drivers/irqchip/irq-bcm6345-l1.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Broadcom BCM6345 style Level 1 interrupt controller driver
   4  *
   5  * Copyright (C) 2014 Broadcom Corporation
   6  * Copyright 2015 Simon Arlott
   7  *
   8  * This is based on the BCM7038 (which supports SMP) but with a single
   9  * enable register instead of separate mask/set/clear registers.
  10  *
  11  * The BCM3380 has a similar mask/status register layout, but each pair
  12  * of words is at separate locations (and SMP is not supported).
  13  *
  14  * ENABLE/STATUS words are packed next to each other for each CPU:
  15  *
  16  * BCM6368:
  17  *   0x1000_0020: CPU0_W0_ENABLE
  18  *   0x1000_0024: CPU0_W1_ENABLE
  19  *   0x1000_0028: CPU0_W0_STATUS                IRQs 31-63
  20  *   0x1000_002c: CPU0_W1_STATUS                IRQs 0-31
  21  *   0x1000_0030: CPU1_W0_ENABLE
  22  *   0x1000_0034: CPU1_W1_ENABLE
  23  *   0x1000_0038: CPU1_W0_STATUS                IRQs 31-63
  24  *   0x1000_003c: CPU1_W1_STATUS                IRQs 0-31
  25  *
  26  * BCM63168:
  27  *   0x1000_0020: CPU0_W0_ENABLE
  28  *   0x1000_0024: CPU0_W1_ENABLE
  29  *   0x1000_0028: CPU0_W2_ENABLE
  30  *   0x1000_002c: CPU0_W3_ENABLE
  31  *   0x1000_0030: CPU0_W0_STATUS        IRQs 96-127
  32  *   0x1000_0034: CPU0_W1_STATUS        IRQs 64-95
  33  *   0x1000_0038: CPU0_W2_STATUS        IRQs 32-63
  34  *   0x1000_003c: CPU0_W3_STATUS        IRQs 0-31
  35  *   0x1000_0040: CPU1_W0_ENABLE
  36  *   0x1000_0044: CPU1_W1_ENABLE
  37  *   0x1000_0048: CPU1_W2_ENABLE
  38  *   0x1000_004c: CPU1_W3_ENABLE
  39  *   0x1000_0050: CPU1_W0_STATUS        IRQs 96-127
  40  *   0x1000_0054: CPU1_W1_STATUS        IRQs 64-95
  41  *   0x1000_0058: CPU1_W2_STATUS        IRQs 32-63
  42  *   0x1000_005c: CPU1_W3_STATUS        IRQs 0-31
  43  *
  44  * IRQs are numbered in CPU native endian order
  45  * (which is big-endian in these examples)
  46  */
  47
  48 #define pr_fmt(fmt)     KBUILD_MODNAME  ": " fmt
  49
  50 #include <linux/bitops.h>
  51 #include <linux/cpumask.h>
  52 #include <linux/kernel.h>
  53 #include <linux/init.h>
  54 #include <linux/interrupt.h>
  55 #include <linux/io.h>
  56 #include <linux/ioport.h>
  57 #include <linux/irq.h>
  58 #include <linux/irqdomain.h>
  59 #include <linux/module.h>
  60 #include <linux/of.h>
  61 #include <linux/of_irq.h>
  62 #include <linux/of_address.h>
  63 #include <linux/platform_device.h>
  64 #include <linux/slab.h>
  65 #include <linux/smp.h>
  66 #include <linux/types.h>
  67 #include <linux/irqchip.h>
  68 #include <linux/irqchip/chained_irq.h>
  69
  70 #define IRQS_PER_WORD           32
  71 #define REG_BYTES_PER_IRQ_WORD  (sizeof(u32) * 2)
  72
  73 struct bcm6345_l1_cpu;
  74
  75 struct bcm6345_l1_chip {
  76         raw_spinlock_t          lock;
  77         unsigned int            n_words;
  78         struct irq_domain       *domain;
  79         struct cpumask          cpumask;
  80         struct bcm6345_l1_cpu   *cpus[NR_CPUS];
  81 };
  82
  83 struct bcm6345_l1_cpu {
  84         struct bcm6345_l1_chip  *intc;
  85         void __iomem            *map_base;
  86         unsigned int            parent_irq;
  87         u32                     enable_cache[];
  88 };
  89
  90 static inline unsigned int reg_enable(struct bcm6345_l1_chip *intc,
  91                                            unsigned int word)
  92 {
  93 #ifdef __BIG_ENDIAN
  94         return (1 * intc->n_words - word - 1) * sizeof(u32);
  95 #else
  96         return (0 * intc->n_words + word) * sizeof(u32);
  97 #endif
  98 }
  99
 100 static inline unsigned int reg_status(struct bcm6345_l1_chip *intc,
 101                                       unsigned int word)
 102 {
 103 #ifdef __BIG_ENDIAN
 104         return (2 * intc->n_words - word - 1) * sizeof(u32);
 105 #else
 106         return (1 * intc->n_words + word) * sizeof(u32);
 107 #endif
 108 }
 109
 110 static inline unsigned int cpu_for_irq(struct bcm6345_l1_chip *intc,
 111                                         struct irq_data *d)
 112 {
 113         return cpumask_first_and(&intc->cpumask, irq_data_get_affinity_mask(d));
 114 }
 115
 116 static void bcm6345_l1_irq_handle(struct irq_desc *desc)
 117 {
 118         struct bcm6345_l1_cpu *cpu = irq_desc_get_handler_data(desc);
 119         struct bcm6345_l1_chip *intc = cpu->intc;
 120         struct irq_chip *chip = irq_desc_get_chip(desc);
