 #include <asm/xive-regs.h>
32 #include <asm/hvcall.h>
33 #include <asm/svm.h>
34 #include <asm/ultravisor.h>
35
36 #include "xive-internal.h"
37
38 static u32 xive_queue_shift;
39
40 struct xive_irq_bitmap {
41 unsigned long *bitmap;
42 unsigned int base;
43 unsigned int count;
44 spinlock_t lock;
45 struct list_head list;
46 };
47
48 static LIST_HEAD(xive_irq_bitmaps);
49
50 static int __init xive_irq_bitmap_add(int base, int count)
51 {
52 struct xive_irq_bitmap *xibm;
53
54 xibm = kzalloc(sizeof(*xibm), GFP_KERNEL);
55 if (!xibm)
56 return -ENOMEM;
57
58 spin_lock_init(&xibm->lock);
59 xibm->base = base;
60 xibm->count = count;
61 xibm->bitmap = bitmap_zalloc(xibm->count, GFP_KERNEL);
62 if (!xibm->bitmap) {
63 kfree(xibm);
64 return -ENOMEM;
65 }
66 list_add(&xibm->list, &xive_irq_bitmaps);
67
68 pr_info("Using IRQ range [%x-%x]", xibm->base,
69 xibm->base + xibm->count - 1);
70 return 0;
71 }
72
73 static void xive_irq_bitmap_remove_all(void)
74 {
75 struct xive_irq_bitmap *xibm, *tmp;
76
77 list_for_each_entry_safe(xibm, tmp, &xive_irq_bitmaps, list) {
78 list_del(&xibm->list);
79 bitmap_free(xibm->bitmap);
80 kfree(xibm);
81 }
82 }
83
84 static int __xive_irq_bitmap_alloc(struct xive_irq_bitmap *xibm)
85 {
86 int irq;
87
88 irq = find_first_zero_bit(xibm->bitmap, xibm->count);
89 if (irq != xibm->count) {
90 set_bit(irq, xibm->bitmap);
91 irq += xibm->base;
92 } else {
93 irq = -ENOMEM;
94 }
95
96 return irq;
97 }
98
99 static int xive_irq_bitmap_alloc(void)
100 {
101 struct xive_irq_bitmap *xibm;
102 unsigned long flags;
103 int irq = -ENOENT;
104
105 list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
106 spin_lock_irqsave(&xibm->lock, flags);
107 irq = __xive_irq_bitmap_alloc(xibm);
108 spin_unlock_irqrestore(&xibm->lock, flags);
109 if (irq >= 0)
110 break;
111 }
112 return irq;
113 }
114
115 static void xive_irq_bitmap_free(int irq)
116 {
117 unsigned long flags;
118 struct xive_irq_bitmap *xibm;
119
120 list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
121 if ((irq >= xibm->base) && (irq < xibm->base + xibm->count)) {
122 spin_lock_irqsave(&xibm->lock, flags);
123 clear_bit(irq - xibm->base, xibm->bitmap);
124 spin_unlock_irqrestore(&xibm->lock, flags);
125 break;
126 }
127 }
128 }
129
130
131 /* Based on the similar routines in RTAS */
132 static unsigned int plpar_busy_delay_time(long rc)
133 {
134 unsigned int ms = 0;
135
136 if (H_IS_LONG_BUSY(rc)) {
137 ms = get_longbusy_msecs(rc);
138 } else if (rc == H_BUSY) {
139 ms = 10; /* seems appropriate for XIVE hcalls */
140 }
141
142 return ms;
143 }
144
145 static unsigned int plpar_busy_delay(int rc)
146 {
147 unsigned int ms;
148
149 ms = plpar_busy_delay_time(rc);
150 if (ms)
151 mdelay(ms);
152
153 return ms;
154 }
155
156 /*
157 * Note: this call has a partition wide scope and can take a while to
158 * complete. If it returns H_LONG_BUSY_* it should be retried
159 * periodically.
