arch/ppc64/kernel/xics.c

   1 /*
   2  * arch/ppc64/kernel/xics.c
   3  *
   4  * Copyright 2000 IBM Corporation.
   5  *
   6  *  This program is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU General Public License
   8  *  as published by the Free Software Foundation; either version
   9  *  2 of the License, or (at your option) any later version.
  10  */
  11 #include <linux/config.h>
  12 #include <linux/types.h>
  13 #include <linux/threads.h>
  14 #include <linux/kernel.h>
  15 #include <linux/irq.h>
  16 #include <linux/smp.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/signal.h>
  19 #include <linux/init.h>
  20 #include <linux/gfp.h>
  21 #include <linux/radix-tree.h>
  22 #include <linux/cpu.h>
  23 #include <asm/prom.h>
  24 #include <asm/io.h>
  25 #include <asm/pgtable.h>
  26 #include <asm/smp.h>
  27 #include <asm/rtas.h>
  28 #include <asm/xics.h>
  29 #include <asm/hvcall.h>
  30 #include <asm/machdep.h>
  31
  32 #include "i8259.h"
  33
  34 static unsigned int xics_startup(unsigned int irq);
  35 static void xics_enable_irq(unsigned int irq);
  36 static void xics_disable_irq(unsigned int irq);
  37 static void xics_mask_and_ack_irq(unsigned int irq);
  38 static void xics_end_irq(unsigned int irq);
  39 static void xics_set_affinity(unsigned int irq_nr, cpumask_t cpumask);
  40
  41 struct hw_interrupt_type xics_pic = {
  42         .typename = " XICS     ",
  43         .startup = xics_startup,
  44         .enable = xics_enable_irq,
  45         .disable = xics_disable_irq,
  46         .ack = xics_mask_and_ack_irq,
  47         .end = xics_end_irq,
  48         .set_affinity = xics_set_affinity
  49 };
  50
  51 struct hw_interrupt_type xics_8259_pic = {
  52         .typename = " XICS/8259",
  53         .ack = xics_mask_and_ack_irq,
  54 };
  55
  56 /* This is used to map real irq numbers to virtual */
  57 static struct radix_tree_root irq_map = RADIX_TREE_INIT(GFP_ATOMIC);
  58
  59 #define XICS_IPI                2
  60 #define XICS_IRQ_SPURIOUS       0
  61
  62 /* Want a priority other than 0.  Various HW issues require this. */
  63 #define DEFAULT_PRIORITY        5
  64
  65 /*
  66  * Mark IPIs as higher priority so we can take them inside interrupts that
  67  * arent marked SA_INTERRUPT
  68  */
  69 #define IPI_PRIORITY            4
  70
  71 struct xics_ipl {
  72         union {
  73                 u32 word;
  74                 u8 bytes[4];
  75         } xirr_poll;
  76         union {
  77                 u32 word;
  78                 u8 bytes[4];
  79         } xirr;
  80         u32 dummy;
  81         union {
  82                 u32 word;
  83                 u8 bytes[4];
  84         } qirr;
  85 };
  86
  87 static struct xics_ipl __iomem *xics_per_cpu[NR_CPUS];
  88
  89 static int xics_irq_8259_cascade = 0;
  90 static int xics_irq_8259_cascade_real = 0;
  91 static unsigned int default_server = 0xFF;
  92 /* also referenced in smp.c... */
  93 unsigned int default_distrib_server = 0;
  94 unsigned int interrupt_server_size = 8;
  95
  96 /*
  97  * XICS only has a single IPI, so encode the messages per CPU
  98  */
  99 struct xics_ipi_struct xics_ipi_message[NR_CPUS] __cacheline_aligned;
 100
 101 /* RTAS service tokens */
 102 int ibm_get_xive;
 103 int ibm_set_xive;
 104 int ibm_int_on;
 105 int ibm_int_off;
 106
 107 typedef struct {
 108         int (*xirr_info_get)(int cpu);
 109         void (*xirr_info_set)(int cpu, int val);
 110         void (*cppr_info)(int cpu, u8 val);
 111         void (*qirr_info)(int cpu, u8 val);
 112 } xics_ops;
 113
 114
 115 /* SMP */
 116
 117 static int pSeries_xirr_info_get(int n_cpu)
 118 {
 119         return in_be32(&xics_per_cpu[n_cpu]->xirr.word);
 120 }
 121
 122 static void pSeries_xirr_info_set(int n_cpu, int value)
 123 {
 124         out_be32(&xics_per_cpu[n_cpu]->xirr.word, value);
 125 }
 126
 127 static void pSeries_cppr_info(int n_cpu, u8 value)
 128 {
 129         out_8(&xics_per_cpu[n_cpu]->xirr.bytes[0], value);
 130 }
 131
 132 static void pSeries_qirr_info(int n_cpu, u8 value)
 133 {
 134         out_8(&xics_per_cpu[n_cpu]->qirr.bytes[0], value);
 135 }
 136
 137 static xics_ops pSeries_ops = {
