1 /* 2 * ip27-irq.c: Highlevel interrupt handling for IP27 architecture. 3 * 4 * Copyright (C) 1999, 2000 Ralf Baechle (ralf@gnu.org) 5 * Copyright (C) 1999, 2000 Silicon Graphics, Inc. 6 * Copyright (C) 1999 - 2001 Kanoj Sarcar 7 */ 8 9 #undef DEBUG 10 11 #include <linux/init.h> 12 #include <linux/irq.h> 13 #include <linux/errno.h> 14 #include <linux/signal.h> 15 #include <linux/sched.h> 16 #include <linux/types.h> 17 #include <linux/interrupt.h> 18 #include <linux/ioport.h> 19 #include <linux/timex.h> 20 #include <linux/slab.h> 21 #include <linux/random.h> 22 #include <linux/smp_lock.h> 23 #include <linux/kernel.h> 24 #include <linux/kernel_stat.h> 25 #include <linux/delay.h> 26 #include <linux/bitops.h> 27 28 #include <asm/bootinfo.h> 29 #include <asm/io.h> 30 #include <asm/mipsregs.h> 31 #include <asm/system.h> 32 33 #include <asm/processor.h> 34 #include <asm/pci/bridge.h> 35 #include <asm/sn/addrs.h> 36 #include <asm/sn/agent.h> 37 #include <asm/sn/arch.h> 38 #include <asm/sn/hub.h> 39 #include <asm/sn/intr.h> 40 41 /* 42 * Linux has a controller-independent x86 interrupt architecture. 43 * every controller has a 'controller-template', that is used 44 * by the main code to do the right thing. Each driver-visible 45 * interrupt source is transparently wired to the apropriate 46 * controller. Thus drivers need not be aware of the 47 * interrupt-controller. 48 * 49 * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC, 50 * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC. 51 * (IO-APICs assumed to be messaging to Pentium local-APICs) 52 * 53 * the code is designed to be easily extended with new/different 54 * interrupt controllers, without having to do assembly magic. 55 */ 56 57 extern asmlinkage void ip27_irq(void); 58 59 extern struct bridge_controller *irq_to_bridge[]; 60 extern int irq_to_slot[]; 61 62 /* 63 * use these macros to get the encoded nasid and widget id 64 * from the irq value 65 */ 66 #define IRQ_TO_BRIDGE(i) irq_to_bridge[(i)] 67 #define SLOT_FROM_PCI_IRQ(i) irq_to_slot[i] 68 69 static inline int alloc_level(int cpu, int irq) 70 { 71 struct hub_data *hub = hub_data(cpu_to_node(cpu)); 72 struct slice_data *si = cpu_data[cpu].data; 73 int level; 74 75 level = find_first_zero_bit(hub->irq_alloc_mask, LEVELS_PER_SLICE); 76 if (level >= LEVELS_PER_SLICE) 77 panic("Cpu %d flooded with devices\n", cpu); 78 79 __set_bit(level, hub->irq_alloc_mask); 80 si->level_to_irq[level] = irq; 81 82 return level; 83 } 84 85 static inline int find_level(cpuid_t *cpunum, int irq) 86 { 87 int cpu, i; 88 89 for_each_online_cpu(cpu) { 90 struct slice_data *si = cpu_data[cpu].data; 91 92 for (i = BASE_PCI_IRQ; i < LEVELS_PER_SLICE; i++) 93 if (si->level_to_irq[i] == irq) { 94 *cpunum = cpu; 95 96 return i; 97 } 98 } 99 100 panic("Could not identify cpu/level for irq %d\n", irq); 101 } 102 103 /* 104 * Find first bit set 105 */ 106 static int ms1bit(unsigned long x) 107 { 108 int b = 0, s; 109 110 s = 16; if (x >> 16 == 0) s = 0; b += s; x >>= s; 111 s = 8; if (x >> 8 == 0) s = 0; b += s; x >>= s; 