1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2004, 2011
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
5 * Holger Smolinski <Holger.Smolinski@de.ibm.com>,
6 * Thomas Spatzier <tspat@de.ibm.com>,
7 *
8 * This file contains interrupt related functions.
9 */
10
11 #include <linux/kernel_stat.h>
12 #include <linux/cpufeature.h>
13 #include <linux/interrupt.h>
14 #include <linux/seq_file.h>
15 #include <linux/proc_fs.h>
16 #include <linux/profile.h>
17 #include <linux/export.h>
18 #include <linux/kernel.h>
19 #include <linux/ftrace.h>
20 #include <linux/errno.h>
21 #include <linux/slab.h>
22 #include <linux/init.h>
23 #include <linux/cpu.h>
24 #include <linux/irq.h>
25 #include <linux/entry-common.h>
26 #include <asm/irq_regs.h>
27 #include <asm/cputime.h>
28 #include <asm/lowcore.h>
29 #include <asm/machine.h>
30 #include <asm/irq.h>
31 #include <asm/hw_irq.h>
32 #include <asm/stacktrace.h>
33 #include <asm/softirq_stack.h>
34 #include <asm/vtime.h>
35 #include <asm/asm.h>
36 #include "entry.h"
37
38 DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
39 EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
40
41 struct irq_class {
42 int irq;
43 char *name;
44 char *desc;
45 };
46
47 /*
48 * The list of "main" irq classes on s390. This is the list of interrupts
49 * that appear both in /proc/stat ("intr" line) and /proc/interrupts.
50 * Historically only external and I/O interrupts have been part of /proc/stat.
51 * We can't add the split external and I/O sub classes since the first field
52 * in the "intr" line in /proc/stat is supposed to be the sum of all other
53 * fields.
54 * Since the external and I/O interrupt fields are already sums we would end
55 * up with having a sum which accounts each interrupt twice.
56 */
57 static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
58 {.irq = EXT_INTERRUPT, .name = "EXT"},
59 {.irq = IO_INTERRUPT, .name = "I/O"},
60 {.irq = THIN_INTERRUPT, .name = "AIO"},
61 };
62
63 /*
64 * The list of split external and I/O interrupts that appear only in
65 * /proc/interrupts.
66 * In addition this list contains non external / I/O events like NMIs.
67 */
68 static const struct irq_class irqclass_sub_desc[] = {
69 {.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"},
70 {.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"},
71 {.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"},
72 {.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"},
73 {.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"},
74 {.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
75 {.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"},
76 {.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"},
77 {.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"},
78 {.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"},
79 {.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
80 {.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
81 {.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"},
82 {.irq = IRQEXT_WTI, .name = "WTI", .desc = "[EXT] Warning Track"},
83 {.irq = IRQIO_CIO, .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
