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 "entry.h" 33 34 DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat); 35 EXPORT_PER_CPU_SYMBOL_GPL(irq_stat); 36 37 struct irq_class { 38 int irq; 39 char *name; 40 char *desc; 41 }; 42 43 /* 44 * The list of "main" irq classes on s390. This is the list of interrupts 45 * that appear both in /proc/stat ("intr" line) and /proc/interrupts. 46 * Historically only external and I/O interrupts have been part of /proc/stat. 47 * We can't add the split external and I/O sub classes since the first field 48 * in the "intr" line in /proc/stat is supposed to be the sum of all other 49 * fields. 50 * Since the external and I/O interrupt fields are already sums we would end 51 * up with having a sum which accounts each interrupt twice. 52 */ 53 static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = { 54 {.irq = EXT_INTERRUPT, .name = "EXT"}, 55 {.irq = IO_INTERRUPT, .name = "I/O"}, 56 {.irq = THIN_INTERRUPT, .name = "AIO"}, 57 }; 58 59 /* 60 * The list of split external and I/O interrupts that appear only in 61 * /proc/interrupts. 62 * In addition this list contains non external / I/O events like NMIs. 63 */ 64 static const struct irq_class irqclass_sub_desc[] = { 65 {.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"}, 66 {.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"}, 67 {.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"}, 68 {.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"}, 69 {.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"}, 70 {.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"}, 71 {.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"}, 72 {.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"}, 73 {.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"}, 74 {.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"}, 75 {.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"}, 76 {.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"}, 77 {.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"}, 78 {.irq = IRQIO_CIO, .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"}, 79 {.irq = IRQIO_DAS, .name = "DAS", .desc = "[I/O] DASD"}, 80 {.irq = IRQIO_C15, .name = "C15", .desc = "[I/O] 3215"}, 81 {.irq = IRQIO_C70, .name = "C70", .desc = "[I/O] 3270"}, 82 {.irq = IRQIO_TAP, .name = "TAP", .desc = "[I/O] Tape"}, 83 {.irq = IRQIO_VMR, .name = "VMR", .desc = "[I/O] Unit Record Devices"}, 84 {.irq = IRQIO_LCS, .name = "LCS", .desc = "[I/O] LCS"}, 85 {.irq = IRQIO_CTC, .name = "CTC", .desc = "[I/O] CTC"}, 86 {.irq = IRQIO_ADM, .name = "ADM", .desc = "[I/O] EADM Subchannel"}, 87 {.irq = IRQIO_CSC, .name = "CSC", .desc = "[I/O] CHSC Subchannel"}, 88 {.irq = IRQIO_VIR, .name = "VIR", .desc = "[I/O] Virtual I/O Devices"}, 89 {.irq = IRQIO_QAI, .name = "QAI", .desc = "[AIO] QDIO Adapter Interrupt"}, 90 {.irq = IRQIO_APB, .name = "APB", .desc = "[AIO] AP Bus"}, 91 {.irq = IRQIO_PCF, .name = "PCF", .desc = "[AIO] PCI Floating Interrupt"}, 92 {.irq = IRQIO_PCD, .name = "PCD", .desc = "[AIO] PCI Directed Interrupt"}, 93 {.irq = IRQIO_MSI, .name = "MSI", .desc = "[AIO] MSI Interrupt"}, 94 {.irq = IRQIO_VAI, .name = "VAI", .desc = "[AIO] Virtual I/O Devices AI"}, 95 {.irq = IRQIO_GAL, .name = "GAL", .desc = "[AIO] GIB Alert"}, 96 {.irq = NMI_NMI, .name = "NMI", .desc = "[NMI] Machine Check"}, 97 {.irq = CPU_RST, .name = "RST", .desc = "[CPU] CPU Restart"}, 98 }; 99 100 static void do_IRQ(struct pt_regs *regs, int irq) 101 { 102 if (tod_after_eq(S390_lowcore.int_clock, 103 S390_lowcore.clock_comparator)) 104 /* Serve timer interrupts first. */ 105 clock_comparator_work(); 106 generic_handle_irq(irq); 107 } 108 109 static int on_async_stack(void) 110 { 111 unsigned long frame = current_frame_address(); 112 113 return !!!