1 /* 2 * Code to handle x86 style IRQs plus some generic interrupt stuff. 3 * 4 * Copyright (C) 1992 Linus Torvalds 5 * Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle 6 * Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org) 7 * Copyright (C) 1999-2000 Grant Grundler 8 * Copyright (c) 2005 Matthew Wilcox 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2, or (at your option) 13 * any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 23 */ 24 #include <linux/bitops.h> 25 #include <linux/errno.h> 26 #include <linux/init.h> 27 #include <linux/interrupt.h> 28 #include <linux/kernel_stat.h> 29 #include <linux/seq_file.h> 30 #include <linux/spinlock.h> 31 #include <linux/types.h> 32 #include <asm/io.h> 33 34 #include <asm/smp.h> 35 36 #undef PARISC_IRQ_CR16_COUNTS 37 38 extern irqreturn_t timer_interrupt(int, void *); 39 extern irqreturn_t ipi_interrupt(int, void *); 40 41 #define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq)) 42 43 /* Bits in EIEM correlate with cpu_irq_action[]. 44 ** Numbered *Big Endian*! (ie bit 0 is MSB) 45 */ 46 static volatile unsigned long cpu_eiem = 0; 47 48 /* 49 ** local ACK bitmap ... habitually set to 1, but reset to zero 50 ** between ->ack() and ->end() of the interrupt to prevent 51 ** re-interruption of a processing interrupt. 52 */ 53 static DEFINE_PER_CPU(unsigned long, local_ack_eiem) = ~0UL; 54 55 static void cpu_mask_irq(unsigned int irq) 56 { 57 unsigned long eirr_bit = EIEM_MASK(irq); 58 59 cpu_eiem &= ~eirr_bit; 60 /* Do nothing on the other CPUs. If they get this interrupt, 61 * The & cpu_eiem in the do_cpu_irq_mask() ensures they won't 62 * handle it, and the set_eiem() at the bottom will ensure it 63 * then gets disabled */ 64 } 65 66 static void cpu_unmask_irq(unsigned int irq) 67 { 68 unsigned long eirr_bit = EIEM_MASK(irq); 69 70 cpu_eiem |= eirr_bit; 71 72 /* This is just a simple NOP IPI. But what it does is cause 73 * all the other CPUs to do a set_eiem(cpu_eiem) at the end 74 * of the interrupt handler */ 75 smp_send_all_nop(); 76 } 77 78 void no_ack_irq(unsigned int irq) { } 79 void no_end_irq(unsigned int irq) { } 80 81 void cpu_ack_irq(unsigned int irq) 82 { 83 unsigned long mask = EIEM_MASK(irq); 84 int cpu = smp_processor_id(); 85 86 /* Clear in EIEM so we can no longer process */ 87 per_cpu(local_ack_eiem, cpu) &= ~mask; 88 89 /* disable the interrupt */ 90 set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu)); 91 92 /* and now ack it */ 93 mtctl(mask, 23); 94 } 95 96 void cpu_eoi_irq(unsigned int irq) 97 { 98 unsigned long mask = EIEM_MASK(irq); 99 int cpu = smp_processor_id(); 100 101 /* set it in the eiems---it's no longer in process */ 102 per_cpu(local_ack_eiem, cpu) |= mask; 103 104 /* enable the interrupt */ 105 set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu)); 106 } 107 108 #ifdef CONFIG_SMP 109 int cpu_check_affinity(unsigned int irq, const struct cpumask *dest) 110 { 111 int cpu_dest; 112 113 /* timer and ipi have to always be received on all CPUs */ 114 if (CHECK_IRQ_PER_CPU(irq)) { 115 /* Bad linux design decision. The mask has already 116 * been set; we must reset it */ 117 cpumask_setall(irq_desc[irq].affinity); 118 return -EINVAL; 119 } 120 121 /* whatever mask they set, we just allow one CPU */ 122 cpu_dest = first_cpu(*dest); 123 124 return cpu_dest; 125 } 126 127 static int cpu_set_affinity_irq(unsigned int irq, const struct cpumask *dest) 128 { 129 int cpu_dest; 130 131 cpu_dest = cpu_check_affinity(irq, dest); 132 if (cpu_dest < 0) 133 return -1; 134 135 cpumask_copy(irq_desc[irq].affinity, dest); 136 137 return 