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 = "CPM", .desc = "[EXT] CPU Measurement" },
46 {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt" },
47 {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
48 {.name = "DAS", .desc = "[I/O] DASD" },
49 {.name = "C15", .desc = "[I/O] 3215" },
50 {.name = "C70", .desc = "[I/O] 3270" },
51 {.name = "TAP", .desc = "[I/O] Tape" },
52 {.name = "VMR", .desc = "[I/O] Unit Record Devices" },
53 {.name = "LCS", .desc = "[I/O] LCS" },
54 {.name = "CLW", .desc = "[I/O] CLAW" },
55 {.name = "CTC", .desc = "[I/O] CTC" },
56 {.name = "APB", .desc = "[I/O] AP Bus" },
57 {.name = "CSC", .desc = "[I/O] CHSC Subchannel" },
58 {.name = "NMI", .desc = "[NMI] Machine Check" },
62 * show_interrupts is needed by /proc/interrupts.
64 int show_interrupts(struct seq_file *p, void *v)
66 int i = *(loff_t *) v, j;
71 for_each_online_cpu(j)
72 seq_printf(p, "CPU%d ",j);
77 seq_printf(p, "%s: ", intrclass_names[i].name);
79 seq_printf(p, "%10u ", kstat_irqs(i));
81 for_each_online_cpu(j)
82 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
84 if (intrclass_names[i].desc)
85 seq_printf(p, " %s", intrclass_names[i].desc);
93 * Switch to the asynchronous interrupt stack for softirq execution.
95 asmlinkage void do_softirq(void)
97 unsigned long flags, old, new;
102 local_irq_save(flags);
104 if (local_softirq_pending()) {
105 /* Get current stack pointer. */
106 asm volatile("la %0,0(15)" : "=a" (old));
107 /* Check against async. stack address range. */
108 new = S390_lowcore.async_stack;
109 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
110 /* Need to switch to the async. stack. */
111 new -= STACK_FRAME_OVERHEAD;
112 ((struct stack_frame *) new)->back_chain = old;
114 asm volatile(" la 15,0(%0)\n"
117 : : "a" (new), "a" (old),
119 : "0", "1", "2", "3", "4", "5", "14",
122 /* We are already on the async stack. */
126 local_irq_restore(flags);
129 #ifdef CONFIG_PROC_FS
130 void init_irq_proc(void)
132 struct proc_dir_entry *root_irq_dir;
134 root_irq_dir = proc_mkdir("irq", NULL);
135 create_prof_cpu_mask(root_irq_dir);
140 * ext_int_hash[index] is the list head for all external interrupts that hash
143 static struct list_head ext_int_hash[256];
145 struct ext_int_info {
146 ext_int_handler_t handler;
148 struct list_head entry;
152 /* ext_int_hash_lock protects the handler lists for external interrupts */
153 DEFINE_SPINLOCK(ext_int_hash_lock);
155 static void __init init_external_interrupts(void)
159 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
160 INIT_LIST_HEAD(&ext_int_hash[idx]);
163 static inline int ext_hash(u16 code)
165 return (code + (code >> 9)) & 0xff;
168 int register_external_interrupt(u16 code, ext_int_handler_t handler)
170 struct ext_int_info *p;
174 p = kmalloc(sizeof(*p), GFP_ATOMIC);
178 p->handler = handler;
179 index = ext_hash(code);
181 spin_lock_irqsave(&ext_int_hash_lock, flags);
182 list_add_rcu(&p->entry, &ext_int_hash[index]);
183 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
186 EXPORT_SYMBOL(register_external_interrupt);
188 int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
190 struct ext_int_info *p;
192 int index = ext_hash(code);
194 spin_lock_irqsave(&ext_int_hash_lock, flags);
195 list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
196 if (p->code == code && p->handler == handler) {
197 list_del_rcu(&p->entry);
200 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
203 EXPORT_SYMBOL(unregister_external_interrupt);
205 void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
206 unsigned int param32, unsigned long param64)
208 struct pt_regs *old_regs;
209 struct ext_int_info *p;
212 old_regs = set_irq_regs(regs);
214 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
215 /* Serve timer interrupts first. */
216 clock_comparator_work();
217 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
218 if (ext_code.code != 0x1004)
219 __get_cpu_var(s390_idle).nohz_delay = 1;
221 index = ext_hash(ext_code.code);
223 list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
224 if (likely(p->code == ext_code.code))
225 p->handler(ext_code, param32, param64);
228 set_irq_regs(old_regs);
231 void __init init_IRQ(void)
233 init_external_interrupts();
236 static DEFINE_SPINLOCK(sc_irq_lock);
237 static int sc_irq_refcount;
239 void service_subclass_irq_register(void)
241 spin_lock(&sc_irq_lock);
242 if (!sc_irq_refcount)
245 spin_unlock(&sc_irq_lock);
247 EXPORT_SYMBOL(service_subclass_irq_register);
249 void service_subclass_irq_unregister(void)
251 spin_lock(&sc_irq_lock);
253 if (!sc_irq_refcount)
255 spin_unlock(&sc_irq_lock);
257 EXPORT_SYMBOL(service_subclass_irq_unregister);