drivers/irqchip/irq-hip04.c

   1 /*
   2  * Hisilicon HiP04 INTC
   3  *
   4  * Copyright (C) 2002-2014 ARM Limited.
   5  * Copyright (c) 2013-2014 Hisilicon Ltd.
   6  * Copyright (c) 2013-2014 Linaro Ltd.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * Interrupt architecture for the HIP04 INTC:
  13  *
  14  * o There is one Interrupt Distributor, which receives interrupts
  15  *   from system devices and sends them to the Interrupt Controllers.
  16  *
  17  * o There is one CPU Interface per CPU, which sends interrupts sent
  18  *   by the Distributor, and interrupts generated locally, to the
  19  *   associated CPU. The base address of the CPU interface is usually
  20  *   aliased so that the same address points to different chips depending
  21  *   on the CPU it is accessed from.
  22  *
  23  * Note that IRQs 0-31 are special - they are local to each CPU.
  24  * As such, the enable set/clear, pending set/clear and active bit
  25  * registers are banked per-cpu for these sources.
  26  */
  27
  28 #include <linux/init.h>
  29 #include <linux/kernel.h>
  30 #include <linux/err.h>
  31 #include <linux/module.h>
  32 #include <linux/list.h>
  33 #include <linux/smp.h>
  34 #include <linux/cpu.h>
  35 #include <linux/cpu_pm.h>
  36 #include <linux/cpumask.h>
  37 #include <linux/io.h>
  38 #include <linux/of.h>
  39 #include <linux/of_address.h>
  40 #include <linux/of_irq.h>
  41 #include <linux/irqdomain.h>
  42 #include <linux/interrupt.h>
  43 #include <linux/slab.h>
  44 #include <linux/irqchip/arm-gic.h>
  45
  46 #include <asm/irq.h>
  47 #include <asm/exception.h>
  48 #include <asm/smp_plat.h>
  49
  50 #include "irq-gic-common.h"
  51 #include "irqchip.h"
  52
  53 #define HIP04_MAX_IRQS          510
  54
  55 struct hip04_irq_data {
  56         void __iomem *dist_base;
  57         void __iomem *cpu_base;
  58         struct irq_domain *domain;
  59         unsigned int nr_irqs;
  60 };
  61
  62 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
  63
  64 /*
  65  * The GIC mapping of CPU interfaces does not necessarily match
  66  * the logical CPU numbering.  Let's use a mapping as returned
  67  * by the GIC itself.
  68  */
  69 #define NR_HIP04_CPU_IF 16
  70 static u16 hip04_cpu_map[NR_HIP04_CPU_IF] __read_mostly;
  71
  72 static struct hip04_irq_data hip04_data __read_mostly;
  73
  74 static inline void __iomem *hip04_dist_base(struct irq_data *d)
  75 {
  76         struct hip04_irq_data *hip04_data = irq_data_get_irq_chip_data(d);
  77         return hip04_data->dist_base;
  78 }
  79
  80 static inline void __iomem *hip04_cpu_base(struct irq_data *d)
  81 {
  82         struct hip04_irq_data *hip04_data = irq_data_get_irq_chip_data(d);
  83         return hip04_data->cpu_base;
  84 }
  85
  86 static inline unsigned int hip04_irq(struct irq_data *d)
  87 {
  88         return d->hwirq;
  89 }
  90
  91 /*
  92  * Routines to acknowledge, disable and enable interrupts
  93  */
  94 static void hip04_mask_irq(struct irq_data *d)
  95 {
  96         u32 mask = 1 << (hip04_irq(d) % 32);
  97
  98         raw_spin_lock(&irq_controller_lock);
  99         writel_relaxed(mask, hip04_dist_base(d) + GIC_DIST_ENABLE_CLEAR +
 100                        (hip04_irq(d) / 32) * 4);
 101         raw_spin_unlock(&irq_controller_lock);
 102 }
 103
 104 static void hip04_unmask_irq(struct irq_data *d)
 105 {
 106         u32 mask = 1 << (hip04_irq(d) % 32);
 107
 108         raw_spin_lock(&irq_controller_lock);
 109         writel_relaxed(mask, hip04_dist_base(d) + GIC_DIST_ENABLE_SET +
 110                        (hip04_irq(d) / 32) * 4);
 111         raw_spin_unlock(&irq_controller_lock);
 112 }
 113
 114 static void hip04_eoi_irq(struct irq_data *d)
 115 {
 116         writel_relaxed(hip04_irq(d), hip04_cpu_base(d) + GIC_CPU_EOI);
 117 }
 118
 119 static int hip04_irq_set_type(struct irq_data *d, unsigned int type)
 120 {
 121         void __iomem *base = hip04_dist_base(d);