0; 138 } 139 #endif 140 141 static struct irq_chip cpu_interrupt_type = { 142 .name = "CPU", 143 .mask = cpu_mask_irq, 144 .unmask = cpu_unmask_irq, 145 .ack = cpu_ack_irq, 146 .eoi = cpu_eoi_irq, 147 #ifdef CONFIG_SMP 148 .set_affinity = cpu_set_affinity_irq, 149 #endif 150 /* XXX: Needs to be written. We managed without it so far, but 151 * we really ought to write it. 152 */ 153 .retrigger = NULL, 154 }; 155 156 int show_interrupts(struct seq_file *p, void *v) 157 { 158 int i = *(loff_t *) v, j; 159 unsigned long flags; 160 161 if (i == 0) { 162 seq_puts(p, " "); 163 for_each_online_cpu(j) 164 seq_printf(p, " CPU%d", j); 165 166 #ifdef PARISC_IRQ_CR16_COUNTS 167 seq_printf(p, " [min/avg/max] (CPU cycle counts)"); 168 #endif 169 seq_putc(p, '\n'); 170 } 171 172 if (i < NR_IRQS) { 173 struct irqaction *action; 174 175 raw_spin_lock_irqsave(&irq_desc[i].lock, flags); 176 action = irq_desc[i].action; 177 if (!action) 178 goto skip; 179 seq_printf(p, "%3d: ", i); 180 #ifdef CONFIG_SMP 181 for_each_online_cpu(j) 182 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); 183 #else 184 seq_printf(p, "%10u ", kstat_irqs(i)); 185 #endif 186 187 seq_printf(p, " %14s", irq_desc[i].chip->name); 188 #ifndef PARISC_IRQ_CR16_COUNTS 189 seq_printf(p, " %s", action->name); 190 191 while ((action = action->next)) 192 seq_printf(p, ", %s", action->name); 193 #else 194 for ( ;action; action = action->next) { 195 unsigned int k, avg, min, max; 196 197 min = max = action->cr16_hist[0]; 198 199 for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) { 200 int hist = action->cr16_hist[k]; 201 202 if (hist) { 203 avg += hist; 204 } else 205 break; 206 207 if (hist > max) max = hist; 208 if (hist < min) min = hist; 209 } 210 211 avg /= k; 212 seq_printf(p, " %s[%d/%d/%d]", action->name, 213 min,avg,max); 214 } 215 #endif 216 217 seq_putc(p, '\n'); 218 skip: 219 raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags); 220 } 221 222 return 0; 223 } 224 225 226 227 /* 228 ** The following form a "set": Virtual IRQ, Transaction Address, Trans Data. 229 ** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit. 230 ** 231 ** To use txn_XXX() interfaces, get a Virtual IRQ first. 232 ** Then use that to get the Transaction address and data. 233 */ 234 235 int cpu_claim_irq(unsigned int irq, struct irq_chip *type, void *data) 236 { 237 if (irq_desc[irq].action) 238 return -EBUSY; 239 if (irq_desc[irq].chip != &cpu_interrupt_type) 240 return -EBUSY; 241 242 /* for iosapic interrupts */ 243 if (type) { 244 set_irq_chip_and_handler(irq, type, handle_level_irq); 245 set_irq_chip_data(irq, data); 246 cpu_unmask_irq(irq); 247 } 248 return 0; 249 } 250 251 int txn_claim_irq(int irq) 252 { 253 return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq; 254 } 255 256 /* 257 * The bits_wide parameter accommodates the limitations of the HW/SW which 258 * use these bits: 259 * Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register) 260 * V-class (EPIC): 6 bits 261 * N/L/A-class (iosapic): 8 bits 262 * PCI 2.2 MSI: 16 bits 263 * Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric) 264 * 265 * On the service provider side: 266 * o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register) 267 * o PA 2.0 wide mode 6-bits (per processor) 268 * o IA64 8-bits (0-256 total) 269 * 270 * So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported 271 * by the processor...and the N/L-class I/O subsystem supports more bits than 272 * PA2.0 has. The first case is the problem. 