GNU Linux-libre 4.14.319-gnu1
[releases.git] / arch / powerpc / sysdev / xive / spapr.c
1 /*
2  * Copyright 2016,2017 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 #define pr_fmt(fmt) "xive: " fmt
11
12 #include <linux/types.h>
13 #include <linux/irq.h>
14 #include <linux/smp.h>
15 #include <linux/interrupt.h>
16 #include <linux/init.h>
17 #include <linux/of.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/cpumask.h>
21 #include <linux/mm.h>
22
23 #include <asm/prom.h>
24 #include <asm/io.h>
25 #include <asm/smp.h>
26 #include <asm/irq.h>
27 #include <asm/errno.h>
28 #include <asm/xive.h>
29 #include <asm/xive-regs.h>
30 #include <asm/hvcall.h>
31
32 #include "xive-internal.h"
33
34 static u32 xive_queue_shift;
35
36 struct xive_irq_bitmap {
37         unsigned long           *bitmap;
38         unsigned int            base;
39         unsigned int            count;
40         spinlock_t              lock;
41         struct list_head        list;
42 };
43
44 static LIST_HEAD(xive_irq_bitmaps);
45
46 static int xive_irq_bitmap_add(int base, int count)
47 {
48         struct xive_irq_bitmap *xibm;
49
50         xibm = kzalloc(sizeof(*xibm), GFP_ATOMIC);
51         if (!xibm)
52                 return -ENOMEM;
53
54         spin_lock_init(&xibm->lock);
55         xibm->base = base;
56         xibm->count = count;
57         xibm->bitmap = kzalloc(xibm->count, GFP_KERNEL);
58         list_add(&xibm->list, &xive_irq_bitmaps);
59
60         pr_info("Using IRQ range [%x-%x]", xibm->base,
61                 xibm->base + xibm->count - 1);
62         return 0;
63 }
64
65 static int __xive_irq_bitmap_alloc(struct xive_irq_bitmap *xibm)
66 {
67         int irq;
68
69         irq = find_first_zero_bit(xibm->bitmap, xibm->count);
70         if (irq != xibm->count) {
71                 set_bit(irq, xibm->bitmap);
72                 irq += xibm->base;
73         } else {
74                 irq = -ENOMEM;
75         }
76
77         return irq;
78 }
79
80 static int xive_irq_bitmap_alloc(void)
81 {
82         struct xive_irq_bitmap *xibm;
83         unsigned long flags;
84         int irq = -ENOENT;
85
86         list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
87                 spin_lock_irqsave(&xibm->lock, flags);
88                 irq = __xive_irq_bitmap_alloc(xibm);
89                 spin_unlock_irqrestore(&xibm->lock, flags);
90                 if (irq >= 0)
91                         break;
92         }
93         return irq;
94 }
95
96 static void xive_irq_bitmap_free(int irq)
97 {
98         unsigned long flags;
99         struct xive_irq_bitmap *xibm;
100
101         list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
102                 if ((irq >= xibm->base) && (irq < xibm->base + xibm->count)) {
103                         spin_lock_irqsave(&xibm->lock, flags);
104                         clear_bit(irq - xibm->base, xibm->bitmap);
105                         spin_unlock_irqrestore(&xibm->lock, flags);
106                         break;
107                 }
108         }
109 }
110
111 static long plpar_int_get_source_info(unsigned long flags,
112                                       unsigned long lisn,
113                                       unsigned long *src_flags,
114                                       unsigned long *eoi_page,
115                                       unsigned long *trig_page,
116                                       unsigned long *esb_shift)