 138         pSeries_xirr_info_get,
 139         pSeries_xirr_info_set,
 140         pSeries_cppr_info,
 141         pSeries_qirr_info
 142 };
 143
 144 static xics_ops *ops = &pSeries_ops;
 145
 146
 147 /* LPAR */
 148
 149 static inline long plpar_eoi(unsigned long xirr)
 150 {
 151         return plpar_hcall_norets(H_EOI, xirr);
 152 }
 153
 154 static inline long plpar_cppr(unsigned long cppr)
 155 {
 156         return plpar_hcall_norets(H_CPPR, cppr);
 157 }
 158
 159 static inline long plpar_ipi(unsigned long servernum, unsigned long mfrr)
 160 {
 161         return plpar_hcall_norets(H_IPI, servernum, mfrr);
 162 }
 163
 164 static inline long plpar_xirr(unsigned long *xirr_ret)
 165 {
 166         unsigned long dummy;
 167         return plpar_hcall(H_XIRR, 0, 0, 0, 0, xirr_ret, &dummy, &dummy);
 168 }
 169
 170 static int pSeriesLP_xirr_info_get(int n_cpu)
 171 {
 172         unsigned long lpar_rc;
 173         unsigned long return_value;
 174
 175         lpar_rc = plpar_xirr(&return_value);
 176         if (lpar_rc != H_Success)
 177                 panic(" bad return code xirr - rc = %lx \n", lpar_rc);
 178         return (int)return_value;
 179 }
 180
 181 static void pSeriesLP_xirr_info_set(int n_cpu, int value)
 182 {
 183         unsigned long lpar_rc;
 184         unsigned long val64 = value & 0xffffffff;
 185
 186         lpar_rc = plpar_eoi(val64);
 187         if (lpar_rc != H_Success)
 188                 panic("bad return code EOI - rc = %ld, value=%lx\n", lpar_rc,
 189                       val64);
 190 }
 191
 192 void pSeriesLP_cppr_info(int n_cpu, u8 value)
 193 {
 194         unsigned long lpar_rc;
 195
 196         lpar_rc = plpar_cppr(value);
 197         if (lpar_rc != H_Success)
 198                 panic("bad return code cppr - rc = %lx\n", lpar_rc);
 199 }
 200
 201 static void pSeriesLP_qirr_info(int n_cpu , u8 value)
 202 {
 203         unsigned long lpar_rc;
 204
 205         lpar_rc = plpar_ipi(get_hard_smp_processor_id(n_cpu), value);
 206         if (lpar_rc != H_Success)
 207                 panic("bad return code qirr - rc = %lx\n", lpar_rc);
 208 }
 209
 210 xics_ops pSeriesLP_ops = {
 211         pSeriesLP_xirr_info_get,
 212         pSeriesLP_xirr_info_set,
 213         pSeriesLP_cppr_info,
 214         pSeriesLP_qirr_info
 215 };
 216
 217 static unsigned int xics_startup(unsigned int virq)
 218 {
 219         unsigned int irq;
 220
 221         irq = irq_offset_down(virq);
 222         if (radix_tree_insert(&irq_map, virt_irq_to_real(irq),
 223                               &virt_irq_to_real_map[irq]) == -ENOMEM)
 224                 printk(KERN_CRIT "Out of memory creating real -> virtual"
 225                        " IRQ mapping for irq %u (real 0x%x)\n",
 226                        virq, virt_irq_to_real(irq));
 227         xics_enable_irq(virq);
 228         return 0;       /* return value is ignored */
 229 }
 230
 231 static unsigned int real_irq_to_virt(unsigned int real_irq)
 232 {
 233         unsigned int *ptr;
 234
 235         ptr = radix_tree_lookup(&irq_map, real_irq);
 236         if (ptr == NULL)
 237                 return NO_IRQ;
 238         return ptr - virt_irq_to_real_map;
 239 }
 240
 241 #ifdef CONFIG_SMP
 242 static int get_irq_server(unsigned int irq)
 243 {
 244         unsigned int server;
 245         /* For the moment only implement delivery to all cpus or one cpu */
 246         cpumask_t cpumask = irq_affinity[irq];
 247         cpumask_t tmp = CPU_MASK_NONE;
 248
 249         if (!distribute_irqs)
 250                 return default_server;
 251
 252         if (cpus_equal(cpumask, CPU_MASK_ALL)) {
 253                 server = default_distrib_server;
 254         } else {
 255                 cpus_and(tmp, cpu_online_map, cpumask);
 256
 257                 if (cpus_empty(tmp))
 258                         server = default_distrib_server;
 259                 else
 260                         server = get_hard_smp_processor_id(first_cpu(tmp));
 261         }
 262
 263         return server;
 264
 265 }
 266 #else
 267 static int get_irq_server(unsigned int irq)
 268 {
 269         return default_server;
 270 }
 271 #endif
 272
