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
  31#define IRQS_PER_WORD           32
  32#define REG_BYTES_PER_IRQ_WORD  (sizeof(u32) * 4)
  33#define MAX_WORDS               8
  34
  35struct bcm7038_l1_cpu;
  36
  37struct bcm7038_l1_chip {
  38        raw_spinlock_t          lock;
  39        unsigned int            n_words;
  40        struct irq_domain       *domain;
  41        struct bcm7038_l1_cpu   *cpus[NR_CPUS];
  42        u8                      affinity[MAX_WORDS * IRQS_PER_WORD];
  43};
  44
  45struct bcm7038_l1_cpu {
  46        void __iomem            *map_base;
  47        u32                     mask_cache[0];
  48};
  49
  50/*
  51 * STATUS/MASK_STATUS/MASK_SET/MASK_CLEAR are packed one right after another:
  52 *
  53 * 7038:
  54 *   0x1000_1400: W0_STATUS
  55 *   0x1000_1404: W1_STATUS
  56 *   0x1000_1408: W0_MASK_STATUS
  57 *   0x1000_140c: W1_MASK_STATUS
  58 *   0x1000_1410: W0_MASK_SET
  59 *   0x1000_1414: W1_MASK_SET
  60 *   0x1000_1418: W0_MASK_CLEAR
  61 *   0x1000_141c: W1_MASK_CLEAR
  62 *
  63 * 7445:
  64 *   0xf03e_1500: W0_STATUS
  65 *   0xf03e_1504: W1_STATUS
  66 *   0xf03e_1508: W2_STATUS
  67 *   0xf03e_150c: W3_STATUS
  68 *   0xf03e_1510: W4_STATUS
  69 *   0xf03e_1514: W0_MASK_STATUS
  70 *   0xf03e_1518: W1_MASK_STATUS
  71 *   [...]
  72 */
  73
  74static inline unsigned int reg_status(struct bcm7038_l1_chip *intc,
  75                                      unsigned int word)
  76{
  77        return (0 * intc->n_words + word) * sizeof(u32);
  78}
  79
  80static inline unsigned int reg_mask_status(struct bcm7038_l1_chip *intc,
  81                                           unsigned int word)
  82{
  83        return (1 * intc->n_words + word) * sizeof(u32);
  84}
  85
  86static inline unsigned int reg_mask_set(struct bcm7038_l1_chip *intc,
  87                                        unsigned int word)
  88{
  89        return (2 * intc->n_words + word) * sizeof(u32);
  90}
  91
  92static inline unsigned int reg_mask_clr(struct bcm7038_l1_chip *intc,
  93                                        unsigned int word)
  94{
  95        return (3 * intc->n_words + word) * sizeof(u32);
  96}
  97
  98static inline u32 l1_readl(void __iomem *reg)
  99{
 100        if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 101                return ioread32be(reg);
 102        else
 103                return readl(reg);
 104}
 105
 106static inline void l1_writel(u32 val, void __iomem *reg)
 107{
 108        if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 109                iowrite32be(val, reg);
 110        else
 111                writel(val, reg);
 112}
 113
 114static void bcm7038_l1_irq_handle(struct irq_desc *desc)
 115{
 116        struct bcm7038_l1_chip *intc = irq_desc_get_handler_data(desc);
 117        struct bcm7038_l1_cpu *cpu;
 118        struct irq_chip *chip = irq_desc_get_chip(desc);
 119        unsigned int idx;
 120
 121#ifdef CONFIG_SMP
 122        cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
 123#else
 124        cpu = intc->cpus[0];
 125#endif
 126
 127        chained_irq_enter(chip, desc);
 128
 129        for (idx = 0; idx < intc->n_words; idx++) {
 130                int base = idx * IRQS_PER_WORD;
 131                unsigned long pending, flags;
 132                int hwirq;
 133
 134                raw_spin_lock_irqsave(&intc->lock, flags);
 135                pending = l1_readl(cpu->map_base + reg_status(intc, idx)) &
 136                          ~cpu->mask_cache[idx];
 137                raw_spin_unlock_irqrestore(&intc->lock, flags);
 138
 139                for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
 140                        generic_handle_irq(irq_find_mapping(intc->domain,
 141                                                            base + hwirq));
 142                }
 143        }
 144
 145        chained_irq_exit(chip, desc);
 146}
 147
 148static void __bcm7038_l1_unmask(struct irq_data *d, unsigned int cpu_idx)