117 {
118         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
119         long rc;
120
121         rc = plpar_hcall(H_INT_GET_SOURCE_INFO, retbuf, flags, lisn);
122         if (rc) {
123                 pr_err("H_INT_GET_SOURCE_INFO lisn=%ld failed %ld\n", lisn, rc);
124                 return rc;
125         }
126
127         *src_flags = retbuf[0];
128         *eoi_page  = retbuf[1];
129         *trig_page = retbuf[2];
130         *esb_shift = retbuf[3];
131
132         pr_devel("H_INT_GET_SOURCE_INFO flags=%lx eoi=%lx trig=%lx shift=%lx\n",
133                 retbuf[0], retbuf[1], retbuf[2], retbuf[3]);
134
135         return 0;
136 }
137
138 #define XIVE_SRC_SET_EISN (1ull << (63 - 62))
139 #define XIVE_SRC_MASK     (1ull << (63 - 63)) /* unused */
140
141 static long plpar_int_set_source_config(unsigned long flags,
142                                         unsigned long lisn,
143                                         unsigned long target,
144                                         unsigned long prio,
145                                         unsigned long sw_irq)
146 {
147         long rc;
148
149
150         pr_devel("H_INT_SET_SOURCE_CONFIG flags=%lx lisn=%lx target=%lx prio=%lx sw_irq=%lx\n",
151                 flags, lisn, target, prio, sw_irq);
152
153
154         rc = plpar_hcall_norets(H_INT_SET_SOURCE_CONFIG, flags, lisn,
155                                 target, prio, sw_irq);
156         if (rc) {
157                 pr_err("H_INT_SET_SOURCE_CONFIG lisn=%ld target=%lx prio=%lx failed %ld\n",
158                        lisn, target, prio, rc);
159                 return rc;
160         }
161
162         return 0;
163 }
164
165 static long plpar_int_get_queue_info(unsigned long flags,
166                                      unsigned long target,
167                                      unsigned long priority,
168                                      unsigned long *esn_page,
169                                      unsigned long *esn_size)
170 {
171         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
172         long rc;
173
174         rc = plpar_hcall(H_INT_GET_QUEUE_INFO, retbuf, flags, target, priority);
175         if (rc) {
176                 pr_err("H_INT_GET_QUEUE_INFO cpu=%ld prio=%ld failed %ld\n",
177                        target, priority, rc);
178                 return rc;
179         }
180
181         *esn_page = retbuf[0];
182         *esn_size = retbuf[1];
183
184         pr_devel("H_INT_GET_QUEUE_INFO page=%lx size=%lx\n",
185                 retbuf[0], retbuf[1]);
186
187         return 0;
188 }
189
190 #define XIVE_EQ_ALWAYS_NOTIFY (1ull << (63 - 63))
191
192 static long plpar_int_set_queue_config(unsigned long flags,
193                                        unsigned long target,
194                                        unsigned long priority,
195                                        unsigned long qpage,
196                                        unsigned long qsize)
197 {
198         long rc;
199
200         pr_devel("H_INT_SET_QUEUE_CONFIG flags=%lx target=%lx priority=%lx qpage=%lx qsize=%lx\n",
201                 flags,  target, priority, qpage, qsize);
202
203         rc = plpar_hcall_norets(H_INT_SET_QUEUE_CONFIG, flags, target,
204                                 priority, qpage, qsize);
205         if (rc) {
206                 pr_err("H_INT_SET_QUEUE_CONFIG cpu=%ld prio=%ld qpage=%lx returned %ld\n",