 273 static void xics_enable_irq(unsigned int virq)
 274 {
 275         unsigned int irq;
 276         int call_status;
 277         unsigned int server;
 278
 279         irq = virt_irq_to_real(irq_offset_down(virq));
 280         if (irq == XICS_IPI)
 281                 return;
 282
 283         server = get_irq_server(virq);
 284         call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server,
 285                                 DEFAULT_PRIORITY);
 286         if (call_status != 0) {
 287                 printk(KERN_ERR "xics_enable_irq: irq=%d: ibm_set_xive "
 288                        "returned %x\n", irq, call_status);
 289                 return;
 290         }
 291
 292         /* Now unmask the interrupt (often a no-op) */
 293         call_status = rtas_call(ibm_int_on, 1, 1, NULL, irq);
 294         if (call_status != 0) {
 295                 printk(KERN_ERR "xics_enable_irq: irq=%d: ibm_int_on "
 296                        "returned %x\n", irq, call_status);
 297                 return;
 298         }
 299 }
 300
 301 static void xics_disable_real_irq(unsigned int irq)
 302 {
 303         int call_status;
 304         unsigned int server;
 305
 306         if (irq == XICS_IPI)
 307                 return;
 308
 309         call_status = rtas_call(ibm_int_off, 1, 1, NULL, irq);
 310         if (call_status != 0) {
 311                 printk(KERN_ERR "xics_disable_real_irq: irq=%d: "
 312                        "ibm_int_off returned %x\n", irq, call_status);
 313                 return;
 314         }
 315
 316         server = get_irq_server(irq);
 317         /* Have to set XIVE to 0xff to be able to remove a slot */
 318         call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server, 0xff);
 319         if (call_status != 0) {
 320                 printk(KERN_ERR "xics_disable_irq: irq=%d: ibm_set_xive(0xff)"
 321                        " returned %x\n", irq, call_status);
 322                 return;
 323         }
 324 }
 325
 326 static void xics_disable_irq(unsigned int virq)
 327 {
 328         unsigned int irq;
 329
 330         irq = virt_irq_to_real(irq_offset_down(virq));
 331         xics_disable_real_irq(irq);
 332 }
 333
 334 static void xics_end_irq(unsigned int irq)
 335 {
 336         int cpu = smp_processor_id();
 337
 338         iosync();
 339         ops->xirr_info_set(cpu, ((0xff << 24) |
 340                                  (virt_irq_to_real(irq_offset_down(irq)))));
 341
 342 }
 343
 344 static void xics_mask_and_ack_irq(unsigned int irq)
 345 {
 346         int cpu = smp_processor_id();
 347
 348         if (irq < irq_offset_value()) {
 349                 i8259_pic.ack(irq);
 350                 iosync();
 351                 ops->xirr_info_set(cpu, ((0xff<<24) |
 352                                          xics_irq_8259_cascade_real));
 353                 iosync();
 354         }
 355 }
 356
 357 int xics_get_irq(struct pt_regs *regs)
 358 {
 359         unsigned int cpu = smp_processor_id();
 360         unsigned int vec;
 361         int irq;
 362
 363         vec = ops->xirr_info_get(cpu);
 364         /*  (vec >> 24) == old priority */
 365         vec &= 0x00ffffff;
 366
 367         /* for sanity, this had better be < NR_IRQS - 16 */
 368         if (vec == xics_irq_8259_cascade_real) {
 369                 irq = i8259_irq(cpu);
 370                 if (irq == -1) {
 371                         /* Spurious cascaded interrupt.  Still must ack xics */
 372                         xics_end_irq(irq_offset_up(xics_irq_8259_cascade));
 373
 374                         irq = -1;
 375                 }
 376         } else if (vec == XICS_IRQ_SPURIOUS) {
 377                 irq = -1;
 378         } else {
 379                 irq = real_irq_to_virt(vec);
 380                 if (irq == NO_IRQ)
 381                         irq = real_irq_to_virt_slowpath(vec);
 382                 if (irq == NO_IRQ) {
 383                         printk(KERN_ERR "Interrupt %d (real) is invalid,"
 384                                " disabling it.\n", vec);
 385                         xics_disable_real_irq(vec);
 386                 } else
 387                         irq = irq_offset_up(irq);
