drivers/irqchip/irq-bcm7038-l1.c

   1 /*
   2  * Broadcom BCM7038 style Level 1 interrupt controller driver
   3  *
   4  * Copyright (C) 2014 Broadcom Corporation
   5  * Author: Kevin Cernekee
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #define pr_fmt(fmt)     KBUILD_MODNAME  ": " fmt
  13
  14 #include <linux/bitops.h>
  15 #include <linux/kconfig.h>
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/io.h>
  20 #include <linux/ioport.h>
  21 #include <linux/irq.h>
  22 #include <linux/irqdomain.h>
  23 #include <linux/module.h>
  24 #include <linux/of.h>
  25 #include <linux/of_irq.h>
  26 #include <linux/of_address.h>
  27 #include <linux/of_platform.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/slab.h>
  30 #include <linux/smp.h>
  31 #include <linux/types.h>
  32 #include <linux/irqchip/chained_irq.h>
  33
  34 #include "irqchip.h"
  35
  36 #define IRQS_PER_WORD           32
  37 #define REG_BYTES_PER_IRQ_WORD  (sizeof(u32) * 4)
  38 #define MAX_WORDS               8
  39
  40 struct bcm7038_l1_cpu;
  41
  42 struct bcm7038_l1_chip {
  43         raw_spinlock_t          lock;
  44         unsigned int            n_words;
  45         struct irq_domain       *domain;
  46         struct bcm7038_l1_cpu   *cpus[NR_CPUS];
  47         u8                      affinity[MAX_WORDS * IRQS_PER_WORD];
  48 };
  49
  50 struct bcm7038_l1_cpu {
  51         void __iomem            *map_base;
  52         u32                     mask_cache[0];
  53 };
  54
  55 /*
  56  * STATUS/MASK_STATUS/MASK_SET/MASK_CLEAR are packed one right after another:
  57  *
  58  * 7038:
  59  *   0x1000_1400: W0_STATUS
  60  *   0x1000_1404: W1_STATUS
  61  *   0x1000_1408: W0_MASK_STATUS
  62  *   0x1000_140c: W1_MASK_STATUS
  63  *   0x1000_1410: W0_MASK_SET
  64  *   0x1000_1414: W1_MASK_SET
  65  *   0x1000_1418: W0_MASK_CLEAR
  66  *   0x1000_141c: W1_MASK_CLEAR
  67  *
  68  * 7445:
  69  *   0xf03e_1500: W0_STATUS
  70  *   0xf03e_1504: W1_STATUS
  71  *   0xf03e_1508: W2_STATUS
  72  *   0xf03e_150c: W3_STATUS
  73  *   0xf03e_1510: W4_STATUS
  74  *   0xf03e_1514: W0_MASK_STATUS
  75  *   0xf03e_1518: W1_MASK_STATUS
  76  *   [...]
  77  */
  78
  79 static inline unsigned int reg_status(struct bcm7038_l1_chip *intc,
  80                                       unsigned int word)
  81 {
  82         return (0 * intc->n_words + word) * sizeof(u32);
  83 }
  84
  85 static inline unsigned int reg_mask_status(struct bcm7038_l1_chip *intc,
  86                                            unsigned int word)
  87 {
  88         return (1 * intc->n_words + word) * sizeof(u32);
  89 }
  90
  91 static inline unsigned int reg_mask_set(struct bcm7038_l1_chip *intc,
  92                                         unsigned int word)
  93 {
  94         return (2 * intc->n_words + word) * sizeof(u32);
  95 }
  96
  97 static inline unsigned int reg_mask_clr(struct bcm7038_l1_chip *intc,
  98                                         unsigned int word)
  99 {
 100         return (3 * intc->n_words + word) * sizeof(u32);
 101 }
 102
 103 static inline u32 l1_readl(void __iomem *reg)
 104 {
 105         if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 106                 return ioread32be(reg);
 107         else
 108                 return readl(reg);
 109 }
 110
 111 static inline void l1_writel(u32 val, void __iomem *reg)
 112 {
 113         if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 114                 iowrite32be(val, reg);
 115         else
 116                 writel(val, reg);
 117 }
 118
 119 static void bcm7038_l1_irq_handle(unsigned int irq, struct irq_desc *desc)
 120 {
 121         struct bcm7038_l1_chip *intc = irq_desc_get_handler_data(desc);
 122         struct bcm7038_l1_cpu *cpu;
 123         struct irq_chip *chip = irq_desc_get_chip(desc);
 124         unsigned int idx;
 125
 126 #ifdef CONFIG_SMP
