arch/mips/sgi-ip27/ip27-irq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * ip27-irq.c: Highlevel interrupt handling for IP27 architecture.
   4  *
   5  * Copyright (C) 1999, 2000 Ralf Baechle (ralf@gnu.org)
   6  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   7  * Copyright (C) 1999 - 2001 Kanoj Sarcar
   8  */
   9
  10 #include <linux/interrupt.h>
  11 #include <linux/irq.h>
  12 #include <linux/ioport.h>
  13 #include <linux/kernel.h>
  14 #include <linux/bitops.h>
  15 #include <linux/sched.h>
  16
  17 #include <asm/io.h>
  18 #include <asm/irq_cpu.h>
  19 #include <asm/sn/addrs.h>
  20 #include <asm/sn/agent.h>
  21 #include <asm/sn/arch.h>
  22 #include <asm/sn/hub.h>
  23 #include <asm/sn/intr.h>
  24 #include <asm/sn/irq_alloc.h>
  25
  26 struct hub_irq_data {
  27         u64     *irq_mask[2];
  28         cpuid_t cpu;
  29 };
  30
  31 static DECLARE_BITMAP(hub_irq_map, IP27_HUB_IRQ_COUNT);
  32
  33 static DEFINE_PER_CPU(unsigned long [2], irq_enable_mask);
  34
  35 static inline int alloc_level(void)
  36 {
  37         int level;
  38
  39 again:
  40         level = find_first_zero_bit(hub_irq_map, IP27_HUB_IRQ_COUNT);
  41         if (level >= IP27_HUB_IRQ_COUNT)
  42                 return -ENOSPC;
  43
  44         if (test_and_set_bit(level, hub_irq_map))
  45                 goto again;
  46
  47         return level;
  48 }
  49
  50 static void enable_hub_irq(struct irq_data *d)
  51 {
  52         struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
  53         unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu);
  54
  55         set_bit(d->hwirq, mask);
  56         __raw_writeq(mask[0], hd->irq_mask[0]);
  57         __raw_writeq(mask[1], hd->irq_mask[1]);
  58 }
  59
  60 static void disable_hub_irq(struct irq_data *d)
  61 {
  62         struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
  63         unsigned long *mask = per_cpu(irq_enable_mask, hd->cpu);
  64
  65         clear_bit(d->hwirq, mask);
  66         __raw_writeq(mask[0], hd->irq_mask[0]);
  67         __raw_writeq(mask[1], hd->irq_mask[1]);
  68 }
  69
  70 static void setup_hub_mask(struct hub_irq_data *hd, const struct cpumask *mask)
  71 {
  72         nasid_t nasid;
  73         int cpu;
  74
  75         cpu = cpumask_first_and(mask, cpu_online_mask);
  76         if (cpu >= nr_cpu_ids)
  77                 cpu = cpumask_any(cpu_online_mask);
  78
  79         nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
  80         hd->cpu = cpu;
  81         if (!cputoslice(cpu)) {
  82                 hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_A);
  83                 hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_A);
  84         } else {
  85                 hd->irq_mask[0] = REMOTE_HUB_PTR(nasid, PI_INT_MASK0_B);
  86                 hd->irq_mask[1] = REMOTE_HUB_PTR(nasid, PI_INT_MASK1_B);
  87         }
  88 }
  89
  90 static int set_affinity_hub_irq(struct irq_data *d, const struct cpumask *mask,
  91                                 bool force)
  92 {
  93         struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
  94
  95         if (!hd)
  96                 return -EINVAL;
  97
  98         if (irqd_is_started(d))
  99                 disable_hub_irq(d);
 100
 101         setup_hub_mask(hd, mask);
 102
 103         if (irqd_is_started(d))
 104                 enable_hub_irq(d);
 105
 106         irq_data_update_effective_affinity(d, cpumask_of(hd->cpu));
 107
 108         return 0;
 109 }
 110
 111 static struct irq_chip hub_irq_type = {
 112         .name             = "HUB",
 113         .irq_mask         = disable_hub_irq,
 114         .irq_unmask       = enable_hub_irq,