160 */
161 static long plpar_int_reset(unsigned long flags)
162 {
163 long rc;
164
165 do {
166 rc = plpar_hcall_norets(H_INT_RESET, flags);
167 } while (plpar_busy_delay(rc));
168
169 if (rc)
170 pr_err("H_INT_RESET failed %ld\n", rc);
171
172 return rc;
173 }
174
175 static long plpar_int_get_source_info(unsigned long flags,
176 unsigned long lisn,
177 unsigned long *src_flags,
178 unsigned long *eoi_page,
179 unsigned long *trig_page,
180 unsigned long *esb_shift)
181 {
182 unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
183 long rc;
184
185 do {
186 rc = plpar_hcall(H_INT_GET_SOURCE_INFO, retbuf, flags, lisn);
187 } while (plpar_busy_delay(rc));
188
189 if (rc) {
190 pr_err("H_INT_GET_SOURCE_INFO lisn=0x%lx failed %ld\n", lisn, rc);
191 return rc;
192 }
193
194 *src_flags = retbuf[0];
195 *eoi_page = retbuf[1];
196 *trig_page = retbuf[2];
197 *esb_shift = retbuf[3];
198
199 pr_debug("H_INT_GET_SOURCE_INFO lisn=0x%lx flags=0x%lx eoi=0x%lx trig=0x%lx shift=0x%lx\n",
200 lisn, retbuf[0], retbuf[1], retbuf[2], retbuf[3]);
201
202 return 0;
203 }
204
205 #define XIVE_SRC_SET_EISN (1ull << (63 - 62))
206 #define XIVE_SRC_MASK (1ull << (63 - 63)) /* unused */
207
208 static long plpar_int_set_source_config(unsigned long flags,
209 unsigned long lisn,
210 unsigned long target,
211 unsigned long prio,
212 unsigned long sw_irq)
213 {
214 long rc;
215
216
217 pr_debug("H_INT_SET_SOURCE_CONFIG flags=0x%lx lisn=0x%lx target=%ld prio=%ld sw_irq=%ld\n",
218 flags, lisn, target, prio, sw_irq);
219
220
221 do {
222 rc = plpar_hcall_norets(H_INT_SET_SOURCE_CONFIG, flags, lisn,
223 target, prio, sw_irq);
224 } while (plpar_busy_delay(rc));
225
226 if (rc) {
227 pr_err("H_INT_SET_SOURCE_CONFIG lisn=0x%lx target=%ld prio=%ld failed %ld\n",
228 lisn, target, prio, rc);
229 return rc;
230 }
231
232 return 0;
233 }
234
235 static long plpar_int_get_source_config(unsigned long flags,
236 unsigned long lisn,
237 unsigned long *target,
238 unsigned long *prio,
239 unsigned long *sw_irq)
240 {
241 unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
242 long rc;
243
244 pr_debug("H_INT_GET_SOURCE_CONFIG flags=0x%lx lisn=0x%lx\n", flags, lisn);
245
246 do {
247 rc = plpar_hcall(H_INT_GET_SOURCE_CONFIG, retbuf, flags, lisn,
248 target, prio, sw_irq);
249 } while (plpar_busy_delay(rc));
250
251 if (rc) {
252 pr_err("H_INT_GET_SOURCE_CONFIG lisn=0x%lx failed %ld\n",
253 lisn, rc);
254 return rc;
255 }
256
257 *target = retbuf[0];
258 *prio = retbuf[1];
259 *sw_irq = retbuf[2];
260
261 pr_debug("H_INT_GET_SOURCE_CONFIG target=%ld prio=%ld sw_irq=%ld\n",
262 retbuf[0], retbuf[1], retbuf[2]);
263
264 return 0;
265 }
266
267 static long plpar_int_get_queue_info(unsigned long flags,
268 unsigned long target,
269 unsigned long priority,
270 unsigned long *esn_page,
271 unsigned long *esn_size)
272 {
273 unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
274 long rc;
275
276 do {
277 rc = plpar_hcall(H_INT_GET_QUEUE_INFO, retbuf, flags, target,
278 priority);
279 } while (plpar_busy_delay(rc));
280
281 if (rc) {
282 pr_err("H_INT_GET_QUEUE_INFO cpu=%ld prio=%ld failed %ld\n",
283 target, priority, rc);
284 return rc;
285 }
286
287 *esn_page = retbuf[0];
288 *esn_size = retbuf[1];
289
