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[] = {
33 [EXTERNAL_INTERRUPT] = {.name = "EXT"},
34 [IO_INTERRUPT] = {.name = "I/O"},
35 [EXTINT_CLK] = {.name = "CLK", .desc = "[EXT] Clock Comparator"},
36 [EXTINT_EXC] = {.name = "EXC", .desc = "[EXT] External Call"},
37 [EXTINT_EMS] = {.name = "EMS", .desc = "[EXT] Emergency Signal"},
38 [EXTINT_TMR] = {.name = "TMR", .desc = "[EXT] CPU Timer"},
39 [EXTINT_TLA] = {.name = "TAL", .desc = "[EXT] Timing Alert"},
40 [EXTINT_PFL] = {.name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
41 [EXTINT_DSD] = {.name = "DSD", .desc = "[EXT] DASD Diag"},
42 [EXTINT_VRT] = {.name = "VRT", .desc = "[EXT] Virtio"},
43 [EXTINT_SCP] = {.name = "SCP", .desc = "[EXT] Service Call"},
44 [EXTINT_IUC] = {.name = "IUC", .desc = "[EXT] IUCV"},
45 [EXTINT_CMS] = {.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
46 [EXTINT_CMC] = {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
47 [EXTINT_CMR] = {.name = "CMR", .desc = "[EXT] CPU-Measurement: RI"},
48 [IOINT_CIO] = {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
49 [IOINT_QAI] = {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
50 [IOINT_DAS] = {.name = "DAS", .desc = "[I/O] DASD"},
51 [IOINT_C15] = {.name = "C15", .desc = "[I/O] 3215"},
52 [IOINT_C70] = {.name = "C70", .desc = "[I/O] 3270"},
53 [IOINT_TAP] = {.name = "TAP", .desc = "[I/O] Tape"},
54 [IOINT_VMR] = {.name = "VMR", .desc = "[I/O] Unit Record Devices"},
55 [IOINT_LCS] = {.name = "LCS", .desc = "[I/O] LCS"},
56 [IOINT_CLW] = {.name = "CLW", .desc = "[I/O] CLAW"},
57 [IOINT_CTC] = {.name = "CTC", .desc = "[I/O] CTC"},
58 [IOINT_APB] = {.name = "APB", .desc = "[I/O] AP Bus"},
59 [IOINT_ADM] = {.name = "ADM", .desc = "[I/O] EADM Subchannel"},
60 [IOINT_CSC] = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},
61 [NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"},
65 * show_interrupts is needed by /proc/interrupts.
67 int show_interrupts(struct seq_file *p, void *v)
69 int i = *(loff_t *) v, j;
74 for_each_online_cpu(j)
75 seq_printf(p, "CPU%d ",j);
80 seq_printf(p, "%s: ", intrclass_names[i].name);
82 seq_printf(p, "%10u ", kstat_irqs(i));
84 for_each_online_cpu(j)
85 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
87 if (intrclass_names[i].desc)
88 seq_printf(p, " %s", intrclass_names[i].desc);
96 * Switch to the asynchronous interrupt stack for softirq execution.
98 asmlinkage void do_softirq(void)
100 unsigned long flags, old, new;
105 local_irq_save(flags);
107 if (local_softirq_pending()) {
108 /* Get current stack pointer. */
109 asm volatile("la %0,0(15)" : "=a" (old));
110 /* Check against async. stack address range. */
111 new = S390_lowcore.async_stack;
112 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
113 /* Need to switch to the async. stack. */
114 new -= STACK_FRAME_OVERHEAD;
115 ((struct stack_frame *) new)->back_chain = old;
117 asm volatile(" la 15,0(%0)\n"
120 : : "a" (new), "a" (old),
122 : "0", "1", "2", "3", "4", "5", "14",
125 /* We are already on the async stack. */
130 local_irq_restore(flags);
133 #ifdef CONFIG_PROC_FS
134 void init_irq_proc(void)
136 struct proc_dir_entry *root_irq_dir;
138 root_irq_dir = proc_mkdir("irq", NULL);
139 create_prof_cpu_mask(root_irq_dir);
144 * ext_int_hash[index] is the list head for all external interrupts that hash
147 static struct list_head ext_int_hash[256];
149 struct ext_int_info {
150 ext_int_handler_t handler;
152 struct list_head entry;
156 /* ext_int_hash_lock protects the handler lists for external interrupts */
157 DEFINE_SPINLOCK(ext_int_hash_lock);
159 static void __init init_external_interrupts(void)
163 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
164 INIT_LIST_HEAD(&ext_int_hash[idx]);
167 static inline int ext_hash(u16 code)
169 return (code + (code >> 9)) & 0xff;
172 int register_external_interrupt(u16 code, ext_int_handler_t handler)
174 struct ext_int_info *p;
178 p = kmalloc(sizeof(*p), GFP_ATOMIC);
182 p->handler = handler;
183 index = ext_hash(code);
185 spin_lock_irqsave(&ext_int_hash_lock, flags);
186 list_add_rcu(&p->entry, &ext_int_hash[index]);
187 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
190 EXPORT_SYMBOL(register_external_interrupt);
192 int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
194 struct ext_int_info *p;
196 int index = ext_hash(code);
198 spin_lock_irqsave(&ext_int_hash_lock, flags);
199 list_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
200 if (p->code == code && p->handler == handler) {
201 list_del_rcu(&p->entry);
205 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
208 EXPORT_SYMBOL(unregister_external_interrupt);
210 void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
211 unsigned int param32, unsigned long param64)
213 struct pt_regs *old_regs;
214 struct ext_int_info *p;
217 old_regs = set_irq_regs(regs);
219 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) {
220 /* Serve timer interrupts first. */
221 clock_comparator_work();
223 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
224 if (ext_code.code != 0x1004)
225 __get_cpu_var(s390_idle).nohz_delay = 1;
227 index = ext_hash(ext_code.code);
229 list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
230 if (likely(p->code == ext_code.code))
231 p->handler(ext_code, param32, param64);
234 set_irq_regs(old_regs);
237 void __init init_IRQ(void)
239 init_external_interrupts();
242 static DEFINE_SPINLOCK(sc_irq_lock);
243 static int sc_irq_refcount;
245 void service_subclass_irq_register(void)
247 spin_lock(&sc_irq_lock);
248 if (!sc_irq_refcount)
251 spin_unlock(&sc_irq_lock);
253 EXPORT_SYMBOL(service_subclass_irq_register);
255 void service_subclass_irq_unregister(void)
257 spin_lock(&sc_irq_lock);
259 if (!sc_irq_refcount)
261 spin_unlock(&sc_irq_lock);
263 EXPORT_SYMBOL(service_subclass_irq_unregister);
265 static DEFINE_SPINLOCK(ma_subclass_lock);
266 static int ma_subclass_refcount;
268 void measurement_alert_subclass_register(void)
270 spin_lock(&ma_subclass_lock);
271 if (!ma_subclass_refcount)
273 ma_subclass_refcount++;
274 spin_unlock(&ma_subclass_lock);
276 EXPORT_SYMBOL(measurement_alert_subclass_register);
278 void measurement_alert_subclass_unregister(void)
280 spin_lock(&ma_subclass_lock);
281 ma_subclass_refcount--;
282 if (!ma_subclass_refcount)
284 spin_unlock(&ma_subclass_lock);
286 EXPORT_SYMBOL(measurement_alert_subclass_unregister);