arm64: dts: qcom: sm8550: add TRNG node
[linux-modified.git] / arch / powerpc / sysdev / xive / spapr.c
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         struct property *prop;
818         u8 max_prio;
819         u32 val;
820         u32 len;
821         const __be32 *reg;
822         int i, err;
823
824         if (xive_spapr_disabled())
825                 return false;
826
827         pr_devel("%s()\n", __func__);
828         np = of_find_compatible_node(NULL, NULL, "ibm,power-ivpe");
829         if (!np) {
830                 pr_devel("not found !\n");
831                 return false;
832         }
833         pr_devel("Found %s\n", np->full_name);
834
835         /* Resource 1 is the OS ring TIMA */
836         if (of_address_to_resource(np, 1, &r)) {
837                 pr_err("Failed to get thread mgmnt area resource\n");
838                 goto err_put;
839         }
840         tima = ioremap(r.start, resource_size(&r));
841         if (!tima) {
842                 pr_err("Failed to map thread mgmnt area\n");
843                 goto err_put;
844         }
845
846         if (!xive_get_max_prio(&max_prio))
847                 goto err_unmap;
848
849         /* Feed the IRQ number allocator with the ranges given in the DT */
850         reg = of_get_property(np, "ibm,xive-lisn-ranges", &len);
851         if (!reg) {
852                 pr_err("Failed to read 'ibm,xive-lisn-ranges' property\n");
853                 goto err_unmap;
854         }
855
856         if (len % (2 * sizeof(u32)) != 0) {
857                 pr_err("invalid 'ibm,xive-lisn-ranges' property\n");
858                 goto err_unmap;
859         }
860
861         for (i = 0; i < len / (2 * sizeof(u32)); i++, reg += 2) {
862                 err = xive_irq_bitmap_add(be32_to_cpu(reg[0]),
863                                           be32_to_cpu(reg[1]));
864                 if (err < 0)
865                         goto err_mem_free;
866         }
867
868         /* Iterate the EQ sizes and pick one */
869         of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, reg, val) {
870                 xive_queue_shift = val;
871                 if (val == PAGE_SHIFT)
872                         break;
873         }
874
875         /* Initialize XIVE core with our backend */
876         if (!xive_core_init(np, &xive_spapr_ops, tima, TM_QW1_OS, max_prio))
877                 goto err_mem_free;
878
879         of_node_put(np);
880         pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
881         return true;
882
883 err_mem_free:
884         xive_irq_bitmap_remove_all();
885 err_unmap:
886         iounmap(tima);
887 err_put:
888         of_node_put(np);
889         return false;
890 }
891
892 machine_arch_initcall(pseries, xive_core_debug_init);