290 pr_debug("H_INT_GET_QUEUE_INFO cpu=%ld prio=%ld page=0x%lx size=0x%lx\n",
291 target, priority, retbuf[0], retbuf[1]);
292
293 return 0;
294 }
295
296 #define XIVE_EQ_ALWAYS_NOTIFY (1ull << (63 - 63))
297
298 static long plpar_int_set_queue_config(unsigned long flags,
299 unsigned long target,
300 unsigned long priority,
301 unsigned long qpage,
302 unsigned long qsize)
303 {
304 long rc;
305
306 pr_debug("H_INT_SET_QUEUE_CONFIG flags=0x%lx target=%ld priority=0x%lx qpage=0x%lx qsize=0x%lx\n",
307 flags, target, priority, qpage, qsize);
308
309 do {
310 rc = plpar_hcall_norets(H_INT_SET_QUEUE_CONFIG, flags, target,
311 priority, qpage, qsize);
312 } while (plpar_busy_delay(rc));
313
314 if (rc) {
315 pr_err("H_INT_SET_QUEUE_CONFIG cpu=%ld prio=%ld qpage=0x%lx returned %ld\n",
316 target, priority, qpage, rc);
317 return rc;
318 }
319
320 return 0;
321 }
322
323 static long plpar_int_sync(unsigned long flags, unsigned long lisn)
324 {
325 long rc;
326
327 do {
328 rc = plpar_hcall_norets(H_INT_SYNC, flags, lisn);
329 } while (plpar_busy_delay(rc));
330
331 if (rc) {
332 pr_err("H_INT_SYNC lisn=0x%lx returned %ld\n", lisn, rc);
333 return rc;
334 }
335
336 return 0;
337 }
338
339 #define XIVE_ESB_FLAG_STORE (1ull << (63 - 63))
340
341 static long plpar_int_esb(unsigned long flags,
342 unsigned long lisn,
343 unsigned long offset,
344 unsigned long in_data,
345 unsigned long *out_data)
346 {
347 unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
348 long rc;
349
350 pr_debug("H_INT_ESB flags=0x%lx lisn=0x%lx offset=0x%lx in=0x%lx\n",
351 flags, lisn, offset, in_data);
352
353 do {
354 rc = plpar_hcall(H_INT_ESB, retbuf, flags, lisn, offset,
355 in_data);
356 } while (plpar_busy_delay(rc));
357
358 if (rc) {
359 pr_err("H_INT_ESB lisn=0x%lx offset=0x%lx returned %ld\n",
360 lisn, offset, rc);
361 return rc;
362 }
363
364 *out_data = retbuf[0];
365
366 return 0;
367 }
368
369 static u64 xive_spapr_esb_rw(u32 lisn, u32 offset, u64 data, bool write)
370 {
371 unsigned long read_data;
372 long rc;
373
374 rc = plpar_int_esb(write ? XIVE_ESB_FLAG_STORE : 0,
375 lisn, offset, data, &read_data);
376 if (rc)
377 return -1;
378
379 return write ? 0 : read_data;
380 }
381
382 #define XIVE_SRC_H_INT_ESB (1ull << (63 - 60))
383 #define XIVE_SRC_LSI (1ull << (63 - 61))
384 #define XIVE_SRC_TRIGGER (1ull << (63 - 62))
385 #define XIVE_SRC_STORE_EOI (1ull << (63 - 63))
386
387 static int xive_spapr_populate_irq_data(u32 hw_irq, struct xive_irq_data *data)
388 {
389 long rc;
390 unsigned long flags;
391 unsigned long eoi_page;
392 unsigned long trig_page;
393 unsigned long esb_shift;
394
395 memset(data, 0, sizeof(*data));
396
397 rc = plpar_int_get_source_info(0, hw_irq, &flags, &eoi_page, &trig_page,
398 &esb_shift);
399 if (rc)
400 return -EINVAL;
401
402 if (flags & XIVE_SRC_H_INT_ESB)
403 data->flags |= XIVE_IRQ_FLAG_H_INT_ESB;
404 if (flags & XIVE_SRC_STORE_EOI)
405 data->flags |= XIVE_IRQ_FLAG_STORE_EOI;
406 if (flags & XIVE_SRC_LSI)
407 data->flags |= XIVE_IRQ_FLAG_LSI;
408 data->eoi_page = eoi_page;
409 data->esb_shift = esb_shift;
410 data->trig_page = trig_page;
411
412 data->hw_irq = hw_irq;
413
414 /*
415 * No chip-id for the sPAPR backend. This has an impact how we
416 * pick a target. See xive_pick_irq_target().
