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 local_irq_restore(flags); 127 } 128 129 #ifdef CONFIG_PROC_FS 130 void init_irq_proc(void) 131 { 132 struct proc_dir_entry *root_irq_dir; 133 134 root_irq_dir = proc_mkdir("irq", NULL); 135 create_prof_cpu_mask(root_irq_dir); 136 } 137 #endif 138 139 /* 140 * ext_int_hash[index] is the list head for all external interrupts that hash 141 * to this index. 142 */ 143 static struct list_head ext_int_hash[256]; 144 145 struct ext_int_info { 146 ext_int_handler_t handler; 147 u16 code; 148 struct list_head entry; 149 struct rcu_head rcu; 150 }; 151 152 /* ext_int_hash_lock protects the handler lists for external interrupts */ 153 DEFINE_SPINLOCK(ext_int_hash_lock); 154 155 static void __init init_external_interrupts(void) 156 { 157 int idx; 158 159 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++) 160 INIT_LIST_HEAD(&ext_int_hash[idx]); 161 } 162 163 static inline int ext_hash(u16 code) 164 { 165 return (code + (code >> 9)) & 0xff; 166 } 167 168 static void ext_int_hash_update(struct rcu_head *head) 169 { 170 struct ext_int_info *p = container_of(head, struct ext_int_info, rcu); 171 172 kfree(p); 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 call_rcu(&p->rcu, ext_int_hash_update); 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, unsigned int ext_int_code, 213 unsigned int param32, unsigned long param64) 214 { 215 struct pt_regs *old_regs; 216 unsigned short code; 217 struct ext_int_info *p; 218 int index; 219 220 code = (unsigned short) ext_int_code; 221 old_regs = set_irq_regs(regs); 222 s390_idle_check(regs, S390_lowcore.int_clock, 223 S390_lowcore.async_enter_timer); 224 irq_enter(); 225 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) 226 /* Serve timer interrupts first. */ 227 clock_comparator_work(); 228 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++; 229 if (code != 0x1004) 230 __get_cpu_var(s390_idle).nohz_delay = 1; 231 232 index = ext_hash(code); 233 rcu_read_lock(); 234 list_for_each_entry_rcu(p, &ext_int_hash[index], entry) 235 if (likely(p->code == code)) 236 p->handler(ext_int_code, param32, param64); 237 rcu_read_unlock(); 238 irq_exit(); 239 set_irq_regs(old_regs); 240 } 241 242 void __init init_IRQ(void) 243 { 244 init_external_interrupts(); 245 } 246 247 static DEFINE_SPINLOCK(sc_irq_lock); 248 static int sc_irq_refcount; 249 250 void service_subclass_irq_register(void) 251 { 252 spin_lock(&sc_irq_lock); 253 if (!sc_irq_refcount) 254 ctl_set_bit(0, 9); 255 sc_irq_refcount++; 256 spin_unlock(&sc_irq_lock); 257 } 258 EXPORT_SYMBOL(service_subclass_irq_register); 259 260 void service_subclass_irq_unregister(void) 261 { 262 spin_lock(&sc_irq_lock); 263 sc_irq_refcount--; 264 if (!sc_irq_refcount) 265 ctl_clear_bit(0, 9); 266 spin_unlock(&sc_irq_lock); 267 } 268 EXPORT_SYMBOL(service_subclass_irq_unregister); 269