84 {.irq = IRQIO_DAS, .name = "DAS", .desc = "[I/O] DASD"},
85 {.irq = IRQIO_C15, .name = "C15", .desc = "[I/O] 3215"},
86 {.irq = IRQIO_C70, .name = "C70", .desc = "[I/O] 3270"},
87 {.irq = IRQIO_TAP, .name = "TAP", .desc = "[I/O] Tape"},
88 {.irq = IRQIO_VMR, .name = "VMR", .desc = "[I/O] Unit Record Devices"},
89 {.irq = IRQIO_CTC, .name = "CTC", .desc = "[I/O] CTC"},
90 {.irq = IRQIO_ADM, .name = "ADM", .desc = "[I/O] EADM Subchannel"},
91 {.irq = IRQIO_CSC, .name = "CSC", .desc = "[I/O] CHSC Subchannel"},
92 {.irq = IRQIO_VIR, .name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
93 {.irq = IRQIO_QAI, .name = "QAI", .desc = "[AIO] QDIO Adapter Interrupt"},
94 {.irq = IRQIO_APB, .name = "APB", .desc = "[AIO] AP Bus"},
95 {.irq = IRQIO_PCF, .name = "PCF", .desc = "[AIO] PCI Floating Interrupt"},
96 {.irq = IRQIO_PCD, .name = "PCD", .desc = "[AIO] PCI Directed Interrupt"},
97 {.irq = IRQIO_MSI, .name = "MSI", .desc = "[AIO] MSI Interrupt"},
98 {.irq = IRQIO_VAI, .name = "VAI", .desc = "[AIO] Virtual I/O Devices AI"},
99 {.irq = IRQIO_GAL, .name = "GAL", .desc = "[AIO] GIB Alert"},
100 {.irq = NMI_NMI, .name = "NMI", .desc = "[NMI] Machine Check"},
101 {.irq = CPU_RST, .name = "RST", .desc = "[CPU] CPU Restart"},
102 };
103
do_IRQ(struct pt_regs * regs,int irq)104 static void do_IRQ(struct pt_regs *regs, int irq)
105 {
106 if (tod_after_eq(get_lowcore()->int_clock,
107 get_lowcore()->clock_comparator))
108 /* Serve timer interrupts first. */
109 clock_comparator_work();
110 generic_handle_irq(irq);
111 }
112
on_async_stack(void)113 static int on_async_stack(void)
114 {
115 unsigned long frame = current_frame_address();
116
117 return ((get_lowcore()->async_stack ^ frame) & ~(THREAD_SIZE - 1)) == 0;
118 }
119
do_irq_async(struct pt_regs * regs,int irq)120 static void do_irq_async(struct pt_regs *regs, int irq)
121 {
122 if (on_async_stack()) {
123 do_IRQ(regs, irq);
124 } else {
125 call_on_stack(2, get_lowcore()->async_stack, void, do_IRQ,
126 struct pt_regs *, regs, int, irq);
127 }
128 }
129
irq_pending(struct pt_regs * regs)130 static int irq_pending(struct pt_regs *regs)
131 {
132 int cc;
133
134 asm volatile(
135 " tpi 0\n"
136 CC_IPM(cc)
137 : CC_OUT(cc, cc)
138 :
139 : CC_CLOBBER);
140 return CC_TRANSFORM(cc);
141 }
142
do_io_irq(struct pt_regs * regs)143 void noinstr do_io_irq(struct pt_regs *regs)
144 {
145 irqentry_state_t state = irqentry_enter(regs);
146 struct pt_regs *old_regs = set_irq_regs(regs);
147 bool from_idle;
148
149 from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);
150 if (from_idle)
151 update_timer_idle();
152
153 irq_enter_rcu();
154
155 if (user_mode(regs)) {
156 update_timer_sys();
157 if (cpu_has_bear())
158 current->thread.last_break = regs->last_break;
159 }
160
161 if (from_idle)
162 account_idle_time_irq();
163
164 set_cpu_flag(CIF_NOHZ_DELAY);
165 do {
166 regs->tpi_info = get_lowcore()->tpi_info;
167 if (get_lowcore()->tpi_info.adapter_IO)
168 do_irq_async(regs, THIN_INTERRUPT);
169 else
170 do_irq_async(regs, IO_INTERRUPT);
171 } while (machine_is_lpar() && irq_pending(regs));
172
173 irq_exit_rcu();
174
175 set_irq_regs(old_regs);
176 irqentry_exit(regs, state);
177
178 if (from_idle)
