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         [NMI_NMI]    = {.name = "NMI", .desc = "[NMI] Machine Check"},
  64 };
  65
  66 /*
  67  * show_interrupts is needed by /proc/interrupts.
  68  */
  69 int show_interrupts(struct seq_file *p, void *v)
  70 {
  71         int i = *(loff_t *) v, j;
  72
  73         get_online_cpus();
  74         if (i == 0) {
  75                 seq_puts(p, "           ");
  76                 for_each_online_cpu(j)
  77                         seq_printf(p, "CPU%d       ",j);
  78                 seq_putc(p, '\n');
  79         }
  80
  81         if (i < NR_IRQS) {
  82                 seq_printf(p, "%s: ", intrclass_names[i].name);
  83 #ifndef CONFIG_SMP
  84                 seq_printf(p, "%10u ", kstat_irqs(i));
  85 #else
  86                 for_each_online_cpu(j)
  87                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  88 #endif
  89                 if (intrclass_names[i].desc)
  90                         seq_printf(p, "  %s", intrclass_names[i].desc);
  91                 seq_putc(p, '\n');
  92         }
  93         put_online_cpus();
  94         return 0;
  95 }
  96
  97 /*
  98  * Switch to the asynchronous interrupt stack for softirq execution.
  99  */
 100 asmlinkage void do_softirq(void)
 101 {
 102         unsigned long flags, old, new;
 103
 104         if (in_interrupt())
 105                 return;
 106
 107         local_irq_save(flags);
 108
 109         if (local_softirq_pending()) {
 110                 /* Get current stack pointer. */
 111                 asm volatile("la %0,0(15)" : "=a" (old));
 112                 /* Check against async. stack address range. */
 113                 new = S390_lowcore.async_stack;
 114                 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
 115                         /* Need to switch to the async. stack. */
 116                         new -= STACK_FRAME_OVERHEAD;
 117                         ((struct stack_frame *) new)->back_chain = old;
 118
 119                         asm volatile("   la    15,0(%0)\n"
 120                                      "   basr  14,%2\n"
 121                                      "   la    15,0(%1)\n"
 122                                      : : "a" (new), "a" (old),
 123                                          "a" (__do_softirq)
 124                                      : "0", "1", "2", "3", "4", "5", "14",
 125                                        "cc", "memory" );
 126                 } else {
 127                         /* We are already on the async stack. */
 128                         __do_softirq();
 129                 }
 130         }
 131
 132         local_irq_restore(flags);
 133 }
 134
 135 #ifdef CONFIG_PROC_FS
 136 void init_irq_proc(void)
 137 {
 138         struct proc_dir_entry *root_irq_dir;
 139
 140         root_irq_dir = proc_mkdir("irq", NULL);
 141         create_prof_cpu_mask(root_irq_dir);
 142 }
 143 #endif
 144
 145 /*
 146  * ext_int_hash[index] is the list head for all external interrupts that hash
 147  * to this index.