 122         unsigned int irq = hip04_irq(d);
 123         int ret;
 124
 125         /* Interrupt configuration for SGIs can't be changed */
 126         if (irq < 16)
 127                 return -EINVAL;
 128
 129         /* SPIs have restrictions on the supported types */
 130         if (irq >= 32 && type != IRQ_TYPE_LEVEL_HIGH &&
 131                          type != IRQ_TYPE_EDGE_RISING)
 132                 return -EINVAL;
 133
 134         raw_spin_lock(&irq_controller_lock);
 135
 136         ret = gic_configure_irq(irq, type, base, NULL);
 137
 138         raw_spin_unlock(&irq_controller_lock);
 139
 140         return ret;
 141 }
 142
 143 #ifdef CONFIG_SMP
 144 static int hip04_irq_set_affinity(struct irq_data *d,
 145                                   const struct cpumask *mask_val,
 146                                   bool force)
 147 {
 148         void __iomem *reg;
 149         unsigned int cpu, shift = (hip04_irq(d) % 2) * 16;
 150         u32 val, mask, bit;
 151
 152         if (!force)
 153                 cpu = cpumask_any_and(mask_val, cpu_online_mask);
 154         else
 155                 cpu = cpumask_first(mask_val);
 156
 157         if (cpu >= NR_HIP04_CPU_IF || cpu >= nr_cpu_ids)
 158                 return -EINVAL;
 159
 160         raw_spin_lock(&irq_controller_lock);
 161         reg = hip04_dist_base(d) + GIC_DIST_TARGET + ((hip04_irq(d) * 2) & ~3);
 162         mask = 0xffff << shift;
 163         bit = hip04_cpu_map[cpu] << shift;
 164         val = readl_relaxed(reg) & ~mask;
 165         writel_relaxed(val | bit, reg);
 166         raw_spin_unlock(&irq_controller_lock);
 167
 168         return IRQ_SET_MASK_OK;
 169 }
 170 #endif
 171
 172 static void __exception_irq_entry hip04_handle_irq(struct pt_regs *regs)
 173 {
 174         u32 irqstat, irqnr;
 175         void __iomem *cpu_base = hip04_data.cpu_base;
 176
 177         do {
 178                 irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK);
 179                 irqnr = irqstat & GICC_IAR_INT_ID_MASK;
 180
 181                 if (likely(irqnr > 15 && irqnr <= HIP04_MAX_IRQS)) {
 182                         handle_domain_irq(hip04_data.domain, irqnr, regs);
 183                         continue;
 184                 }
 185                 if (irqnr < 16) {
 186                         writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI);
 187 #ifdef CONFIG_SMP
 188                         handle_IPI(irqnr, regs);
 189 #endif
 190                         continue;
 191                 }
 192                 break;
 193         } while (1);
 194 }
 195
 196 static struct irq_chip hip04_irq_chip = {
 197         .name                   = "HIP04 INTC",
 198         .irq_mask               = hip04_mask_irq,
 199         .irq_unmask             = hip04_unmask_irq,
 200         .irq_eoi                = hip04_eoi_irq,
 201         .irq_set_type           = hip04_irq_set_type,
 202 #ifdef CONFIG_SMP
 203         .irq_set_affinity       = hip04_irq_set_affinity,
 204 #endif
 205 };
 206
 207 static u16 hip04_get_cpumask(struct hip04_irq_data *intc)
 208 {
 209         void __iomem *base = intc->dist_base;
 210         u32 mask, i;
 211
 212         for (i = mask = 0; i < 32; i += 2) {
 213                 mask = readl_relaxed(base + GIC_DIST_TARGET + i * 2);
 214                 mask |= mask >> 16;
 215                 if (mask)
 216                         break;
 217         }
 218
 219         if (!mask)
 220                 pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
 221
 222         return mask;
 223 }
 224
 225 static void __init hip04_irq_dist_init(struct hip04_irq_data *intc)
 226 {
 227         unsigned int i;
 228         u32 cpumask;
 229         unsigned int nr_irqs = intc->nr_irqs;
 230         void __iomem *base = intc->dist_base;
 231
 232         writel_relaxed(0, base + GIC_DIST_CTRL);
 233
 234         /*
 235          * Set all global interrupts to this CPU only.
