arch/s390/kernel/irq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Copyright IBM Corp. 2004, 2011
   4  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
   5  *               Holger Smolinski <Holger.Smolinski@de.ibm.com>,
   6  *               Thomas Spatzier <tspat@de.ibm.com>,
   7  *
   8  * This file contains interrupt related functions.
   9  */
  10
  11 #include <linux/kernel_stat.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/proc_fs.h>
  15 #include <linux/profile.h>
  16 #include <linux/export.h>
  17 #include <linux/kernel.h>
  18 #include <linux/ftrace.h>
  19 #include <linux/errno.h>
  20 #include <linux/slab.h>
  21 #include <linux/init.h>
  22 #include <linux/cpu.h>
  23 #include <linux/irq.h>
  24 #include <asm/irq_regs.h>
  25 #include <asm/cputime.h>
  26 #include <asm/lowcore.h>
  27 #include <asm/irq.h>
  28 #include <asm/hw_irq.h>
  29 #include <asm/stacktrace.h>
  30 #include "entry.h"
  31
  32 DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
  33 EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
  34
  35 struct irq_class {
  36         int irq;
  37         char *name;
  38         char *desc;
  39 };
  40
  41 /*
  42  * The list of "main" irq classes on s390. This is the list of interrupts
  43  * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
  44  * Historically only external and I/O interrupts have been part of /proc/stat.
  45  * We can't add the split external and I/O sub classes since the first field
  46  * in the "intr" line in /proc/stat is supposed to be the sum of all other
  47  * fields.
  48  * Since the external and I/O interrupt fields are already sums we would end
  49  * up with having a sum which accounts each interrupt twice.
  50  */
  51 static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
  52         {.irq = EXT_INTERRUPT,  .name = "EXT"},
  53         {.irq = IO_INTERRUPT,   .name = "I/O"},
  54         {.irq = THIN_INTERRUPT, .name = "AIO"},
  55 };
  56
  57 /*
  58  * The list of split external and I/O interrupts that appear only in
  59  * /proc/interrupts.
  60  * In addition this list contains non external / I/O events like NMIs.
  61  */
  62 static const struct irq_class irqclass_sub_desc[] = {
  63         {.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"},
  64         {.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"},
  65         {.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"},
  66         {.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"},
  67         {.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"},
  68         {.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
  69         {.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"},
  70         {.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"},
  71         {.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"},
  72         {.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"},
  73         {.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
  74         {.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
  75         {.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"},
  76         {.irq = IRQIO_CIO,  .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
  77         {.irq = IRQIO_DAS,  .name = "DAS", .desc = "[I/O] DASD"},
  78         {.irq = IRQIO_C15,  .name = "C15", .desc = "[I/O] 3215"},
  79         {.irq = IRQIO_C70,  .name = "C70", .desc = "[I/O] 3270"},
  80         {.irq = IRQIO_TAP,  .name = "TAP", .desc = "[I/O] Tape"},
  81         {.irq = IRQIO_VMR,  .name = "VMR", .desc = "[I/O] Unit Record Devices"},
  82         {.irq = IRQIO_LCS,  .name = "LCS", .desc = "[I/O] LCS"},
  83         {.irq = IRQIO_CTC,  .name = "CTC", .desc = "[I/O] CTC"},
  84         {.irq = IRQIO_ADM,  .name = "ADM", .desc = "[I/O] EADM Subchannel"},
  85         {.irq = IRQIO_CSC,  .name = "CSC", .desc = "[I/O] CHSC Subchannel"},
  86         {.irq = IRQIO_VIR,  .name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
  87         {.irq = IRQIO_QAI,  .name = "QAI", .desc = "[AIO] QDIO Adapter Interrupt"},
  88         {.irq = IRQIO_APB,  .name = "APB", .desc = "[AIO] AP Bus"},
  89         {.irq = IRQIO_PCF,  .name = "PCF", .desc = "[AIO] PCI Floating Interrupt"},
  90         {.irq = IRQIO_PCD,  .name = "PCD", .desc = "[AIO] PCI Directed Interrupt"},
  91         {.irq = IRQIO_MSI,  .name = "MSI", .desc = "[AIO] MSI Interrupt"},