 388         }
 389         return irq;
 390 }
 391
 392 #ifdef CONFIG_SMP
 393
 394 irqreturn_t xics_ipi_action(int irq, void *dev_id, struct pt_regs *regs)
 395 {
 396         int cpu = smp_processor_id();
 397
 398         ops->qirr_info(cpu, 0xff);
 399
 400         WARN_ON(cpu_is_offline(cpu));
 401
 402         while (xics_ipi_message[cpu].value) {
 403                 if (test_and_clear_bit(PPC_MSG_CALL_FUNCTION,
 404                                        &xics_ipi_message[cpu].value)) {
 405                         mb();
 406                         smp_message_recv(PPC_MSG_CALL_FUNCTION, regs);
 407                 }
 408                 if (test_and_clear_bit(PPC_MSG_RESCHEDULE,
 409                                        &xics_ipi_message[cpu].value)) {
 410                         mb();
 411                         smp_message_recv(PPC_MSG_RESCHEDULE, regs);
 412                 }
 413 #if 0
 414                 if (test_and_clear_bit(PPC_MSG_MIGRATE_TASK,
 415                                        &xics_ipi_message[cpu].value)) {
 416                         mb();
 417                         smp_message_recv(PPC_MSG_MIGRATE_TASK, regs);
 418                 }
 419 #endif
 420 #ifdef CONFIG_DEBUGGER
 421                 if (test_and_clear_bit(PPC_MSG_DEBUGGER_BREAK,
 422                                        &xics_ipi_message[cpu].value)) {
 423                         mb();
 424                         smp_message_recv(PPC_MSG_DEBUGGER_BREAK, regs);
 425                 }
 426 #endif
 427         }
 428         return IRQ_HANDLED;
 429 }
 430
 431 void xics_cause_IPI(int cpu)
 432 {
 433         ops->qirr_info(cpu, IPI_PRIORITY);
 434 }
 435
 436 void xics_setup_cpu(void)
 437 {
 438         int cpu = smp_processor_id();
 439
 440         ops->cppr_info(cpu, 0xff);
 441         iosync();
 442 }
 443
 444 #endif /* CONFIG_SMP */
 445
 446 void xics_init_IRQ(void)
 447 {
 448         int i;
 449         unsigned long intr_size = 0;
 450         struct device_node *np;
 451         uint *ireg, ilen, indx = 0;
 452         unsigned long intr_base = 0;
 453         struct xics_interrupt_node {
 454                 unsigned long addr;
 455                 unsigned long size;
 456         } intnodes[NR_CPUS];
 457
 458         ppc64_boot_msg(0x20, "XICS Init");
 459
 460         ibm_get_xive = rtas_token("ibm,get-xive");
 461         ibm_set_xive = rtas_token("ibm,set-xive");
 462         ibm_int_on  = rtas_token("ibm,int-on");
 463         ibm_int_off = rtas_token("ibm,int-off");
 464
 465         np = of_find_node_by_type(NULL, "PowerPC-External-Interrupt-Presentation");
 466         if (!np)
 467                 panic("xics_init_IRQ: can't find interrupt presentation");
 468
 469 nextnode:
 470         ireg = (uint *)get_property(np, "ibm,interrupt-server-ranges", NULL);
 471         if (ireg) {
 472                 /*
 473                  * set node starting index for this node
 474                  */
 475                 indx = *ireg;
 476         }
 477
 478         ireg = (uint *)get_property(np, "reg", &ilen);
 479         if (!ireg)
 480                 panic("xics_init_IRQ: can't find interrupt reg property");
 481
 482         while (ilen) {
 483                 intnodes[indx].addr = (unsigned long)*ireg++ << 32;
 484                 ilen -= sizeof(uint);
 485                 intnodes[indx].addr |= *ireg++;
 486                 ilen -= sizeof(uint);
 487                 intnodes[indx].size = (unsigned long)*ireg++ << 32;
 488                 ilen -= sizeof(uint);
 489                 intnodes[indx].size |= *ireg++;
 490                 ilen -= sizeof(uint);
 491                 indx++;
 492                 if (indx >= NR_CPUS) break;
 493         }
 494
 495         np = of_find_node_by_type(np, "PowerPC-External-Interrupt-Presentation");
 496         if ((indx < NR_CPUS) && np) goto nextnode;
 497
 498         /* Find the server numbers for the boot cpu. */
 499         for (np = of_find_node_by_type(NULL, "cpu");
 500              np;
 501              np = of_find_node_by_type(np, "cpu")) {
 502                 ireg = (uint *)get_property(np, "reg", &ilen);
 503                 if (ireg && ireg[0] == boot_cpuid_phys) {