 115         .irq_set_affinity = set_affinity_hub_irq,
 116 };
 117
 118 static int hub_domain_alloc(struct irq_domain *domain, unsigned int virq,
 119                             unsigned int nr_irqs, void *arg)
 120 {
 121         struct irq_alloc_info *info = arg;
 122         struct hub_irq_data *hd;
 123         struct hub_data *hub;
 124         struct irq_desc *desc;
 125         int swlevel;
 126
 127         if (nr_irqs > 1 || !info)
 128                 return -EINVAL;
 129
 130         hd = kzalloc(sizeof(*hd), GFP_KERNEL);
 131         if (!hd)
 132                 return -ENOMEM;
 133
 134         swlevel = alloc_level();
 135         if (unlikely(swlevel < 0)) {
 136                 kfree(hd);
 137                 return -EAGAIN;
 138         }
 139         irq_domain_set_info(domain, virq, swlevel, &hub_irq_type, hd,
 140                             handle_level_irq, NULL, NULL);
 141
 142         /* use CPU connected to nearest hub */
 143         hub = hub_data(NASID_TO_COMPACT_NODEID(info->nasid));
 144         setup_hub_mask(hd, &hub->h_cpus);
 145         info->nasid = cpu_to_node(hd->cpu);
 146
 147         /* Make sure it's not already pending when we connect it. */
 148         REMOTE_HUB_CLR_INTR(info->nasid, swlevel);
 149
 150         desc = irq_to_desc(virq);
 151         desc->irq_common_data.node = info->nasid;
 152         cpumask_copy(desc->irq_common_data.affinity, &hub->h_cpus);
 153
 154         return 0;
 155 }
 156
 157 static void hub_domain_free(struct irq_domain *domain,
 158                             unsigned int virq, unsigned int nr_irqs)
 159 {
 160         struct irq_data *irqd;
 161
 162         if (nr_irqs > 1)
 163                 return;
 164
 165         irqd = irq_domain_get_irq_data(domain, virq);
 166         if (irqd && irqd->chip_data)
 167                 kfree(irqd->chip_data);
 168 }
 169
 170 static const struct irq_domain_ops hub_domain_ops = {
 171         .alloc = hub_domain_alloc,
 172         .free  = hub_domain_free,
 173 };
 174
 175 /*
 176  * This code is unnecessarily complex, because we do
 177  * intr enabling. Basically, once we grab the set of intrs we need
 178  * to service, we must mask _all_ these interrupts; firstly, to make
 179  * sure the same intr does not intr again, causing recursion that
 180  * can lead to stack overflow. Secondly, we can not just mask the
 181  * one intr we are do_IRQing, because the non-masked intrs in the
 182  * first set might intr again, causing multiple servicings of the
 183  * same intr. This effect is mostly seen for intercpu intrs.
 184  * Kanoj 05.13.00
 185  */
 186
 187 static void ip27_do_irq_mask0(struct irq_desc *desc)
 188 {
 189         cpuid_t cpu = smp_processor_id();
 190         unsigned long *mask = per_cpu(irq_enable_mask, cpu);
 191         struct irq_domain *domain;
 192         u64 pend0;
 193         int irq;
 194
 195         /* copied from Irix intpend0() */
 196         pend0 = LOCAL_HUB_L(PI_INT_PEND0);
 197
 198         pend0 &= mask[0];               /* Pick intrs we should look at */
 199         if (!pend0)
 200                 return;
 201
 202 #ifdef CONFIG_SMP
 203         if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) {
 204                 LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ);
 205                 scheduler_ipi();
 206         } else if (pend0 & (1UL << CPU_RESCHED_B_IRQ)) {
 207                 LOCAL_HUB_CLR_INTR(CPU_RESCHED_B_IRQ);
 208                 scheduler_ipi();
 209         } else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
 210                 LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
 211                 generic_smp_call_function_interrupt();