  92         {.irq = IRQIO_VAI,  .name = "VAI", .desc = "[AIO] Virtual I/O Devices AI"},
  93         {.irq = IRQIO_GAL,  .name = "GAL", .desc = "[AIO] GIB Alert"},
  94         {.irq = NMI_NMI,    .name = "NMI", .desc = "[NMI] Machine Check"},
  95         {.irq = CPU_RST,    .name = "RST", .desc = "[CPU] CPU Restart"},
  96 };
  97
  98 void __init init_IRQ(void)
  99 {
 100         BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
 101         init_cio_interrupts();
 102         init_airq_interrupts();
 103         init_ext_interrupts();
 104 }
 105
 106 void do_IRQ(struct pt_regs *regs, int irq)
 107 {
 108         struct pt_regs *old_regs;
 109
 110         old_regs = set_irq_regs(regs);
 111         irq_enter();
 112         if (tod_after_eq(S390_lowcore.int_clock,
 113                          S390_lowcore.clock_comparator))
 114                 /* Serve timer interrupts first. */
 115                 clock_comparator_work();
 116         generic_handle_irq(irq);
 117         irq_exit();
 118         set_irq_regs(old_regs);
 119 }
 120
 121 static void show_msi_interrupt(struct seq_file *p, int irq)
 122 {
 123         struct irq_desc *desc;
 124         unsigned long flags;
 125         int cpu;
 126
 127         irq_lock_sparse();
 128         desc = irq_to_desc(irq);
 129         if (!desc)
 130                 goto out;
 131
 132         raw_spin_lock_irqsave(&desc->lock, flags);
 133         seq_printf(p, "%3d: ", irq);
 134         for_each_online_cpu(cpu)
 135                 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
 136
 137         if (desc->irq_data.chip)
 138                 seq_printf(p, " %8s", desc->irq_data.chip->name);
 139
 140         if (desc->action)
 141                 seq_printf(p, "  %s", desc->action->name);
 142
 143         seq_putc(p, '\n');
 144         raw_spin_unlock_irqrestore(&desc->lock, flags);
 145 out:
 146         irq_unlock_sparse();
 147 }
 148
 149 /*
 150  * show_interrupts is needed by /proc/interrupts.
 151  */
 152 int show_interrupts(struct seq_file *p, void *v)
 153 {
 154         int index = *(loff_t *) v;
 155         int cpu, irq;
 156
 157         get_online_cpus();
 158         if (index == 0) {
 159                 seq_puts(p, "           ");
 160                 for_each_online_cpu(cpu)
 161                         seq_printf(p, "CPU%-8d", cpu);
 162                 seq_putc(p, '\n');
 163         }
 164         if (index < NR_IRQS_BASE) {
 165                 seq_printf(p, "%s: ", irqclass_main_desc[index].name);
 166                 irq = irqclass_main_desc[index].irq;
 167                 for_each_online_cpu(cpu)
 168                         seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
 169                 seq_putc(p, '\n');
 170                 goto out;
 171         }
 172         if (index < nr_irqs) {
 173                 show_msi_interrupt(p, index);
 174                 goto out;
 175         }
 176         for (index = 0; index < NR_ARCH_IRQS; index++) {
 177                 seq_printf(p, "%s: ", irqclass_sub_desc[index].name);
 178                 irq = irqclass_sub_desc[index].irq;
 179                 for_each_online_cpu(cpu)
 180                         seq_printf(p, "%10u ",
 181                                    per_cpu(irq_stat, cpu).irqs[irq]);
 182                 if (irqclass_sub_desc[index].desc)
 183                         seq_printf(p, "  %s", irqclass_sub_desc[index].desc);
 184                 seq_putc(p, '\n');
 185         }
 186 out:
 187         put_online_cpus();
 188         return 0;
 189 }
 190
 191 unsigned int arch_dynirq_lower_bound(unsigned int from)
 192 {
 193         return from < NR_IRQS_BASE ? NR_IRQS_BASE : from;
 194 }
 195
 196 /*
 197  * Switch to the asynchronous interrupt stack for softirq execution.
 198  */
 199 void do_softirq_own_stack(void)
 200 {
 201         unsigned long old, new;
 202
 203         old = current_stack_pointer();
 204         /* Check against async. stack address range. */
 205         new = S390_lowcore.async_stack;
 206         if (((new - old) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)) != 0) {
 207                 CALL_ON_STACK(__do_softirq, new, 0);
 208         } else {
 209                 /* We are already on the async stack. */
 210                 __do_softirq();
 211         }
 212 }
 213
 214 /*
 215  * ext_int_hash[index] is the list head for all external interrupts that hash
 216  * to this index.