 127         cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
 128 #else
 129         cpu = intc->cpus[0];
 130 #endif
 131
 132         chained_irq_enter(chip, desc);
 133
 134         for (idx = 0; idx < intc->n_words; idx++) {
 135                 int base = idx * IRQS_PER_WORD;
 136                 unsigned long pending, flags;
 137                 int hwirq;
 138
 139                 raw_spin_lock_irqsave(&intc->lock, flags);
 140                 pending = l1_readl(cpu->map_base + reg_status(intc, idx)) &
 141                           ~cpu->mask_cache[idx];
 142                 raw_spin_unlock_irqrestore(&intc->lock, flags);
 143
 144                 for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
 145                         generic_handle_irq(irq_find_mapping(intc->domain,
 146                                                             base + hwirq));
 147                 }
 148         }
 149
 150         chained_irq_exit(chip, desc);
 151 }
 152
 153 static void __bcm7038_l1_unmask(struct irq_data *d, unsigned int cpu_idx)
 154 {
 155         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 156         u32 word = d->hwirq / IRQS_PER_WORD;
 157         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 158
 159         intc->cpus[cpu_idx]->mask_cache[word] &= ~mask;
 160         l1_writel(mask, intc->cpus[cpu_idx]->map_base +
 161                         reg_mask_clr(intc, word));
 162 }
 163
 164 static void __bcm7038_l1_mask(struct irq_data *d, unsigned int cpu_idx)
 165 {
 166         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 167         u32 word = d->hwirq / IRQS_PER_WORD;
 168         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 169
 170         intc->cpus[cpu_idx]->mask_cache[word] |= mask;
 171         l1_writel(mask, intc->cpus[cpu_idx]->map_base +
 172                         reg_mask_set(intc, word));
 173 }
 174
 175 static void bcm7038_l1_unmask(struct irq_data *d)
 176 {
 177         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 178         unsigned long flags;
 179
 180         raw_spin_lock_irqsave(&intc->lock, flags);
 181         __bcm7038_l1_unmask(d, intc->affinity[d->hwirq]);
 182         raw_spin_unlock_irqrestore(&intc->lock, flags);
 183 }
 184
 185 static void bcm7038_l1_mask(struct irq_data *d)
 186 {
 187         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 188         unsigned long flags;
 189
 190         raw_spin_lock_irqsave(&intc->lock, flags);
 191         __bcm7038_l1_mask(d, intc->affinity[d->hwirq]);
 192         raw_spin_unlock_irqrestore(&intc->lock, flags);
 193 }
 194
 195 static int bcm7038_l1_set_affinity(struct irq_data *d,
 196                                    const struct cpumask *dest,
 197                                    bool force)
 198 {
 199         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 200         unsigned long flags;
 201         irq_hw_number_t hw = d->hwirq;
 202         u32 word = hw / IRQS_PER_WORD;
 203         u32 mask = BIT(hw % IRQS_PER_WORD);
 204         unsigned int first_cpu = cpumask_any_and(dest, cpu_online_mask);
 205         bool was_disabled;
 206
 207         raw_spin_lock_irqsave(&intc->lock, flags);
 208
 209         was_disabled = !!(intc->cpus[intc->affinity[hw]]->mask_cache[word] &
 210                           mask);
 211         __bcm7038_l1_mask(d, intc->affinity[hw]);
 212         intc->affinity[hw] = first_cpu;
 213         if (!was_disabled)
 214                 __bcm7038_l1_unmask(d, first_cpu);
 215
 216         raw_spin_unlock_irqrestore(&intc->lock, flags);
 217         return 0;
 218 }
 219
 220 static int __init bcm7038_l1_init_one(struct device_node *dn,
 221                                       unsigned int idx,
 222                                       struct bcm7038_l1_chip *intc)
 223 {
 224         struct resource res;
 225         resource_size_t sz;
