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); 289