arch/s390/kernel/irq.c

   1 /*
   2  *    Copyright IBM Corp. 2004, 2011
   3  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
   4  *               Holger Smolinski <Holger.Smolinski@de.ibm.com>,
   5  *               Thomas Spatzier <tspat@de.ibm.com>,
   6  *
   7  * This file contains interrupt related functions.
   8  */
   9
  10 #include <linux/kernel_stat.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/proc_fs.h>
  14 #include <linux/profile.h>
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/ftrace.h>
  18 #include <linux/errno.h>
  19 #include <linux/slab.h>
  20 #include <linux/cpu.h>
  21 #include <asm/irq_regs.h>
  22 #include <asm/cputime.h>
  23 #include <asm/lowcore.h>
  24 #include <asm/irq.h>
  25 #include "entry.h"
  26
  27 struct irq_class {
  28         char *name;
  29         char *desc;
  30 };
  31
  32 static const struct irq_class intrclass_names[] = {
  33         [EXTERNAL_INTERRUPT] = {.name = "EXT"},
  34         [IO_INTERRUPT]       = {.name = "I/O"},
  35         [EXTINT_CLK] = {.name = "CLK", .desc = "[EXT] Clock Comparator"},
  36         [EXTINT_EXC] = {.name = "EXC", .desc = "[EXT] External Call"},
  37         [EXTINT_EMS] = {.name = "EMS", .desc = "[EXT] Emergency Signal"},
  38         [EXTINT_TMR] = {.name = "TMR", .desc = "[EXT] CPU Timer"},
  39         [EXTINT_TLA] = {.name = "TAL", .desc = "[EXT] Timing Alert"},
  40         [EXTINT_PFL] = {.name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
  41         [EXTINT_DSD] = {.name = "DSD", .desc = "[EXT] DASD Diag"},
  42         [EXTINT_VRT] = {.name = "VRT", .desc = "[EXT] Virtio"},
  43         [EXTINT_SCP] = {.name = "SCP", .desc = "[EXT] Service Call"},
  44         [EXTINT_IUC] = {.name = "IUC", .desc = "[EXT] IUCV"},
  45         [EXTINT_CMS] = {.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
  46         [EXTINT_CMC] = {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
  47         [EXTINT_CMR] = {.name = "CMR", .desc = "[EXT] CPU-Measurement: RI"},
  48         [IOINT_CIO]  = {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
  49         [IOINT_QAI]  = {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
  50         [IOINT_DAS]  = {.name = "DAS", .desc = "[I/O] DASD"},
  51         [IOINT_C15]  = {.name = "C15", .desc = "[I/O] 3215"},
  52         [IOINT_C70]  = {.name = "C70", .desc = "[I/O] 3270"},
  53         [IOINT_TAP]  = {.name = "TAP", .desc = "[I/O] Tape"},
  54         [IOINT_VMR]  = {.name = "VMR", .desc = "[I/O] Unit Record Devices"},
  55         [IOINT_LCS]  = {.name = "LCS", .desc = "[I/O] LCS"},
  56         [IOINT_CLW]  = {.name = "CLW", .desc = "[I/O] CLAW"},
  57         [IOINT_CTC]  = {.name = "CTC", .desc = "[I/O] CTC"},
  58         [IOINT_APB]  = {.name = "APB", .desc = "[I/O] AP Bus"},
  59         [IOINT_ADM]  = {.name = "ADM", .desc = "[I/O] EADM Subchannel"},
  60         [IOINT_CSC]  = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},
  61         [IOINT_PCI]  = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },
  62         [IOINT_MSI] =  {.name = "MSI", .desc = "[I/O] MSI Interrupt" },
  63         [IOINT_VIR]  = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
  64         [NMI_NMI]    = {.name = "NMI", .desc = "[NMI] Machine Check"},
  65 };
  66
  67 /*
  68  * show_interrupts is needed by /proc/interrupts.
  69  */
  70 int show_interrupts(struct seq_file *p, void *v)
  71 {
  72         int i = *(loff_t *) v, j;
  73
  74         get_online_cpus();
  75         if (i == 0) {
  76                 seq_puts(p, "           ");
  77                 for_each_online_cpu(j)
  78                         seq_printf(p, "CPU%d       ",j);
  79                 seq_putc(p, '\n');
  80         }
  81
  82         if (i < NR_IRQS) {
  83                 seq_printf(p, "%s: ", intrclass_names[i].name);
  84 #ifndef CONFIG_SMP
  85                 seq_printf(p, "%10u ", kstat_irqs(i));
  86 #else
  87                 for_each_online_cpu(j)
  88                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  89 #endif
  90                 if (intrclass_names[i].desc)
  91                         seq_printf(p, "  %s", intrclass_names[i].desc);
  92                 seq_putc(p, '\n');
  93         }
  94         put_online_cpus();
  95         return 0;
  96 }
  97
  98 /*
  99  * Switch to the asynchronous interrupt stack for softirq execution.