 504                         ireg = (uint *)get_property(np, "ibm,ppc-interrupt-gserver#s",
 505                                                     &ilen);
 506                         i = ilen / sizeof(int);
 507                         if (ireg && i > 0) {
 508                                 default_server = ireg[0];
 509                                 default_distrib_server = ireg[i-1]; /* take last element */
 510                         }
 511                         ireg = (uint *)get_property(np,
 512                                         "ibm,interrupt-server#-size", NULL);
 513                         if (ireg)
 514                                 interrupt_server_size = *ireg;
 515                         break;
 516                 }
 517         }
 518         of_node_put(np);
 519
 520         intr_base = intnodes[0].addr;
 521         intr_size = intnodes[0].size;
 522
 523         np = of_find_node_by_type(NULL, "interrupt-controller");
 524         if (!np) {
 525                 printk(KERN_WARNING "xics: no ISA interrupt controller\n");
 526                 xics_irq_8259_cascade_real = -1;
 527                 xics_irq_8259_cascade = -1;
 528         } else {
 529                 ireg = (uint *) get_property(np, "interrupts", NULL);
 530                 if (!ireg)
 531                         panic("xics_init_IRQ: can't find ISA interrupts property");
 532
 533                 xics_irq_8259_cascade_real = *ireg;
 534                 xics_irq_8259_cascade
 535                         = virt_irq_create_mapping(xics_irq_8259_cascade_real);
 536                 of_node_put(np);
 537         }
 538
 539         if (systemcfg->platform == PLATFORM_PSERIES) {
 540 #ifdef CONFIG_SMP
 541                 for_each_cpu(i) {
 542                         int hard_id;
 543
 544                         /* FIXME: Do this dynamically! --RR */
 545                         if (!cpu_present(i))
 546                                 continue;
 547
 548                         hard_id = get_hard_smp_processor_id(i);
 549                         xics_per_cpu[i] = ioremap(intnodes[hard_id].addr,
 550                                                   intnodes[hard_id].size);
 551                 }
 552 #else
 553                 xics_per_cpu[0] = ioremap(intr_base, intr_size);
 554 #endif /* CONFIG_SMP */
 555         } else if (systemcfg->platform == PLATFORM_PSERIES_LPAR) {
 556                 ops = &pSeriesLP_ops;
 557         }
 558
 559         xics_8259_pic.enable = i8259_pic.enable;
 560         xics_8259_pic.disable = i8259_pic.disable;
 561         for (i = 0; i < 16; ++i)
 562                 get_irq_desc(i)->handler = &xics_8259_pic;
 563         for (; i < NR_IRQS; ++i)
 564                 get_irq_desc(i)->handler = &xics_pic;
 565
 566         ops->cppr_info(boot_cpuid, 0xff);
 567         iosync();
 568
 569         ppc64_boot_msg(0x21, "XICS Done");
 570 }
 571
 572 /*
 573  * We cant do this in init_IRQ because we need the memory subsystem up for
 574  * request_irq()
 575  */
 576 static int __init xics_setup_i8259(void)
 577 {
 578         if (ppc64_interrupt_controller == IC_PPC_XIC &&
 579             xics_irq_8259_cascade != -1) {
 580                 if (request_irq(irq_offset_up(xics_irq_8259_cascade),
 581                                 no_action, 0, "8259 cascade", NULL))
 582                         printk(KERN_ERR "xics_setup_i8259: couldn't get 8259 "
 583                                         "cascade\n");
 584                 i8259_init(0);
 585         }
 586         return 0;
 587 }
 588 arch_initcall(xics_setup_i8259);
 589
 590 #ifdef CONFIG_SMP
 591 void xics_request_IPIs(void)
 592 {
 593         virt_irq_to_real_map[XICS_IPI] = XICS_IPI;
 594
 595         /* IPIs are marked SA_INTERRUPT as they must run with irqs disabled */
 596         request_irq(irq_offset_up(XICS_IPI), xics_ipi_action, SA_INTERRUPT,
 597                     "IPI", NULL);
 598         get_irq_desc(irq_offset_up(XICS_IPI))->status |= IRQ_PER_CPU;
 599 }
 600 #endif
 601
 602 static void xics_set_affinity(unsigned int virq, cpumask_t cpumask)
 603 {
 604         unsigned int irq;
 605         int status;
