drivers/irqchip/irq-mips-gic.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2008 Ralf Baechle (ralf@linux-mips.org)
   7  * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
   8  */
   9
  10 #define pr_fmt(fmt) "irq-mips-gic: " fmt
  11
  12 #include <linux/bitfield.h>
  13 #include <linux/bitmap.h>
  14 #include <linux/clocksource.h>
  15 #include <linux/cpuhotplug.h>
  16 #include <linux/init.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/irq.h>
  19 #include <linux/irqchip.h>
  20 #include <linux/irqdomain.h>
  21 #include <linux/of_address.h>
  22 #include <linux/percpu.h>
  23 #include <linux/sched.h>
  24 #include <linux/smp.h>
  25
  26 #include <asm/mips-cps.h>
  27 #include <asm/setup.h>
  28 #include <asm/traps.h>
  29
  30 #include <dt-bindings/interrupt-controller/mips-gic.h>
  31
  32 #define GIC_MAX_INTRS           256
  33 #define GIC_MAX_LONGS           BITS_TO_LONGS(GIC_MAX_INTRS)
  34
  35 /* Add 2 to convert GIC CPU pin to core interrupt */
  36 #define GIC_CPU_PIN_OFFSET      2
  37
  38 /* Mapped interrupt to pin X, then GIC will generate the vector (X+1). */
  39 #define GIC_PIN_TO_VEC_OFFSET   1
  40
  41 /* Convert between local/shared IRQ number and GIC HW IRQ number. */
  42 #define GIC_LOCAL_HWIRQ_BASE    0
  43 #define GIC_LOCAL_TO_HWIRQ(x)   (GIC_LOCAL_HWIRQ_BASE + (x))
  44 #define GIC_HWIRQ_TO_LOCAL(x)   ((x) - GIC_LOCAL_HWIRQ_BASE)
  45 #define GIC_SHARED_HWIRQ_BASE   GIC_NUM_LOCAL_INTRS
  46 #define GIC_SHARED_TO_HWIRQ(x)  (GIC_SHARED_HWIRQ_BASE + (x))
  47 #define GIC_HWIRQ_TO_SHARED(x)  ((x) - GIC_SHARED_HWIRQ_BASE)
  48
  49 void __iomem *mips_gic_base;
  50
  51 static DEFINE_PER_CPU_READ_MOSTLY(unsigned long[GIC_MAX_LONGS], pcpu_masks);
  52
  53 static DEFINE_SPINLOCK(gic_lock);
  54 static struct irq_domain *gic_irq_domain;
  55 static int gic_shared_intrs;
  56 static unsigned int gic_cpu_pin;
  57 static struct irq_chip gic_level_irq_controller, gic_edge_irq_controller;
  58
  59 #ifdef CONFIG_GENERIC_IRQ_IPI
  60 static DECLARE_BITMAP(ipi_resrv, GIC_MAX_INTRS);
  61 static DECLARE_BITMAP(ipi_available, GIC_MAX_INTRS);
  62 #endif /* CONFIG_GENERIC_IRQ_IPI */
  63
  64 static struct gic_all_vpes_chip_data {
  65         u32     map;
  66         bool    mask;
  67 } gic_all_vpes_chip_data[GIC_NUM_LOCAL_INTRS];
  68
  69 static void gic_clear_pcpu_masks(unsigned int intr)
  70 {
  71         unsigned int i;
  72
  73         /* Clear the interrupt's bit in all pcpu_masks */
  74         for_each_possible_cpu(i)
  75                 clear_bit(intr, per_cpu_ptr(pcpu_masks, i));
  76 }
  77
  78 static bool gic_local_irq_is_routable(int intr)
  79 {
  80         u32 vpe_ctl;
  81
  82         /* All local interrupts are routable in EIC mode. */
  83         if (cpu_has_veic)
  84                 return true;
  85
  86         vpe_ctl = read_gic_vl_ctl();
  87         switch (intr) {
  88         case GIC_LOCAL_INT_TIMER:
  89                 return vpe_ctl & GIC_VX_CTL_TIMER_ROUTABLE;
  90         case GIC_LOCAL_INT_PERFCTR:
  91                 return vpe_ctl & GIC_VX_CTL_PERFCNT_ROUTABLE;
  92         case GIC_LOCAL_INT_FDC:
  93                 return vpe_ctl & GIC_VX_CTL_FDC_ROUTABLE;
  94         case GIC_LOCAL_INT_SWINT0:
  95         case GIC_LOCAL_INT_SWINT1:
  96                 return vpe_ctl & GIC_VX_CTL_SWINT_ROUTABLE;
  97         default:
  98                 return true;
  99         }
 100 }
 101
 102 static void gic_bind_eic_interrupt(int irq, int set)
 103 {
 104         /* Convert irq vector # to hw int # */
 105         irq -= GIC_PIN_TO_VEC_OFFSET;
 106
 107         /* Set irq to use shadow set */
 108         write_gic_vl_eic_shadow_set(irq, set);
 109 }