((S390_lowcore.async_stack - frame) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)); 114 } 115 116 static void do_irq_async(struct pt_regs *regs, int irq) 117 { 118 if (on_async_stack()) 119 do_IRQ(regs, irq); 120 else 121 CALL_ON_STACK(do_IRQ, S390_lowcore.async_stack, 2, regs, irq); 122 } 123 124 static int irq_pending(struct pt_regs *regs) 125 { 126 int cc; 127 128 asm volatile("tpi 0\n" 129 "ipm %0" : "=d" (cc) : : "cc"); 130 return cc >> 28; 131 } 132 133 void noinstr do_io_irq(struct pt_regs *regs) 134 { 135 irqentry_state_t state = irqentry_enter(regs); 136 struct pt_regs *old_regs = set_irq_regs(regs); 137 int from_idle; 138 139 irq_enter(); 140 141 if (user_mode(regs)) 142 update_timer_sys(); 143 144 from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit; 145 if (from_idle) 146 account_idle_time_irq(); 147 148 do { 149 memcpy(®s->int_code, &S390_lowcore.subchannel_id, 12); 150 if (S390_lowcore.io_int_word & BIT(31)) 151 do_irq_async(regs, THIN_INTERRUPT); 152 else 153 do_irq_async(regs, IO_INTERRUPT); 154 } while (MACHINE_IS_LPAR && irq_pending(regs)); 155 156 irq_exit(); 157 set_irq_regs(old_regs); 158 irqentry_exit(regs, state); 159 160 if (from_idle) 161 regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT); 162 } 163 164 void noinstr do_ext_irq(struct pt_regs *regs) 165 { 166 irqentry_state_t state = irqentry_enter(regs); 167 struct pt_regs *old_regs = set_irq_regs(regs); 168 int from_idle; 169 170 irq_enter(); 171 172 if (user_mode(regs)) 173 update_timer_sys(); 174 175 memcpy(®s->int_code, &S390_lowcore.ext_cpu_addr, 4); 176 regs->int_parm = S390_lowcore.ext_params; 177 regs->int_parm_long = *(unsigned long *)S390_lowcore.ext_params2; 178 179 from_idle = !user_mode(regs) && regs->psw.addr == (unsigned long)psw_idle_exit; 180 if (from_idle) 181 account_idle_time_irq(); 182 183 do_irq_async(regs, EXT_INTERRUPT); 184 185 irq_exit(); 186 set_irq_regs(old_regs); 187 irqentry_exit(regs, state); 188 189 if (from_idle) 190 regs->psw.mask &= ~(PSW_MASK_EXT | PSW_MASK_IO | PSW_MASK_WAIT); 191 } 192 193 static void show_msi_interrupt(struct seq_file *p, int irq) 194 { 195 struct irq_desc *desc; 196 unsigned long flags; 197 int cpu; 198 199 irq_lock_sparse(); 200 desc = irq_to_desc(irq); 201 if (!desc) 202 goto out; 203 204 raw_spin_lock_irqsave(&desc->lock, flags); 205 seq_printf(p, "%3d: ", irq); 206 for_each_online_cpu(cpu) 207 seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, cpu)); 208 209 if (desc->irq_data.chip) 210 seq_printf(p, " %8s", desc->irq_data.chip->name); 211 212 if (desc->action) 213 seq_printf(p, " %s", desc->action->name); 214 215 seq_putc(p, '\n'); 216 raw_spin_unlock_irqrestore(&desc->lock, flags); 217 out: 218 irq_unlock_sparse(); 219 } 220 221 /* 222 * show_interrupts is needed by /proc/interrupts. 223 */ 224 int show_interrupts(struct seq_file *p, void *v) 225 { 226 int index = *(loff_t *) v; 227 int cpu, irq; 228 229 get_online_cpus(); 230 if (index == 0) { 231 seq_puts(p, " "); 232 for_each_online_cpu(cpu) 233 seq_printf(p, "CPU%-8d", cpu); 234 seq_putc(p, '\n'); 235 } 236 if (index < NR_IRQS_BASE) { 237 seq_printf(p, "%s: ", irqclass_main_desc[index].name); 238 irq = irqclass_main_desc[index].irq; 239 for_each_online_cpu(cpu) 240 seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu)); 241 seq_putc(p, '\n'); 242 goto out; 243 } 244 if (index < nr_irqs) { 245 show_msi_interrupt(p, index); 246 goto out; 247 } 248 for (index = 0; index < NR_ARCH_IRQS; index++) { 249 seq_printf(p, "%s: ", irqclass_sub_desc[index].name); 250 irq = irqclass_sub_desc[index].irq; 251 for_each_online_cpu(cpu) 252 seq_printf(p, "%10u ", 253 per_cpu(irq_stat, cpu).irqs[irq]); 254 if (irqclass_sub_desc[index].desc) 255 seq_printf(p, " %s", irqclass_sub_desc[index].desc); 256 seq_putc(p, '\n'); 257 } 258 out: 259 put_online_cpus(); 260 return 0; 261 } 262 263 unsigned int arch_dynirq_lower_bound(unsigned int from) 264 { 265 return from < NR_IRQS_BASE ? NR_IRQS_BASE : from; 266 } 267 268 /* 269 * Switch to the asynchronous interrupt stack for softirq execution. 