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/naca.h>
  28 #include <asm/rtas.h>
  29 #include <asm/xics.h>
  30 #include <asm/hvcall.h>
  31 #include <asm/machdep.h>
  32
  33 #include "i8259.h"
  34
  35 static unsigned int xics_startup(unsigned int irq);
  36 static void xics_enable_irq(unsigned int irq);
  37 static void xics_disable_irq(unsigned int irq);
  38 static void xics_mask_and_ack_irq(unsigned int irq);
  39 static void xics_end_irq(unsigned int irq);
  40 static void xics_set_affinity(unsigned int irq_nr, cpumask_t cpumask);
  41
  42 struct hw_interrupt_type xics_pic = {
  43         .typename = " XICS     ",
  44         .startup = xics_startup,
  45         .enable = xics_enable_irq,
  46         .disable = xics_disable_irq,
  47         .ack = xics_mask_and_ack_irq,
  48         .end = xics_end_irq,
  49         .set_affinity = xics_set_affinity
  50 };
  51
  52 struct hw_interrupt_type xics_8259_pic = {
  53         .typename = " XICS/8259",
  54         .ack = xics_mask_and_ack_irq,
  55 };
  56
  57 /* This is used to map real irq numbers to virtual */
  58 static struct radix_tree_root irq_map = RADIX_TREE_INIT(GFP_ATOMIC);
  59
  60 #define XICS_IPI                2
  61 #define XICS_IRQ_SPURIOUS       0
  62
  63 /* Want a priority other than 0.  Various HW issues require this. */
  64 #define DEFAULT_PRIORITY        5
  65
  66 /*
  67  * Mark IPIs as higher priority so we can take them inside interrupts that
  68  * arent marked SA_INTERRUPT
  69  */
  70 #define IPI_PRIORITY            4
  71
  72 struct xics_ipl {
  73         union {
  74                 u32 word;
  75                 u8 bytes[4];
  76         } xirr_poll;
  77         union {
  78                 u32 word;
  79                 u8 bytes[4];
  80         } xirr;
  81         u32 dummy;
  82         union {
  83                 u32 word;
  84                 u8 bytes[4];
  85         } qirr;
  86 };
  87
  88 static struct xics_ipl *xics_per_cpu[NR_CPUS];
  89
  90 static int xics_irq_8259_cascade = 0;
  91 static int xics_irq_8259_cascade_real = 0;
  92 static unsigned int default_server = 0xFF;
  93 /* also referenced in smp.c... */
  94 unsigned int default_distrib_server = 0;
  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 xics_per_cpu[n_cpu]->xirr.word;
 120 }
 121
 122 static void pSeries_xirr_info_set(int n_cpu, int value)
 123 {
 124         xics_per_cpu[n_cpu]->xirr.word = value;
 125 }
 126
 127 static void pSeries_cppr_info(int n_cpu, u8 value)
 128 {
 129         xics_per_cpu[n_cpu]->xirr.bytes[0] = value;
 130 }
 131
 132 static void pSeries_qirr_info(int n_cpu, u8 value)
 133 {
 134         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         virq = irq_offset_down(virq);
 220         if (radix_tree_insert(&irq_map, virt_irq_to_real(virq),
 221                               &virt_irq_to_real_map[virq]) == -ENOMEM)
 222                 printk(KERN_CRIT "Out of memory creating real -> virtual"
 223                        " IRQ mapping for irq %u (real 0x%x)\n",
 224                        virq, virt_irq_to_real(virq));
 225         return 0;       /* return value is ignored */
 226 }
 227
 228 static unsigned int real_irq_to_virt(unsigned int real_irq)
 229 {
 230         unsigned int *ptr;
 231
 232         ptr = radix_tree_lookup(&irq_map, real_irq);
 233         if (ptr == NULL)
 234                 return NO_IRQ;
 235         return ptr - virt_irq_to_real_map;
 236 }
 237
 238 #ifdef CONFIG_SMP
 239 static int get_irq_server(unsigned int irq)
 240 {
 241         unsigned int server;
 242
 243 #ifdef CONFIG_IRQ_ALL_CPUS
 244         /* For the moment only implement delivery to all cpus or one cpu */
 245         if (smp_threads_ready) {
 246                 cpumask_t cpumask = irq_affinity[irq];
 247                 cpumask_t tmp = CPU_MASK_NONE;
 248                 if (cpus_equal(cpumask, CPU_MASK_ALL)) {
 249                         server = default_distrib_server;
 250                 } else {
 251                         cpus_and(tmp, cpu_online_map, cpumask);
 252
 253                         if (cpus_empty(tmp))
 254                                 server = default_distrib_server;
 255                         else
 256                                 server = get_hard_smp_processor_id(first_cpu(tmp));