273 */ 274 int txn_alloc_irq(unsigned int bits_wide) 275 { 276 int irq; 277 278 /* never return irq 0 cause that's the interval timer */ 279 for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) { 280 if (cpu_claim_irq(irq, NULL, NULL) < 0) 281 continue; 282 if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide)) 283 continue; 284 return irq; 285 } 286 287 /* unlikely, but be prepared */ 288 return -1; 289 } 290 291 292 unsigned long txn_affinity_addr(unsigned int irq, int cpu) 293 { 294 #ifdef CONFIG_SMP 295 cpumask_copy(irq_desc[irq].affinity, cpumask_of(cpu)); 296 #endif 297 298 return per_cpu(cpu_data, cpu).txn_addr; 299 } 300 301 302 unsigned long txn_alloc_addr(unsigned int virt_irq) 303 { 304 static int next_cpu = -1; 305 306 next_cpu++; /* assign to "next" CPU we want this bugger on */ 307 308 /* validate entry */ 309 while ((next_cpu < nr_cpu_ids) && 310 (!per_cpu(cpu_data, next_cpu).txn_addr || 311 !cpu_online(next_cpu))) 312 next_cpu++; 313 314 if (next_cpu >= nr_cpu_ids) 315 next_cpu = 0; /* nothing else, assign monarch */ 316 317 return txn_affinity_addr(virt_irq, next_cpu); 318 } 319 320 321 unsigned int txn_alloc_data(unsigned int virt_irq) 322 { 323 return virt_irq - CPU_IRQ_BASE; 324 } 325 326 static inline int eirr_to_irq(unsigned long eirr) 327 { 328 int bit = fls_long(eirr); 329 return (BITS_PER_LONG - bit) + TIMER_IRQ; 330 } 331 332 /* ONLY called from entry.S:intr_extint() */ 333 void do_cpu_irq_mask(struct pt_regs *regs) 334 { 335 struct pt_regs *old_regs; 336 unsigned long eirr_val; 337 int irq, cpu = smp_processor_id(); 338 #ifdef CONFIG_SMP 339 cpumask_t dest; 340 #endif 341 342 old_regs = set_irq_regs(regs); 343 local_irq_disable(); 344 irq_enter(); 345 346 eirr_val = mfctl(23) & cpu_eiem & per_cpu(local_ack_eiem, cpu); 347 if (!eirr_val) 348 goto set_out; 349 irq = eirr_to_irq(eirr_val); 350 351 #ifdef CONFIG_SMP 352 cpumask_copy(&dest, irq_desc[irq].affinity); 353 if (CHECK_IRQ_PER_CPU(irq_desc[irq].status) && 354 !cpu_isset(smp_processor_id(), dest)) { 355 int cpu = first_cpu(dest); 356 357 printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n", 358 irq, smp_processor_id(), cpu); 359 gsc_writel(irq + CPU_IRQ_BASE, 360 per_cpu(cpu_data, cpu).hpa); 361 goto set_out; 362 } 363 #endif 364 generic_handle_irq(irq); 365 366 out: 367 irq_exit(); 368 set_irq_regs(old_regs); 369 return; 370 371 set_out: 372 set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu)); 373 goto out; 374 } 375 376 static struct irqaction timer_action = { 377 .handler = timer_interrupt, 378 .name = "timer", 379 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL, 380 }; 381 382 #ifdef CONFIG_SMP 383 static struct irqaction ipi_action = { 384 .handler = ipi_interrupt, 385 .name = "IPI", 386 .flags = IRQF_DISABLED | IRQF_PERCPU, 387 }; 388 #endif 389 390 static void claim_cpu_irqs(void) 391 { 392 int i; 393 for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) { 394 set_irq_chip_and_handler(i, &cpu_interrupt_type, 395 handle_level_irq); 396 } 397 398 set_irq_handler(TIMER_IRQ, handle_percpu_irq); 399 setup_irq(TIMER_IRQ, &timer_action); 400 #ifdef CONFIG_SMP 401 set_irq_handler(IPI_IRQ, handle_percpu_irq); 402 setup_irq(IPI_IRQ, &ipi_action); 403 #endif 404 } 405 406 void __init init_IRQ(void) 407 { 408 local_irq_disable(); /* PARANOID - should already be disabled */ 409 mtctl(~0UL, 23); /* EIRR : clear all pending external intr */ 410 claim_cpu_irqs(); 411 #ifdef CONFIG_SMP 412 if (!cpu_eiem) 413 cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ); 414 #else 415 cpu_eiem = EIEM_MASK(TIMER_IRQ); 416 #endif 417 set_eiem(cpu_eiem); /* EIEM : enable all external intr */ 418 419 } 420 421