207                        target, priority, qpage, rc);
208                 return  rc;
209         }
210
211         return 0;
212 }
213
214 static long plpar_int_sync(unsigned long flags, unsigned long lisn)
215 {
216         long rc;
217
218         rc = plpar_hcall_norets(H_INT_SYNC, flags, lisn);
219         if (rc) {
220                 pr_err("H_INT_SYNC lisn=%ld returned %ld\n", lisn, rc);
221                 return  rc;
222         }
223
224         return 0;
225 }
226
227 #define XIVE_ESB_FLAG_STORE (1ull << (63 - 63))
228
229 static long plpar_int_esb(unsigned long flags,
230                           unsigned long lisn,
231                           unsigned long offset,
232                           unsigned long in_data,
233                           unsigned long *out_data)
234 {
235         unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
236         long rc;
237
238         pr_devel("H_INT_ESB flags=%lx lisn=%lx offset=%lx in=%lx\n",
239                 flags,  lisn, offset, in_data);
240
241         rc = plpar_hcall(H_INT_ESB, retbuf, flags, lisn, offset, in_data);
242         if (rc) {
243                 pr_err("H_INT_ESB lisn=%ld offset=%ld returned %ld\n",
244                        lisn, offset, rc);
245                 return  rc;
246         }
247
248         *out_data = retbuf[0];
249
250         return 0;
251 }
252
253 static u64 xive_spapr_esb_rw(u32 lisn, u32 offset, u64 data, bool write)
254 {
255         unsigned long read_data;
256         long rc;
257
258         rc = plpar_int_esb(write ? XIVE_ESB_FLAG_STORE : 0,
259                            lisn, offset, data, &read_data);
260         if (rc)
261                 return -1;
262
263         return write ? 0 : read_data;
264 }
265
266 #define XIVE_SRC_H_INT_ESB     (1ull << (63 - 60))
267 #define XIVE_SRC_LSI           (1ull << (63 - 61))
268 #define XIVE_SRC_TRIGGER       (1ull << (63 - 62))
269 #define XIVE_SRC_STORE_EOI     (1ull << (63 - 63))
270
271 static int xive_spapr_populate_irq_data(u32 hw_irq, struct xive_irq_data *data)
272 {
273         long rc;
274         unsigned long flags;
275         unsigned long eoi_page;
276         unsigned long trig_page;
277         unsigned long esb_shift;
278
279         memset(data, 0, sizeof(*data));
280
281         rc = plpar_int_get_source_info(0, hw_irq, &flags, &eoi_page, &trig_page,
282                                        &esb_shift);
283         if (rc)
284                 return  -EINVAL;
285
286         if (flags & XIVE_SRC_H_INT_ESB)
287                 data->flags  |= XIVE_IRQ_FLAG_H_INT_ESB;
288         if (flags & XIVE_SRC_STORE_EOI)
289                 data->flags  |= XIVE_IRQ_FLAG_STORE_EOI;
290         if (flags & XIVE_SRC_LSI)
291                 data->flags  |= XIVE_IRQ_FLAG_LSI;
292         data->eoi_page  = eoi_page;
293         data->esb_shift = esb_shift;
294         data->trig_page = trig_page;
295
296         data->hw_irq = hw_irq;
297
298         /*
299          * No chip-id for the sPAPR backend. This has an impact how we
300          * pick a target. See xive_pick_irq_target().
301          */
302         data->src_chip = XIVE_INVALID_CHIP_ID;
303
304         /*
305          * When the H_INT_ESB flag is set, the H_INT_ESB hcall should
306          * be used for interrupt management. Skip the remapping of the
307          * ESB pages which are not available.