417 */
418 data->src_chip = XIVE_INVALID_CHIP_ID;
419
420 /*
421 * When the H_INT_ESB flag is set, the H_INT_ESB hcall should
422 * be used for interrupt management. Skip the remapping of the
423 * ESB pages which are not available.
424 */
425 if (data->flags & XIVE_IRQ_FLAG_H_INT_ESB)
426 return 0;
427
428 data->eoi_mmio = ioremap(data->eoi_page, 1u << data->esb_shift);
429 if (!data->eoi_mmio) {
430 pr_err("Failed to map EOI page for irq 0x%x\n", hw_irq);
431 return -ENOMEM;
432 }
433
434 /* Full function page supports trigger */
435 if (flags & XIVE_SRC_TRIGGER) {
436 data->trig_mmio = data->eoi_mmio;
437 return 0;
438 }
439
440 data->trig_mmio = ioremap(data->trig_page, 1u << data->esb_shift);
441 if (!data->trig_mmio) {
442 iounmap(data->eoi_mmio);
443 pr_err("Failed to map trigger page for irq 0x%x\n", hw_irq);
444 return -ENOMEM;
445 }
446 return 0;
447 }
448
449 static int xive_spapr_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
450 {
451 long rc;
452
453 rc = plpar_int_set_source_config(XIVE_SRC_SET_EISN, hw_irq, target,
454 prio, sw_irq);
455
456 return rc == 0 ? 0 : -ENXIO;
457 }
458
459 static int xive_spapr_get_irq_config(u32 hw_irq, u32 *target, u8 *prio,
460 u32 *sw_irq)
461 {
462 long rc;
463 unsigned long h_target;
464 unsigned long h_prio;
465 unsigned long h_sw_irq;
466
467 rc = plpar_int_get_source_config(0, hw_irq, &h_target, &h_prio,
468 &h_sw_irq);
469
470 *target = h_target;
471 *prio = h_prio;
472 *sw_irq = h_sw_irq;
473
474 return rc == 0 ? 0 : -ENXIO;
475 }
476
477 /* This can be called multiple time to change a queue configuration */
478 static int xive_spapr_configure_queue(u32 target, struct xive_q *q, u8 prio,
479 __be32 *qpage, u32 order)
480 {
481 s64 rc = 0;
482 unsigned long esn_page;
483 unsigned long esn_size;
484 u64 flags, qpage_phys;
485
486 /* If there's an actual queue page, clean it */
487 if (order) {
488 if (WARN_ON(!qpage))
489 return -EINVAL;
490 qpage_phys = __pa(qpage);
491 } else {
492 qpage_phys = 0;
493 }
494
495 /* Initialize the rest of the fields */
496 q->msk = order ? ((1u << (order - 2)) - 1) : 0;
497 q->idx = 0;
498 q->toggle = 0;
499
500 rc = plpar_int_get_queue_info(0, target, prio, &esn_page, &esn_size);
501 if (rc) {
502 pr_err("Error %lld getting queue info CPU %d prio %d\n", rc,
503 target, prio);
504 rc = -EIO;
505 goto fail;
506 }
507
508 /* TODO: add support for the notification page */
509 q->eoi_phys = esn_page;
510
511 /* Default is to always notify */
512 flags = XIVE_EQ_ALWAYS_NOTIFY;
513
514 /* Configure and enable the queue in HW */
515 rc = plpar_int_set_queue_config(flags, target, prio, qpage_phys, order);
516 if (rc) {
517 pr_err("Error %lld setting queue for CPU %d prio %d\n", rc,
518 target, prio);
519 rc = -EIO;
520 } else {
521 q->qpage = qpage;
522 if (is_secure_guest())
523 uv_share_page(PHYS_PFN(qpage_phys),
