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