 606         int xics_status[2];
 607         unsigned long newmask;
 608         cpumask_t tmp = CPU_MASK_NONE;
 609
 610         irq = virt_irq_to_real(irq_offset_down(virq));
 611         if (irq == XICS_IPI || irq == NO_IRQ)
 612                 return;
 613
 614         status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
 615
 616         if (status) {
 617                 printk(KERN_ERR "xics_set_affinity: irq=%d ibm,get-xive "
 618                        "returns %d\n", irq, status);
 619                 return;
 620         }
 621
 622         /* For the moment only implement delivery to all cpus or one cpu */
 623         if (cpus_equal(cpumask, CPU_MASK_ALL)) {
 624                 newmask = default_distrib_server;
 625         } else {
 626                 cpus_and(tmp, cpu_online_map, cpumask);
 627                 if (cpus_empty(tmp))
 628                         return;
 629                 newmask = get_hard_smp_processor_id(first_cpu(tmp));
 630         }
 631
 632         status = rtas_call(ibm_set_xive, 3, 1, NULL,
 633                                 irq, newmask, xics_status[1]);
 634
 635         if (status) {
 636                 printk(KERN_ERR "xics_set_affinity: irq=%d ibm,set-xive "
 637                        "returns %d\n", irq, status);
 638                 return;
 639         }
 640 }
 641
 642 #ifdef CONFIG_HOTPLUG_CPU
 643
 644 /* Interrupts are disabled. */
 645 void xics_migrate_irqs_away(void)
 646 {
 647         int status;
 648         unsigned int irq, virq, cpu = smp_processor_id();
 649
 650         /* Reject any interrupt that was queued to us... */
 651         ops->cppr_info(cpu, 0);
 652         iosync();
 653
 654         /* remove ourselves from the global interrupt queue */
 655         status = rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
 656                 (1UL << interrupt_server_size) - 1 - default_distrib_server, 0);
 657         WARN_ON(status < 0);
 658
 659         /* Allow IPIs again... */
 660         ops->cppr_info(cpu, DEFAULT_PRIORITY);
 661         iosync();
 662
 663         for_each_irq(virq) {
 664                 irq_desc_t *desc;
 665                 int xics_status[2];
 666                 unsigned long flags;
 667
 668                 /* We cant set affinity on ISA interrupts */
 669                 if (virq < irq_offset_value())
 670                         continue;
 671
 672                 desc = get_irq_desc(virq);
 673                 irq = virt_irq_to_real(irq_offset_down(virq));
 674
 675                 /* We need to get IPIs still. */
 676                 if (irq == XICS_IPI || irq == NO_IRQ)
 677                         continue;
 678
 679                 /* We only need to migrate enabled IRQS */
 680                 if (desc == NULL || desc->handler == NULL
 681                     || desc->action == NULL
 682                     || desc->handler->set_affinity == NULL)
 683                         continue;
 684
 685                 spin_lock_irqsave(&desc->lock, flags);
 686
 687                 status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
 688                 if (status) {
 689                         printk(KERN_ERR "migrate_irqs_away: irq=%d "
 690                                         "ibm,get-xive returns %d\n",
 691                                         virq, status);
 692                         goto unlock;
 693                 }
 694
 695                 /*
 696                  * We only support delivery to all cpus or to one cpu.
 697                  * The irq has to be migrated only in the single cpu
 698                  * case.
 699                  */
 700                 if (xics_status[0] != get_hard_smp_processor_id(cpu))
 701                         goto unlock;
 702
 703                 printk(KERN_WARNING "IRQ %d affinity broken off cpu %u\n",
 704                        virq, cpu);
 705
 706                 /* Reset affinity to all cpus */
 707                 desc->handler->set_affinity(virq, CPU_MASK_ALL);
 708                 irq_affinity[virq] = CPU_MASK_ALL;
 709 unlock:
 710                 spin_unlock_irqrestore(&desc->lock, flags);
 711         }
 712 }
 713 #endif