524 1 << xive_alloc_order(order));
525 }
526 fail:
527 return rc;
528 }
529
530 static int xive_spapr_setup_queue(unsigned int cpu, struct xive_cpu *xc,
531 u8 prio)
532 {
533 struct xive_q *q = &xc->queue[prio];
534 __be32 *qpage;
535
536 qpage = xive_queue_page_alloc(cpu, xive_queue_shift);
537 if (IS_ERR(qpage))
538 return PTR_ERR(qpage);
539
540 return xive_spapr_configure_queue(get_hard_smp_processor_id(cpu),
541 q, prio, qpage, xive_queue_shift);
542 }
543
544 static void xive_spapr_cleanup_queue(unsigned int cpu, struct xive_cpu *xc,
545 u8 prio)
546 {
547 struct xive_q *q = &xc->queue[prio];
548 unsigned int alloc_order;
549 long rc;
550 int hw_cpu = get_hard_smp_processor_id(cpu);
551
552 rc = plpar_int_set_queue_config(0, hw_cpu, prio, 0, 0);
553 if (rc)
554 pr_err("Error %ld setting queue for CPU %d prio %d\n", rc,
555 hw_cpu, prio);
556
557 alloc_order = xive_alloc_order(xive_queue_shift);
558 if (is_secure_guest())
559 uv_unshare_page(PHYS_PFN(__pa(q->qpage)), 1 << alloc_order);
560 free_pages((unsigned long)q->qpage, alloc_order);
561 q->qpage = NULL;
562 }
563
564 static bool xive_spapr_match(struct device_node *node)
565 {
566 /* Ignore cascaded controllers for the moment */
567 return true;
568 }
569
570 #ifdef CONFIG_SMP
571 static int xive_spapr_get_ipi(unsigned int cpu, struct xive_cpu *xc)
572 {
573 int irq = xive_irq_bitmap_alloc();
574
575 if (irq < 0) {
576 pr_err("Failed to allocate IPI on CPU %d\n", cpu);
577 return -ENXIO;
578 }
579
580 xc->hw_ipi = irq;
581 return 0;
582 }
583
584 static void xive_spapr_put_ipi(unsigned int cpu, struct xive_cpu *xc)
585 {
586 if (xc->hw_ipi == XIVE_BAD_IRQ)
587 return;
588
589 xive_irq_bitmap_free(xc->hw_ipi);
590 xc->hw_ipi = XIVE_BAD_IRQ;
591 }
592 #endif /* CONFIG_SMP */
593
594 static void xive_spapr_shutdown(void)
595 {
596 plpar_int_reset(0);
597 }
598
599 /*
600 * Perform an "ack" cycle on the current thread. Grab the pending
601 * active priorities and update the CPPR to the most favored one.
602 */
603 static void xive_spapr_update_pending(struct xive_cpu *xc)
604 {
605 u8 nsr, cppr;
606 u16 ack;
607
608 /*
609 * Perform the "Acknowledge O/S to Register" cycle.
610 *
611 * Let's speedup the access to the TIMA using the raw I/O
612 * accessor as we don't need the synchronisation routine of
613 * the higher level ones
614 */
615 ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_OS_REG));
616
617 /* Synchronize subsequent queue accesses */
618 mb();
619
620 /*
621 * Grab the CPPR and the "NSR" field which indicates the source
622 * of the interrupt (if any)
623 */
624 cppr = ack & 0xff;
625 nsr = ack >> 8;
626
627 if (nsr & TM_QW1_NSR_EO) {
628 if (cppr == 0xff)
629 return;
630 /* Mark the priority pending */
631 xc->pending_prio |= 1 << cppr;
632
633 /*
634 * A new interrupt should never have a CPPR less favored
635 * than our current one.
