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