Merge tag 'amlogic-fixes' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/khilm...
[linux-2.6-block.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         /*
297          * No chip-id for the sPAPR backend. This has an impact how we
298          * pick a target. See xive_pick_irq_target().
299          */
300         data->src_chip = XIVE_INVALID_CHIP_ID;
301
302         data->eoi_mmio = ioremap(data->eoi_page, 1u << data->esb_shift);
303         if (!data->eoi_mmio) {
304                 pr_err("Failed to map EOI page for irq 0x%x\n", hw_irq);
305                 return -ENOMEM;
306         }
307
308         data->hw_irq = hw_irq;
309
310         /* Full function page supports trigger */
311         if (flags & XIVE_SRC_TRIGGER) {
312                 data->trig_mmio = data->eoi_mmio;
313                 return 0;
314         }
315
316         data->trig_mmio = ioremap(data->trig_page, 1u << data->esb_shift);
317         if (!data->trig_mmio) {
318                 pr_err("Failed to map trigger page for irq 0x%x\n", hw_irq);
319                 return -ENOMEM;
320         }
321         return 0;
322 }
323
324 static int xive_spapr_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
325 {
326         long rc;
327
328         rc = plpar_int_set_source_config(XIVE_SRC_SET_EISN, hw_irq, target,
329                                          prio, sw_irq);
330
331         return rc == 0 ? 0 : -ENXIO;
332 }
333
334 /* This can be called multiple time to change a queue configuration */
335 static int xive_spapr_configure_queue(u32 target, struct xive_q *q, u8 prio,
336                                    __be32 *qpage, u32 order)
337 {
338         s64 rc = 0;
339         unsigned long esn_page;
340         unsigned long esn_size;
341         u64 flags, qpage_phys;
342
343         /* If there's an actual queue page, clean it */
344         if (order) {
345                 if (WARN_ON(!qpage))
346                         return -EINVAL;
347                 qpage_phys = __pa(qpage);
348         } else {
349                 qpage_phys = 0;
350         }
351
352         /* Initialize the rest of the fields */
353         q->msk = order ? ((1u << (order - 2)) - 1) : 0;
354         q->idx = 0;
355         q->toggle = 0;
356
357         rc = plpar_int_get_queue_info(0, target, prio, &esn_page, &esn_size);
358         if (rc) {
359                 pr_err("Error %lld getting queue info CPU %d prio %d\n", rc,
360                        target, prio);
361                 rc = -EIO;
362                 goto fail;
363         }
364
365         /* TODO: add support for the notification page */
366         q->eoi_phys = esn_page;
367
368         /* Default is to always notify */
369         flags = XIVE_EQ_ALWAYS_NOTIFY;
370
371         /* Configure and enable the queue in HW */
372         rc = plpar_int_set_queue_config(flags, target, prio, qpage_phys, order);
373         if (rc) {
374                 pr_err("Error %lld setting queue for CPU %d prio %d\n", rc,
375                        target, prio);
376                 rc = -EIO;
377         } else {
378                 q->qpage = qpage;
379         }
380 fail:
381         return rc;
382 }
383
384 static int xive_spapr_setup_queue(unsigned int cpu, struct xive_cpu *xc,
385                                   u8 prio)
386 {
387         struct xive_q *q = &xc->queue[prio];
388         __be32 *qpage;
389
390         qpage = xive_queue_page_alloc(cpu, xive_queue_shift);
391         if (IS_ERR(qpage))
392                 return PTR_ERR(qpage);
393
394         return xive_spapr_configure_queue(get_hard_smp_processor_id(cpu),
395                                           q, prio, qpage, xive_queue_shift);
396 }
397
398 static void xive_spapr_cleanup_queue(unsigned int cpu, struct xive_cpu *xc,
399                                   u8 prio)
400 {
401         struct xive_q *q = &xc->queue[prio];
402         unsigned int alloc_order;
403         long rc;
404         int hw_cpu = get_hard_smp_processor_id(cpu);
405
406         rc = plpar_int_set_queue_config(0, hw_cpu, prio, 0, 0);
407         if (rc)
408                 pr_err("Error %ld setting queue for CPU %d prio %d\n", rc,
409                        hw_cpu, prio);
410
411         alloc_order = xive_alloc_order(xive_queue_shift);
412         free_pages((unsigned long)q->qpage, alloc_order);
413         q->qpage = NULL;