636 */
637 if (cppr >= xc->cppr)
638 pr_err("CPU %d odd ack CPPR, got %d at %d\n",
639 smp_processor_id(), cppr, xc->cppr);
640
641 /* Update our idea of what the CPPR is */
642 xc->cppr = cppr;
643 }
644 }
645
646 static void xive_spapr_setup_cpu(unsigned int cpu, struct xive_cpu *xc)
647 {
648 /* Only some debug on the TIMA settings */
649 pr_debug("(HW value: %08x %08x %08x)\n",
650 in_be32(xive_tima + TM_QW1_OS + TM_WORD0),
651 in_be32(xive_tima + TM_QW1_OS + TM_WORD1),
652 in_be32(xive_tima + TM_QW1_OS + TM_WORD2));
653 }
654
655 static void xive_spapr_teardown_cpu(unsigned int cpu, struct xive_cpu *xc)
656 {
657 /* Nothing to do */;
658 }
659
660 static void xive_spapr_sync_source(u32 hw_irq)
661 {
662 /* Specs are unclear on what this is doing */
663 plpar_int_sync(0, hw_irq);
664 }
665
666 static int xive_spapr_debug_show(struct seq_file *m, void *private)
667 {
668 struct xive_irq_bitmap *xibm;
669 char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
670
671 if (!buf)
672 return -ENOMEM;
673
674 list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
675 memset(buf, 0, PAGE_SIZE);
676 bitmap_print_to_pagebuf(true, buf, xibm->bitmap, xibm->count);
677 seq_printf(m, "bitmap #%d: %s", xibm->count, buf);
678 }
679 kfree(buf);
680
681 return 0;
682 }
683
684 static const struct xive_ops xive_spapr_ops = {
685 .populate_irq_data = xive_spapr_populate_irq_data,
686 .configure_irq = xive_spapr_configure_irq,
687 .get_irq_config = xive_spapr_get_irq_config,
688 .setup_queue = xive_spapr_setup_queue,
689 .cleanup_queue = xive_spapr_cleanup_queue,
690 .match = xive_spapr_match,
691 .shutdown = xive_spapr_shutdown,
692 .update_pending = xive_spapr_update_pending,
693 .setup_cpu = xive_spapr_setup_cpu,
694 .teardown_cpu = xive_spapr_teardown_cpu,
695 .sync_source = xive_spapr_sync_source,
696 .esb_rw = xive_spapr_esb_rw,
697 #ifdef CONFIG_SMP
698 .get_ipi = xive_spapr_get_ipi,
699 .put_ipi = xive_spapr_put_ipi,
700 .debug_show = xive_spapr_debug_show,
701 #endif /* CONFIG_SMP */
702 .name = "spapr",
703 };
704
705 /*
706 * get max priority from "/ibm,plat-res-int-priorities"
707 */
708 static bool __init xive_get_max_prio(u8 *max_prio)
709 {
710 struct device_node *rootdn;
711 const __be32 *reg;
712 u32 len;
713 int prio, found;
714
715 rootdn = of_find_node_by_path("/");
716 if (!rootdn) {
717 pr_err("not root node found !\n");
718 return false;
719 }
720
721 reg = of_get_property(rootdn, "ibm,plat-res-int-priorities", &len);
722 of_node_put(rootdn);
723 if (!reg) {
724 pr_err("Failed to read 'ibm,plat-res-int-priorities' property\n");
725 return false;
726 }
727
728 if (len % (2 * sizeof(u32)) != 0) {
729 pr_err("invalid 'ibm,plat-res-int-priorities' property\n");
730 return false;
731 }
732
733 /* HW supports priorities in the range [0-7] and 0xFF is a
734 * wildcard priority used to mask. We scan the ranges reserved
735 * by the hypervisor to find the lowest priority we can use.
