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 <linux/irq.h>
22 #include <asm/irq_regs.h>
23 #include <asm/cputime.h>
24 #include <asm/lowcore.h>
26 #include <asm/hw_irq.h>
29 DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
30 EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
38 * The list of "main" irq classes on s390. This is the list of interrupts
39 * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
40 * Historically only external and I/O interrupts have been part of /proc/stat.
41 * We can't add the split external and I/O sub classes since the first field
42 * in the "intr" line in /proc/stat is supposed to be the sum of all other
44 * Since the external and I/O interrupt fields are already sums we would end
45 * up with having a sum which accounts each interrupt twice.
47 static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
48 [EXT_INTERRUPT] = {.name = "EXT"},
49 [IO_INTERRUPT] = {.name = "I/O"},
50 [THIN_INTERRUPT] = {.name = "AIO"},
54 * The list of split external and I/O interrupts that appear only in
56 * In addition this list contains non external / I/O events like NMIs.
58 static const struct irq_class irqclass_sub_desc[NR_ARCH_IRQS] = {
59 [IRQEXT_CLK] = {.name = "CLK", .desc = "[EXT] Clock Comparator"},
60 [IRQEXT_EXC] = {.name = "EXC", .desc = "[EXT] External Call"},
61 [IRQEXT_EMS] = {.name = "EMS", .desc = "[EXT] Emergency Signal"},
62 [IRQEXT_TMR] = {.name = "TMR", .desc = "[EXT] CPU Timer"},
63 [IRQEXT_TLA] = {.name = "TAL", .desc = "[EXT] Timing Alert"},
64 [IRQEXT_PFL] = {.name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
65 [IRQEXT_DSD] = {.name = "DSD", .desc = "[EXT] DASD Diag"},
66 [IRQEXT_VRT] = {.name = "VRT", .desc = "[EXT] Virtio"},
67 [IRQEXT_SCP] = {.name = "SCP", .desc = "[EXT] Service Call"},
68 [IRQEXT_IUC] = {.name = "IUC", .desc = "[EXT] IUCV"},
69 [IRQEXT_CMS] = {.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
70 [IRQEXT_CMC] = {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
71 [IRQEXT_CMR] = {.name = "CMR", .desc = "[EXT] CPU-Measurement: RI"},
72 [IRQIO_CIO] = {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
73 [IRQIO_QAI] = {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
74 [IRQIO_DAS] = {.name = "DAS", .desc = "[I/O] DASD"},
75 [IRQIO_C15] = {.name = "C15", .desc = "[I/O] 3215"},
76 [IRQIO_C70] = {.name = "C70", .desc = "[I/O] 3270"},
77 [IRQIO_TAP] = {.name = "TAP", .desc = "[I/O] Tape"},
78 [IRQIO_VMR] = {.name = "VMR", .desc = "[I/O] Unit Record Devices"},
79 [IRQIO_LCS] = {.name = "LCS", .desc = "[I/O] LCS"},
80 [IRQIO_CLW] = {.name = "CLW", .desc = "[I/O] CLAW"},
81 [IRQIO_CTC] = {.name = "CTC", .desc = "[I/O] CTC"},
82 [IRQIO_APB] = {.name = "APB", .desc = "[I/O] AP Bus"},
83 [IRQIO_ADM] = {.name = "ADM", .desc = "[I/O] EADM Subchannel"},
84 [IRQIO_CSC] = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},
85 [IRQIO_PCI] = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },
86 [IRQIO_MSI] = {.name = "MSI", .desc = "[I/O] MSI Interrupt" },
87 [IRQIO_VIR] = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
88 [NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"},
89 [CPU_RST] = {.name = "RST", .desc = "[CPU] CPU Restart"},
92 void __init init_IRQ(void)
94 irq_reserve_irqs(0, THIN_INTERRUPT);
95 init_cio_interrupts();
96 init_airq_interrupts();
97 init_ext_interrupts();
100 void do_IRQ(struct pt_regs *regs, int irq)
102 struct pt_regs *old_regs;
104 old_regs = set_irq_regs(regs);
106 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
107 /* Serve timer interrupts first. */
108 clock_comparator_work();
109 generic_handle_irq(irq);
111 set_irq_regs(old_regs);
115 * show_interrupts is needed by /proc/interrupts.