 217  */
 218 static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
 219
 220 struct ext_int_info {
 221         ext_int_handler_t handler;
 222         struct hlist_node entry;
 223         struct rcu_head rcu;
 224         u16 code;
 225 };
 226
 227 /* ext_int_hash_lock protects the handler lists for external interrupts */
 228 static DEFINE_SPINLOCK(ext_int_hash_lock);
 229
 230 static inline int ext_hash(u16 code)
 231 {
 232         BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
 233
 234         return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
 235 }
 236
 237 int register_external_irq(u16 code, ext_int_handler_t handler)
 238 {
 239         struct ext_int_info *p;
 240         unsigned long flags;
 241         int index;
 242
 243         p = kmalloc(sizeof(*p), GFP_ATOMIC);
 244         if (!p)
 245                 return -ENOMEM;
 246         p->code = code;
 247         p->handler = handler;
 248         index = ext_hash(code);
 249
 250         spin_lock_irqsave(&ext_int_hash_lock, flags);
 251         hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
 252         spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 253         return 0;
 254 }
 255 EXPORT_SYMBOL(register_external_irq);
 256
 257 int unregister_external_irq(u16 code, ext_int_handler_t handler)
 258 {
 259         struct ext_int_info *p;
 260         unsigned long flags;
 261         int index = ext_hash(code);
 262
 263         spin_lock_irqsave(&ext_int_hash_lock, flags);
 264         hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
 265                 if (p->code == code && p->handler == handler) {
 266                         hlist_del_rcu(&p->entry);
 267                         kfree_rcu(p, rcu);
 268                 }
 269         }
 270         spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 271         return 0;
 272 }
 273 EXPORT_SYMBOL(unregister_external_irq);
 274
 275 static irqreturn_t do_ext_interrupt(int irq, void *dummy)
 276 {
 277         struct pt_regs *regs = get_irq_regs();
 278         struct ext_code ext_code;
 279         struct ext_int_info *p;
 280         int index;
 281
 282         ext_code = *(struct ext_code *) &regs->int_code;
 283         if (ext_code.code != EXT_IRQ_CLK_COMP)
 284                 set_cpu_flag(CIF_NOHZ_DELAY);
 285
 286         index = ext_hash(ext_code.code);
 287         rcu_read_lock();
 288         hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
 289                 if (unlikely(p->code != ext_code.code))
 290                         continue;
 291                 p->handler(ext_code, regs->int_parm, regs->int_parm_long);
 292         }
 293         rcu_read_unlock();
 294         return IRQ_HANDLED;
 295 }
 296
 297 static struct irqaction external_interrupt = {
 298         .name    = "EXT",
 299         .handler = do_ext_interrupt,
 300 };
 301
 302 void __init init_ext_interrupts(void)
 303 {
 304         int idx;
 305
 306         for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
 307                 INIT_HLIST_HEAD(&ext_int_hash[idx]);
 308
 309         irq_set_chip_and_handler(EXT_INTERRUPT,
 310                                  &dummy_irq_chip, handle_percpu_irq);
 311         setup_irq(EXT_INTERRUPT, &external_interrupt);
 312 }
 313
 314 static DEFINE_SPINLOCK(irq_subclass_lock);
 315 static unsigned char irq_subclass_refcount[64];
 316
 317 void irq_subclass_register(enum irq_subclass subclass)
 318 {
 319         spin_lock(&irq_subclass_lock);
 320         if (!irq_subclass_refcount[subclass])
 321                 ctl_set_bit(0, subclass);
 322         irq_subclass_refcount[subclass]++;
 323         spin_unlock(&irq_subclass_lock);
 324 }
 325 EXPORT_SYMBOL(irq_subclass_register);
 326
 327 void irq_subclass_unregister(enum irq_subclass subclass)
 328 {
 329         spin_lock(&irq_subclass_lock);
 330         irq_subclass_refcount[subclass]--;
 331         if (!irq_subclass_refcount[subclass])
 332                 ctl_clear_bit(0, subclass);
 333         spin_unlock(&irq_subclass_lock);
 334 }
 335 EXPORT_SYMBOL(irq_subclass_unregister);