308          */
309         if (data->flags & XIVE_IRQ_FLAG_H_INT_ESB)
310                 return 0;
311
312         data->eoi_mmio = ioremap(data->eoi_page, 1u << data->esb_shift);
313         if (!data->eoi_mmio) {
314                 pr_err("Failed to map EOI page for irq 0x%x\n", hw_irq);
315                 return -ENOMEM;
316         }
317
318         /* Full function page supports trigger */
319         if (flags & XIVE_SRC_TRIGGER) {
320                 data->trig_mmio = data->eoi_mmio;
321                 return 0;
322         }
323
324         data->trig_mmio = ioremap(data->trig_page, 1u << data->esb_shift);
325         if (!data->trig_mmio) {
326                 iounmap(data->eoi_mmio);
327                 pr_err("Failed to map trigger page for irq 0x%x\n", hw_irq);
328                 return -ENOMEM;
329         }
330         return 0;
331 }
332
333 static int xive_spapr_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
334 {
335         long rc;
336
337         rc = plpar_int_set_source_config(XIVE_SRC_SET_EISN, hw_irq, target,
338                                          prio, sw_irq);
339
340         return rc == 0 ? 0 : -ENXIO;
341 }
342
343 /* This can be called multiple time to change a queue configuration */
344 static int xive_spapr_configure_queue(u32 target, struct xive_q *q, u8 prio,
345                                    __be32 *qpage, u32 order)
346 {
347         s64 rc = 0;
348         unsigned long esn_page;
349         unsigned long esn_size;
350         u64 flags, qpage_phys;
351
352         /* If there's an actual queue page, clean it */
353         if (order) {
354                 if (WARN_ON(!qpage))
355                         return -EINVAL;
356                 qpage_phys = __pa(qpage);
357         } else {
358                 qpage_phys = 0;
359         }
360
361         /* Initialize the rest of the fields */
362         q->msk = order ? ((1u << (order - 2)) - 1) : 0;
363         q->idx = 0;
364         q->toggle = 0;
365
366         rc = plpar_int_get_queue_info(0, target, prio, &esn_page, &esn_size);
367         if (rc) {
368                 pr_err("Error %lld getting queue info CPU %d prio %d\n", rc,
369                        target, prio);
370                 rc = -EIO;
371                 goto fail;
372         }
373
374         /* TODO: add support for the notification page */
375         q->eoi_phys = esn_page;
376
377         /* Default is to always notify */
378         flags = XIVE_EQ_ALWAYS_NOTIFY;
379
380         /* Configure and enable the queue in HW */
381         rc = plpar_int_set_queue_config(flags, target, prio, qpage_phys, order);
382         if (rc) {
383                 pr_err("Error %lld setting queue for CPU %d prio %d\n", rc,
384                        target, prio);
385                 rc = -EIO;
386         } else {
387                 q->qpage = qpage;
388         }
389 fail:
390         return rc;
391 }
392
393 static int xive_spapr_setup_queue(unsigned int cpu, struct xive_cpu *xc,
394                                   u8 prio)
395 {
396         struct xive_q *q = &xc->queue[prio];
397         __be32 *qpage;
398
399         qpage = xive_queue_page_alloc(cpu, xive_queue_shift);
400         if (IS_ERR(qpage))
401                 return PTR_ERR(qpage);
402
403         return xive_spapr_configure_queue(get_hard_smp_processor_id(cpu),
404                                           q, prio, qpage, xive_queue_shift);
405 }
406
407 static void xive_spapr_cleanup_queue(unsigned int cpu, struct xive_cpu *xc,
408                                   u8 prio)
409 {
410         struct xive_q *q = &xc->queue[prio];
411         unsigned int alloc_order;
412         long rc;
413         int hw_cpu = get_hard_smp_processor_id(cpu);
414
415         rc = plpar_int_set_queue_config(0, hw_cpu, prio, 0, 0);
416         if (rc)
417                 pr_err("Error %ld setting queue for CPU %d prio %d\n", rc,
418                        hw_cpu, prio);
419
420         alloc_order = xive_alloc_order(xive_queue_shift);
421         free_pages((unsigned long)q->qpage, alloc_order);
422         q->qpage = NULL;
423 }
424
425 static bool xive_spapr_match(struct device_node *node)
426 {
427         /* Ignore cascaded controllers for the moment */
428         return 1;
429 }
430
431 #ifdef CONFIG_SMP
432 static int xive_spapr_get_ipi(unsigned int cpu, struct xive_cpu *xc)
433 {
434         int irq = xive_irq_bitmap_alloc();
435
436         if (irq < 0) {
437                 pr_err("Failed to allocate IPI on CPU %d\n", cpu);
438                 return -ENXIO;
439         }
440
441         xc->hw_ipi = irq;
442         return 0;
443 }
444
445 static void xive_spapr_put_ipi(unsigned int cpu, struct xive_cpu *xc)
446 {
447         if (xc->hw_ipi == XIVE_BAD_IRQ)
448                 return;
449
450         xive_irq_bitmap_free(xc->hw_ipi);
451         xc->hw_ipi = XIVE_BAD_IRQ;
452 }
453 #endif /* CONFIG_SMP */
454
455 static void xive_spapr_shutdown(void)
456 {
457         long rc;
458
459         rc = plpar_hcall_norets(H_INT_RESET, 0);
460         if (rc)
461                 pr_err("H_INT_RESET failed %ld\n", rc);
462 }
463
464 /*
465  * Perform an "ack" cycle on the current thread. Grab the pending
466  * active priorities and update the CPPR to the most favored one.
