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
);