 110
 111 static void gic_send_ipi(struct irq_data *d, unsigned int cpu)
 112 {
 113         irq_hw_number_t hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(d));
 114
 115         write_gic_wedge(GIC_WEDGE_RW | hwirq);
 116 }
 117
 118 int gic_get_c0_compare_int(void)
 119 {
 120         if (!gic_local_irq_is_routable(GIC_LOCAL_INT_TIMER))
 121                 return MIPS_CPU_IRQ_BASE + cp0_compare_irq;
 122         return irq_create_mapping(gic_irq_domain,
 123                                   GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_TIMER));
 124 }
 125
 126 int gic_get_c0_perfcount_int(void)
 127 {
 128         if (!gic_local_irq_is_routable(GIC_LOCAL_INT_PERFCTR)) {
 129                 /* Is the performance counter shared with the timer? */
 130                 if (cp0_perfcount_irq < 0)
 131                         return -1;
 132                 return MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
 133         }
 134         return irq_create_mapping(gic_irq_domain,
 135                                   GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_PERFCTR));
 136 }
 137
 138 int gic_get_c0_fdc_int(void)
 139 {
 140         if (!gic_local_irq_is_routable(GIC_LOCAL_INT_FDC)) {
 141                 /* Is the FDC IRQ even present? */
 142                 if (cp0_fdc_irq < 0)
 143                         return -1;
 144                 return MIPS_CPU_IRQ_BASE + cp0_fdc_irq;
 145         }
 146
 147         return irq_create_mapping(gic_irq_domain,
 148                                   GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_FDC));
 149 }
 150
 151 static void gic_handle_shared_int(bool chained)
 152 {
 153         unsigned int intr;
 154         unsigned long *pcpu_mask;
 155         DECLARE_BITMAP(pending, GIC_MAX_INTRS);
 156
 157         /* Get per-cpu bitmaps */
 158         pcpu_mask = this_cpu_ptr(pcpu_masks);
 159
 160         if (mips_cm_is64)
 161                 __ioread64_copy(pending, addr_gic_pend(),
 162                                 DIV_ROUND_UP(gic_shared_intrs, 64));
 163         else
 164                 __ioread32_copy(pending, addr_gic_pend(),
 165                                 DIV_ROUND_UP(gic_shared_intrs, 32));
 166
 167         bitmap_and(pending, pending, pcpu_mask, gic_shared_intrs);
 168
 169         for_each_set_bit(intr, pending, gic_shared_intrs) {
 170                 if (chained)
 171                         generic_handle_domain_irq(gic_irq_domain,
 172                                                   GIC_SHARED_TO_HWIRQ(intr));
 173                 else
 174                         do_domain_IRQ(gic_irq_domain,
 175                                       GIC_SHARED_TO_HWIRQ(intr));
 176         }
 177 }
 178
 179 static void gic_mask_irq(struct irq_data *d)
 180 {
 181         unsigned int intr = GIC_HWIRQ_TO_SHARED(d->hwirq);
 182
 183         write_gic_rmask(intr);
 184         gic_clear_pcpu_masks(intr);
 185 }
 186
 187 static void gic_unmask_irq(struct irq_data *d)
 188 {
 189         unsigned int intr = GIC_HWIRQ_TO_SHARED(d->hwirq);
 190         unsigned int cpu;
 191
 192         write_gic_smask(intr);
 193
 194         gic_clear_pcpu_masks(intr);
 195         cpu = cpumask_first(irq_data_get_effective_affinity_mask(d));
 196         set_bit(intr, per_cpu_ptr(pcpu_masks, cpu));
 197 }
 198
 199 static void gic_ack_irq(struct irq_data *d)
 200 {
 201         unsigned int irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
 202
 203         write_gic_wedge(irq);
 204 }
 205
 206 static int gic_set_type(struct irq_data *d, unsigned int type)
 207 {
 208         unsigned int irq, pol, trig, dual;
 209         unsigned long flags;
