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>,
7 * This file contains interrupt related functions.
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>
32 static const struct irq_class intrclass_names[] = {
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 = "CMS", .desc = "[EXT] CPU-Measurement: Sampling" },
46 {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter" },
47 {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt" },
48 {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
49 {.name = "DAS", .desc = "[I/O] DASD" },
50 {.name = "C15", .desc = "[I/O] 3215" },
51 {.name = "C70", .desc = "[I/O] 3270" },
52 {.name = "TAP", .desc = "[I/O] Tape" },
53 {.name = "VMR", .desc = "[I/O] Unit Record Devices" },
54 {.name = "LCS", .desc = "[I/O] LCS" },
55 {.name = "CLW", .desc = "[I/O] CLAW" },
56 {.name = "CTC", .desc = "[I/O] CTC" },
57 {.name = "APB", .desc = "[I/O] AP Bus" },
58 {.name = "CSC", .desc = "[I/O] CHSC Subchannel" },
59 {.name = "NMI", .desc = "[NMI] Machine Check" },
63 * show_interrupts is needed by /proc/interrupts.
65 int show_interrupts(struct seq_file *p, void *v)
67 int i = *(loff_t *) v, j;
72 for_each_online_cpu(j)
73 seq_printf(p, "CPU%d ",j);
78 seq_printf(p, "%s: ", intrclass_names[i].name);
80 seq_printf(p, "%10u ", kstat_irqs(i));
82 for_each_online_cpu(j)
83 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
85 if (intrclass_names[i].desc)
86 seq_printf(p, " %s", intrclass_names[i].desc);
94 * Switch to the asynchronous interrupt stack for softirq execution.
96 asmlinkage void do_softirq(void)
98 unsigned long flags, old, new;
103 local_irq_save(flags);
105 if (local_softirq_pending()) {
106 /* Get current stack pointer. */
107 asm volatile("la %0,0(15)" : "=a" (old));
108 /* Check against async. stack address range. */
109 new = S390_lowcore.async_stack;
110 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
111 /* Need to switch to the async. stack. */
112 new -= STACK_FRAME_OVERHEAD;
113 ((struct stack_frame *) new)->back_chain = old;
115 asm volatile(" la 15,0(%0)\n"
118 : : "a" (new), "a" (old),
120 : "0", "1", "2", "3", "4", "5", "14",
123 /* We are already on the async stack. */
128 local_irq_restore(flags);
131 #ifdef CONFIG_PROC_FS
132 void init_irq_proc(void)
134 struct proc_dir_entry *root_irq_dir;
136 root_irq_dir = proc_mkdir("irq", NULL);
137 create_prof_cpu_mask(root_irq_dir);
142 * ext_int_hash[index] is the list head for all external interrupts that hash
145 static struct list_head ext_int_hash[256];
147 struct ext_int_info {
148 ext_int_handler_t handler;
150 struct list_head entry;
154 /* ext_int_hash_lock protects the handler lists for external interrupts */
155 DEFINE_SPINLOCK(ext_int_hash_lock);
157 static void __init init_external_interrupts(void)
161 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
162 INIT_LIST_HEAD(&ext_int_hash[idx]);
165 static inline int ext_hash(u16 code)
167 return (code + (code >> 9)) & 0xff;
170 int register_external_interrupt(u16 code, ext_int_handler_t handler)
172 struct ext_int_info *p;
176 p = kmalloc(sizeof(*p), GFP_ATOMIC);
180 p->handler = handler;
181 index = ext_hash(code);
183 spin_lock_irqsave(&ext_int_hash_lock, flags);
184 list_add_rcu(&p->entry, &ext_int_hash[index]);
185 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
188 EXPORT_SYMBOL(register_external_interrupt);
190 int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
192 struct ext_int_info *p;
194 int index = ext_hash(code);
196 spin_lock_irqsave(&ext_int_hash_lock, flags);
197 list_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
198 if (p->code == code && p->handler == handler) {
199 list_del_rcu(&p->entry);
203 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
206 EXPORT_SYMBOL(unregister_external_interrupt);
208 void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
209 unsigned int param32, unsigned long param64)
211 struct pt_regs *old_regs;
212 struct ext_int_info *p;
215 old_regs = set_irq_regs(regs);
217 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) {
218 /* Serve timer interrupts first. */
219 clock_comparator_work();
221 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
222 if (ext_code.code != 0x1004)
223 __get_cpu_var(s390_idle).nohz_delay = 1;
225 index = ext_hash(ext_code.code);
227 list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
228 if (likely(p->code == ext_code.code))
229 p->handler(ext_code, param32, param64);
232 set_irq_regs(old_regs);
235 void __init init_IRQ(void)
237 init_external_interrupts();
240 static DEFINE_SPINLOCK(sc_irq_lock);
241 static int sc_irq_refcount;
243 void service_subclass_irq_register(void)
245 spin_lock(&sc_irq_lock);
246 if (!sc_irq_refcount)
249 spin_unlock(&sc_irq_lock);
251 EXPORT_SYMBOL(service_subclass_irq_register);
253 void service_subclass_irq_unregister(void)
255 spin_lock(&sc_irq_lock);
257 if (!sc_irq_refcount)
259 spin_unlock(&sc_irq_lock);
261 EXPORT_SYMBOL(service_subclass_irq_unregister);
263 static DEFINE_SPINLOCK(ma_subclass_lock);
264 static int ma_subclass_refcount;
266 void measurement_alert_subclass_register(void)
268 spin_lock(&ma_subclass_lock);
269 if (!ma_subclass_refcount)
271 ma_subclass_refcount++;
272 spin_unlock(&ma_subclass_lock);
274 EXPORT_SYMBOL(measurement_alert_subclass_register);
276 void measurement_alert_subclass_unregister(void)
278 spin_lock(&ma_subclass_lock);
279 ma_subclass_refcount--;
280 if (!ma_subclass_refcount)
282 spin_unlock(&ma_subclass_lock);
284 EXPORT_SYMBOL(measurement_alert_subclass_unregister);