Merge remote-tracking branch 's5p/for-next'
[linux-2.6/next.git] / arch / s390 / kernel / irq.c
blob1f4050d45f78766c8fc43cc54b628b873e079b38
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>,
7 * This file contains interrupt related functions.
8 */
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"
27 struct irq_class {
28 char *name;
29 char *desc;
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" },
60 * show_interrupts is needed by /proc/interrupts.
62 int show_interrupts(struct seq_file *p, void *v)
64 int i = *(loff_t *) v, j;
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');
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');
86 put_online_cpus();
87 return 0;
91 * Switch to the asynchronous interrupt stack for softirq execution.
93 asmlinkage void do_softirq(void)
95 unsigned long flags, old, new;
97 if (in_interrupt())
98 return;
100 local_irq_save(flags);
102 if (local_softirq_pending()) {
103 /* Get current stack pointer. */
104 asm volatile("la %0,0(15)" : "=a" (old));
105 /* Check against async. stack address range. */
106 new = S390_lowcore.async_stack;
107 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
108 /* Need to switch to the async. stack. */
109 new -= STACK_FRAME_OVERHEAD;
110 ((struct stack_frame *) new)->back_chain = old;
112 asm volatile(" la 15,0(%0)\n"
113 " basr 14,%2\n"
114 " la 15,0(%1)\n"
115 : : "a" (new), "a" (old),
116 "a" (__do_softirq)
117 : "0", "1", "2", "3", "4", "5", "14",
118 "cc", "memory" );
119 } else
120 /* We are already on the async stack. */
121 __do_softirq();
124 local_irq_restore(flags);
127 #ifdef CONFIG_PROC_FS
128 void init_irq_proc(void)
130 struct proc_dir_entry *root_irq_dir;
132 root_irq_dir = proc_mkdir("irq", NULL);
133 create_prof_cpu_mask(root_irq_dir);
135 #endif
138 * ext_int_hash[index] is the list head for all external interrupts that hash
139 * to this index.
141 static struct list_head ext_int_hash[256];
143 struct ext_int_info {
144 ext_int_handler_t handler;
145 u16 code;
146 struct list_head entry;
147 struct rcu_head rcu;
150 /* ext_int_hash_lock protects the handler lists for external interrupts */
151 DEFINE_SPINLOCK(ext_int_hash_lock);
153 static void __init init_external_interrupts(void)
155 int idx;
157 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
158 INIT_LIST_HEAD(&ext_int_hash[idx]);
161 static inline int ext_hash(u16 code)
163 return (code + (code >> 9)) & 0xff;
166 static void ext_int_hash_update(struct rcu_head *head)
168 struct ext_int_info *p = container_of(head, struct ext_int_info, rcu);
170 kfree(p);
173 int register_external_interrupt(u16 code, ext_int_handler_t handler)
175 struct ext_int_info *p;
176 unsigned long flags;
177 int index;
179 p = kmalloc(sizeof(*p), GFP_ATOMIC);
180 if (!p)
181 return -ENOMEM;
182 p->code = code;
183 p->handler = handler;
184 index = ext_hash(code);
186 spin_lock_irqsave(&ext_int_hash_lock, flags);
187 list_add_rcu(&p->entry, &ext_int_hash[index]);
188 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
189 return 0;
191 EXPORT_SYMBOL(register_external_interrupt);
193 int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
195 struct ext_int_info *p;
196 unsigned long flags;
197 int index = ext_hash(code);
199 spin_lock_irqsave(&ext_int_hash_lock, flags);
200 list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
201 if (p->code == code && p->handler == handler) {
202 list_del_rcu(&p->entry);
203 call_rcu(&p->rcu, ext_int_hash_update);
205 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
206 return 0;
208 EXPORT_SYMBOL(unregister_external_interrupt);
210 void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code,
211 unsigned int param32, unsigned long param64)
213 struct pt_regs *old_regs;
214 unsigned short code;
215 struct ext_int_info *p;
216 int index;
218 code = (unsigned short) ext_int_code;
219 old_regs = set_irq_regs(regs);
220 s390_idle_check(regs, S390_lowcore.int_clock,
221 S390_lowcore.async_enter_timer);
222 irq_enter();
223 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
224 /* Serve timer interrupts first. */
225 clock_comparator_work();
226 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
227 if (code != 0x1004)
228 __get_cpu_var(s390_idle).nohz_delay = 1;
230 index = ext_hash(code);
231 rcu_read_lock();
232 list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
233 if (likely(p->code == code))
234 p->handler(ext_int_code, param32, param64);
235 rcu_read_unlock();
236 irq_exit();
237 set_irq_regs(old_regs);
240 void __init init_IRQ(void)
242 init_external_interrupts();
245 static DEFINE_SPINLOCK(sc_irq_lock);
246 static int sc_irq_refcount;
248 void service_subclass_irq_register(void)
250 spin_lock(&sc_irq_lock);
251 if (!sc_irq_refcount)
252 ctl_set_bit(0, 9);
253 sc_irq_refcount++;
254 spin_unlock(&sc_irq_lock);
256 EXPORT_SYMBOL(service_subclass_irq_register);
258 void service_subclass_irq_unregister(void)
260 spin_lock(&sc_irq_lock);
261 sc_irq_refcount--;
262 if (!sc_irq_refcount)
263 ctl_clear_bit(0, 9);
264 spin_unlock(&sc_irq_lock);
266 EXPORT_SYMBOL(service_subclass_irq_unregister);