 210
 211         irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
 212
 213         spin_lock_irqsave(&gic_lock, flags);
 214         switch (type & IRQ_TYPE_SENSE_MASK) {
 215         case IRQ_TYPE_EDGE_FALLING:
 216                 pol = GIC_POL_FALLING_EDGE;
 217                 trig = GIC_TRIG_EDGE;
 218                 dual = GIC_DUAL_SINGLE;
 219                 break;
 220         case IRQ_TYPE_EDGE_RISING:
 221                 pol = GIC_POL_RISING_EDGE;
 222                 trig = GIC_TRIG_EDGE;
 223                 dual = GIC_DUAL_SINGLE;
 224                 break;
 225         case IRQ_TYPE_EDGE_BOTH:
 226                 pol = 0; /* Doesn't matter */
 227                 trig = GIC_TRIG_EDGE;
 228                 dual = GIC_DUAL_DUAL;
 229                 break;
 230         case IRQ_TYPE_LEVEL_LOW:
 231                 pol = GIC_POL_ACTIVE_LOW;
 232                 trig = GIC_TRIG_LEVEL;
 233                 dual = GIC_DUAL_SINGLE;
 234                 break;
 235         case IRQ_TYPE_LEVEL_HIGH:
 236         default:
 237                 pol = GIC_POL_ACTIVE_HIGH;
 238                 trig = GIC_TRIG_LEVEL;
 239                 dual = GIC_DUAL_SINGLE;
 240                 break;
 241         }
 242
 243         change_gic_pol(irq, pol);
 244         change_gic_trig(irq, trig);
 245         change_gic_dual(irq, dual);
 246
 247         if (trig == GIC_TRIG_EDGE)
 248                 irq_set_chip_handler_name_locked(d, &gic_edge_irq_controller,
 249                                                  handle_edge_irq, NULL);
 250         else
 251                 irq_set_chip_handler_name_locked(d, &gic_level_irq_controller,
 252                                                  handle_level_irq, NULL);
 253         spin_unlock_irqrestore(&gic_lock, flags);
 254
 255         return 0;
 256 }
 257
 258 #ifdef CONFIG_SMP
 259 static int gic_set_affinity(struct irq_data *d, const struct cpumask *cpumask,
 260                             bool force)
 261 {
 262         unsigned int irq = GIC_HWIRQ_TO_SHARED(d->hwirq);
 263         unsigned long flags;
 264         unsigned int cpu;
 265
 266         cpu = cpumask_first_and(cpumask, cpu_online_mask);
 267         if (cpu >= NR_CPUS)
 268                 return -EINVAL;
 269
 270         /* Assumption : cpumask refers to a single CPU */
 271         spin_lock_irqsave(&gic_lock, flags);
 272
 273         /* Re-route this IRQ */
 274         write_gic_map_vp(irq, BIT(mips_cm_vp_id(cpu)));
 275
 276         /* Update the pcpu_masks */
 277         gic_clear_pcpu_masks(irq);
 278         if (read_gic_mask(irq))
 279                 set_bit(irq, per_cpu_ptr(pcpu_masks, cpu));
 280
 281         irq_data_update_effective_affinity(d, cpumask_of(cpu));
 282         spin_unlock_irqrestore(&gic_lock, flags);
 283
 284         return IRQ_SET_MASK_OK;
 285 }
 286 #endif
 287
 288 static struct irq_chip gic_level_irq_controller = {
 289         .name                   =       "MIPS GIC",
 290         .irq_mask               =       gic_mask_irq,
 291         .irq_unmask             =       gic_unmask_irq,
 292         .irq_set_type           =       gic_set_type,
 293 #ifdef CONFIG_SMP
 294         .irq_set_affinity       =       gic_set_affinity,
 295 #endif
 296 };
 297
 298 static struct irq_chip gic_edge_irq_controller = {
 299         .name                   =       "MIPS GIC",
 300         .irq_ack                =       gic_ack_irq,
 301         .irq_mask               =       gic_mask_irq,
 302         .irq_unmask             =       gic_unmask_irq,
 303         .irq_set_type           =       gic_set_type,
 304 #ifdef CONFIG_SMP
 305         .irq_set_affinity       =       gic_set_affinity,