 236          */
 237         cpumask = hip04_get_cpumask(intc);
 238         cpumask |= cpumask << 16;
 239         for (i = 32; i < nr_irqs; i += 2)
 240                 writel_relaxed(cpumask, base + GIC_DIST_TARGET + ((i * 2) & ~3));
 241
 242         gic_dist_config(base, nr_irqs, NULL);
 243
 244         writel_relaxed(1, base + GIC_DIST_CTRL);
 245 }
 246
 247 static void hip04_irq_cpu_init(struct hip04_irq_data *intc)
 248 {
 249         void __iomem *dist_base = intc->dist_base;
 250         void __iomem *base = intc->cpu_base;
 251         unsigned int cpu_mask, cpu = smp_processor_id();
 252         int i;
 253
 254         /*
 255          * Get what the GIC says our CPU mask is.
 256          */
 257         BUG_ON(cpu >= NR_HIP04_CPU_IF);
 258         cpu_mask = hip04_get_cpumask(intc);
 259         hip04_cpu_map[cpu] = cpu_mask;
 260
 261         /*
 262          * Clear our mask from the other map entries in case they're
 263          * still undefined.
 264          */
 265         for (i = 0; i < NR_HIP04_CPU_IF; i++)
 266                 if (i != cpu)
 267                         hip04_cpu_map[i] &= ~cpu_mask;
 268
 269         gic_cpu_config(dist_base, NULL);
 270
 271         writel_relaxed(0xf0, base + GIC_CPU_PRIMASK);
 272         writel_relaxed(1, base + GIC_CPU_CTRL);
 273 }
 274
 275 #ifdef CONFIG_SMP
 276 static void hip04_raise_softirq(const struct cpumask *mask, unsigned int irq)
 277 {
 278         int cpu;
 279         unsigned long flags, map = 0;
 280
 281         raw_spin_lock_irqsave(&irq_controller_lock, flags);
 282
 283         /* Convert our logical CPU mask into a physical one. */
 284         for_each_cpu(cpu, mask)
 285                 map |= hip04_cpu_map[cpu];
 286
 287         /*
 288          * Ensure that stores to Normal memory are visible to the
 289          * other CPUs before they observe us issuing the IPI.
 290          */
 291         dmb(ishst);
 292
 293         /* this always happens on GIC0 */
 294         writel_relaxed(map << 8 | irq, hip04_data.dist_base + GIC_DIST_SOFTINT);
 295
 296         raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
 297 }
 298 #endif
 299
 300 static int hip04_irq_domain_map(struct irq_domain *d, unsigned int irq,
 301                                 irq_hw_number_t hw)
 302 {
 303         if (hw < 32) {
 304                 irq_set_percpu_devid(irq);
 305                 irq_set_chip_and_handler(irq, &hip04_irq_chip,
 306                                          handle_percpu_devid_irq);
 307                 set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
 308         } else {
 309                 irq_set_chip_and_handler(irq, &hip04_irq_chip,
 310                                          handle_fasteoi_irq);
 311                 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 312         }
 313         irq_set_chip_data(irq, d->host_data);
 314         return 0;
 315 }
 316
 317 static int hip04_irq_domain_xlate(struct irq_domain *d,
 318                                   struct device_node *controller,
 319                                   const u32 *intspec, unsigned int intsize,
 320                                   unsigned long *out_hwirq,
 321                                   unsigned int *out_type)
 322 {
 323         unsigned long ret = 0;
 324
 325         if (d->of_node != controller)
 326                 return -EINVAL;
 327         if (intsize < 3)
 328                 return -EINVAL;
 329
 330         /* Get the interrupt number and add 16 to skip over SGIs */
 331         *out_hwirq = intspec[1] + 16;
 332
 333         /* For SPIs, we need to add 16 more to get the irq ID number */
 334         if (!intspec[0])
 335                 *out_hwirq += 16;
 336
 337         *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
 338
 339         return ret;
 340 }
 341
 342 #ifdef CONFIG_SMP
 343 static int hip04_irq_secondary_init(struct notifier_block *nfb,
 344                                     unsigned long action,
 345                                     void *hcpu)
 346 {
 347         if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
 348                 hip04_irq_cpu_init(&hip04_data);
 349         return NOTIFY_OK;
 350 }
 351
 352 /*
 353  * Notifier for enabling the INTC CPU interface. Set an arbitrarily high
 354  * priority because the GIC needs to be up before the ARM generic timers.