 257                 }
 258         } else {
 259                 server = default_server;
 260         }
 261 #else
 262         server = default_server;
 263 #endif
 264         return server;
 265
 266 }
 267 #else
 268 static int get_irq_server(unsigned int irq)
 269 {
 270         return default_server;
 271 }
 272 #endif
 273
 274 static void xics_enable_irq(unsigned int virq)
 275 {
 276         unsigned int irq;
 277         int call_status;
 278         unsigned int server;
 279
 280         irq = virt_irq_to_real(irq_offset_down(virq));
 281         if (irq == XICS_IPI)
 282                 return;
 283
 284         server = get_irq_server(virq);
 285         call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server,
 286                                 DEFAULT_PRIORITY);
 287         if (call_status != 0) {
 288                 printk(KERN_ERR "xics_enable_irq: irq=%d: ibm_set_xive "
 289                        "returned %x\n", irq, call_status);
 290                 return;
 291         }
 292
 293         /* Now unmask the interrupt (often a no-op) */
 294         call_status = rtas_call(ibm_int_on, 1, 1, NULL, irq);
 295         if (call_status != 0) {
 296                 printk(KERN_ERR "xics_enable_irq: irq=%d: ibm_int_on "
 297                        "returned %x\n", irq, call_status);
 298                 return;
 299         }
 300 }
 301
 302 static void xics_disable_real_irq(unsigned int irq)
 303 {
 304         int call_status;
 305         unsigned int server;
 306
 307         if (irq == XICS_IPI)
 308                 return;
 309
 310         call_status = rtas_call(ibm_int_off, 1, 1, NULL, irq);
 311         if (call_status != 0) {
 312                 printk(KERN_ERR "xics_disable_real_irq: irq=%d: "
 313                        "ibm_int_off returned %x\n", irq, call_status);
 314                 return;
 315         }
 316
 317         server = get_irq_server(irq);
 318         /* Have to set XIVE to 0xff to be able to remove a slot */
 319         call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server, 0xff);
 320         if (call_status != 0) {
 321                 printk(KERN_ERR "xics_disable_irq: irq=%d: ibm_set_xive(0xff)"
 322                        " returned %x\n", irq, call_status);
 323                 return;
 324         }
 325 }
 326
 327 static void xics_disable_irq(unsigned int virq)
 328 {
 329         unsigned int irq;
 330
 331         irq = virt_irq_to_real(irq_offset_down(virq));
 332         xics_disable_real_irq(irq);
 333 }
 334
 335 static void xics_end_irq(unsigned int irq)
 336 {
 337         int cpu = smp_processor_id();
 338
 339         iosync();
 340         ops->xirr_info_set(cpu, ((0xff << 24) |
 341                                  (virt_irq_to_real(irq_offset_down(irq)))));
 342
 343 }
 344
 345 static void xics_mask_and_ack_irq(unsigned int irq)
 346 {
 347         int cpu = smp_processor_id();
 348
 349         if (irq < irq_offset_value()) {
 350                 i8259_pic.ack(irq);
 351                 iosync();
 352                 ops->xirr_info_set(cpu, ((0xff<<24) |
 353                                          xics_irq_8259_cascade_real));
 354                 iosync();
 355         }
 356 }
 357
 358 int xics_get_irq(struct pt_regs *regs)
 359 {
 360         unsigned int cpu = smp_processor_id();
 361         unsigned int vec;
 362         int irq;
 363
 364         vec = ops->xirr_info_get(cpu);
 365         /*  (vec >> 24) == old priority */
 366         vec &= 0x00ffffff;
 367
 368         /* for sanity, this had better be < NR_IRQS - 16 */
 369         if (vec == xics_irq_8259_cascade_real) {
 370                 irq = i8259_irq(cpu);
 371                 if (irq == -1) {
 372                         /* Spurious cascaded interrupt.  Still must ack xics */
 373                         xics_end_irq(irq_offset_up(xics_irq_8259_cascade));
 374
 375                         irq = -1;
 376                 }
 377         } else if (vec == XICS_IRQ_SPURIOUS) {
 378                 irq = -1;
 379         } else {
 380                 irq = real_irq_to_virt(vec);
 381                 if (irq == NO_IRQ)
 382                         irq = real_irq_to_virt_slowpath(vec);
 383                 if (irq == NO_IRQ) {
 384                         printk(KERN_ERR "Interrupt %d (real) is invalid,"