 226         struct bcm7038_l1_cpu *cpu;
 227         unsigned int i, n_words, parent_irq;
 228
 229         if (of_address_to_resource(dn, idx, &res))
 230                 return -EINVAL;
 231         sz = resource_size(&res);
 232         n_words = sz / REG_BYTES_PER_IRQ_WORD;
 233
 234         if (n_words > MAX_WORDS)
 235                 return -EINVAL;
 236         else 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(sizeof(*cpu) + n_words * sizeof(u32),
 242                                         GFP_KERNEL);
 243         if (!cpu)
 244                 return -ENOMEM;
 245
 246         cpu->map_base = ioremap(res.start, sz);
 247         if (!cpu->map_base)
 248                 return -ENOMEM;
 249
 250         for (i = 0; i < n_words; i++) {
 251                 l1_writel(0xffffffff, cpu->map_base + reg_mask_set(intc, i));
 252                 cpu->mask_cache[i] = 0xffffffff;
 253         }
 254
 255         parent_irq = irq_of_parse_and_map(dn, idx);
 256         if (!parent_irq) {
 257                 pr_err("failed to map parent interrupt %d\n", parent_irq);
 258                 return -EINVAL;
 259         }
 260         irq_set_handler_data(parent_irq, intc);
 261         irq_set_chained_handler(parent_irq, bcm7038_l1_irq_handle);
 262
 263         return 0;
 264 }
 265
 266 static struct irq_chip bcm7038_l1_irq_chip = {
 267         .name                   = "bcm7038-l1",
 268         .irq_mask               = bcm7038_l1_mask,
 269         .irq_unmask             = bcm7038_l1_unmask,
 270         .irq_set_affinity       = bcm7038_l1_set_affinity,
 271 };
 272
 273 static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
 274                           irq_hw_number_t hw_irq)
 275 {
 276         irq_set_chip_and_handler(virq, &bcm7038_l1_irq_chip, handle_level_irq);
 277         irq_set_chip_data(virq, d->host_data);
 278         return 0;
 279 }
 280
 281 static const struct irq_domain_ops bcm7038_l1_domain_ops = {
 282         .xlate                  = irq_domain_xlate_onecell,
 283         .map                    = bcm7038_l1_map,
 284 };
 285
 286 int __init bcm7038_l1_of_init(struct device_node *dn,
 287                               struct device_node *parent)
 288 {
 289         struct bcm7038_l1_chip *intc;
 290         int idx, ret;
 291
 292         intc = kzalloc(sizeof(*intc), GFP_KERNEL);
 293         if (!intc)
 294                 return -ENOMEM;
 295
 296         raw_spin_lock_init(&intc->lock);
 297         for_each_possible_cpu(idx) {
 298                 ret = bcm7038_l1_init_one(dn, idx, intc);
 299                 if (ret < 0) {
 300                         if (idx)
 301                                 break;
 302                         pr_err("failed to remap intc L1 registers\n");
 303                         goto out_free;
 304                 }
 305         }
 306
 307         intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
 308                                              &bcm7038_l1_domain_ops,
 309                                              intc);
 310         if (!intc->domain) {
 311                 ret = -ENOMEM;
 312                 goto out_unmap;
 313         }
 314
 315         pr_info("registered BCM7038 L1 intc (mem: 0x%p, IRQs: %d)\n",
 316                 intc->cpus[0]->map_base, IRQS_PER_WORD * intc->n_words);
 317
 318         return 0;
 319
 320 out_unmap:
 321         for_each_possible_cpu(idx) {
 322                 struct bcm7038_l1_cpu *cpu = intc->cpus[idx];
 323
 324                 if (cpu) {
 325                         if (cpu->map_base)
 326                                 iounmap(cpu->map_base);
 327                         kfree(cpu);
 328                 }
 329         }
 330 out_free:
 331         kfree(intc);
 332         return ret;
 333 }
 334
 335 IRQCHIP_DECLARE(bcm7038_l1, "brcm,bcm7038-l1-intc", bcm7038_l1_of_init);