drivers/irqchip/irq-bcm7038-l1.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Broadcom BCM7038 style Level 1 interrupt controller driver
   4  *
   5  * Copyright (C) 2014 Broadcom Corporation
   6  * Author: Kevin Cernekee
   7  */
   8
   9 #define pr_fmt(fmt)     KBUILD_MODNAME  ": " fmt
  10
  11 #include <linux/bitops.h>
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/io.h>
  16 #include <linux/ioport.h>
  17 #include <linux/irq.h>
  18 #include <linux/irqdomain.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/of_address.h>
  23 #include <linux/of_platform.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/slab.h>
  26 #include <linux/smp.h>
  27 #include <linux/types.h>
  28 #include <linux/irqchip.h>
  29 #include <linux/irqchip/chained_irq.h>
  30 #include <linux/syscore_ops.h>
  31 #ifdef CONFIG_ARM
  32 #include <asm/smp_plat.h>
  33 #endif
  34
  35 #define IRQS_PER_WORD           32
  36 #define REG_BYTES_PER_IRQ_WORD  (sizeof(u32) * 4)
  37 #define MAX_WORDS               8
  38
  39 struct bcm7038_l1_cpu;
  40
  41 struct bcm7038_l1_chip {
  42         raw_spinlock_t          lock;
  43         unsigned int            n_words;
  44         struct irq_domain       *domain;
  45         struct bcm7038_l1_cpu   *cpus[NR_CPUS];
  46 #ifdef CONFIG_PM_SLEEP
  47         struct list_head        list;
  48         u32                     wake_mask[MAX_WORDS];
  49 #endif
  50         u32                     irq_fwd_mask[MAX_WORDS];
  51         u8                      affinity[MAX_WORDS * IRQS_PER_WORD];
  52 };
  53
  54 struct bcm7038_l1_cpu {
  55         void __iomem            *map_base;
  56         u32                     mask_cache[];
  57 };
  58
  59 /*
  60  * STATUS/MASK_STATUS/MASK_SET/MASK_CLEAR are packed one right after another:
  61  *
  62  * 7038:
  63  *   0x1000_1400: W0_STATUS
  64  *   0x1000_1404: W1_STATUS
  65  *   0x1000_1408: W0_MASK_STATUS
  66  *   0x1000_140c: W1_MASK_STATUS
  67  *   0x1000_1410: W0_MASK_SET
  68  *   0x1000_1414: W1_MASK_SET
  69  *   0x1000_1418: W0_MASK_CLEAR
  70  *   0x1000_141c: W1_MASK_CLEAR
  71  *
  72  * 7445:
  73  *   0xf03e_1500: W0_STATUS
  74  *   0xf03e_1504: W1_STATUS
  75  *   0xf03e_1508: W2_STATUS
  76  *   0xf03e_150c: W3_STATUS
  77  *   0xf03e_1510: W4_STATUS
  78  *   0xf03e_1514: W0_MASK_STATUS
  79  *   0xf03e_1518: W1_MASK_STATUS
  80  *   [...]
  81  */
  82
  83 static inline unsigned int reg_status(struct bcm7038_l1_chip *intc,
  84                                       unsigned int word)
  85 {
  86         return (0 * intc->n_words + word) * sizeof(u32);
  87 }
  88
  89 static inline unsigned int reg_mask_status(struct bcm7038_l1_chip *intc,
  90                                            unsigned int word)
  91 {
  92         return (1 * intc->n_words + word) * sizeof(u32);
  93 }
  94
  95 static inline unsigned int reg_mask_set(struct bcm7038_l1_chip *intc,
  96                                         unsigned int word)
  97 {
  98         return (2 * intc->n_words + word) * sizeof(u32);
  99 }
 100
 101 static inline unsigned int reg_mask_clr(struct bcm7038_l1_chip *intc,
 102                                         unsigned int word)
 103 {
 104         return (3 * intc->n_words + word) * sizeof(u32);
 105 }
 106
 107 static inline u32 l1_readl(void __iomem *reg)
 108 {
 109         if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 110                 return ioread32be(reg);
 111         else
 112                 return readl(reg);
 113 }
 114
 115 static inline void l1_writel(u32 val, void __iomem *reg)
 116 {
 117         if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 118                 iowrite32be(val, reg);
 119         else
 120                 writel(val, reg);
 121 }
 122
 123 static void bcm7038_l1_irq_handle(struct irq_desc *desc)
 124 {
 125         struct bcm7038_l1_chip *intc = irq_desc_get_handler_data(desc);
 126         struct bcm7038_l1_cpu *cpu;
 127         struct irq_chip *chip = irq_desc_get_chip(desc);
 128         unsigned int idx;
 129
 130 #ifdef CONFIG_SMP
 131         cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
 132 #else
 133         cpu = intc->cpus[0];
 134 #endif
 135
 136         chained_irq_enter(chip, desc);
 137
 138         for (idx = 0; idx < intc->n_words; idx++) {
 139                 int base = idx * IRQS_PER_WORD;
 140                 unsigned long pending, flags;
