linux/arch/s390/kernel/irq.c
<<
>>
Prefs
   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 <linux/entry-common.h>
  25#include <asm/irq_regs.h>
  26#include <asm/cputime.h>
  27#include <asm/lowcore.h>
  28#include <asm/irq.h>
  29#include <asm/hw_irq.h>
  30#include <asm/stacktrace.h>
  31#include <asm/softirq_stack.h>
  32#include "entry.h"
  33
  34DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
  35EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
  36
  37struct irq_class {
  38        int irq;
  39        char *name;
  40        char *desc;
  41};
  42
  43/*
  44 * The list of "main" irq classes on s390. This is the list of interrupts
  45 * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
  46 * Historically only external and I/O interrupts have been part of /proc/stat.
  47 * We can't add the split external and I/O sub classes since the first field
  48 * in the "intr" line in /proc/stat is supposed to be the sum of all other
  49 * fields.
  50 * Since the external and I/O interrupt fields are already sums we would end
  51 * up with having a sum which accounts each interrupt twice.
  52 */
  53static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
  54        {.irq = EXT_INTERRUPT,  .name = "EXT"},
  55        {.irq = IO_INTERRUPT,   .name = "I/O"},
  56        {.irq = THIN_INTERRUPT, .name = "AIO"},
  57};
  58
  59/*
  60 * The list of split external and I/O interrupts that appear only in
  61 * /proc/interrupts.
  62 * In addition this list contains non external / I/O events like NMIs.
  63 */
  64static const struct irq_class irqclass_sub_desc[] = {
  65        {.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"},
  66        {.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"},
  67        {.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"},
  68        {.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"},
  69        {.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"},
  70        {.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
  71        {.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"},
  72        {.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"},
  73        {.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"},
  74        {.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"},
  75        {.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
  76        {.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
  77        {.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"},
  78        {.irq = IRQIO_CIO,  .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
  79        {.irq = IRQIO_DAS,  .name = "DAS", .desc = "[I/O] DASD"},
  80        {.irq = IRQIO_C15,  .name = "C15", .desc = "[I/O] 3215"},
  81        {.irq = IRQIO_C70,  .name = "C70", .desc = "[I/O] 3270"},
  82        {.irq = IRQIO_TAP,  .name = "TAP", .desc = "[I/O] Tape"},
  83        {.irq = IRQIO_VMR,  .name = "VMR", .desc = "[I/O] Unit Record Devices"},
  84        {.irq = IRQIO_LCS,  .name = "LCS", .desc = "[I/O] LCS"},
  85        {.irq = IRQIO_CTC,  .name = "CTC", .desc = "[I/O] CTC"},
  86        {.irq = IRQIO_ADM,  .name = "ADM", .desc = "[I/O] EADM Subchannel"},
  87        {.irq = IRQIO_CSC,  .name = "CSC", .desc = "[I/O] CHSC Subchannel"},
  88        {.irq = IRQIO_VIR,  .name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
  89        {.irq = IRQIO_QAI,  .name = "QAI", .desc = "[AIO] QDIO Adapter Interrupt"},
  90        {.irq = IRQIO_APB,  .name = "APB", .desc = "[AIO] AP Bus"},
  91        {.irq = IRQIO_PCF,  .name = "PCF", .desc = "[AIO] PCI Floating Interrupt"},
  92        {.irq = IRQIO_PCD,  .name = "PCD", .desc = "[AIO] PCI Directed Interrupt"},
  93        {.irq = IRQIO_MSI,  .name = "MSI", .desc = "[AIO] MSI Interrupt"},
  94        {.irq = IRQIO_VAI,  .name = "VAI", .desc = "[AIO] Virtual I/O Devices AI"},
  95        {.irq = IRQIO_GAL,  .name = "GAL", .desc = "[AIO] GIB Alert"},
  96        {.irq = NMI_NMI,    .name = "NMI", .desc = "[NMI] Machine Check"},
  97        {.irq = CPU_RST,    .name = "RST", .desc = "[CPU] CPU Restart"},
  98};
  99
 100static void do_IRQ(struct pt_regs *regs, int irq)
 101{
 102        if (tod_after_eq(S390_lowcore.int_clock,
 103                         S390_lowcore.clock_comparator))
 104                /* Serve timer interrupts first. */
 105                clock_comparator_work();
 106        generic_handle_irq(irq);
 107}
 108
 109static int on_async_stack(void)
 110{
 111        unsigned long frame = current_frame_address();
 112
 113        return ((S390_lowcore.async_stack ^ frame) & ~(THREAD_SIZE - 1)) == 0;
 114}
 115
 116static void do_irq_async(struct pt_regs *regs, int irq)
 117{
 118        if (on_async_stack()) {
 119                do_IRQ(regs, irq);
 120        } else {
 121                call_on_stack(2, S390_lowcore.async_stack, void, do_IRQ,
 122                              struct pt_regs *, regs, int, irq);
