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