414 }
415
416 static bool xive_spapr_match(struct device_node *node)
417 {
418         /* Ignore cascaded controllers for the moment */
419         return 1;
420 }
421
422 #ifdef CONFIG_SMP
423 static int xive_spapr_get_ipi(unsigned int cpu, struct xive_cpu *xc)
424 {
425         int irq = xive_irq_bitmap_alloc();
426
427         if (irq < 0) {
428                 pr_err("Failed to allocate IPI on CPU %d\n", cpu);
429                 return -ENXIO;
430         }
431
432         xc->hw_ipi = irq;
433         return 0;
434 }
435
436 static void xive_spapr_put_ipi(unsigned int cpu, struct xive_cpu *xc)
437 {
438         if (!xc->hw_ipi)
439                 return;
440
441         xive_irq_bitmap_free(xc->hw_ipi);
442         xc->hw_ipi = 0;
443 }
444 #endif /* CONFIG_SMP */
445
446 static void xive_spapr_shutdown(void)
447 {
448         long rc;
449
450         rc = plpar_hcall_norets(H_INT_RESET, 0);
451         if (rc)
452                 pr_err("H_INT_RESET failed %ld\n", rc);
453 }
454
455 /*
456  * Perform an "ack" cycle on the current thread. Grab the pending
457  * active priorities and update the CPPR to the most favored one.
458  */
459 static void xive_spapr_update_pending(struct xive_cpu *xc)
460 {
461         u8 nsr, cppr;
462         u16 ack;
463
464         /*
465          * Perform the "Acknowledge O/S to Register" cycle.
466          *
467          * Let's speedup the access to the TIMA using the raw I/O
468          * accessor as we don't need the synchronisation routine of
469          * the higher level ones
470          */
471         ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_OS_REG));
472
473         /* Synchronize subsequent queue accesses */
474         mb();
475
476         /*
477          * Grab the CPPR and the "NSR" field which indicates the source
478          * of the interrupt (if any)
479          */
480         cppr = ack & 0xff;
481         nsr = ack >> 8;
482
483         if (nsr & TM_QW1_NSR_EO) {
484                 if (cppr == 0xff)
485                         return;
486                 /* Mark the priority pending */
487                 xc->pending_prio |= 1 << cppr;
488
489                 /*
490                  * A new interrupt should never have a CPPR less favored
491                  * than our current one.
492                  */
493                 if (cppr >= xc->cppr)
494                         pr_err("CPU %d odd ack CPPR, got %d at %d\n",
495                                smp_processor_id(), cppr, xc->cppr);
496
497                 /* Update our idea of what the CPPR is */
498                 xc->cppr = cppr;
499         }
500 }
501
502 static void xive_spapr_eoi(u32 hw_irq)
503 {
504         /* Not used */;
505 }
506
507 static void xive_spapr_setup_cpu(unsigned int cpu, struct xive_cpu *xc)
508 {
509         /* Only some debug on the TIMA settings */
510         pr_debug("(HW value: %08x %08x %08x)\n",
511                  in_be32(xive_tima + TM_QW1_OS + TM_WORD0),
512                  in_be32(xive_tima + TM_QW1_OS + TM_WORD1),
513                  in_be32(xive_tima + TM_QW1_OS + TM_WORD2));
514 }
515
516 static void xive_spapr_teardown_cpu(unsigned int cpu, struct xive_cpu *xc)
517 {
518         /* Nothing to do */;
519 }
520
521 static void xive_spapr_sync_source(u32 hw_irq)
522 {
523         /* Specs are unclear on what this is doing */
524         plpar_int_sync(0, hw_irq);
525 }
526
527 static const struct xive_ops xive_spapr_ops = {
528         .populate_irq_data      = xive_spapr_populate_irq_data,
529         .configure_irq          = xive_spapr_configure_irq,
530         .setup_queue            = xive_spapr_setup_queue,
531         .cleanup_queue          = xive_spapr_cleanup_queue,
532         .match                  = xive_spapr_match,
533         .shutdown               = xive_spapr_shutdown,
534         .update_pending         = xive_spapr_update_pending,
535         .eoi                    = xive_spapr_eoi,
536         .setup_cpu              = xive_spapr_setup_cpu,
537         .teardown_cpu           = xive_spapr_teardown_cpu,
538         .sync_source            = xive_spapr_sync_source,
539         .esb_rw                 = xive_spapr_esb_rw,
540 #ifdef CONFIG_SMP
541         .get_ipi                = xive_spapr_get_ipi,
542         .put_ipi                = xive_spapr_put_ipi,
543 #endif /* CONFIG_SMP */
