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 * For compatibilty only. S/390 specific setup of interrupts et al. is done 92 * much later in init_channel_subsystem(). 93 */ 94 void __init init_IRQ(void) 95 { 96 /* nothing... */ 97 } 98 99 /* 100 * Switch to the asynchronous interrupt stack for softirq execution. 101 */ 102 asmlinkage void do_softirq(void) 103 { 104 unsigned long flags, old, new; 105 106 if (in_interrupt()) 107 return; 108 109 local_irq_save(flags); 110 111 if (local_softirq_pending()) { 112 /* Get current stack pointer. */ 113 asm volatile("la %0,0(15)" : "=a" (old)); 114 /* Check against async. stack address range. */ 115 new = S390_lowcore.async_stack; 116 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) { 117 /* Need to switch to the async. stack. */ 118 new -= STACK_FRAME_OVERHEAD; 119 ((struct stack_frame *) new)->back_chain = old; 120 121 asm volatile(" la 15,0(%0)\n" 122 " basr 14,%2\n" 123 " la 15,0(%1)\n" 124 : : "a" (new), "a" (old), 125 "a" (__do_softirq) 126 : "0", "1", "2", "3", "4", "5", "14", 127 "cc", "memory" ); 128 } else 129 /* We are already on the async stack. */ 130 __do_softirq(); 131 } 132 133 local_irq_restore(flags); 134 } 135 136 #ifdef CONFIG_PROC_FS 137 void init_irq_proc(void) 138 { 139 struct proc_dir_entry *root_irq_dir; 140 141 root_irq_dir = proc_mkdir("irq", NULL); 142 create_prof_cpu_mask(root_irq_dir); 143 } 144 #endif 145 146 /* 147 * ext_int_hash[index] is the start of the list for all external interrupts 148 * that hash to this index. With the current set of external interrupts 149 * (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000 150 * iucv and 0x2603 pfault) this is always the first element. 151 */ 152 153 struct ext_int_info { 154 struct ext_int_info *next; 155 ext_int_handler_t handler; 156 u16 code; 157 }; 158 159 static struct ext_int_info *ext_int_hash[256]; 160 161 static inline int ext_hash(u16 code) 162 { 163 return (code + (code >> 9)) & 0xff; 164 } 165 166 int register_external_interrupt(u16 code, ext_int_handler_t handler) 167 { 168 struct ext_int_info *p; 169 int index; 170 171 p = kmalloc(sizeof(*p), GFP_ATOMIC); 172 if (!p) 173 return -ENOMEM; 174 p->code = code; 175 p->handler = handler; 176 index = ext_hash(code); 177 p->next = ext_int_hash[index]; 178 ext_int_hash[index] = p; 179 return 0; 180 } 181 EXPORT_SYMBOL(register_external_interrupt); 182 183 int unregister_external_interrupt(u16 code, ext_int_handler_t handler) 184 { 185 struct ext_int_info *p, *q; 186 int index; 187 188 index = ext_hash(code); 189 q = NULL; 190 p = ext_int_hash[index]; 191 while (p) { 192 if (p->code == code && p->handler == handler) 193 break; 194 q = p; 195 p = p->next; 196 } 197 if (!p) 198 return -ENOENT; 199 if (q) 200 q->next = p->next; 201 else 202 ext_int_hash[index] = p->next; 203 kfree(p); 204 return 0; 205 } 206 EXPORT_SYMBOL(unregister_external_interrupt); 207 208 void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code, 209 unsigned int param32, unsigned long param64) 210 { 211 struct pt_regs *old_regs; 212 unsigned short code; 213 struct ext_int_info *p; 214 int index; 215 216 code = (unsigned short) ext_int_code; 217 old_regs = set_irq_regs(regs); 218 s390_idle_check(regs, S390_lowcore.int_clock, 219 S390_lowcore.async_enter_timer); 220 irq_enter(); 221 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) 222 /* Serve timer interrupts first. */ 223 clock_comparator_work(); 224 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++; 225 if (code != 0x1004) 226 __get_cpu_var(s390_idle).nohz_delay = 1; 227 index = ext_hash(code); 228 for (p = ext_int_hash[index]; p; p = p->next) { 229 if (likely(p->code == code)) 230 p->handler(ext_int_code, param32, param64); 231 } 232 irq_exit(); 233 set_irq_regs(old_regs); 234 } 235 236 static DEFINE_SPINLOCK(sc_irq_lock); 237 static int sc_irq_refcount; 238 239 void service_subclass_irq_register(void) 240 { 241 spin_lock(&sc_irq_lock); 242 if (!sc_irq_refcount) 243 ctl_set_bit(0, 9); 244 sc_irq_refcount++; 245 spin_unlock(&sc_irq_lock); 246 } 247 EXPORT_SYMBOL(service_subclass_irq_register); 248 249 void service_subclass_irq_unregister(void) 250 { 251 spin_lock(&sc_irq_lock); 252 sc_irq_refcount--; 253 if (!sc_irq_refcount) 254 ctl_clear_bit(0, 9); 255 spin_unlock(&sc_irq_lock); 256 } 257 EXPORT_SYMBOL(service_subclass_irq_unregister); 258