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>,
6 *
7 * This file contains interrupt related functions.
8 */
9
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"
26
27 struct irq_class {
28 char *name;
29 char *desc;
30 };
31
32 static const struct irq_class intrclass_names[] = {
33 {.name = "EXT" },
34 {.name = "I/O" },
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" },
59 };
60
61 /*
62 * show_interrupts is needed by /proc/interrupts.
63 */
show_interrupts(struct seq_file * p,void * v)64 int show_interrupts(struct seq_file *p, void *v)
65 {
66 int i = *(loff_t *) v, j;
67
68 get_online_cpus();
69 if (i == 0) {
70 seq_puts(p, " ");
71 for_each_online_cpu(j)
72 seq_printf(p, "CPU%d ",j);
73 seq_putc(p, '\n');
74 }
75
76 if (i < NR_IRQS) {
77 seq_printf(p, "%s: ", intrclass_names[i].name);
78 #ifndef CONFIG_SMP
79 seq_printf(p, "%10u ", kstat_irqs(i));
80 #else
81 for_each_online_cpu(j)
82 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
83 #endif
84 if (intrclass_names[i].desc)
85 seq_printf(p, " %s", intrclass_names[i].desc);
86 seq_putc(p, '\n');
87 }
88 put_online_cpus();
89 return 0;
90 }
91
92 /*
93 * Switch to the asynchronous interrupt stack for softirq execution.
94 */
do_softirq(void)95 asmlinkage void do_softirq(void)
96 {
97 unsigned long flags, old, new;
98
99 if (in_interrupt())
100 return;
101
102 local_irq_save(flags);
103
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;
113
114 asm volatile(" la 15,0(%0)\n"
115 " basr 14,%2\n"
116 " la 15,0(%1)\n"
117 : : "a" (new), "a" (old),
118 "a" (__do_softirq)
119 : "0", "1", "2", "3", "4", "5", "14",
120 "cc", "memory" );
121 } else
122 /* We are already on the async stack. */
123 __do_softirq();
124 }
125
126 local_irq_restore(flags);
127 }
128
129 #ifdef CONFIG_PROC_FS
init_irq_proc(void)130 void init_irq_proc(void)
131 {
132 struct proc_dir_entry *root_irq_dir;
133
134 root_irq_dir = proc_mkdir("irq", NULL);
135 create_prof_cpu_mask(root_irq_dir);
136 }
137 #endif
138
139 /*
140 * ext_int_hash[index] is the list head for all external interrupts that hash
141 * to this index.
142 */
143 static struct list_head ext_int_hash[256];
144
145 struct ext_int_info {
146 ext_int_handler_t handler;
147 u16 code;
148 struct list_head entry;
149 struct rcu_head rcu;
150 };
151
152 /* ext_int_hash_lock protects the handler lists for external interrupts */
153 DEFINE_SPINLOCK(ext_int_hash_lock);
154
init_external_interrupts(void)155 static void __init init_external_interrupts(void)
156 {
157 int idx;
158
159 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
160 INIT_LIST_HEAD(&ext_int_hash[idx]);
161 }
162
ext_hash(u16 code)163 static inline int ext_hash(u16 code)
164 {
165 return (code + (code >> 9)) & 0xff;
166 }
167
ext_int_hash_update(struct rcu_head * head)168 static void ext_int_hash_update(struct rcu_head *head)
169 {
170 struct ext_int_info *p = container_of(head, struct ext_int_info, rcu);
171
172 kfree(p);
173 }
174
register_external_interrupt(u16 code,ext_int_handler_t handler)175 int register_external_interrupt(u16 code, ext_int_handler_t handler)
176 {
177 struct ext_int_info *p;
178 unsigned long flags;
179 int index;
180
181 p = kmalloc(sizeof(*p), GFP_ATOMIC);
182 if (!p)
183 return -ENOMEM;
184 p->code = code;
185 p->handler = handler;
186 index = ext_hash(code);
187
188 spin_lock_irqsave(&ext_int_hash_lock, flags);
189 list_add_rcu(&p->entry, &ext_int_hash[index]);
190 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
191 return 0;
192 }
193 EXPORT_SYMBOL(register_external_interrupt);
194
unregister_external_interrupt(u16 code,ext_int_handler_t handler)195 int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
196 {
197 struct ext_int_info *p;
198 unsigned long flags;
199 int index = ext_hash(code);
200
201 spin_lock_irqsave(&ext_int_hash_lock, flags);
202 list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
203 if (p->code == code && p->handler == handler) {
204 list_del_rcu(&p->entry);
205 call_rcu(&p->rcu, ext_int_hash_update);
206 }
207 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
208 return 0;
209 }
210 EXPORT_SYMBOL(unregister_external_interrupt);
211
do_extint(struct pt_regs * regs,unsigned int ext_int_code,unsigned int param32,unsigned long param64)212 void __irq_entry do_extint(struct pt_regs *regs, unsigned int ext_int_code,
213 unsigned int param32, unsigned long param64)
214 {
215 struct pt_regs *old_regs;
216 unsigned short code;
217 struct ext_int_info *p;
218 int index;
219
220 code = (unsigned short) ext_int_code;
221 old_regs = set_irq_regs(regs);
222 s390_idle_check(regs, S390_lowcore.int_clock,
223 S390_lowcore.async_enter_timer);
224 irq_enter();
225 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
226 /* Serve timer interrupts first. */
227 clock_comparator_work();
228 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
229 if (code != 0x1004)
230 __get_cpu_var(s390_idle).nohz_delay = 1;
231
232 index = ext_hash(code);
233 rcu_read_lock();
234 list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
235 if (likely(p->code == code))
236 p->handler(ext_int_code, param32, param64);
237 rcu_read_unlock();
238 irq_exit();
239 set_irq_regs(old_regs);
240 }
241
init_IRQ(void)242 void __init init_IRQ(void)
243 {
244 init_external_interrupts();
245 }
246
247 static DEFINE_SPINLOCK(sc_irq_lock);
248 static int sc_irq_refcount;
249
service_subclass_irq_register(void)250 void service_subclass_irq_register(void)
251 {
252 spin_lock(&sc_irq_lock);
253 if (!sc_irq_refcount)
254 ctl_set_bit(0, 9);
255 sc_irq_refcount++;
256 spin_unlock(&sc_irq_lock);
257 }
258 EXPORT_SYMBOL(service_subclass_irq_register);
259
service_subclass_irq_unregister(void)260 void service_subclass_irq_unregister(void)
261 {
262 spin_lock(&sc_irq_lock);
263 sc_irq_refcount--;
264 if (!sc_irq_refcount)
265 ctl_clear_bit(0, 9);
266 spin_unlock(&sc_irq_lock);
267 }
268 EXPORT_SYMBOL(service_subclass_irq_unregister);
269