 141                 int hwirq;
 142
 143                 raw_spin_lock_irqsave(&intc->lock, flags);
 144                 pending = l1_readl(cpu->map_base + reg_status(intc, idx)) &
 145                           ~cpu->mask_cache[idx];
 146                 raw_spin_unlock_irqrestore(&intc->lock, flags);
 147
 148                 for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
 149                         generic_handle_irq(irq_find_mapping(intc->domain,
 150                                                             base + hwirq));
 151                 }
 152         }
 153
 154         chained_irq_exit(chip, desc);
 155 }
 156
 157 static void __bcm7038_l1_unmask(struct irq_data *d, unsigned int cpu_idx)
 158 {
 159         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 160         u32 word = d->hwirq / IRQS_PER_WORD;
 161         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 162
 163         intc->cpus[cpu_idx]->mask_cache[word] &= ~mask;
 164         l1_writel(mask, intc->cpus[cpu_idx]->map_base +
 165                         reg_mask_clr(intc, word));
 166 }
 167
 168 static void __bcm7038_l1_mask(struct irq_data *d, unsigned int cpu_idx)
 169 {
 170         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 171         u32 word = d->hwirq / IRQS_PER_WORD;
 172         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 173
 174         intc->cpus[cpu_idx]->mask_cache[word] |= mask;
 175         l1_writel(mask, intc->cpus[cpu_idx]->map_base +
 176                         reg_mask_set(intc, word));
 177 }
 178
 179 static void bcm7038_l1_unmask(struct irq_data *d)
 180 {
 181         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 182         unsigned long flags;
 183
 184         raw_spin_lock_irqsave(&intc->lock, flags);
 185         __bcm7038_l1_unmask(d, intc->affinity[d->hwirq]);
 186         raw_spin_unlock_irqrestore(&intc->lock, flags);
 187 }
 188
 189 static void bcm7038_l1_mask(struct irq_data *d)
 190 {
 191         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 192         unsigned long flags;
 193
 194         raw_spin_lock_irqsave(&intc->lock, flags);
 195         __bcm7038_l1_mask(d, intc->affinity[d->hwirq]);
 196         raw_spin_unlock_irqrestore(&intc->lock, flags);
 197 }
 198
 199 static int bcm7038_l1_set_affinity(struct irq_data *d,
 200                                    const struct cpumask *dest,
 201                                    bool force)
 202 {
 203         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 204         unsigned long flags;
 205         irq_hw_number_t hw = d->hwirq;
 206         u32 word = hw / IRQS_PER_WORD;
 207         u32 mask = BIT(hw % IRQS_PER_WORD);
 208         unsigned int first_cpu = cpumask_any_and(dest, cpu_online_mask);
 209         bool was_disabled;
 210
 211         raw_spin_lock_irqsave(&intc->lock, flags);
 212
 213         was_disabled = !!(intc->cpus[intc->affinity[hw]]->mask_cache[word] &
 214                           mask);
 215         __bcm7038_l1_mask(d, intc->affinity[hw]);
 216         intc->affinity[hw] = first_cpu;
 217         if (!was_disabled)
 218                 __bcm7038_l1_unmask(d, first_cpu);
 219
 220         raw_spin_unlock_irqrestore(&intc->lock, flags);
 221         irq_data_update_effective_affinity(d, cpumask_of(first_cpu));
 222
 223         return 0;
 224 }
 225
 226 #ifdef CONFIG_SMP
 227 static void bcm7038_l1_cpu_offline(struct irq_data *d)
 228 {
 229         struct cpumask *mask = irq_data_get_affinity_mask(d);
 230         int cpu = smp_processor_id();
 231         cpumask_t new_affinity;
 232
 233         /* This CPU was not on the affinity mask */
 234         if (!cpumask_test_cpu(cpu, mask))
 235                 return;
 236
 237         if (cpumask_weight(mask) > 1) {
 238                 /*
 239                  * Multiple CPU affinity, remove this CPU from the affinity
 240                  * mask
 241                  */
 242                 cpumask_copy(&new_affinity, mask);
 243                 cpumask_clear_cpu(cpu, &new_affinity);
 244         } else {
 245                 /* Only CPU, put on the lowest online CPU */
 246                 cpumask_clear(&new_affinity);
 247                 cpumask_set_cpu(cpumask_first(cpu_online_mask), &new_affinity);
 248         }
 249         irq_set_affinity_locked(d, &new_affinity, false);
 250 }
 251 #endif
 252
 253 static int __init bcm7038_l1_init_one(struct device_node *dn,
