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