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 [NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"}, 62 }; 63 64 /* 65 * show_interrupts is needed by /proc/interrupts. 66 */ 67 int show_interrupts(struct seq_file *p, void *v) 68 { 69 int i = *(loff_t *) v, j; 70 71 get_online_cpus(); 72 if (i == 0) { 73 seq_puts(p, " "); 74 for_each_online_cpu(j) 75 seq_printf(p, "CPU%d ",j); 76 seq_putc(p, '\n'); 77 } 78 79 if (i < NR_IRQS) { 80 seq_printf(p, "%s: ", intrclass_names[i].name); 81 #ifndef CONFIG_SMP 82 seq_printf(p, "%10u ", kstat_irqs(i)); 83 #else 84 for_each_online_cpu(j) 85 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); 86 #endif 87 if (intrclass_names[i].desc) 88 seq_printf(p, " %s", intrclass_names[i].desc); 89 seq_putc(p, '\n'); 90 } 91 put_online_cpus(); 92 return 0; 93 } 94 95 /* 96 * Switch to the asynchronous interrupt stack for softirq execution. 97 */ 98 asmlinkage void do_softirq(void) 99 { 100 unsigned long flags, old, new; 101 102 if (in_interrupt()) 103 return; 104 105 local_irq_save(flags); 106 107 if (local_softirq_pending()) { 108 /* Get current stack pointer. */ 109 asm volatile("la %0,0(15)" : "=a" (old)); 110 /* Check against async. stack address range. */ 111 new = S390_lowcore.async_stack; 112 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) { 113 /* Need to switch to the async. stack. */ 114 new -= STACK_FRAME_OVERHEAD; 115 ((struct stack_frame *) new)->back_chain = old; 116 117 asm volatile(" la 15,0(%0)\n" 118 " basr 14,%2\n" 119 " la 15,0(%1)\n" 120 : : "a" (new), "a" (old), 121 "a" (__do_softirq) 122 : "0", "1", "2", "3", "4", "5", "14", 123 "cc", "memory" ); 124 } else { 125 /* We are already on the async stack. */ 126 __do_softirq(); 127 } 128 } 129 130 local_irq_restore(flags); 131 } 132 133 #ifdef CONFIG_PROC_FS 134 void init_irq_proc(void) 135 { 136 struct proc_dir_entry *root_irq_dir; 137 138 root_irq_dir = proc_mkdir("irq", NULL); 139 create_prof_cpu_mask(root_irq_dir); 140 } 141 #endif 142 143 /* 144 * ext_int_hash[index] is the list head for all external interrupts that hash 145 * to this index. 146 */ 147 static struct list_head ext_int_hash[256]; 148 149 struct ext_int_info { 150 ext_int_handler_t handler; 151 u16 code; 152 struct list_head entry; 153 struct rcu_head rcu; 154 }; 155 156 /* ext_int_hash_lock protects the handler lists for external interrupts */ 157 DEFINE_SPINLOCK(ext_int_hash_lock); 158 159 static void __init init_external_interrupts(void) 160 { 161 int idx; 162 163 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++) 164 INIT_LIST_HEAD(&ext_int_hash[idx]); 165 } 166 167 static inline int ext_hash(u16 code) 168 { 169 return (code + (code >> 9)) & 0xff; 170 } 171 172 int register_external_interrupt(u16 code, ext_int_handler_t handler) 173 { 174 struct ext_int_info *p; 175 unsigned long flags; 176 int index; 177 178 p = kmalloc(sizeof(*p), GFP_ATOMIC); 179 if (!p) 180 return -ENOMEM; 181 p->code = code; 182 p->handler = handler; 183 index = ext_hash(code); 184 185 spin_lock_irqsave(&ext_int_hash_lock, flags); 186 list_add_rcu(&p->entry, &ext_int_hash[index]); 187 spin_unlock_irqrestore(&ext_int_hash_lock, flags); 188 return 0; 189 } 190 EXPORT_SYMBOL(register_external_interrupt); 191 192 int unregister_external_interrupt(u16 code, ext_int_handler_t handler) 193 { 194 struct ext_int_info *p; 195 unsigned long flags; 196 int index = ext_hash(code); 197 198 spin_lock_irqsave(&ext_int_hash_lock, flags); 199 list_for_each_entry_rcu(p, &ext_int_hash[index], entry) { 200 if (p->code == code && p->handler == handler) { 201 list_del_rcu(&p->entry); 202 kfree_rcu(p, rcu); 203 } 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, struct ext_code ext_code, 211 unsigned int param32, unsigned long param64) 212 { 213 struct pt_regs *old_regs; 214 struct ext_int_info *p; 215 int index; 216 217 old_regs = set_irq_regs(regs); 218 irq_enter(); 219 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) { 220 /* Serve timer interrupts first. */ 221 clock_comparator_work(); 222 } 223 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++; 224 if (ext_code.code != 0x1004) 225 __get_cpu_var(s390_idle).nohz_delay = 1; 226 227 index = ext_hash(ext_code.code); 228 rcu_read_lock(); 229 list_for_each_entry_rcu(p, &ext_int_hash[index], entry) 230 if (likely(p->code == ext_code.code)) 231 p->handler(ext_code, param32, param64); 232 rcu_read_unlock(); 233 irq_exit(); 234 set_irq_regs(old_regs); 235 } 236 237 void __init init_IRQ(void) 238 { 239 init_external_interrupts(); 240 } 241 242 static DEFINE_SPINLOCK(sc_irq_lock); 243 static int sc_irq_refcount; 244 245 void service_subclass_irq_register(void) 246 { 247 spin_lock(&sc_irq_lock); 248 if (!sc_irq_refcount) 249 ctl_set_bit(0, 9); 250 sc_irq_refcount++; 251 spin_unlock(&sc_irq_lock); 252 } 253 EXPORT_SYMBOL(service_subclass_irq_register); 254 255 void service_subclass_irq_unregister(void) 256 { 257 spin_lock(&sc_irq_lock); 258 sc_irq_refcount--; 259 if (!sc_irq_refcount) 260 ctl_clear_bit(0, 9); 261 spin_unlock(&sc_irq_lock); 262 } 263 EXPORT_SYMBOL(service_subclass_irq_unregister); 264 265 static DEFINE_SPINLOCK(ma_subclass_lock); 266 static int ma_subclass_refcount; 267 268 void measurement_alert_subclass_register(void) 269 { 270 spin_lock(&ma_subclass_lock); 271 if (!ma_subclass_refcount) 272 ctl_set_bit(0, 5); 273 ma_subclass_refcount++; 274 spin_unlock(&ma_subclass_lock); 275 } 276 EXPORT_SYMBOL(measurement_alert_subclass_register); 277 278 void measurement_alert_subclass_unregister(void) 279 { 280 spin_lock(&ma_subclass_lock); 281 ma_subclass_refcount--; 282 if (!ma_subclass_refcount) 283 ctl_clear_bit(0, 5); 284 spin_unlock(&ma_subclass_lock); 285 } 286 EXPORT_SYMBOL(measurement_alert_subclass_unregister); 287