467  */
468 static void xive_spapr_update_pending(struct xive_cpu *xc)
469 {
470         u8 nsr, cppr;
471         u16 ack;
472
473         /*
474          * Perform the "Acknowledge O/S to Register" cycle.
475          *
476          * Let's speedup the access to the TIMA using the raw I/O
477          * accessor as we don't need the synchronisation routine of
478          * the higher level ones
479          */
480         ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_OS_REG));
481
482         /* Synchronize subsequent queue accesses */
483         mb();
484
485         /*
486          * Grab the CPPR and the "NSR" field which indicates the source
487          * of the interrupt (if any)
488          */
489         cppr = ack & 0xff;
490         nsr = ack >> 8;
491
492         if (nsr & TM_QW1_NSR_EO) {
493                 if (cppr == 0xff)
494                         return;
495                 /* Mark the priority pending */
496                 xc->pending_prio |= 1 << cppr;
497
498                 /*
499                  * A new interrupt should never have a CPPR less favored
500                  * than our current one.
501                  */
502                 if (cppr >= xc->cppr)
503                         pr_err("CPU %d odd ack CPPR, got %d at %d\n",
504                                smp_processor_id(), cppr, xc->cppr);
505
506                 /* Update our idea of what the CPPR is */
507                 xc->cppr = cppr;
508         }
509 }
510
511 static void xive_spapr_eoi(u32 hw_irq)
512 {
513         /* Not used */;
514 }
515
516 static void xive_spapr_setup_cpu(unsigned int cpu, struct xive_cpu *xc)
517 {
518         /* Only some debug on the TIMA settings */
519         pr_debug("(HW value: %08x %08x %08x)\n",
520                  in_be32(xive_tima + TM_QW1_OS + TM_WORD0),
521                  in_be32(xive_tima + TM_QW1_OS + TM_WORD1),
522                  in_be32(xive_tima + TM_QW1_OS + TM_WORD2));
523 }
524
525 static void xive_spapr_teardown_cpu(unsigned int cpu, struct xive_cpu *xc)
526 {
527         /* Nothing to do */;
528 }
529
530 static void xive_spapr_sync_source(u32 hw_irq)
531 {
532         /* Specs are unclear on what this is doing */
533         plpar_int_sync(0, hw_irq);
534 }
535
536 static const struct xive_ops xive_spapr_ops = {
537         .populate_irq_data      = xive_spapr_populate_irq_data,
538         .configure_irq          = xive_spapr_configure_irq,
539         .setup_queue            = xive_spapr_setup_queue,
540         .cleanup_queue          = xive_spapr_cleanup_queue,
541         .match                  = xive_spapr_match,
542         .shutdown               = xive_spapr_shutdown,
543         .update_pending         = xive_spapr_update_pending,
544         .eoi                    = xive_spapr_eoi,
545         .setup_cpu              = xive_spapr_setup_cpu,
546         .teardown_cpu           = xive_spapr_teardown_cpu,
547         .sync_source            = xive_spapr_sync_source,
548         .esb_rw                 = xive_spapr_esb_rw,
549 #ifdef CONFIG_SMP
550         .get_ipi                = xive_spapr_get_ipi,
551         .put_ipi                = xive_spapr_put_ipi,
552 #endif /* CONFIG_SMP */
553         .name                   = "spapr",
554 };
555
556 /*
557  * get max priority from "/ibm,plat-res-int-priorities"
558  */
559 static bool xive_get_max_prio(u8 *max_prio)
560 {
561         struct device_node *rootdn;
562         const __be32 *reg;
563         u32 len;
564         int prio, found;
565
566         rootdn = of_find_node_by_path("/");
567         if (!rootdn) {
568                 pr_err("not root node found !\n");
569                 return false;
570         }
571
572         reg = of_get_property(rootdn, "ibm,plat-res-int-priorities", &len);
573         of_node_put(rootdn);
574         if (!reg) {
575                 pr_err("Failed to read 'ibm,plat-res-int-priorities' property\n");
576                 return false;
577         }
578
579         if (len % (2 * sizeof(u32)) != 0) {
580                 pr_err("invalid 'ibm,plat-res-int-priorities' property\n");
581                 return false;
582         }
583
584         /* HW supports priorities in the range [0-7] and 0xFF is a
585          * wildcard priority used to mask. We scan the ranges reserved
586          * by the hypervisor to find the lowest priority we can use.