 355  */
 356 static struct notifier_block hip04_irq_cpu_notifier = {
 357         .notifier_call  = hip04_irq_secondary_init,
 358         .priority       = 100,
 359 };
 360 #endif
 361
 362 static const struct irq_domain_ops hip04_irq_domain_ops = {
 363         .map    = hip04_irq_domain_map,
 364         .xlate  = hip04_irq_domain_xlate,
 365 };
 366
 367 static int __init
 368 hip04_of_init(struct device_node *node, struct device_node *parent)
 369 {
 370         irq_hw_number_t hwirq_base = 16;
 371         int nr_irqs, irq_base, i;
 372
 373         if (WARN_ON(!node))
 374                 return -ENODEV;
 375
 376         hip04_data.dist_base = of_iomap(node, 0);
 377         WARN(!hip04_data.dist_base, "fail to map hip04 intc dist registers\n");
 378
 379         hip04_data.cpu_base = of_iomap(node, 1);
 380         WARN(!hip04_data.cpu_base, "unable to map hip04 intc cpu registers\n");
 381
 382         /*
 383          * Initialize the CPU interface map to all CPUs.
 384          * It will be refined as each CPU probes its ID.
 385          */
 386         for (i = 0; i < NR_HIP04_CPU_IF; i++)
 387                 hip04_cpu_map[i] = 0xffff;
 388
 389         /*
 390          * Find out how many interrupts are supported.
 391          * The HIP04 INTC only supports up to 510 interrupt sources.
 392          */
 393         nr_irqs = readl_relaxed(hip04_data.dist_base + GIC_DIST_CTR) & 0x1f;
 394         nr_irqs = (nr_irqs + 1) * 32;
 395         if (nr_irqs > HIP04_MAX_IRQS)
 396                 nr_irqs = HIP04_MAX_IRQS;
 397         hip04_data.nr_irqs = nr_irqs;
 398
 399         nr_irqs -= hwirq_base; /* calculate # of irqs to allocate */
 400
 401         irq_base = irq_alloc_descs(-1, hwirq_base, nr_irqs, numa_node_id());
 402         if (IS_ERR_VALUE(irq_base)) {
 403                 pr_err("failed to allocate IRQ numbers\n");
 404                 return -EINVAL;
 405         }
 406
 407         hip04_data.domain = irq_domain_add_legacy(node, nr_irqs, irq_base,
 408                                                   hwirq_base,
 409                                                   &hip04_irq_domain_ops,
 410                                                   &hip04_data);
 411
 412         if (WARN_ON(!hip04_data.domain))
 413                 return -EINVAL;
 414
 415 #ifdef CONFIG_SMP
 416         set_smp_cross_call(hip04_raise_softirq);
 417         register_cpu_notifier(&hip04_irq_cpu_notifier);
 418 #endif
 419         set_handle_irq(hip04_handle_irq);
 420
 421         hip04_irq_dist_init(&hip04_data);
 422         hip04_irq_cpu_init(&hip04_data);
 423
 424         return 0;
 425 }
 426 IRQCHIP_DECLARE(hip04_intc, "hisilicon,hip04-intc", hip04_of_init);