112 s = 4; if (x >> 4 == 0) s = 0; b += s; x >>= s; 113 s = 2; if (x >> 2 == 0) s = 0; b += s; x >>= s; 114 s = 1; if (x >> 1 == 0) s = 0; b += s; 115 116 return b; 117 } 118 119 /* 120 * This code is unnecessarily complex, because we do IRQF_DISABLED 121 * intr enabling. Basically, once we grab the set of intrs we need 122 * to service, we must mask _all_ these interrupts; firstly, to make 123 * sure the same intr does not intr again, causing recursion that 124 * can lead to stack overflow. Secondly, we can not just mask the 125 * one intr we are do_IRQing, because the non-masked intrs in the 126 * first set might intr again, causing multiple servicings of the 127 * same intr. This effect is mostly seen for intercpu intrs. 128 * Kanoj 05.13.00 129 */ 130 131 static void ip27_do_irq_mask0(void) 132 { 133 int irq, swlevel; 134 hubreg_t pend0, mask0; 135 cpuid_t cpu = smp_processor_id(); 136 int pi_int_mask0 = 137 (cputoslice(cpu) == 0) ? PI_INT_MASK0_A : PI_INT_MASK0_B; 138 139 /* copied from Irix intpend0() */ 140 pend0 = LOCAL_HUB_L(PI_INT_PEND0); 141 mask0 = LOCAL_HUB_L(pi_int_mask0); 142 143 pend0 &= mask0; /* Pick intrs we should look at */ 144 if (!pend0) 145 return; 146 147 swlevel = ms1bit(pend0); 148 #ifdef CONFIG_SMP 149 if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) { 150 LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ); 151 } else if (pend0 & (1UL << CPU_RESCHED_B_IRQ)) { 152 LOCAL_HUB_CLR_INTR(CPU_RESCHED_B_IRQ); 153 } else if (pend0 & (1UL << CPU_CALL_A_IRQ)) { 154 LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ); 155 smp_call_function_interrupt(); 156 } else if (pend0 & (1UL << CPU_CALL_B_IRQ)) { 157 LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ); 158 smp_call_function_interrupt(); 159 } else 160 #endif 161 { 162 /* "map" swlevel to irq */ 163 struct slice_data *si = cpu_data[cpu].data; 164 165 irq = si->level_to_irq[swlevel]; 166 do_IRQ(irq); 167 } 168 169 LOCAL_HUB_L(PI_INT_PEND0); 170 } 171 172 static void ip27_do_irq_mask1(void) 173 { 174 int irq, swlevel; 175 hubreg_t pend1, mask1; 176 cpuid_t cpu = smp_processor_id(); 177 int pi_int_mask1 = (cputoslice(cpu) == 0) ? PI_INT_MASK1_A : PI_INT_MASK1_B; 178 struct slice_data *si = cpu_data[cpu].data; 179 180 /* copied from Irix intpend0() */ 181 pend1 = LOCAL_HUB_L(PI_INT_PEND1); 182 mask1 = LOCAL_HUB_L(pi_int_mask1); 183 184 pend1 &= mask1; /* Pick intrs we should look at */ 185 if (!pend1) 186 return; 187 188 swlevel = ms1bit(pend1); 189 /* "map" swlevel to irq */ 190 irq = si->level_to_irq[swlevel]; 191 LOCAL_HUB_CLR_INTR(swlevel); 192 do_IRQ(irq); 193 194 LOCAL_HUB_L(PI_INT_PEND1); 195 } 196 197 static void ip27_prof_timer(void) 198 { 199 panic("CPU %d got a profiling interrupt", smp_processor_id()); 200 } 201 202 static void ip27_hub_error(void) 203 { 204 panic("CPU %d got a hub error interrupt", smp_processor_id()); 205 } 206 207 static int intr_connect_level(int cpu, int bit) 208 { 209 nasid_t nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu)); 210 struct slice_data *si = cpu_data[cpu].data; 