 149{
 150        struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 151        u32 word = d->hwirq / IRQS_PER_WORD;
 152        u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 153
 154        intc->cpus[cpu_idx]->mask_cache[word] &= ~mask;
 155        l1_writel(mask, intc->cpus[cpu_idx]->map_base +
 156                        reg_mask_clr(intc, word));
 157}
 158
 159static void __bcm7038_l1_mask(struct irq_data *d, unsigned int cpu_idx)
 160{
 161        struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 162        u32 word = d->hwirq / IRQS_PER_WORD;
 163        u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 164
 165        intc->cpus[cpu_idx]->mask_cache[word] |= mask;
 166        l1_writel(mask, intc->cpus[cpu_idx]->map_base +
 167                        reg_mask_set(intc, word));
 168}
 169
 170static void bcm7038_l1_unmask(struct irq_data *d)
 171{
 172        struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 173        unsigned long flags;
 174
 175        raw_spin_lock_irqsave(&intc->lock, flags);
 176        __bcm7038_l1_unmask(d, intc->affinity[d->hwirq]);
 177        raw_spin_unlock_irqrestore(&intc->lock, flags);
 178}
 179
 180static void bcm7038_l1_mask(struct irq_data *d)
 181{
 182        struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 183        unsigned long flags;
 184
 185        raw_spin_lock_irqsave(&intc->lock, flags);
 186        __bcm7038_l1_mask(d, intc->affinity[d->hwirq]);
 187        raw_spin_unlock_irqrestore(&intc->lock, flags);
 188}
 189
 190static int bcm7038_l1_set_affinity(struct irq_data *d,
 191                                   const struct cpumask *dest,
 192                                   bool force)
 193{
 194        struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 195        unsigned long flags;
 196        irq_hw_number_t hw = d->hwirq;
 197        u32 word = hw / IRQS_PER_WORD;
 198        u32 mask = BIT(hw % IRQS_PER_WORD);
 199        unsigned int first_cpu = cpumask_any_and(dest, cpu_online_mask);
 200        bool was_disabled;
 201
 202        raw_spin_lock_irqsave(&intc->lock, flags);
 203
 204        was_disabled = !!(intc->cpus[intc->affinity[hw]]->mask_cache[word] &
 205                          mask);
 206        __bcm7038_l1_mask(d, intc->affinity[hw]);
 207        intc->affinity[hw] = first_cpu;
 208        if (!was_disabled)
 209                __bcm7038_l1_unmask(d, first_cpu);
 210
 211        raw_spin_unlock_irqrestore(&intc->lock, flags);
 212        irq_data_update_effective_affinity(d, cpumask_of(first_cpu));
 213
 214        return 0;
 215}
 216
 217#ifdef CONFIG_SMP
 218static void bcm7038_l1_cpu_offline(struct irq_data *d)
 219{
 220        struct cpumask *mask = irq_data_get_affinity_mask(d);
 221        int cpu = smp_processor_id();
 222        cpumask_t new_affinity;
 223
 224        /* This CPU was not on the affinity mask */
 225        if (!cpumask_test_cpu(cpu, mask))
 226                return;
 227
 228        if (cpumask_weight(mask) > 1) {
 229                /*
 230                 * Multiple CPU affinity, remove this CPU from the affinity
 231                 * mask
 232                 */
 233                cpumask_copy(&new_affinity, mask);
 234                cpumask_clear_cpu(cpu, &new_affinity);
 235        } else {
 236                /* Only CPU, put on the lowest online CPU */
 237                cpumask_clear(&new_affinity);
 238                cpumask_set_cpu(cpumask_first(cpu_online_mask), &new_affinity);
 239        }
 240        irq_set_affinity_locked(d, &new_affinity, false);
 241}
 242#endif
 243
 244static int __init bcm7038_l1_init_one(struct device_node *dn,
 245                                      unsigned int idx,
 246                                      struct bcm7038_l1_chip *intc)
 247{
 248        struct resource res;
 249        resource_size_t sz;
 250        struct bcm7038_l1_cpu *cpu;
 251        unsigned int i, n_words, parent_irq;