117 int show_interrupts(struct seq_file *p, void *v)
119 int irq = *(loff_t *) v;
125 for_each_online_cpu(cpu)
126 seq_printf(p, "CPU%d ", cpu);
131 if (irq >= NR_IRQS_BASE)
133 seq_printf(p, "%s: ", irqclass_main_desc[irq].name);
134 for_each_online_cpu(cpu)
135 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
139 for (irq = 0; irq < NR_ARCH_IRQS; irq++) {
140 seq_printf(p, "%s: ", irqclass_sub_desc[irq].name);
141 for_each_online_cpu(cpu)
142 seq_printf(p, "%10u ",
143 per_cpu(irq_stat, cpu).irqs[irq]);
144 if (irqclass_sub_desc[irq].desc)
145 seq_printf(p, " %s", irqclass_sub_desc[irq].desc);
153 int arch_show_interrupts(struct seq_file *p, int prec)
159 * Switch to the asynchronous interrupt stack for softirq execution.
161 void do_softirq_own_stack(void)
163 unsigned long old, new;
165 /* Get current stack pointer. */
166 asm volatile("la %0,0(15)" : "=a" (old));
167 /* Check against async. stack address range. */
168 new = S390_lowcore.async_stack;
169 if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
170 /* Need to switch to the async. stack. */
171 new -= STACK_FRAME_OVERHEAD;
172 ((struct stack_frame *) new)->back_chain = old;
173 asm volatile(" la 15,0(%0)\n"
176 : : "a" (new), "a" (old),
178 : "0", "1", "2", "3", "4", "5", "14",
181 /* We are already on the async stack. */
187 * ext_int_hash[index] is the list head for all external interrupts that hash
190 static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
192 struct ext_int_info {
193 ext_int_handler_t handler;
194 struct hlist_node entry;
199 /* ext_int_hash_lock protects the handler lists for external interrupts */
200 static DEFINE_SPINLOCK(ext_int_hash_lock);
202 static inline int ext_hash(u16 code)
204 BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
206 return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
209 int register_external_interrupt(u16 code, ext_int_handler_t handler)
211 struct ext_int_info *p;
215 p = kmalloc(sizeof(*p), GFP_ATOMIC);
219 p->handler = handler;
220 index = ext_hash(code);
222 spin_lock_irqsave(&ext_int_hash_lock, flags);
223 hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
224 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
227 EXPORT_SYMBOL(register_external_interrupt);
229 int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
231 struct ext_int_info *p;
233 int index = ext_hash(code);
235 spin_lock_irqsave(&ext_int_hash_lock, flags);
236 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
237 if (p->code == code && p->handler == handler) {
238 hlist_del_rcu(&p->entry);
242 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
245 EXPORT_SYMBOL(unregister_external_interrupt);
247 static irqreturn_t do_ext_interrupt(int irq, void *dummy)
249 struct pt_regs *regs = get_irq_regs();
250 struct ext_code ext_code;
251 struct ext_int_info *p;
254 ext_code = *(struct ext_code *) ®s->int_code;
255 if (ext_code.code != 0x1004)
256 __get_cpu_var(s390_idle).nohz_delay = 1;
258 index = ext_hash(ext_code.code);
260 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
261 if (unlikely(p->code != ext_code.code))
263 p->handler(ext_code, regs->int_parm, regs->int_parm_long);
269 static struct irqaction external_interrupt = {
271 .handler = do_ext_interrupt,
274 void __init init_ext_interrupts(void)
278 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
279 INIT_HLIST_HEAD(&ext_int_hash[idx]);
281 irq_set_chip_and_handler(EXT_INTERRUPT,
282 &dummy_irq_chip, handle_percpu_irq);
283 setup_irq(EXT_INTERRUPT, &external_interrupt);
286 static DEFINE_SPINLOCK(irq_subclass_lock);
287 static unsigned char irq_subclass_refcount[64];
289 void irq_subclass_register(enum irq_subclass subclass)
291 spin_lock(&irq_subclass_lock);
292 if (!irq_subclass_refcount[subclass])
293 ctl_set_bit(0, subclass);
294 irq_subclass_refcount[subclass]++;
295 spin_unlock(&irq_subclass_lock);
297 EXPORT_SYMBOL(irq_subclass_register);
299 void irq_subclass_unregister(enum irq_subclass subclass)
301 spin_lock(&irq_subclass_lock);
302 irq_subclass_refcount[subclass]--;
303 if (!irq_subclass_refcount[subclass])
304 ctl_clear_bit(0, subclass);
305 spin_unlock(&irq_subclass_lock);
307 EXPORT_SYMBOL(irq_subclass_unregister);