211 unsigned long flags; 212 213 set_bit(bit, si->irq_enable_mask); 214 215 local_irq_save(flags); 216 if (!cputoslice(cpu)) { 217 REMOTE_HUB_S(nasid, PI_INT_MASK0_A, si->irq_enable_mask[0]); 218 REMOTE_HUB_S(nasid, PI_INT_MASK1_A, si->irq_enable_mask[1]); 219 } else { 220 REMOTE_HUB_S(nasid, PI_INT_MASK0_B, si->irq_enable_mask[0]); 221 REMOTE_HUB_S(nasid, PI_INT_MASK1_B, si->irq_enable_mask[1]); 222 } 223 local_irq_restore(flags); 224 225 return 0; 226 } 227 228 static int intr_disconnect_level(int cpu, int bit) 229 { 230 nasid_t nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu)); 231 struct slice_data *si = cpu_data[cpu].data; 232 233 clear_bit(bit, si->irq_enable_mask); 234 235 if (!cputoslice(cpu)) { 236 REMOTE_HUB_S(nasid, PI_INT_MASK0_A, si->irq_enable_mask[0]); 237 REMOTE_HUB_S(nasid, PI_INT_MASK1_A, si->irq_enable_mask[1]); 238 } else { 239 REMOTE_HUB_S(nasid, PI_INT_MASK0_B, si->irq_enable_mask[0]); 240 REMOTE_HUB_S(nasid, PI_INT_MASK1_B, si->irq_enable_mask[1]); 241 } 242 243 return 0; 244 } 245 246 /* Startup one of the (PCI ...) IRQs routes over a bridge. */ 247 static unsigned int startup_bridge_irq(unsigned int irq) 248 { 249 struct bridge_controller *bc; 250 bridgereg_t device; 251 bridge_t *bridge; 252 int pin, swlevel; 253 cpuid_t cpu; 254 255 pin = SLOT_FROM_PCI_IRQ(irq); 256 bc = IRQ_TO_BRIDGE(irq); 257 bridge = bc->base; 258 259 pr_debug("bridge_startup(): irq= 0x%x pin=%d\n", irq, pin); 260 /* 261 * "map" irq to a swlevel greater than 6 since the first 6 bits 262 * of INT_PEND0 are taken 263 */ 264 swlevel = find_level(&cpu, irq); 265 bridge->b_int_addr[pin].addr = (0x20000 | swlevel | (bc->nasid << 8)); 266 bridge->b_int_enable |= (1 << pin); 267 bridge->b_int_enable |= 0x7ffffe00; /* more stuff in int_enable */ 268 269 /* 270 * Enable sending of an interrupt clear packt to the hub on a high to 271 * low transition of the interrupt pin. 272 * 273 * IRIX sets additional bits in the address which are documented as 274 * reserved in the bridge docs. 275 */ 276 bridge->b_int_mode |= (1UL << pin); 277 278 /* 279 * We assume the bridge to have a 1:1 mapping between devices 280 * (slots) and intr pins. 281 */ 282 device = bridge->b_int_device; 283 device &= ~(7 << (pin*3)); 284 device |= (pin << (pin*3)); 285 bridge->b_int_device = device; 286 287 bridge->b_wid_tflush; 288 289 return 0; /* Never anything pending. */ 290 } 291 292 /* Shutdown one of the (PCI ...) IRQs routes over a bridge. */ 293 static void shutdown_bridge_irq(unsigned int irq) 294 { 295 struct bridge_controller *bc = IRQ_TO_BRIDGE(irq); 296 struct hub_data *hub = hub_data(cpu_to_node(bc->irq_cpu)); 297 bridge_t *bridge = bc->base; 298 int pin, swlevel; 299 cpuid_t cpu; 300 301 pr_debug("bridge_shutdown: irq 0x%x\n", irq); 302 pin = SLOT_FROM_PCI_IRQ(irq); 303 304 /* 305 * map irq to a swlevel greater than 6 since the first 6 bits 306 * of INT_PEND0 are taken 307 */ 308 swlevel = find_level(&cpu, irq); 309 intr_disconnect_level(cpu, swlevel); 310 311 __clear_bit(swlevel, hub->irq_alloc_mask); 312 313 bridge->b_int_enable &= ~(1 << pin); 314 bridge->b_wid_tflush; 315 } 316 317 static inline void enable_bridge_irq(unsigned int irq) 318 { 319 cpuid_t cpu; 320 int swlevel; 321 322 swlevel = find_level(&cpu, irq); /* Criminal offence */ 323 intr_connect_level(cpu, swlevel); 324 } 325 326 static inline void disable_bridge_irq(unsigned int irq) 327 { 328 cpuid_t cpu; 329 int swlevel; 330 331 swlevel = find_level(&cpu, irq); /* Criminal offence */ 332 intr_disconnect_level(cpu, swlevel); 333 } 334 335 static struct irq_chip bridge_irq_type = { 336 .name = "bridge", 337 .startup = startup_bridge_irq, 338 .shutdown = shutdown_bridge_irq, 339 .ack = disable_bridge_irq, 340 .mask = disable_bridge_irq, 341 .mask_ack = disable_bridge_irq, 342 .unmask = enable_bridge_irq, 343 }; 344 345 void __devinit register_bridge_irq(unsigned int irq) 346 { 347 set_irq_chip_and_handler(irq, &bridge_irq_type, handle_level_irq); 348 } 349 350 int __devinit request_bridge_irq(struct bridge_controller *bc) 351 { 352 int irq = allocate_irqno(); 353 int swlevel, cpu; 354 nasid_t nasid; 355 356 if (irq < 0) 357 return irq; 358 359 /* 360 * "map" irq to a swlevel greater than 6 since the first 6 bits 361 * of INT_PEND0 are taken 362 */ 363 cpu = bc->irq_cpu; 364 swlevel = alloc_level(cpu, irq); 365 if (unlikely(swlevel < 0)) { 366 free_irqno(irq); 367 368 return -EAGAIN; 369 } 370 371 /* Make sure it's not already pending when we connect it. */ 372 nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu)); 373 REMOTE_HUB_CLR_INTR(nasid, swlevel); 374 375 intr_connect_level(cpu, swlevel); 376 377 register_bridge_irq(irq); 378 379 return irq; 380 } 381 382 extern void ip27_rt_timer_interrupt(void); 383 384 asmlinkage void plat_irq_dispatch(void) 385 { 386 unsigned long pending = read_c0_cause() & read_c0_status(); 387 388 if (pending & CAUSEF_IP4) 389 ip27_rt_timer_interrupt(); 390 else if (pending & CAUSEF_IP2) /* PI_INT_PEND_0 or CC_PEND_{A|B} */ 391 ip27_do_irq_mask0(); 392 else if (pending & CAUSEF_IP3) /* PI_INT_PEND_1 */ 393 ip27_do_irq_mask1(); 394 else if (pending & CAUSEF_IP5) 395 ip27_prof_timer(); 396 else if (pending & CAUSEF_IP6) 397 ip27_hub_error(); 398 } 399 400 void __init arch_init_irq(void) 401 { 402 } 403 404 void install_ipi(void) 405 { 406 int slice = LOCAL_HUB_L(PI_CPU_NUM); 407 int cpu = smp_processor_id(); 408 struct slice_data *si = cpu_data[cpu].data; 409 struct hub_data *hub = hub_data(cpu_to_node(cpu)); 410 int resched, call; 411 412 resched = CPU_RESCHED_A_IRQ + slice; 413 __set_bit(resched, hub->irq_alloc_mask); 414 __set_bit(resched, si->irq_enable_mask); 415 LOCAL_HUB_CLR_INTR(resched); 416 417 call = CPU_CALL_A_IRQ + slice; 418 __set_bit(call, hub->irq_alloc_mask); 419 __set_bit(call, si->irq_enable_mask); 420 LOCAL_HUB_CLR_INTR(call); 421 422 if (slice == 0) { 423 LOCAL_HUB_S(PI_INT_MASK0_A, si->irq_enable_mask[0]); 424 LOCAL_HUB_S(PI_INT_MASK1_A, si->irq_enable_mask[1]); 425 } else { 426 LOCAL_HUB_S(PI_INT_MASK0_B, si->irq_enable_mask[0]); 427 LOCAL_HUB_S(PI_INT_MASK1_B, si->irq_enable_mask[1]); 428 } 429 } 430