 121         unsigned int idx;
 122
 123         chained_irq_enter(chip, desc);
 124
 125         for (idx = 0; idx < intc->n_words; idx++) {
 126                 int base = idx * IRQS_PER_WORD;
 127                 unsigned long pending;
 128                 irq_hw_number_t hwirq;
 129
 130                 pending = __raw_readl(cpu->map_base + reg_status(intc, idx));
 131                 pending &= __raw_readl(cpu->map_base + reg_enable(intc, idx));
 132
 133                 for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
 134                         if (generic_handle_domain_irq(intc->domain, base + hwirq))
 135                                 spurious_interrupt();
 136                 }
 137         }
 138
 139         chained_irq_exit(chip, desc);
 140 }
 141
 142 static inline void __bcm6345_l1_unmask(struct irq_data *d)
 143 {
 144         struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
 145         u32 word = d->hwirq / IRQS_PER_WORD;
 146         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 147         unsigned int cpu_idx = cpu_for_irq(intc, d);
 148
 149         intc->cpus[cpu_idx]->enable_cache[word] |= mask;
 150         __raw_writel(intc->cpus[cpu_idx]->enable_cache[word],
 151                 intc->cpus[cpu_idx]->map_base + reg_enable(intc, word));
 152 }
 153
 154 static inline void __bcm6345_l1_mask(struct irq_data *d)
 155 {
 156         struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
 157         u32 word = d->hwirq / IRQS_PER_WORD;
 158         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 159         unsigned int cpu_idx = cpu_for_irq(intc, d);
 160
 161         intc->cpus[cpu_idx]->enable_cache[word] &= ~mask;
 162         __raw_writel(intc->cpus[cpu_idx]->enable_cache[word],
 163                 intc->cpus[cpu_idx]->map_base + reg_enable(intc, word));
 164 }
 165
 166 static void bcm6345_l1_unmask(struct irq_data *d)
 167 {
 168         struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
 169         unsigned long flags;
 170
 171         raw_spin_lock_irqsave(&intc->lock, flags);
 172         __bcm6345_l1_unmask(d);
 173         raw_spin_unlock_irqrestore(&intc->lock, flags);
 174 }
 175
 176 static void bcm6345_l1_mask(struct irq_data *d)
 177 {
 178         struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
 179         unsigned long flags;
 180
 181         raw_spin_lock_irqsave(&intc->lock, flags);
 182         __bcm6345_l1_mask(d);
 183         raw_spin_unlock_irqrestore(&intc->lock, flags);
 184 }
 185
 186 static int bcm6345_l1_set_affinity(struct irq_data *d,
 187                                    const struct cpumask *dest,
 188                                    bool force)
 189 {
 190         struct bcm6345_l1_chip *intc = irq_data_get_irq_chip_data(d);
 191         u32 word = d->hwirq / IRQS_PER_WORD;
 192         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 193         unsigned int old_cpu = cpu_for_irq(intc, d);
 194         unsigned int new_cpu;
 195         unsigned long flags;
 196         bool enabled;
 197
 198         new_cpu = cpumask_first_and_and(&intc->cpumask, dest, cpu_online_mask);
 199         if (new_cpu >= nr_cpu_ids)
 200                 return -EINVAL;
 201
 202         dest = cpumask_of(new_cpu);
 203
 204         raw_spin_lock_irqsave(&intc->lock, flags);
 205         if (old_cpu != new_cpu) {
 206                 enabled = intc->cpus[old_cpu]->enable_cache[word] & mask;
 207                 if (enabled)
 208                         __bcm6345_l1_mask(d);
 209                 irq_data_update_affinity(d, dest);
 210                 if (enabled)
 211                         __bcm6345_l1_unmask(d);
 212         } else {
 213                 irq_data_update_affinity(d, dest);
 214         }
 215         raw_spin_unlock_irqrestore(&intc->lock, flags);
 216
 217         irq_data_update_effective_affinity(d, cpumask_of(new_cpu));
 218
 219         return IRQ_SET_MASK_OK_NOCOPY;
 220 }
 221
 222 static int __init bcm6345_l1_init_one(struct device_node *dn,
 223                                       unsigned int idx,
 224                                       struct bcm6345_l1_chip *intc)
 225 {
 226         struct resource res;
 227         resource_size_t sz;
 228         struct bcm6345_l1_cpu *cpu;
 229         unsigned int i, n_words;
 230
 231         if (of_address_to_resource(dn, idx, &res))