 148  */
 149 static struct list_head ext_int_hash[256];
 150
 151 struct ext_int_info {
 152         ext_int_handler_t handler;
 153         u16 code;
 154         struct list_head entry;
 155         struct rcu_head rcu;
 156 };
 157
 158 /* ext_int_hash_lock protects the handler lists for external interrupts */
 159 DEFINE_SPINLOCK(ext_int_hash_lock);
 160
 161 static void __init init_external_interrupts(void)
 162 {
 163         int idx;
 164
 165         for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
 166                 INIT_LIST_HEAD(&ext_int_hash[idx]);
 167 }
 168
 169 static inline int ext_hash(u16 code)
 170 {
 171         return (code + (code >> 9)) & 0xff;
 172 }
 173
 174 int register_external_interrupt(u16 code, ext_int_handler_t handler)
 175 {
 176         struct ext_int_info *p;
 177         unsigned long flags;
 178         int index;
 179
 180         p = kmalloc(sizeof(*p), GFP_ATOMIC);
 181         if (!p)
 182                 return -ENOMEM;
 183         p->code = code;
 184         p->handler = handler;
 185         index = ext_hash(code);
 186
 187         spin_lock_irqsave(&ext_int_hash_lock, flags);
 188         list_add_rcu(&p->entry, &ext_int_hash[index]);
 189         spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 190         return 0;
 191 }
 192 EXPORT_SYMBOL(register_external_interrupt);
 193
 194 int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
 195 {
 196         struct ext_int_info *p;
 197         unsigned long flags;
 198         int index = ext_hash(code);
 199
 200         spin_lock_irqsave(&ext_int_hash_lock, flags);
 201         list_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
 202                 if (p->code == code && p->handler == handler) {
 203                         list_del_rcu(&p->entry);
 204                         kfree_rcu(p, rcu);
 205                 }
 206         }
 207         spin_unlock_irqrestore(&ext_int_hash_lock, flags);
 208         return 0;
 209 }
 210 EXPORT_SYMBOL(unregister_external_interrupt);
 211
 212 void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
 213                            unsigned int param32, unsigned long param64)
 214 {
 215         struct pt_regs *old_regs;
 216         struct ext_int_info *p;
 217         int index;
 218
 219         old_regs = set_irq_regs(regs);
 220         irq_enter();
 221         if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) {
 222                 /* Serve timer interrupts first. */
 223                 clock_comparator_work();
 224         }
 225         kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
 226         if (ext_code.code != 0x1004)
 227                 __get_cpu_var(s390_idle).nohz_delay = 1;
 228
 229         index = ext_hash(ext_code.code);
 230         rcu_read_lock();
 231         list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
 232                 if (likely(p->code == ext_code.code))
 233                         p->handler(ext_code, param32, param64);
 234         rcu_read_unlock();
 235         irq_exit();
 236         set_irq_regs(old_regs);
 237 }
 238
 239 void __init init_IRQ(void)
 240 {
 241         init_external_interrupts();
 242 }
 243
 244 static DEFINE_SPINLOCK(sc_irq_lock);
 245 static int sc_irq_refcount;
 246
 247 void service_subclass_irq_register(void)
 248 {
 249         spin_lock(&sc_irq_lock);
 250         if (!sc_irq_refcount)
 251                 ctl_set_bit(0, 9);
 252         sc_irq_refcount++;
 253         spin_unlock(&sc_irq_lock);
 254 }
 255 EXPORT_SYMBOL(service_subclass_irq_register);
 256
 257 void service_subclass_irq_unregister(void)
 258 {
 259         spin_lock(&sc_irq_lock);
 260         sc_irq_refcount--;
 261         if (!sc_irq_refcount)
 262                 ctl_clear_bit(0, 9);
 263         spin_unlock(&sc_irq_lock);
 264 }
 265 EXPORT_SYMBOL(service_subclass_irq_unregister);
 266
 267 static DEFINE_SPINLOCK(ma_subclass_lock);
 268 static int ma_subclass_refcount;
 269
 270 void measurement_alert_subclass_register(void)
 271 {
 272         spin_lock(&ma_subclass_lock);
 273         if (!ma_subclass_refcount)
 274                 ctl_set_bit(0, 5);
 275         ma_subclass_refcount++;
 276         spin_unlock(&ma_subclass_lock);
 277 }
 278 EXPORT_SYMBOL(measurement_alert_subclass_register);
 279
 280 void measurement_alert_subclass_unregister(void)
 281 {
 282         spin_lock(&ma_subclass_lock);
 283         ma_subclass_refcount--;
 284         if (!ma_subclass_refcount)
 285                 ctl_clear_bit(0, 5);
 286         spin_unlock(&ma_subclass_lock);
 287 }
 288 EXPORT_SYMBOL(measurement_alert_subclass_unregister);