 306 #endif
 307         .ipi_send_single        =       gic_send_ipi,
 308 };
 309
 310 static void gic_handle_local_int(bool chained)
 311 {
 312         unsigned long pending, masked;
 313         unsigned int intr;
 314
 315         pending = read_gic_vl_pend();
 316         masked = read_gic_vl_mask();
 317
 318         bitmap_and(&pending, &pending, &masked, GIC_NUM_LOCAL_INTRS);
 319
 320         for_each_set_bit(intr, &pending, GIC_NUM_LOCAL_INTRS) {
 321                 if (chained)
 322                         generic_handle_domain_irq(gic_irq_domain,
 323                                                   GIC_LOCAL_TO_HWIRQ(intr));
 324                 else
 325                         do_domain_IRQ(gic_irq_domain,
 326                                       GIC_LOCAL_TO_HWIRQ(intr));
 327         }
 328 }
 329
 330 static void gic_mask_local_irq(struct irq_data *d)
 331 {
 332         int intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
 333
 334         write_gic_vl_rmask(BIT(intr));
 335 }
 336
 337 static void gic_unmask_local_irq(struct irq_data *d)
 338 {
 339         int intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
 340
 341         write_gic_vl_smask(BIT(intr));
 342 }
 343
 344 static struct irq_chip gic_local_irq_controller = {
 345         .name                   =       "MIPS GIC Local",
 346         .irq_mask               =       gic_mask_local_irq,
 347         .irq_unmask             =       gic_unmask_local_irq,
 348 };
 349
 350 static void gic_mask_local_irq_all_vpes(struct irq_data *d)
 351 {
 352         struct gic_all_vpes_chip_data *cd;
 353         unsigned long flags;
 354         int intr, cpu;
 355
 356         intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
 357         cd = irq_data_get_irq_chip_data(d);
 358         cd->mask = false;
 359
 360         spin_lock_irqsave(&gic_lock, flags);
 361         for_each_online_cpu(cpu) {
 362                 write_gic_vl_other(mips_cm_vp_id(cpu));
 363                 write_gic_vo_rmask(BIT(intr));
 364         }
 365         spin_unlock_irqrestore(&gic_lock, flags);
 366 }
 367
 368 static void gic_unmask_local_irq_all_vpes(struct irq_data *d)
 369 {
 370         struct gic_all_vpes_chip_data *cd;
 371         unsigned long flags;
 372         int intr, cpu;
 373
 374         intr = GIC_HWIRQ_TO_LOCAL(d->hwirq);
 375         cd = irq_data_get_irq_chip_data(d);
 376         cd->mask = true;
 377
 378         spin_lock_irqsave(&gic_lock, flags);
 379         for_each_online_cpu(cpu) {
 380                 write_gic_vl_other(mips_cm_vp_id(cpu));
 381                 write_gic_vo_smask(BIT(intr));
 382         }
 383         spin_unlock_irqrestore(&gic_lock, flags);
 384 }
 385
 386 static void gic_all_vpes_irq_cpu_online(void)
 387 {
 388         static const unsigned int local_intrs[] = {
 389                 GIC_LOCAL_INT_TIMER,
 390                 GIC_LOCAL_INT_PERFCTR,
 391                 GIC_LOCAL_INT_FDC,
 392         };
 393         unsigned long flags;
 394         int i;
 395
 396         spin_lock_irqsave(&gic_lock, flags);
 397
 398         for (i = 0; i < ARRAY_SIZE(local_intrs); i++) {
 399                 unsigned int intr = local_intrs[i];
 400                 struct gic_all_vpes_chip_data *cd;
 401
 402                 cd = &gic_all_vpes_chip_data[intr];
 403                 write_gic_vl_map(mips_gic_vx_map_reg(intr), cd->map);
 404                 if (cd->mask)
 405                         write_gic_vl_smask(BIT(intr));
 406         }
 407
 408         spin_unlock_irqrestore(&gic_lock, flags);
 409 }
 410
 411 static struct irq_chip gic_all_vpes_local_irq_controller = {
