linux/drivers/irqchip/irq-bcm7038-l1.c
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   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
  39struct bcm7038_l1_cpu;
  40
  41struct 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
  54struct 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
  83static 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
  89static 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
  95static 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
 101static 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
 107static 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
 115static 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
 123static 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
 157static 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
 168static 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
 179static 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
 189static 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
 199static 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
 227static 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
 253static 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 */
 323static LIST_HEAD(bcm7038_l1_intcs_list);
 324static DEFINE_RAW_SPINLOCK(bcm7038_l1_intcs_lock);
 325
 326static 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
 352static 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
 373static struct syscore_ops bcm7038_l1_syscore_ops = {
 374        .suspend        = bcm7038_l1_suspend,
 375        .resume         = bcm7038_l1_resume,
 376};
 377
 378static 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
 396static 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
 409static 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
 425static const struct irq_domain_ops bcm7038_l1_domain_ops = {
 426        .xlate                  = irq_domain_xlate_onecell,
 427        .map                    = bcm7038_l1_map,
 428};
 429
 430static 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
 474out_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        }
 484out_free:
 485        kfree(intc);
 486        return ret;
 487}
 488
 489IRQCHIP_DECLARE(bcm7038_l1, "brcm,bcm7038-l1-intc", bcm7038_l1_of_init);
 490