736 */
737 found = 0xFF;
738 for (prio = 0; prio < 8; prio++) {
739 int reserved = 0;
740 int i;
741
742 for (i = 0; i < len / (2 * sizeof(u32)); i++) {
743 int base = be32_to_cpu(reg[2 * i]);
744 int range = be32_to_cpu(reg[2 * i + 1]);
745
746 if (prio >= base && prio < base + range)
747 reserved++;
748 }
749
750 if (!reserved)
751 found = prio;
752 }
753
754 if (found == 0xFF) {
755 pr_err("no valid priority found in 'ibm,plat-res-int-priorities'\n");
756 return false;
757 }
758
759 *max_prio = found;
760 return true;
761 }
762
763 static const u8 *__init get_vec5_feature(unsigned int index)
764 {
765 unsigned long root, chosen;
766 int size;
767 const u8 *vec5;
768
769 root = of_get_flat_dt_root();
770 chosen = of_get_flat_dt_subnode_by_name(root, "chosen");
771 if (chosen == -FDT_ERR_NOTFOUND)
772 return NULL;
773
774 vec5 = of_get_flat_dt_prop(chosen, "ibm,architecture-vec-5", &size);
775 if (!vec5)
776 return NULL;
777
778 if (size <= index)
779 return NULL;
780
781 return vec5 + index;
782 }
783
784 static bool __init xive_spapr_disabled(void)
785 {
786 const u8 *vec5_xive;
787
788 vec5_xive = get_vec5_feature(OV5_INDX(OV5_XIVE_SUPPORT));
789 if (vec5_xive) {
790 u8 val;
791
792 val = *vec5_xive & OV5_FEAT(OV5_XIVE_SUPPORT);
793 switch (val) {
794 case OV5_FEAT(OV5_XIVE_EITHER):
795 case OV5_FEAT(OV5_XIVE_LEGACY):
796 break;
797 case OV5_FEAT(OV5_XIVE_EXPLOIT):
798 /* Hypervisor only supports XIVE */
799 if (xive_cmdline_disabled)
800 pr_warn("WARNING: Ignoring cmdline option xive=off\n");
801 return false;
802 default:
803 pr_warn("%s: Unknown xive support option: 0x%x\n",
804 __func__, val);
805 break;
806 }
807 }
808
809 return xive_cmdline_disabled;
810 }
811
812 bool __init xive_spapr_init(void)
813 {
814 struct device_node *np;
815 struct resource r;
816 void __iomem *tima;
817 u8 max_prio;
818 u32 val;
819 u32 len;
820 const __be32 *reg;
821 int i, err;
822
823 if (xive_spapr_disabled())
824 return false;
825
826 pr_devel("%s()\n", __func__);
827 np = of_find_compatible_node(NULL, NULL, "ibm,power-ivpe");
828 if (!np) {
829 pr_devel("not found !\n");
830 return false;
831 }
832 pr_devel("Found %s\n", np->full_name);
833
834 /* Resource 1 is the OS ring TIMA */
835 if (of_address_to_resource(np, 1, &r)) {
836 pr_err("Failed to get thread mgmnt area resource\n");
837 goto err_put;
838 }
839 tima = ioremap(r.start, resource_size(&r));
840 if (!tima) {
841 pr_err("Failed to map thread mgmnt area\n");
842 goto err_put;
843 }
844
845 if (!xive_get_max_prio(&max_prio))
846 goto err_unmap;
847
848 /* Feed the IRQ number allocator with the ranges given in the DT */
849 reg = of_get_property(np, "ibm,xive-lisn-ranges", &len);
850 if (!reg) {
851 pr_err("Failed to read 'ibm,xive-lisn-ranges' property\n");
852 goto err_unmap;
853 }
854
855 if (len % (2 * sizeof(u32)) != 0) {
856 pr_err("invalid 'ibm,xive-lisn-ranges' property\n");
857 goto err_unmap;
858 }
859
860 for (i = 0; i < len / (2 * sizeof(u32)); i++, reg += 2) {
861 err = xive_irq_bitmap_add(be32_to_cpu(reg[0]),
862 be32_to_cpu(reg[1]));
863 if (err < 0)
864 goto err_mem_free;
865 }
866
867 /* Iterate the EQ sizes and pick one */
868 of_property_for_each_u32(np, "ibm,xive-eq-sizes", val) {
869 xive_queue_shift = val;
870 if (val == PAGE_SHIFT)
871 break;
872 }
873
874 /* Initialize XIVE core with our backend */
875 if (!xive_core_init(np, &xive_spapr_ops, tima, TM_QW1_OS, max_prio))
876 goto err_mem_free;
877
878 of_node_put(np);
879 pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
880 return true;
881
882 err_mem_free:
883 xive_irq_bitmap_remove_all();
884 err_unmap:
885 iounmap(tima);
886 err_put:
887 of_node_put(np);
888 return false;
889 }
890
891 machine_arch_initcall(pseries, xive_core_debug_init);
892
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.