 412         .name                   = "MIPS GIC Local",
 413         .irq_mask               = gic_mask_local_irq_all_vpes,
 414         .irq_unmask             = gic_unmask_local_irq_all_vpes,
 415 };
 416
 417 static void __gic_irq_dispatch(void)
 418 {
 419         gic_handle_local_int(false);
 420         gic_handle_shared_int(false);
 421 }
 422
 423 static void gic_irq_dispatch(struct irq_desc *desc)
 424 {
 425         gic_handle_local_int(true);
 426         gic_handle_shared_int(true);
 427 }
 428
 429 static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq,
 430                                      irq_hw_number_t hw, unsigned int cpu)
 431 {
 432         int intr = GIC_HWIRQ_TO_SHARED(hw);
 433         struct irq_data *data;
 434         unsigned long flags;
 435
 436         data = irq_get_irq_data(virq);
 437
 438         spin_lock_irqsave(&gic_lock, flags);
 439         write_gic_map_pin(intr, GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin);
 440         write_gic_map_vp(intr, BIT(mips_cm_vp_id(cpu)));
 441         irq_data_update_effective_affinity(data, cpumask_of(cpu));
 442         spin_unlock_irqrestore(&gic_lock, flags);
 443
 444         return 0;
 445 }
 446
 447 static int gic_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
 448                                 const u32 *intspec, unsigned int intsize,
 449                                 irq_hw_number_t *out_hwirq,
 450                                 unsigned int *out_type)
 451 {
 452         if (intsize != 3)
 453                 return -EINVAL;
 454
 455         if (intspec[0] == GIC_SHARED)
 456                 *out_hwirq = GIC_SHARED_TO_HWIRQ(intspec[1]);
 457         else if (intspec[0] == GIC_LOCAL)
 458                 *out_hwirq = GIC_LOCAL_TO_HWIRQ(intspec[1]);
 459         else
 460                 return -EINVAL;
 461         *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
 462
 463         return 0;
 464 }
 465
 466 static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
 467                               irq_hw_number_t hwirq)
 468 {
 469         struct gic_all_vpes_chip_data *cd;
 470         unsigned long flags;
 471         unsigned int intr;
 472         int err, cpu;
 473         u32 map;
 474
 475         if (hwirq >= GIC_SHARED_HWIRQ_BASE) {
 476 #ifdef CONFIG_GENERIC_IRQ_IPI
 477                 /* verify that shared irqs don't conflict with an IPI irq */
 478                 if (test_bit(GIC_HWIRQ_TO_SHARED(hwirq), ipi_resrv))
 479                         return -EBUSY;
 480 #endif /* CONFIG_GENERIC_IRQ_IPI */
 481
 482                 err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
 483                                                     &gic_level_irq_controller,
 484                                                     NULL);
 485                 if (err)
 486                         return err;
 487
 488                 irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
 489                 return gic_shared_irq_domain_map(d, virq, hwirq, 0);
 490         }
 491
 492         intr = GIC_HWIRQ_TO_LOCAL(hwirq);
 493         map = GIC_MAP_PIN_MAP_TO_PIN | gic_cpu_pin;
 494
 495         /*
 496          * If adding support for more per-cpu interrupts, keep the
 497          * array in gic_all_vpes_irq_cpu_online() in sync.
 498          */
 499         switch (intr) {
 500         case GIC_LOCAL_INT_TIMER:
 501         case GIC_LOCAL_INT_PERFCTR:
 502         case GIC_LOCAL_INT_FDC:
 503                 /*
 504                  * HACK: These are all really percpu interrupts, but
 505                  * the rest of the MIPS kernel code does not use the
 506                  * percpu IRQ API for them.