 212         } else if (pend0 & (1UL << CPU_CALL_B_IRQ)) {
 213                 LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ);
 214                 generic_smp_call_function_interrupt();
 215         } else
 216 #endif
 217         {
 218                 domain = irq_desc_get_handler_data(desc);
 219                 irq = irq_linear_revmap(domain, __ffs(pend0));
 220                 if (irq)
 221                         generic_handle_irq(irq);
 222                 else
 223                         spurious_interrupt();
 224         }
 225
 226         LOCAL_HUB_L(PI_INT_PEND0);
 227 }
 228
 229 static void ip27_do_irq_mask1(struct irq_desc *desc)
 230 {
 231         cpuid_t cpu = smp_processor_id();
 232         unsigned long *mask = per_cpu(irq_enable_mask, cpu);
 233         struct irq_domain *domain;
 234         u64 pend1;
 235         int irq;
 236
 237         /* copied from Irix intpend0() */
 238         pend1 = LOCAL_HUB_L(PI_INT_PEND1);
 239
 240         pend1 &= mask[1];               /* Pick intrs we should look at */
 241         if (!pend1)
 242                 return;
 243
 244         domain = irq_desc_get_handler_data(desc);
 245         irq = irq_linear_revmap(domain, __ffs(pend1) + 64);
 246         if (irq)
 247                 generic_handle_irq(irq);
 248         else
 249                 spurious_interrupt();
 250
 251         LOCAL_HUB_L(PI_INT_PEND1);
 252 }
 253
 254 void install_ipi(void)
 255 {
 256         int cpu = smp_processor_id();
 257         unsigned long *mask = per_cpu(irq_enable_mask, cpu);
 258         int slice = LOCAL_HUB_L(PI_CPU_NUM);
 259         int resched, call;
 260
 261         resched = CPU_RESCHED_A_IRQ + slice;
 262         set_bit(resched, mask);
 263         LOCAL_HUB_CLR_INTR(resched);
 264
 265         call = CPU_CALL_A_IRQ + slice;
 266         set_bit(call, mask);
 267         LOCAL_HUB_CLR_INTR(call);
 268
 269         if (slice == 0) {
 270                 LOCAL_HUB_S(PI_INT_MASK0_A, mask[0]);
 271                 LOCAL_HUB_S(PI_INT_MASK1_A, mask[1]);
 272         } else {
 273                 LOCAL_HUB_S(PI_INT_MASK0_B, mask[0]);
 274                 LOCAL_HUB_S(PI_INT_MASK1_B, mask[1]);
 275         }
 276 }
 277
 278 void __init arch_init_irq(void)
 279 {
 280         struct irq_domain *domain;
 281         struct fwnode_handle *fn;
 282         int i;
 283
 284         mips_cpu_irq_init();
 285
 286         /*
 287          * Some interrupts are reserved by hardware or by software convention.
 288          * Mark these as reserved right away so they won't be used accidentally
 289          * later.
 290          */
 291         for (i = 0; i <= BASE_PCI_IRQ; i++)
 292                 set_bit(i, hub_irq_map);
 293
 294         set_bit(IP_PEND0_6_63, hub_irq_map);
 295
 296         for (i = NI_BRDCAST_ERR_A; i <= MSC_PANIC_INTR; i++)
 297                 set_bit(i, hub_irq_map);
 298
 299         fn = irq_domain_alloc_named_fwnode("HUB");
 300         WARN_ON(fn == NULL);
 301         if (!fn)
 302                 return;
 303         domain = irq_domain_create_linear(fn, IP27_HUB_IRQ_COUNT,
 304                                           &hub_domain_ops, NULL);
 305         WARN_ON(domain == NULL);
 306         if (!domain)
 307                 return;
 308
 309         irq_set_default_host(domain);
 310
 311         irq_set_percpu_devid(IP27_HUB_PEND0_IRQ);
 312         irq_set_chained_handler_and_data(IP27_HUB_PEND0_IRQ, ip27_do_irq_mask0,
 313                                          domain);
 314         irq_set_percpu_devid(IP27_HUB_PEND1_IRQ);
 315         irq_set_chained_handler_and_data(IP27_HUB_PEND1_IRQ, ip27_do_irq_mask1,
 316                                          domain);
 317 }