544         .name                   = "spapr",
545 };
546
547 /*
548  * get max priority from "/ibm,plat-res-int-priorities"
549  */
550 static bool xive_get_max_prio(u8 *max_prio)
551 {
552         struct device_node *rootdn;
553         const __be32 *reg;
554         u32 len;
555         int prio, found;
556
557         rootdn = of_find_node_by_path("/");
558         if (!rootdn) {
559                 pr_err("not root node found !\n");
560                 return false;
561         }
562
563         reg = of_get_property(rootdn, "ibm,plat-res-int-priorities", &len);
564         if (!reg) {
565                 pr_err("Failed to read 'ibm,plat-res-int-priorities' property\n");
566                 return false;
567         }
568
569         if (len % (2 * sizeof(u32)) != 0) {
570                 pr_err("invalid 'ibm,plat-res-int-priorities' property\n");
571                 return false;
572         }
573
574         /* HW supports priorities in the range [0-7] and 0xFF is a
575          * wildcard priority used to mask. We scan the ranges reserved
576          * by the hypervisor to find the lowest priority we can use.
577          */
578         found = 0xFF;
579         for (prio = 0; prio < 8; prio++) {
580                 int reserved = 0;
581                 int i;
582
583                 for (i = 0; i < len / (2 * sizeof(u32)); i++) {
584                         int base  = be32_to_cpu(reg[2 * i]);
585                         int range = be32_to_cpu(reg[2 * i + 1]);
586
587                         if (prio >= base && prio < base + range)
588                                 reserved++;
589                 }
590
591                 if (!reserved)
592                         found = prio;
593         }
594
595         if (found == 0xFF) {
596                 pr_err("no valid priority found in 'ibm,plat-res-int-priorities'\n");
597                 return false;
598         }
599
600         *max_prio = found;
601         return true;
602 }
603
604 bool __init xive_spapr_init(void)
605 {
606         struct device_node *np;
607         struct resource r;
608         void __iomem *tima;
609         struct property *prop;
610         u8 max_prio;
611         u32 val;
612         u32 len;
613         const __be32 *reg;
614         int i;
615
616         if (xive_cmdline_disabled)
617                 return false;
618
619         pr_devel("%s()\n", __func__);
620         np = of_find_compatible_node(NULL, NULL, "ibm,power-ivpe");
621         if (!np) {
622                 pr_devel("not found !\n");
623                 return false;
624         }
625         pr_devel("Found %s\n", np->full_name);
626
627         /* Resource 1 is the OS ring TIMA */
628         if (of_address_to_resource(np, 1, &r)) {
629                 pr_err("Failed to get thread mgmnt area resource\n");
630                 return false;
631         }
632         tima = ioremap(r.start, resource_size(&r));
633         if (!tima) {
634                 pr_err("Failed to map thread mgmnt area\n");
635                 return false;
636         }
637
638         if (!xive_get_max_prio(&max_prio))
639                 return false;
640
641         /* Feed the IRQ number allocator with the ranges given in the DT */
642         reg = of_get_property(np, "ibm,xive-lisn-ranges", &len);
643         if (!reg) {
644                 pr_err("Failed to read 'ibm,xive-lisn-ranges' property\n");
645                 return false;
646         }
647
648         if (len % (2 * sizeof(u32)) != 0) {
649                 pr_err("invalid 'ibm,xive-lisn-ranges' property\n");
650                 return false;
651         }
652
653         for (i = 0; i < len / (2 * sizeof(u32)); i++, reg += 2)
654                 xive_irq_bitmap_add(be32_to_cpu(reg[0]),
655                                     be32_to_cpu(reg[1]));
656
657         /* Iterate the EQ sizes and pick one */
658         of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, reg, val) {
659                 xive_queue_shift = val;
660                 if (val == PAGE_SHIFT)
661                         break;
662         }
663
664         /* Initialize XIVE core with our backend */
665         if (!xive_core_init(&xive_spapr_ops, tima, TM_QW1_OS, max_prio))
666                 return false;
667
668         pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
669         return true;
670 }