587          */
588         found = 0xFF;
589         for (prio = 0; prio < 8; prio++) {
590                 int reserved = 0;
591                 int i;
592
593                 for (i = 0; i < len / (2 * sizeof(u32)); i++) {
594                         int base  = be32_to_cpu(reg[2 * i]);
595                         int range = be32_to_cpu(reg[2 * i + 1]);
596
597                         if (prio >= base && prio < base + range)
598                                 reserved++;
599                 }
600
601                 if (!reserved)
602                         found = prio;
603         }
604
605         if (found == 0xFF) {
606                 pr_err("no valid priority found in 'ibm,plat-res-int-priorities'\n");
607                 return false;
608         }
609
610         *max_prio = found;
611         return true;
612 }
613
614 bool __init xive_spapr_init(void)
615 {
616         struct device_node *np;
617         struct resource r;
618         void __iomem *tima;
619         struct property *prop;
620         u8 max_prio;
621         u32 val;
622         u32 len;
623         const __be32 *reg;
624         int i;
625
626         if (xive_cmdline_disabled)
627                 return false;
628
629         pr_devel("%s()\n", __func__);
630         np = of_find_compatible_node(NULL, NULL, "ibm,power-ivpe");
631         if (!np) {
632                 pr_devel("not found !\n");
633                 return false;
634         }
635         pr_devel("Found %s\n", np->full_name);
636
637         /* Resource 1 is the OS ring TIMA */
638         if (of_address_to_resource(np, 1, &r)) {
639                 pr_err("Failed to get thread mgmnt area resource\n");
640                 return false;
641         }
642         tima = ioremap(r.start, resource_size(&r));
643         if (!tima) {
644                 pr_err("Failed to map thread mgmnt area\n");
645                 return false;
646         }
647
648         if (!xive_get_max_prio(&max_prio))
649                 return false;
650
651         /* Feed the IRQ number allocator with the ranges given in the DT */
652         reg = of_get_property(np, "ibm,xive-lisn-ranges", &len);
653         if (!reg) {
654                 pr_err("Failed to read 'ibm,xive-lisn-ranges' property\n");
655                 return false;
656         }
657
658         if (len % (2 * sizeof(u32)) != 0) {
659                 pr_err("invalid 'ibm,xive-lisn-ranges' property\n");
660                 return false;
661         }
662
663         for (i = 0; i < len / (2 * sizeof(u32)); i++, reg += 2)
664                 xive_irq_bitmap_add(be32_to_cpu(reg[0]),
665                                     be32_to_cpu(reg[1]));
666
667         /* Iterate the EQ sizes and pick one */
668         of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, reg, val) {
669                 xive_queue_shift = val;
670                 if (val == PAGE_SHIFT)
671                         break;
672         }
673
674         /* Initialize XIVE core with our backend */
675         if (!xive_core_init(&xive_spapr_ops, tima, TM_QW1_OS, max_prio))
676                 return false;
677
678         pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
679         return true;
680 }