 123        }
 124}
 125
 126static int irq_pending(struct pt_regs *regs)
 127{
 128        int cc;
 129
 130        asm volatile("tpi 0\n"
 131                     "ipm %0" : "=d" (cc) : : "cc");
 132        return cc >> 28;
 133}
 134
 135void noinstr do_io_irq(struct pt_regs *regs)
 136{
 137        irqentry_state_t state = irqentry_enter(regs);
 138        struct pt_regs *old_regs = set_irq_regs(regs);
 139        int from_idle;
 140
 141        irq_enter();
 142
 143        if (user_mode(regs))
 144                update_timer_sys();
 145
 146        from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
 147        if (from_idle)
 148                account_idle_time_irq();
 149
 150        do {
 151                regs->tpi_info = S390_lowcore.tpi_info;
 152                if (S390_lowcore.tpi_info.adapter_IO)
 153                        do_irq_async(regs, THIN_INTERRUPT);
 154                else
 155                        do_irq_async(regs, IO_INTERRUPT);
 156        } while (MACHINE_IS_LPAR && irq_pending(regs));
 157
 158        irq_exit();
 159        set_irq_regs(old_regs);
 160        irqentry_exit(regs, state);
 161
 162        if (from_idle)
 163                regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
 164}
 165
 166void noinstr do_ext_irq(struct pt_regs *regs)
 167{
 168        irqentry_state_t state = irqentry_enter(regs);
 169        struct pt_regs *old_regs = set_irq_regs(regs);
 170        int from_idle;
 171
 172        irq_enter();
 173
 174        if (user_mode(regs))
 175                update_timer_sys();
 176
 177        regs->int_code = S390_lowcore.ext_int_code_addr;
 178        regs->int_parm = S390_lowcore.ext_params;
 179        regs->int_parm_long = S390_lowcore.ext_params2;
 180
 181        from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit;
 182        if (from_idle)
 183                account_idle_time_irq();
 184
 185        do_irq_async(regs, EXT_INTERRUPT);
 186
 187        irq_exit();
 188        set_irq_regs(old_regs);
 189        irqentry_exit(regs, state);
 190
 191        if (from_idle)
 192                regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
 193}
 194
 195static void show_msi_interrupt(struct seq_file *p, int irq)
 196{
 197        struct irq_desc *desc;
 198        unsigned long flags;
 199        int cpu;
 200
 201        irq_lock_sparse();
 202        desc = irq_to_desc(irq);
 203        if (!desc)
 204                goto out;
 205
 206        raw_spin_lock_irqsave(&desc->lock, flags);
 207        seq_printf(p, "%3d: ", irq);
 208        for_each_online_cpu(cpu)
 209                seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, cpu));
 210
 211        if (desc->irq_data.chip)
 212                seq_printf(p, " %8s", desc->irq_data.chip->name);
 213
 214        if (desc->action)
 215                seq_printf(p, "  %s", desc->action->name);
 216
 217        seq_putc(p, '\n');
 218        raw_spin_unlock_irqrestore(&desc->lock, flags);
 219out:
 220        irq_unlock_sparse();
 221}
 222
 223/*
 224 * show_interrupts is needed by /proc/interrupts.
 225 */
 226int show_interrupts(struct seq_file *p, void *v)
 227{
 228        int index = *(loff_t *) v;
 229        int cpu, irq;
 230
 231        cpus_read_lock();
 232        if (index == 0) {
 233                seq_puts(p, "           ");
 234                for_each_online_cpu(cpu)
 235                        seq_printf(p, "CPU%-8d", cpu);
 236                seq_putc(p, '\n');
 237        }
 238        if (index < NR_IRQS_BASE) {
 239                seq_printf(p, "%s: ", irqclass_main_desc[index].name);
 240                irq = irqclass_main_desc[index].irq;
 241                for_each_online_cpu(cpu)
 242                        seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
 243                seq_putc(p, '\n');
 244                goto out;
 245        }
 246        if (index < nr_irqs) {
 247                show_msi_interrupt(p, index);
 248                goto out;
 249        }
 250        for (index = 0; index < NR_ARCH_IRQS; index++) {
 251                seq_printf(p, "%s: ", irqclass_sub_desc[index].name);
 252                irq = irqclass_sub_desc[index].irq;
 253                for_each_online_cpu(cpu)
 254                        seq_printf(p, "%10u ",
 255                                   per_cpu(irq_stat, cpu).irqs[irq]);
 256                if (irqclass_sub_desc[index].desc)
 257                        seq_printf(p, "  %s", irqclass_sub_desc[index].desc);
 258                seq_putc(p, '\n');
 259        }
 260out:
 261        cpus_read_unlock();
 262        return 0;
 263}
 264
 265unsigned int arch_dynirq_lower_bound(unsigned int from)
 266{
 267        return from < NR_IRQS_BASE ? NR_IRQS_BASE : from;
 268}
 269
 270/*
 271 * ext_int_hash[index] is the list head for all external interrupts that hash
 272 * to this index.