 252
 253        if (of_address_to_resource(dn, idx, &res))
 254                return -EINVAL;
 255        sz = resource_size(&res);
 256        n_words = sz / REG_BYTES_PER_IRQ_WORD;
 257
 258        if (n_words > MAX_WORDS)
 259                return -EINVAL;
 260        else if (!intc->n_words)
 261                intc->n_words = n_words;
 262        else if (intc->n_words != n_words)
 263                return -EINVAL;
 264
 265        cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
 266                                        GFP_KERNEL);
 267        if (!cpu)
 268                return -ENOMEM;
 269
 270        cpu->map_base = ioremap(res.start, sz);
 271        if (!cpu->map_base)
 272                return -ENOMEM;
 273
 274        for (i = 0; i < n_words; i++) {
 275                l1_writel(0xffffffff, cpu->map_base + reg_mask_set(intc, i));
 276                cpu->mask_cache[i] = 0xffffffff;
 277        }
 278
 279        parent_irq = irq_of_parse_and_map(dn, idx);
 280        if (!parent_irq) {
 281                pr_err("failed to map parent interrupt %d\n", parent_irq);
 282                return -EINVAL;
 283        }
 284        irq_set_chained_handler_and_data(parent_irq, bcm7038_l1_irq_handle,
 285                                         intc);
 286
 287        return 0;
 288}
 289
 290static struct irq_chip bcm7038_l1_irq_chip = {
 291        .name                   = "bcm7038-l1",
 292        .irq_mask               = bcm7038_l1_mask,
 293        .irq_unmask             = bcm7038_l1_unmask,
 294        .irq_set_affinity       = bcm7038_l1_set_affinity,
 295#ifdef CONFIG_SMP
 296        .irq_cpu_offline        = bcm7038_l1_cpu_offline,
 297#endif
 298};
 299
 300static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
 301                          irq_hw_number_t hw_irq)
 302{
 303        irq_set_chip_and_handler(virq, &bcm7038_l1_irq_chip, handle_level_irq);
 304        irq_set_chip_data(virq, d->host_data);
 305        irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
 306        return 0;
 307}
 308
 309static const struct irq_domain_ops bcm7038_l1_domain_ops = {
 310        .xlate                  = irq_domain_xlate_onecell,
 311        .map                    = bcm7038_l1_map,
 312};
 313
 314int __init bcm7038_l1_of_init(struct device_node *dn,
 315                              struct device_node *parent)
 316{
 317        struct bcm7038_l1_chip *intc;
 318        int idx, ret;
 319
 320        intc = kzalloc(sizeof(*intc), GFP_KERNEL);
 321        if (!intc)
 322                return -ENOMEM;
 323
 324        raw_spin_lock_init(&intc->lock);
 325        for_each_possible_cpu(idx) {
 326                ret = bcm7038_l1_init_one(dn, idx, intc);
 327                if (ret < 0) {
 328                        if (idx)
 329                                break;
 330                        pr_err("failed to remap intc L1 registers\n");
 331                        goto out_free;
 332                }
 333        }
 334
 335        intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
 336                                             &bcm7038_l1_domain_ops,
 337                                             intc);
 338        if (!intc->domain) {
 339                ret = -ENOMEM;
 340                goto out_unmap;
 341        }
 342
 343        pr_info("registered BCM7038 L1 intc (%pOF, IRQs: %d)\n",
 344                dn, IRQS_PER_WORD * intc->n_words);
 345
 346        return 0;
 347
 348out_unmap:
 349        for_each_possible_cpu(idx) {
 350                struct bcm7038_l1_cpu *cpu = intc->cpus[idx];
 351
 352                if (cpu) {
 353                        if (cpu->map_base)
 354                                iounmap(cpu->map_base);
 355                        kfree(cpu);
 356                }
 357        }
 358out_free:
 359        kfree(intc);
 360        return ret;
 361}
 362
 363IRQCHIP_DECLARE(bcm7038_l1, "brcm,bcm7038-l1-intc", bcm7038_l1_of_init);
 364