179 regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
180 }
181
do_ext_irq(struct pt_regs * regs)182 void noinstr do_ext_irq(struct pt_regs *regs)
183 {
184 irqentry_state_t state = irqentry_enter(regs);
185 struct pt_regs *old_regs = set_irq_regs(regs);
186 bool from_idle;
187
188 from_idle = test_and_clear_cpu_flag(CIF_ENABLED_WAIT);
189 if (from_idle)
190 update_timer_idle();
191
192 irq_enter_rcu();
193
194 if (user_mode(regs)) {
195 update_timer_sys();
196 if (cpu_has_bear())
197 current->thread.last_break = regs->last_break;
198 }
199
200 regs->int_code = get_lowcore()->ext_int_code_addr;
201 regs->int_parm = get_lowcore()->ext_params;
202 regs->int_parm_long = get_lowcore()->ext_params2;
203
204 if (from_idle)
205 account_idle_time_irq();
206
207 do_irq_async(regs, EXT_INTERRUPT);
208
209 irq_exit_rcu();
210 set_irq_regs(old_regs);
211 irqentry_exit(regs, state);
212
213 if (from_idle)
214 regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT);
215 }
216
show_msi_interrupt(struct seq_file * p,int irq)217 static void show_msi_interrupt(struct seq_file *p, int irq)
218 {
219 struct irq_desc *desc;
220 unsigned long flags;
221 int cpu;
222
223 rcu_read_lock();
224 desc = irq_to_desc(irq);
225 if (!desc)
226 goto out;
227
228 raw_spin_lock_irqsave(&desc->lock, flags);
229 seq_printf(p, "%3d: ", irq);
230 for_each_online_cpu(cpu)
231 seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, cpu));
232
233 if (desc->irq_data.chip)
234 seq_printf(p, " %8s", desc->irq_data.chip->name);
235
236 if (desc->action)
237 seq_printf(p, " %s", desc->action->name);
238
239 seq_putc(p, '\n');
240 raw_spin_unlock_irqrestore(&desc->lock, flags);
241 out:
242 rcu_read_unlock();
243 }
244
245 /*
246 * show_interrupts is needed by /proc/interrupts.
247 */
show_interrupts(struct seq_file * p,void * v)248 int show_interrupts(struct seq_file *p, void *v)
249 {
250 int index = *(loff_t *) v;
251 int cpu, irq;
252
253 cpus_read_lock();
254 if (index == 0) {
255 seq_puts(p, " ");
256 for_each_online_cpu(cpu)
257 seq_printf(p, "CPU%-8d", cpu);
258 seq_putc(p, '\n');
259 }
260 if (index < NR_IRQS_BASE) {
261 seq_printf(p, "%s: ", irqclass_main_desc[index].name);
262 irq = irqclass_main_desc[index].irq;
263 for_each_online_cpu(cpu)
264 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
265 seq_putc(p, '\n');
266 goto out;
267 }
268 if (index < irq_get_nr_irqs()) {
269 show_msi_interrupt(p, index);
270 goto out;
271 }
272 for (index = 0; index < NR_ARCH_IRQS; index++) {
273 seq_printf(p, "%s: ", irqclass_sub_desc[index].name);
274 irq = irqclass_sub_desc[index].irq;
275 for_each_online_cpu(cpu)
276 seq_printf(p, "%10u ",
277 per_cpu(irq_stat, cpu).irqs[irq]);
278 if (irqclass_sub_desc[index].desc)
279 seq_printf(p, " %s", irqclass_sub_desc[index].desc);
280 seq_putc(p, '\n');
281 }
282 out:
283 cpus_read_unlock();
284 return 0;
285 }
286
arch_dynirq_lower_bound(unsigned int from)287 unsigned int arch_dynirq_lower_bound(unsigned int from)
288 {
289 return from < NR_IRQS_BASE ? NR_IRQS_BASE : from;
290 }
291
292 /*
293 * ext_int_hash[index] is the list head for all external interrupts that hash
294 * to this index.