 254                                       unsigned int idx,
 255                                       struct bcm7038_l1_chip *intc)
 256 {
 257         struct resource res;
 258         resource_size_t sz;
 259         struct bcm7038_l1_cpu *cpu;
 260         unsigned int i, n_words, parent_irq;
 261         int ret;
 262
 263         if (of_address_to_resource(dn, idx, &res))
 264                 return -EINVAL;
 265         sz = resource_size(&res);
 266         n_words = sz / REG_BYTES_PER_IRQ_WORD;
 267
 268         if (n_words > MAX_WORDS)
 269                 return -EINVAL;
 270         else if (!intc->n_words)
 271                 intc->n_words = n_words;
 272         else if (intc->n_words != n_words)
 273                 return -EINVAL;
 274
 275         ret = of_property_read_u32_array(dn , "brcm,int-fwd-mask",
 276                                          intc->irq_fwd_mask, n_words);
 277         if (ret != 0 && ret != -EINVAL) {
 278                 /* property exists but has the wrong number of words */
 279                 pr_err("invalid brcm,int-fwd-mask property\n");
 280                 return -EINVAL;
 281         }
 282
 283         cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
 284                                         GFP_KERNEL);
 285         if (!cpu)
 286                 return -ENOMEM;
 287
 288         cpu->map_base = ioremap(res.start, sz);
 289         if (!cpu->map_base)
 290                 return -ENOMEM;
 291
 292         for (i = 0; i < n_words; i++) {
 293                 l1_writel(~intc->irq_fwd_mask[i],
 294                           cpu->map_base + reg_mask_set(intc, i));
 295                 l1_writel(intc->irq_fwd_mask[i],
 296                           cpu->map_base + reg_mask_clr(intc, i));
 297                 cpu->mask_cache[i] = ~intc->irq_fwd_mask[i];
 298         }
 299
 300         parent_irq = irq_of_parse_and_map(dn, idx);
 301         if (!parent_irq) {
 302                 pr_err("failed to map parent interrupt %d\n", parent_irq);
 303                 return -EINVAL;
 304         }
 305
 306         if (of_property_read_bool(dn, "brcm,irq-can-wake"))
 307                 enable_irq_wake(parent_irq);
 308
 309         irq_set_chained_handler_and_data(parent_irq, bcm7038_l1_irq_handle,
 310                                          intc);
 311
 312         return 0;
 313 }
 314
 315 #ifdef CONFIG_PM_SLEEP
 316 /*
 317  * We keep a list of bcm7038_l1_chip used for suspend/resume. This hack is
 318  * used because the struct chip_type suspend/resume hooks are not called
 319  * unless chip_type is hooked onto a generic_chip. Since this driver does
 320  * not use generic_chip, we need to manually hook our resume/suspend to
 321  * syscore_ops.
 322  */
 323 static LIST_HEAD(bcm7038_l1_intcs_list);
 324 static DEFINE_RAW_SPINLOCK(bcm7038_l1_intcs_lock);
 325
 326 static int bcm7038_l1_suspend(void)
 327 {
 328         struct bcm7038_l1_chip *intc;
 329         int boot_cpu, word;
 330         u32 val;
 331
 332         /* Wakeup interrupt should only come from the boot cpu */
 333 #ifdef CONFIG_SMP
 334         boot_cpu = cpu_logical_map(0);
 335 #else
 336         boot_cpu = 0;
 337 #endif
 338
 339         list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
 340                 for (word = 0; word < intc->n_words; word++) {
 341                         val = intc->wake_mask[word] | intc->irq_fwd_mask[word];
 342                         l1_writel(~val,
 343                                 intc->cpus[boot_cpu]->map_base + reg_mask_set(intc, word));
 344                         l1_writel(val,
 345                                 intc->cpus[boot_cpu]->map_base + reg_mask_clr(intc, word));
 346                 }
 347         }
 348
 349         return 0;
 350 }
 351
 352 static void bcm7038_l1_resume(void)
 353 {
 354         struct bcm7038_l1_chip *intc;
 355         int boot_cpu, word;
 356
 357 #ifdef CONFIG_SMP
 358         boot_cpu = cpu_logical_map(0);
 359 #else
 360         boot_cpu = 0;
 361 #endif
 362
 363         list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
 364                 for (word = 0; word < intc->n_words; word++) {
 365                         l1_writel(intc->cpus[boot_cpu]->mask_cache[word],
 366                                 intc->cpus[boot_cpu]->map_base + reg_mask_set(intc, word));
 367                         l1_writel(~intc->cpus[boot_cpu]->mask_cache[word],