 100  */
 101 asmlinkage void do_softirq(void)
 102 {
 103         unsigned long flags, old, new;
 104
 105         if (in_interrupt())
 106                 return;
 107
 108         local_irq_save(flags);
 109
 110         if (local_softirq_pending()) {
 111                 /* Get current stack pointer. */
 112                 asm volatile("la %0,0(15)" : "=a" (old));
 113                 /* Check against async. stack address range. */
 114                 new = S390_lowcore.async_stack;
 115                 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
 116                         /* Need to switch to the async. stack. */
 117                         new -= STACK_FRAME_OVERHEAD;
 118                         ((struct stack_frame *) new)->back_chain = old;
 119
 120                         asm volatile("   la    15,0(%0)\n"
 121                                      "   basr  14,%2\n"
 122                                      "   la    15,0(%1)\n"
 123                                      : : "a" (new), "a" (old),
 124                                          "a" (__do_softirq)
 125                                      : "0", "1", "2", "3", "4", "5", "14",
 126                                        "cc", "memory" );
 127                 } else {
 128                         /* We are already on the async stack. */
 129                         __do_softirq();
 130                 }
 131         }
 132
 133         local_irq_restore(flags);
 134 }
 135
 136 #ifdef CONFIG_PROC_FS
 137 void init_irq_proc(void)
 138 {
 139         struct proc_dir_entry *root_irq_dir;
 140
 141         root_irq_dir = proc_mkdir("irq", NULL);
 142         create_prof_cpu_mask(root_irq_dir);
 143 }
 144 #endif
 145
 146 /*
 147  * ext_int_hash[index] is the list head for all external interrupts that hash
 148  * to this index.
 149  */
 150 static struct list_head ext_int_hash[256];
 151
 152 struct ext_int_info {
 153         ext_int_handler_t handler;
 154         u16 code;
 155         struct list_head entry;
 156         struct rcu_head rcu;
 157 };
 158
 159 /* ext_int_hash_lock protects the handler lists for external interrupts */
 160 DEFINE_SPINLOCK(ext_int_hash_lock);
 161
 162 static void __init init_external_interrupts(void)
 163 {
 164         int idx;
 165
 166         for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
 167                 INIT_LIST_HEAD(&ext_int_hash[idx]);
 168 }
 169
 170 static inline int ext_hash(u16 code)
 171 {
 172         return (code + (code >> 9)) & 0xff;
 173 }
 174
 175 int register_external_interrupt(u16 code, ext_int_handler_t handler)
 176 {
 177         struct ext_int_info *p;
 178         unsigned long flags;
 179         int index;
 180
 181         p = kmalloc(sizeof(*p), GFP_ATOMIC);
 182         if (!p)
 183                 return -ENOMEM;
 184         p->code = code;
 185         p->handler = handler;
 186         index = ext_hash(code);
 187
 188         spin_lock_irqsave(&ext_int_hash_lock, flags);
 189         list_add_rcu(&p->entry, &ext_int_hash[index]);
 190         spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 191         return 0;
 192 }
 193 EXPORT_SYMBOL(register_external_interrupt);
 194
 195 int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
 196 {
 197         struct ext_int_info *p;
 198         unsigned long flags;
 199         int index = ext_hash(code);
 200
 201         spin_lock_irqsave(&ext_int_hash_lock, flags);
 202         list_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
 203                 if (p->code == code && p->handler == handler) {
 204                         list_del_rcu(&p->entry);
 205                         kfree_rcu(p, rcu);
 206                 }
 207         }
 208         spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 209         return 0;
 210 }
 211 EXPORT_SYMBOL(unregister_external_interrupt);
 212
 213 void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
 214                            unsigned int param32, unsigned long param64)
 215 {
 216         struct pt_regs *old_regs;
 217         struct ext_int_info *p;
 218         int index;
 219
 220         old_regs = set_irq_regs(regs);
 221         irq_enter();
 222         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) {
 223                 /* Serve timer interrupts first. */
 224                 clock_comparator_work();
 225         }
 226         kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
 227         if (ext_code.code != 0x1004)
 228                 __get_cpu_var(s390_idle).nohz_delay = 1;
 229
 230         index = ext_hash(ext_code.code);
 231         rcu_read_lock();
 232         list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
 233                 if (likely(p->code == ext_code.code))
 234                         p->handler(ext_code, param32, param64);
 235         rcu_read_unlock();
 236         irq_exit();
 237         set_irq_regs(old_regs);
 238 }
 239
 240 void __init init_IRQ(void)
 241 {
 242         init_external_interrupts();
 243 }
 244
 245 static DEFINE_SPINLOCK(sc_irq_lock);
 246 static int sc_irq_refcount;
 247
 248 void service_subclass_irq_register(void)
 249 {
 250         spin_lock(&sc_irq_lock);
 251         if (!sc_irq_refcount)
 252                 ctl_set_bit(0, 9);
 253         sc_irq_refcount++;
 254         spin_unlock(&sc_irq_lock);
 255 }
 256 EXPORT_SYMBOL(service_subclass_irq_register);
 257
 258 void service_subclass_irq_unregister(void)
 259 {
 260         spin_lock(&sc_irq_lock);
 261         sc_irq_refcount--;
 262         if (!sc_irq_refcount)
 263                 ctl_clear_bit(0, 9);
 264         spin_unlock(&sc_irq_lock);
 265 }
 266 EXPORT_SYMBOL(service_subclass_irq_unregister);
 267
 268 static DEFINE_SPINLOCK(ma_subclass_lock);
 269 static int ma_subclass_refcount;
 270
 271 void measurement_alert_subclass_register(void)
 272 {
 273         spin_lock(&ma_subclass_lock);
 274         if (!ma_subclass_refcount)
 275                 ctl_set_bit(0, 5);
 276         ma_subclass_refcount++;
 277         spin_unlock(&ma_subclass_lock);
 278 }
 279 EXPORT_SYMBOL(measurement_alert_subclass_register);
 280
 281 void measurement_alert_subclass_unregister(void)
 282 {
 283         spin_lock(&ma_subclass_lock);
 284         ma_subclass_refcount--;
 285         if (!ma_subclass_refcount)
 286                 ctl_clear_bit(0, 5);
 287         spin_unlock(&ma_subclass_lock);
 288 }
 289 EXPORT_SYMBOL(measurement_alert_subclass_unregister);