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