 368                                 intc->cpus[boot_cpu]->map_base + reg_mask_clr(intc, word));
 369                 }
 370         }
 371 }
 372
 373 static struct syscore_ops bcm7038_l1_syscore_ops = {
 374         .suspend        = bcm7038_l1_suspend,
 375         .resume         = bcm7038_l1_resume,
 376 };
 377
 378 static int bcm7038_l1_set_wake(struct irq_data *d, unsigned int on)
 379 {
 380         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 381         unsigned long flags;
 382         u32 word = d->hwirq / IRQS_PER_WORD;
 383         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 384
 385         raw_spin_lock_irqsave(&intc->lock, flags);
 386         if (on)
 387                 intc->wake_mask[word] |= mask;
 388         else
 389                 intc->wake_mask[word] &= ~mask;
 390         raw_spin_unlock_irqrestore(&intc->lock, flags);
 391
 392         return 0;
 393 }
 394 #endif
 395
 396 static struct irq_chip bcm7038_l1_irq_chip = {
 397         .name                   = "bcm7038-l1",
 398         .irq_mask               = bcm7038_l1_mask,
 399         .irq_unmask             = bcm7038_l1_unmask,
 400         .irq_set_affinity       = bcm7038_l1_set_affinity,
 401 #ifdef CONFIG_SMP
 402         .irq_cpu_offline        = bcm7038_l1_cpu_offline,
 403 #endif
 404 #ifdef CONFIG_PM_SLEEP
 405         .irq_set_wake           = bcm7038_l1_set_wake,
 406 #endif
 407 };
 408
 409 static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
 410                           irq_hw_number_t hw_irq)
 411 {
 412         struct bcm7038_l1_chip *intc = d->host_data;
 413         u32 mask = BIT(hw_irq % IRQS_PER_WORD);
 414         u32 word = hw_irq / IRQS_PER_WORD;
 415
 416         if (intc->irq_fwd_mask[word] & mask)
 417                 return -EPERM;
 418
 419         irq_set_chip_and_handler(virq, &bcm7038_l1_irq_chip, handle_level_irq);
 420         irq_set_chip_data(virq, d->host_data);
 421         irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
 422         return 0;
 423 }
 424
 425 static const struct irq_domain_ops bcm7038_l1_domain_ops = {
 426         .xlate                  = irq_domain_xlate_onecell,
 427         .map                    = bcm7038_l1_map,
 428 };
 429
 430 static int __init bcm7038_l1_of_init(struct device_node *dn,
 431                               struct device_node *parent)
 432 {
 433         struct bcm7038_l1_chip *intc;
 434         int idx, ret;
 435
 436         intc = kzalloc(sizeof(*intc), GFP_KERNEL);
 437         if (!intc)
 438                 return -ENOMEM;
 439
 440         raw_spin_lock_init(&intc->lock);
 441         for_each_possible_cpu(idx) {
 442                 ret = bcm7038_l1_init_one(dn, idx, intc);
 443                 if (ret < 0) {
 444                         if (idx)
 445                                 break;
 446                         pr_err("failed to remap intc L1 registers\n");
 447                         goto out_free;
 448                 }
 449         }
 450
 451         intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
 452                                              &bcm7038_l1_domain_ops,
 453                                              intc);
 454         if (!intc->domain) {
 455                 ret = -ENOMEM;
 456                 goto out_unmap;
 457         }
 458
 459 #ifdef CONFIG_PM_SLEEP
 460         /* Add bcm7038_l1_chip into a list */
 461         raw_spin_lock(&bcm7038_l1_intcs_lock);
 462         list_add_tail(&intc->list, &bcm7038_l1_intcs_list);
 463         raw_spin_unlock(&bcm7038_l1_intcs_lock);
 464
 465         if (list_is_singular(&bcm7038_l1_intcs_list))
 466                 register_syscore_ops(&bcm7038_l1_syscore_ops);
 467 #endif
 468
 469         pr_info("registered BCM7038 L1 intc (%pOF, IRQs: %d)\n",
 470                 dn, IRQS_PER_WORD * intc->n_words);
 471
 472         return 0;
 473
 474 out_unmap:
 475         for_each_possible_cpu(idx) {
 476                 struct bcm7038_l1_cpu *cpu = intc->cpus[idx];
 477
 478                 if (cpu) {
 479                         if (cpu->map_base)
 480                                 iounmap(cpu->map_base);
 481                         kfree(cpu);
 482                 }
 483         }
 484 out_free:
 485         kfree(intc);
 486         return ret;
 487 }
 488
 489 IRQCHIP_DECLARE(bcm7038_l1, "brcm,bcm7038-l1-intc", bcm7038_l1_of_init);