270 */ 271 void do_softirq_own_stack(void) 272 { 273 unsigned long old, new; 274 275 old = current_stack_pointer(); 276 /* Check against async. stack address range. */ 277 new = S390_lowcore.async_stack; 278 if (((new - old) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)) != 0) { 279 CALL_ON_STACK(__do_softirq, new, 0); 280 } else { 281 /* We are already on the async stack. */ 282 __do_softirq(); 283 } 284 } 285 286 /* 287 * ext_int_hash[index] is the list head for all external interrupts that hash 288 * to this index. 289 */ 290 static struct hlist_head ext_int_hash[32] ____cacheline_aligned; 291 292 struct ext_int_info { 293 ext_int_handler_t handler; 294 struct hlist_node entry; 295 struct rcu_head rcu; 296 u16 code; 297 }; 298 299 /* ext_int_hash_lock protects the handler lists for external interrupts */ 300 static DEFINE_SPINLOCK(ext_int_hash_lock); 301 302 static inline int ext_hash(u16 code) 303 { 304 BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash))); 305 306 return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1); 307 } 308 309 int register_external_irq(u16 code, ext_int_handler_t handler) 310 { 311 struct ext_int_info *p; 312 unsigned long flags; 313 int index; 314 315 p = kmalloc(sizeof(*p), GFP_ATOMIC); 316 if (!p) 317 return -ENOMEM; 318 p->code = code; 319 p->handler = handler; 320 index = ext_hash(code); 321 322 spin_lock_irqsave(&ext_int_hash_lock, flags); 323 hlist_add_head_rcu(&p->entry, &ext_int_hash[index]); 324 spin_unlock_irqrestore(&ext_int_hash_lock, flags); 325 return 0; 326 } 327 EXPORT_SYMBOL(register_external_irq); 328 329 int unregister_external_irq(u16 code, ext_int_handler_t handler) 330 { 331 struct ext_int_info *p; 332 unsigned long flags; 333 int index = ext_hash(code); 334 335 spin_lock_irqsave(&ext_int_hash_lock, flags); 336 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) { 337 if (p->code == code && p->handler == handler) { 338 hlist_del_rcu(&p->entry); 339 kfree_rcu(p, rcu); 340 } 341 } 342 spin_unlock_irqrestore(&ext_int_hash_lock, flags); 343 return 0; 344 } 345 EXPORT_SYMBOL(unregister_external_irq); 346 347 static irqreturn_t do_ext_interrupt(int irq, void *dummy) 348 { 349 struct pt_regs *regs = get_irq_regs(); 350 struct ext_code ext_code; 351 struct ext_int_info *p; 352 int index; 353 354 ext_code = *(struct ext_code *) ®s->int_code; 355 if (ext_code.code != EXT_IRQ_CLK_COMP) 356 set_cpu_flag(CIF_NOHZ_DELAY); 357 358 index = ext_hash(ext_code.code); 359 rcu_read_lock(); 360 hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) { 361 if (unlikely(p->code != ext_code.code)) 362 continue; 363 p->handler(ext_code, regs->int_parm, regs->int_parm_long); 364 } 365 rcu_read_unlock(); 366 return IRQ_HANDLED; 367 } 368 369 static void __init init_ext_interrupts(void) 370 { 371 int idx; 372 373 for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++) 374 INIT_HLIST_HEAD(&ext_int_hash[idx]); 375 376 irq_set_chip_and_handler(EXT_INTERRUPT, 377 &dummy_irq_chip, handle_percpu_irq); 378 if (request_irq(EXT_INTERRUPT, do_ext_interrupt, 0, "EXT", NULL)) 379 panic("Failed to register EXT interrupt\n"); 380 } 381 382 void __init init_IRQ(void) 383 { 384 BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS); 385 init_cio_interrupts(); 386 init_airq_interrupts(); 387 init_ext_interrupts(); 388 } 389 390 static DEFINE_SPINLOCK(irq_subclass_lock); 391 static unsigned char irq_subclass_refcount[64]; 392 393 void irq_subclass_register(enum irq_subclass subclass) 394 { 395 spin_lock(&irq_subclass_lock); 396 if (!irq_subclass_refcount[subclass]) 397 ctl_set_bit(0, subclass); 398 irq_subclass_refcount[subclass]++; 399 spin_unlock(&irq_subclass_lock); 400 } 401 EXPORT_SYMBOL(irq_subclass_register); 402 403 void irq_subclass_unregister(enum irq_subclass subclass) 404 { 405 spin_lock(&irq_subclass_lock); 406 irq_subclass_refcount[subclass]--; 407 if (!irq_subclass_refcount[subclass]) 408 ctl_clear_bit(0, subclass); 409 spin_unlock(&irq_subclass_lock); 410 } 411 EXPORT_SYMBOL(irq_subclass_unregister); 412