 507                  */
 508                 cd = &gic_all_vpes_chip_data[intr];
 509                 cd->map = map;
 510                 err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
 511                                                     &gic_all_vpes_local_irq_controller,
 512                                                     cd);
 513                 if (err)
 514                         return err;
 515
 516                 irq_set_handler(virq, handle_percpu_irq);
 517                 break;
 518
 519         default:
 520                 err = irq_domain_set_hwirq_and_chip(d, virq, hwirq,
 521                                                     &gic_local_irq_controller,
 522                                                     NULL);
 523                 if (err)
 524                         return err;
 525
 526                 irq_set_handler(virq, handle_percpu_devid_irq);
 527                 irq_set_percpu_devid(virq);
 528                 break;
 529         }
 530
 531         if (!gic_local_irq_is_routable(intr))
 532                 return -EPERM;
 533
 534         spin_lock_irqsave(&gic_lock, flags);
 535         for_each_online_cpu(cpu) {
 536                 write_gic_vl_other(mips_cm_vp_id(cpu));
 537                 write_gic_vo_map(mips_gic_vx_map_reg(intr), map);
 538         }
 539         spin_unlock_irqrestore(&gic_lock, flags);
 540
 541         return 0;
 542 }
 543
 544 static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq,
 545                                 unsigned int nr_irqs, void *arg)
 546 {
 547         struct irq_fwspec *fwspec = arg;
 548         irq_hw_number_t hwirq;
 549
 550         if (fwspec->param[0] == GIC_SHARED)
 551                 hwirq = GIC_SHARED_TO_HWIRQ(fwspec->param[1]);
 552         else
 553                 hwirq = GIC_LOCAL_TO_HWIRQ(fwspec->param[1]);
 554
 555         return gic_irq_domain_map(d, virq, hwirq);
 556 }
 557
 558 void gic_irq_domain_free(struct irq_domain *d, unsigned int virq,
 559                          unsigned int nr_irqs)
 560 {
 561 }
 562
 563 static const struct irq_domain_ops gic_irq_domain_ops = {
 564         .xlate = gic_irq_domain_xlate,
 565         .alloc = gic_irq_domain_alloc,
 566         .free = gic_irq_domain_free,
 567         .map = gic_irq_domain_map,
 568 };
 569
 570 #ifdef CONFIG_GENERIC_IRQ_IPI
 571
 572 static int gic_ipi_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
 573                                 const u32 *intspec, unsigned int intsize,
 574                                 irq_hw_number_t *out_hwirq,
 575                                 unsigned int *out_type)
 576 {
 577         /*
 578          * There's nothing to translate here. hwirq is dynamically allocated and
 579          * the irq type is always edge triggered.
 580          * */
 581         *out_hwirq = 0;
 582         *out_type = IRQ_TYPE_EDGE_RISING;
 583
 584         return 0;
 585 }
 586
 587 static int gic_ipi_domain_alloc(struct irq_domain *d, unsigned int virq,
 588                                 unsigned int nr_irqs, void *arg)
 589 {
 590         struct cpumask *ipimask = arg;
 591         irq_hw_number_t hwirq, base_hwirq;
 592         int cpu, ret, i;
 593
 594         base_hwirq = find_first_bit(ipi_available, gic_shared_intrs);
 595         if (base_hwirq == gic_shared_intrs)
 596                 return -ENOMEM;
 597
 598         /* check that we have enough space */
 599         for (i = base_hwirq; i < nr_irqs; i++) {
 600                 if (!test_bit(i, ipi_available))
 601                         return -EBUSY;
 602         }
 603         bitmap_clear(ipi_available, base_hwirq, nr_irqs);
 604
 605         /* map the hwirq for each cpu consecutively */
 606         i = 0;
 607         for_each_cpu(cpu, ipimask) {
 608                 hwirq = GIC_SHARED_TO_HWIRQ(base_hwirq + i);
 609
 610                 ret = irq_domain_set_hwirq_and_chip(d, virq + i, hwirq,
 611                                                     &gic_edge_irq_controller,
 612                                                     NULL);
 613                 if (ret)
 614                         goto error;
 615
 616                 ret = irq_domain_set_hwirq_and_chip(d->parent, virq + i, hwirq,
 617                                                     &gic_edge_irq_controller,
 618                                                     NULL);
 619                 if (ret)
 620                         goto error;
 621
 622                 ret = irq_set_irq_type(virq + i, IRQ_TYPE_EDGE_RISING);
 623                 if (ret)
 624                         goto error;
 625
 626                 ret = gic_shared_irq_domain_map(d, virq + i, hwirq, cpu);