295 */
296 static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
297
298 struct ext_int_info {
299 ext_int_handler_t handler;
300 struct hlist_node entry;
301 struct rcu_head rcu;
302 u16 code;
303 };
304
305 /* ext_int_hash_lock protects the handler lists for external interrupts */
306 static DEFINE_SPINLOCK(ext_int_hash_lock);
307
ext_hash(u16 code)308 static inline int ext_hash(u16 code)
309 {
310 BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
311
312 return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
313 }
314
register_external_irq(u16 code,ext_int_handler_t handler)315 int register_external_irq(u16 code, ext_int_handler_t handler)
316 {
317 struct ext_int_info *p;
318 unsigned long flags;
319 int index;
320
321 p = kmalloc_obj(*p, GFP_ATOMIC);
322 if (!p)
323 return -ENOMEM;
324 p->code = code;
325 p->handler = handler;
326 index = ext_hash(code);
327
328 spin_lock_irqsave(&ext_int_hash_lock, flags);
329 hlist_add_head_rcu(&p->entry, &ext_int_hash[index]);
330 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
331 return 0;
332 }
333 EXPORT_SYMBOL(register_external_irq);
334
unregister_external_irq(u16 code,ext_int_handler_t handler)335 int unregister_external_irq(u16 code, ext_int_handler_t handler)
336 {
337 struct ext_int_info *p;
338 unsigned long flags;
339 int index = ext_hash(code);
340
341 spin_lock_irqsave(&ext_int_hash_lock, flags);
342 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
343 if (p->code == code && p->handler == handler) {
344 hlist_del_rcu(&p->entry);
345 kfree_rcu(p, rcu);
346 }
347 }
348 spin_unlock_irqrestore(&ext_int_hash_lock, flags);
349 return 0;
350 }
351 EXPORT_SYMBOL(unregister_external_irq);
352
do_ext_interrupt(int irq,void * dummy)353 static irqreturn_t do_ext_interrupt(int irq, void *dummy)
354 {
355 struct pt_regs *regs = get_irq_regs();
356 struct ext_code ext_code;
357 struct ext_int_info *p;
358 int index;
359
360 ext_code.int_code = regs->int_code;
361 if (ext_code.code != EXT_IRQ_CLK_COMP)
362 set_cpu_flag(CIF_NOHZ_DELAY);
363
364 index = ext_hash(ext_code.code);
365 rcu_read_lock();
366 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
367 if (unlikely(p->code != ext_code.code))
368 continue;
369 p->handler(ext_code, regs->int_parm, regs->int_parm_long);
370 }
371 rcu_read_unlock();
372 return IRQ_HANDLED;
373 }
374
init_ext_interrupts(void)375 static void __init init_ext_interrupts(void)
376 {
377 int idx;
378
379 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
380 INIT_HLIST_HEAD(&ext_int_hash[idx]);
381
382 irq_set_chip_and_handler(EXT_INTERRUPT,
383 &dummy_irq_chip, handle_percpu_irq);
384 if (request_irq(EXT_INTERRUPT, do_ext_interrupt, 0, "EXT", NULL))
385 panic("Failed to register EXT interrupt\n");
386 }
387
init_IRQ(void)388 void __init init_IRQ(void)
389 {
390 BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS);
391 init_cio_interrupts();
392 init_airq_interrupts();
393 init_ext_interrupts();
394 }
395
396 static DEFINE_SPINLOCK(irq_subclass_lock);
397 static unsigned char irq_subclass_refcount[64];
398
irq_subclass_register(enum irq_subclass subclass)399 void irq_subclass_register(enum irq_subclass subclass)
400 {
401 spin_lock(&irq_subclass_lock);
402 if (!irq_subclass_refcount[subclass])
403 system_ctl_set_bit(0, subclass);
404 irq_subclass_refcount[subclass]++;
405 spin_unlock(&irq_subclass_lock);
406 }
407 EXPORT_SYMBOL(irq_subclass_register);
408
irq_subclass_unregister(enum irq_subclass subclass)409 void irq_subclass_unregister(enum irq_subclass subclass)
410 {
411 spin_lock(&irq_subclass_lock);
412 irq_subclass_refcount[subclass]--;
413 if (!irq_subclass_refcount[subclass])
414 system_ctl_clear_bit(0, subclass);
415 spin_unlock(&irq_subclass_lock);
416 }
417 EXPORT_SYMBOL(irq_subclass_unregister);
418