 232                 return -EINVAL;
 233         sz = resource_size(&res);
 234         n_words = sz / REG_BYTES_PER_IRQ_WORD;
 235
 236         if (!intc->n_words)
 237                 intc->n_words = n_words;
 238         else if (intc->n_words != n_words)
 239                 return -EINVAL;
 240
 241         cpu = intc->cpus[idx] = kzalloc(struct_size(cpu, enable_cache, n_words),
 242                                         GFP_KERNEL);
 243         if (!cpu)
 244                 return -ENOMEM;
 245
 246         cpu->intc = intc;
 247         cpu->map_base = ioremap(res.start, sz);
 248         if (!cpu->map_base)
 249                 return -ENOMEM;
 250
 251         if (!request_mem_region(res.start, sz, res.name))
 252                 pr_err("failed to request intc memory");
 253
 254         for (i = 0; i < n_words; i++) {
 255                 cpu->enable_cache[i] = 0;
 256                 __raw_writel(0, cpu->map_base + reg_enable(intc, i));
 257         }
 258
 259         cpu->parent_irq = irq_of_parse_and_map(dn, idx);
 260         if (!cpu->parent_irq) {
 261                 pr_err("failed to map parent interrupt %d\n", cpu->parent_irq);
 262                 return -EINVAL;
 263         }
 264         irq_set_chained_handler_and_data(cpu->parent_irq,
 265                                                 bcm6345_l1_irq_handle, cpu);
 266
 267         return 0;
 268 }
 269
 270 static struct irq_chip bcm6345_l1_irq_chip = {
 271         .name                   = "bcm6345-l1",
 272         .irq_mask               = bcm6345_l1_mask,
 273         .irq_unmask             = bcm6345_l1_unmask,
 274         .irq_set_affinity       = bcm6345_l1_set_affinity,
 275 };
 276
 277 static int bcm6345_l1_map(struct irq_domain *d, unsigned int virq,
 278                           irq_hw_number_t hw_irq)
 279 {
 280         irq_set_chip_and_handler(virq,
 281                 &bcm6345_l1_irq_chip, handle_percpu_irq);
 282         irq_set_chip_data(virq, d->host_data);
 283         irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(virq)));
 284         return 0;
 285 }
 286
 287 static const struct irq_domain_ops bcm6345_l1_domain_ops = {
 288         .xlate                  = irq_domain_xlate_onecell,
 289         .map                    = bcm6345_l1_map,
 290 };
 291
 292 static int __init bcm6345_l1_of_init(struct device_node *dn,
 293                               struct device_node *parent)
 294 {
 295         struct bcm6345_l1_chip *intc;
 296         unsigned int idx;
 297         int ret;
 298
 299         intc = kzalloc(sizeof(*intc), GFP_KERNEL);
 300         if (!intc)
 301                 return -ENOMEM;
 302
 303         for_each_possible_cpu(idx) {
 304                 ret = bcm6345_l1_init_one(dn, idx, intc);
 305                 if (ret)
 306                         pr_err("failed to init intc L1 for cpu %d: %d\n",
 307                                 idx, ret);
 308                 else
 309                         cpumask_set_cpu(idx, &intc->cpumask);
 310         }
 311
 312         if (cpumask_empty(&intc->cpumask)) {
 313                 ret = -ENODEV;
 314                 goto out_free;
 315         }
 316
 317         raw_spin_lock_init(&intc->lock);
 318
 319         intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
 320                                              &bcm6345_l1_domain_ops,
 321                                              intc);
 322         if (!intc->domain) {
 323                 ret = -ENOMEM;
 324                 goto out_unmap;
 325         }
 326
 327         pr_info("registered BCM6345 L1 intc (IRQs: %d)\n",
 328                         IRQS_PER_WORD * intc->n_words);
 329         for_each_cpu(idx, &intc->cpumask) {
 330                 struct bcm6345_l1_cpu *cpu = intc->cpus[idx];
 331
 332                 pr_info("  CPU%u (irq = %d)\n", idx, cpu->parent_irq);
 333         }
 334
 335         return 0;
 336
 337 out_unmap:
 338         for_each_possible_cpu(idx) {
 339                 struct bcm6345_l1_cpu *cpu = intc->cpus[idx];
 340
 341                 if (cpu) {
 342                         if (cpu->map_base)
 343                                 iounmap(cpu->map_base);
 344                         kfree(cpu);
 345                 }
 346         }
 347 out_free:
 348         kfree(intc);
 349         return ret;
 350 }
 351
 352 IRQCHIP_DECLARE(bcm6345_l1, "brcm,bcm6345-l1-intc", bcm6345_l1_of_init);