 627                 if (ret)
 628                         goto error;
 629
 630                 i++;
 631         }
 632
 633         return 0;
 634 error:
 635         bitmap_set(ipi_available, base_hwirq, nr_irqs);
 636         return ret;
 637 }
 638
 639 static void gic_ipi_domain_free(struct irq_domain *d, unsigned int virq,
 640                                 unsigned int nr_irqs)
 641 {
 642         irq_hw_number_t base_hwirq;
 643         struct irq_data *data;
 644
 645         data = irq_get_irq_data(virq);
 646         if (!data)
 647                 return;
 648
 649         base_hwirq = GIC_HWIRQ_TO_SHARED(irqd_to_hwirq(data));
 650         bitmap_set(ipi_available, base_hwirq, nr_irqs);
 651 }
 652
 653 static int gic_ipi_domain_match(struct irq_domain *d, struct device_node *node,
 654                                 enum irq_domain_bus_token bus_token)
 655 {
 656         bool is_ipi;
 657
 658         switch (bus_token) {
 659         case DOMAIN_BUS_IPI:
 660                 is_ipi = d->bus_token == bus_token;
 661                 return (!node || to_of_node(d->fwnode) == node) && is_ipi;
 662                 break;
 663         default:
 664                 return 0;
 665         }
 666 }
 667
 668 static const struct irq_domain_ops gic_ipi_domain_ops = {
 669         .xlate = gic_ipi_domain_xlate,
 670         .alloc = gic_ipi_domain_alloc,
 671         .free = gic_ipi_domain_free,
 672         .match = gic_ipi_domain_match,
 673 };
 674
 675 static int gic_register_ipi_domain(struct device_node *node)
 676 {
 677         struct irq_domain *gic_ipi_domain;
 678         unsigned int v[2], num_ipis;
 679
 680         gic_ipi_domain = irq_domain_add_hierarchy(gic_irq_domain,
 681                                                   IRQ_DOMAIN_FLAG_IPI_PER_CPU,
 682                                                   GIC_NUM_LOCAL_INTRS + gic_shared_intrs,
 683                                                   node, &gic_ipi_domain_ops, NULL);
 684         if (!gic_ipi_domain) {
 685                 pr_err("Failed to add IPI domain");
 686                 return -ENXIO;
 687         }
 688
 689         irq_domain_update_bus_token(gic_ipi_domain, DOMAIN_BUS_IPI);
 690
 691         if (node &&
 692             !of_property_read_u32_array(node, "mti,reserved-ipi-vectors", v, 2)) {
 693                 bitmap_set(ipi_resrv, v[0], v[1]);
 694         } else {
 695                 /*
 696                  * Reserve 2 interrupts per possible CPU/VP for use as IPIs,
 697                  * meeting the requirements of arch/mips SMP.
 698                  */
 699                 num_ipis = 2 * num_possible_cpus();
 700                 bitmap_set(ipi_resrv, gic_shared_intrs - num_ipis, num_ipis);
 701         }
 702
 703         bitmap_copy(ipi_available, ipi_resrv, GIC_MAX_INTRS);
 704
 705         return 0;
 706 }
 707
 708 #else /* !CONFIG_GENERIC_IRQ_IPI */
 709
 710 static inline int gic_register_ipi_domain(struct device_node *node)
 711 {
 712         return 0;
 713 }
 714
 715 #endif /* !CONFIG_GENERIC_IRQ_IPI */
 716
 717 static int gic_cpu_startup(unsigned int cpu)
 718 {
 719         /* Enable or disable EIC */
 720         change_gic_vl_ctl(GIC_VX_CTL_EIC,
 721                           cpu_has_veic ? GIC_VX_CTL_EIC : 0);
 722
 723         /* Clear all local IRQ masks (ie. disable all local interrupts) */
 724         write_gic_vl_rmask(~0);
 725
 726         /* Enable desired interrupts */
 727         gic_all_vpes_irq_cpu_online();
 728
 729         return 0;
 730 }
 731
 732 static int __init gic_of_init(struct device_node *node,
 733                               struct device_node *parent)
 734 {
 735         unsigned int cpu_vec, i, gicconfig;
 736         unsigned long reserved;
 737         phys_addr_t gic_base;
 738         struct resource res;
 739         size_t gic_len;
 740         int ret;
 741
 742         /* Find the first available CPU vector. */
 743         i = 0;
 744         reserved = (C_SW0 | C_SW1) >> __ffs(C_SW0);
 745         while (!of_property_read_u32_index(node, "mti,reserved-cpu-vectors",
 746                                            i++, &cpu_vec))
 747                 reserved |= BIT(cpu_vec);
 748
 749         cpu_vec = find_first_zero_bit(&reserved, hweight_long(ST0_IM));
 750         if (cpu_vec == hweight_long(ST0_IM)) {
 751                 pr_err("No CPU vectors available\n");
 752                 return -ENODEV;
 753         }
 754
 755         if (of_address_to_resource(node, 0, &res)) {
 756                 /*
 757                  * Probe the CM for the GIC base address if not specified
 758                  * in the device-tree.