 273 */
 274static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
 275
 276struct ext_int_info {
 277        ext_int_handler_t handler;
 278        struct hlist_node entry;
 279        struct rcu_head rcu;
 280        u16 code;
 281};
 282
 283/* ext_int_hash_lock protects the handler lists for external interrupts */
 284static DEFINE_SPINLOCK(ext_int_hash_lock);
 285
 286static inline int ext_hash(u16 code)
 287{
 288        BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
 289
 290        return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
 291}
 292
 293int register_external_irq(u16 code, ext_int_handler_t handler)
 294{
 295        struct ext_int_info *p;
 296        unsigned long flags;
 297        int index;
 298
 299        p = kmalloc(sizeof(*p), GFP_ATOMIC);
 300        if (!p)
 301                return -ENOMEM;
 302        p->code = code;
 303        p->handler = handler;
 304        index = ext_hash(code);
 305
 306        spin_lock_irqsave(&ext_int_hash_lock, flags);
 307        hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
 308        spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 309        return 0;
 310}
 311EXPORT_SYMBOL(register_external_irq);
 312
 313int unregister_external_irq(u16 code, ext_int_handler_t handler)
 314{
 315        struct ext_int_info *p;
 316        unsigned long flags;
 317        int index = ext_hash(code);
 318
 319        spin_lock_irqsave(&ext_int_hash_lock, flags);
 320        hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
 321                if (p->code == code && p->handler == handler) {
 322                        hlist_del_rcu(&p->entry);
 323                        kfree_rcu(p, rcu);
 324                }
 325        }
 326        spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 327        return 0;
 328}
 329EXPORT_SYMBOL(unregister_external_irq);
 330
 331static irqreturn_t do_ext_interrupt(int irq, void *dummy)
 332{
 333        struct pt_regs *regs = get_irq_regs();
 334        struct ext_code ext_code;
 335        struct ext_int_info *p;
 336        int index;
 337
 338        ext_code = *(struct ext_code *) &regs->int_code;
 339        if (ext_code.code != EXT_IRQ_CLK_COMP)
 340                set_cpu_flag(CIF_NOHZ_DELAY);
 341
 342        index = ext_hash(ext_code.code);
 343        rcu_read_lock();
 344        hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
 345                if (unlikely(p->code != ext_code.code))
 346                        continue;
 347                p->handler(ext_code, regs->int_parm, regs->int_parm_long);
 348        }
 349        rcu_read_unlock();
 350        return IRQ_HANDLED;
 351}
 352
 353static void __init init_ext_interrupts(void)
 354{
 355        int idx;
 356
 357        for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
 358                INIT_HLIST_HEAD(&ext_int_hash[idx]);
 359
 360        irq_set_chip_and_handler(EXT_INTERRUPT,
 361                                 &dummy_irq_chip, handle_percpu_irq);
 362        if (request_irq(EXT_INTERRUPT, do_ext_interrupt, 0, "EXT", NULL))
 363                panic("Failed to register EXT interrupt\n");
 364}
 365
 366void __init init_IRQ(void)
 367{
 368        BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
 369        init_cio_interrupts();
 370        init_airq_interrupts();
 371        init_ext_interrupts();
 372}
 373
 374static DEFINE_SPINLOCK(irq_subclass_lock);
 375static unsigned char irq_subclass_refcount[64];
 376
 377void irq_subclass_register(enum irq_subclass subclass)
 378{
 379        spin_lock(&irq_subclass_lock);
 380        if (!irq_subclass_refcount[subclass])
 381                ctl_set_bit(0, subclass);
 382        irq_subclass_refcount[subclass]++;
 383        spin_unlock(&irq_subclass_lock);
 384}
 385EXPORT_SYMBOL(irq_subclass_register);
 386
 387void irq_subclass_unregister(enum irq_subclass subclass)
 388{
 389        spin_lock(&irq_subclass_lock);
 390        irq_subclass_refcount[subclass]--;
 391        if (!irq_subclass_refcount[subclass])
 392                ctl_clear_bit(0, subclass);
 393        spin_unlock(&irq_subclass_lock);
 394}
 395EXPORT_SYMBOL(irq_subclass_unregister);
 396