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 = "IPI", .desc = "[EXT] Signal Processor" }, 37 {.name = "TMR", .desc = "[EXT] CPU Timer" }, 38 {.name = "TAL", .desc = "[EXT] Timing Alert" }, 39 {.name = "PFL", .desc = "[EXT] Pseudo Page Fault" }, 40 {.name = "DSD", .desc = "[EXT] DASD Diag" }, 41 {.name = "VRT", .desc = "[EXT] Virtio" }, 42 {.name = "SCP", .desc = "[EXT] Service Call" }, 43 {.name = "IUC", .desc = "[EXT] IUCV" }, 44 {.name = "CPM", .desc = "[EXT] CPU Measurement" }, 45 {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" }, 46 {.name = "QDI", .desc = "[I/O] QDIO Interrupt" }, 47 {.name = "DAS", .desc = "[I/O] DASD" }, 48 {.name = "C15", .desc = "[I/O] 3215" }, 49 {.name = "C70", .desc = "[I/O] 3270" }, 50 {.name = "TAP", .desc = "[I/O] Tape" }, 51 {.name = "VMR", .desc = "[I/O] Unit Record Devices" }, 52 {.name = "LCS", .desc = "[I/O] LCS" }, 53 {.name = "CLW", .desc = "[I/O] CLAW" }, 54 {.name = "CTC", .desc = "[I/O] CTC" }, 55 {.name = "APB", .desc = "[I/O] AP Bus" }, 56 {.name = "NMI", .desc = "[NMI] Machine Check" }, 57 }; 58 59 /* 60 * show_interrupts is needed by /proc/interrupts. 61 */ 62 int show_interrupts(struct seq_file *p, void *v) 63 { 64 int i = *(loff_t *) v, j; 65 66 get_online_cpus(); 67 if (i == 0) { 68 seq_puts(p, " "); 69 for_each_online_cpu(j) 70 seq_printf(p, "CPU%d ",j); 71 seq_putc(p, '\n'); 72 } 73 74 if (i < NR_IRQS) { 75 seq_printf(p, "%s: ", intrclass_names[i].name); 76 #ifndef CONFIG_SMP 77 seq_printf(p, "%10u ", kstat_irqs(i)); 78 #else 79 for_each_online_cpu(j) 80 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); 81 #endif 82 if (intrclass_names[i].desc) 83 seq_printf(p, " %s", intrclass_names[i].desc); 84 seq_putc(p, '\n'); 85 } 86 put_online_cpus(); 87 return 0; 88 } 89 90 /* 91 * Switch to the asynchronous interrupt stack for softirq execution. 92 */ 93 asmlinkage void do_softirq(void) 94 { 95 unsigned long flags, old, new; 96 97 if (in_interrupt()) 98 return; 99 100 local_irq_save(flags); 101 102 if (local_softirq_pending()) { 103 /* Get current stack pointer. */ 104 asm volatile("la %0,0(15)" : "=a" (old)); 105 /* Check against async. stack address range. */ 106 new = S390_lowcore.async_stack; 107 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) { 108 /* Need to switch to the async. stack. */ 109 new -= STACK_FRAME_OVERHEAD; 110 ((struct stack_frame *) new)->back_chain = old; 111 112 asm volatile(" la 15,0(%0)\n" 113 " basr 14,%2\n" 114 " la 15,0(%1)\n" 115 : : "a" (new), "a" (old), 116 "a" (__do_softirq) 117 : "0", "1", "2", "3", "4", "5", "14", 118 "cc", "memory" ); 119 } else 120 /* We are already on the async stack. */ 121 __do_softirq(); 122 } 123 124 local_irq_restore(flags); 125 } 126 127 #ifdef CONFIG_PROC_FS 128 void init_irq_proc(void) 129 { 130 struct proc_dir_entry *root_irq_dir; 131 132 root_irq_dir = proc_mkdir("irq", NULL); 133 create_prof_cpu_mask(root_irq_dir); 134 } 135 #endif 136 137 /* 138 * ext_int_hash[index] is the list head for all external interrupts that hash 139 * to this index. 140 */ 141 static struct list_head ext_int_hash[256]; 142 143 struct ext_int_info { 144 ext_int_handler_t handler; 145 u16 code; 146 struct list_head entry; 147 struct rcu_head rcu; 148 }; 149 150 /* ext_int_hash_lock protects the handler lists for external interrupts */ 151 DEFINE_SPINLOCK(ext_int_hash_lock); 152 153 static void __init init_external_interrupts(void) 154 { 155 int idx; 156 157 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++) 158 INIT_LIST_HEAD(&ext_int_hash[idx]); 159 } 160 161 static inline int ext_hash(u16 code) 162 { 163 return (code + (code >> 9)) & 0xff; 164 } 165 166 static void ext_int_hash_update(struct rcu_head *head) 167 { 168 struct ext_int_info *p = container_of(head, struct ext_int_info, rcu); 169 170 kfree(p); 171 } 172 173 int register_external_interrupt(u16 code, ext_int_handler_t handler) 174 { 175 struct ext_int_info *p; 176 unsigned long flags; 177 int index; 178 179 p = kmalloc(sizeof(*p), GFP_ATOMIC); 180 if (!p) 181 return -ENOMEM; 182 p->code = code; 183 p->handler = handler; 184 index = ext_hash(code); 185 186 spin_lock_irqsave(&ext_int_hash_lock, flags); 187 list_add_rcu(&p->entry, &ext_int_hash[index]); 188 spin_unlock_irqrestore(&ext_int_hash_lock, flags); 189 return 0; 190 } 191 EXPORT_SYMBOL(register_external_interrupt); 192 193 int unregister_external_interrupt(u16 code, ext_int_handler_t handler) 194 { 195 struct ext_int_info *p; 196 unsigned long flags; 197 int index = ext_hash(code); 198 199 spin_lock_irqsave(&ext_int_hash_lock, flags); 200 list_for_each_entry_rcu(p, &ext_int_hash[index], entry) 201 if (p->code == code && p->handler == handler) { 202 list_del_rcu(&p->entry); 203 call_rcu(&p->rcu, ext_int_hash_update); 204 } 205 spin_unlock_irqrestore(&ext_int_hash_lock, flags); 206 return 0; 207 } 208 EXPORT_SYMBOL(unregister_external_interrupt); 209 210 void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code, 211 unsigned int param32, unsigned long param64) 212 { 213 struct pt_regs *old_regs; 214 unsigned short code; 215 struct ext_int_info *p; 216 int index; 217 218 code = (unsigned short) ext_int_code; 219 old_regs = set_irq_regs(regs); 220 s390_idle_check(regs, S390_lowcore.int_clock, 221 S390_lowcore.async_enter_timer); 222 irq_enter(); 223 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) 224 /* Serve timer interrupts first. */ 225 clock_comparator_work(); 226 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++; 227 if (code != 0x1004) 228 __get_cpu_var(s390_idle).nohz_delay = 1; 229 230 index = ext_hash(code); 231 rcu_read_lock(); 232 list_for_each_entry_rcu(p, &ext_int_hash[index], entry) 233 if (likely(p->code == code)) 234 p->handler(ext_int_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