 759                  */
 760                 if (mips_cm_present()) {
 761                         gic_base = read_gcr_gic_base() &
 762                                 ~CM_GCR_GIC_BASE_GICEN;
 763                         gic_len = 0x20000;
 764                         pr_warn("Using inherited base address %pa\n",
 765                                 &gic_base);
 766                 } else {
 767                         pr_err("Failed to get memory range\n");
 768                         return -ENODEV;
 769                 }
 770         } else {
 771                 gic_base = res.start;
 772                 gic_len = resource_size(&res);
 773         }
 774
 775         if (mips_cm_present()) {
 776                 write_gcr_gic_base(gic_base | CM_GCR_GIC_BASE_GICEN);
 777                 /* Ensure GIC region is enabled before trying to access it */
 778                 __sync();
 779         }
 780
 781         mips_gic_base = ioremap(gic_base, gic_len);
 782         if (!mips_gic_base) {
 783                 pr_err("Failed to ioremap gic_base\n");
 784                 return -ENOMEM;
 785         }
 786
 787         gicconfig = read_gic_config();
 788         gic_shared_intrs = FIELD_GET(GIC_CONFIG_NUMINTERRUPTS, gicconfig);
 789         gic_shared_intrs = (gic_shared_intrs + 1) * 8;
 790
 791         if (cpu_has_veic) {
 792                 /* Always use vector 1 in EIC mode */
 793                 gic_cpu_pin = 0;
 794                 set_vi_handler(gic_cpu_pin + GIC_PIN_TO_VEC_OFFSET,
 795                                __gic_irq_dispatch);
 796         } else {
 797                 gic_cpu_pin = cpu_vec - GIC_CPU_PIN_OFFSET;
 798                 irq_set_chained_handler(MIPS_CPU_IRQ_BASE + cpu_vec,
 799                                         gic_irq_dispatch);
 800         }
 801
 802         gic_irq_domain = irq_domain_add_simple(node, GIC_NUM_LOCAL_INTRS +
 803                                                gic_shared_intrs, 0,
 804                                                &gic_irq_domain_ops, NULL);
 805         if (!gic_irq_domain) {
 806                 pr_err("Failed to add IRQ domain");
 807                 return -ENXIO;
 808         }
 809
 810         ret = gic_register_ipi_domain(node);
 811         if (ret)
 812                 return ret;
 813
 814         board_bind_eic_interrupt = &gic_bind_eic_interrupt;
 815
 816         /* Setup defaults */
 817         for (i = 0; i < gic_shared_intrs; i++) {
 818                 change_gic_pol(i, GIC_POL_ACTIVE_HIGH);
 819                 change_gic_trig(i, GIC_TRIG_LEVEL);
 820                 write_gic_rmask(i);
 821         }
 822
 823         return cpuhp_setup_state(CPUHP_AP_IRQ_MIPS_GIC_STARTING,
 824                                  "irqchip/mips/gic:starting",
 825                                  gic_cpu_startup, NULL);
 826 }
 827 IRQCHIP_DECLARE(mips_gic, "mti,gic", gic_of_init);