 385                                " disabling it.\n", vec);
 386                         xics_disable_real_irq(vec);
 387                 } else
 388                         irq = irq_offset_up(irq);
 389         }
 390         return irq;
 391 }
 392
 393 #ifdef CONFIG_SMP
 394
 395 irqreturn_t xics_ipi_action(int irq, void *dev_id, struct pt_regs *regs)
 396 {
 397         int cpu = smp_processor_id();
 398
 399         ops->qirr_info(cpu, 0xff);
 400
 401         WARN_ON(cpu_is_offline(cpu));
 402
 403         while (xics_ipi_message[cpu].value) {
 404                 if (test_and_clear_bit(PPC_MSG_CALL_FUNCTION,
 405                                        &xics_ipi_message[cpu].value)) {
 406                         mb();
 407                         smp_message_recv(PPC_MSG_CALL_FUNCTION, regs);
 408                 }
 409                 if (test_and_clear_bit(PPC_MSG_RESCHEDULE,
 410                                        &xics_ipi_message[cpu].value)) {
 411                         mb();
 412                         smp_message_recv(PPC_MSG_RESCHEDULE, regs);
 413                 }
 414 #if 0
 415                 if (test_and_clear_bit(PPC_MSG_MIGRATE_TASK,
 416                                        &xics_ipi_message[cpu].value)) {
 417                         mb();
 418                         smp_message_recv(PPC_MSG_MIGRATE_TASK, regs);
 419                 }
 420 #endif
 421 #ifdef CONFIG_DEBUGGER
 422                 if (test_and_clear_bit(PPC_MSG_DEBUGGER_BREAK,
 423                                        &xics_ipi_message[cpu].value)) {
 424                         mb();
 425                         smp_message_recv(PPC_MSG_DEBUGGER_BREAK, regs);
 426                 }
 427 #endif
 428         }
 429         return IRQ_HANDLED;
 430 }
 431
 432 void xics_cause_IPI(int cpu)
 433 {
 434         ops->qirr_info(cpu, IPI_PRIORITY);
 435 }
 436
 437 void xics_setup_cpu(void)
 438 {
 439         int cpu = smp_processor_id();
 440
 441         ops->cppr_info(cpu, 0xff);
 442         iosync();
 443 }
 444
 445 #endif /* CONFIG_SMP */
 446
 447 void xics_init_IRQ(void)
 448 {
 449         int i;
 450         unsigned long intr_size = 0;
 451         struct device_node *np;
 452         uint *ireg, ilen, indx = 0;
 453         unsigned long intr_base = 0;
 454         struct xics_interrupt_node {
 455                 unsigned long addr;
 456                 unsigned long size;
 457         } inodes[NR_CPUS];
 458
 459         ppc64_boot_msg(0x20, "XICS Init");
 460
 461         ibm_get_xive = rtas_token("ibm,get-xive");
 462         ibm_set_xive = rtas_token("ibm,set-xive");
 463         ibm_int_on  = rtas_token("ibm,int-on");
 464         ibm_int_off = rtas_token("ibm,int-off");
 465
 466         np = of_find_node_by_type(NULL, "PowerPC-External-Interrupt-Presentation");
 467         if (!np)
 468                 panic("xics_init_IRQ: can't find interrupt presentation");
 469
 470 nextnode:
 471         ireg = (uint *)get_property(np, "ibm,interrupt-server-ranges", NULL);
 472         if (ireg) {
 473                 /*
 474                  * set node starting index for this node
 475                  */
 476                 indx = *ireg;
 477         }
 478
 479         ireg = (uint *)get_property(np, "reg", &ilen);
 480         if (!ireg)
 481                 panic("xics_init_IRQ: can't find interrupt reg property");
 482
 483         while (ilen) {
 484                 inodes[indx].addr = (unsigned long long)*ireg++ << 32;
 485                 ilen -= sizeof(uint);
 486                 inodes[indx].addr |= *ireg++;
 487                 ilen -= sizeof(uint);
 488                 inodes[indx].size = (unsigned long long)*ireg++ << 32;
 489                 ilen -= sizeof(uint);
 490                 inodes[indx].size |= *ireg++;
 491                 ilen -= sizeof(uint);
 492                 indx++;
 493                 if (indx >= NR_CPUS) break;
 494         }
 495
 496         np = of_find_node_by_type(np, "PowerPC-External-Interrupt-Presentation");
 497         if ((indx < NR_CPUS) && np) goto nextnode;
 498
 499         /* Find the server numbers for the boot cpu. */
 500         for (np = of_find_node_by_type(NULL, "cpu");
 501              np;
 502              np = of_find_node_by_type(np, "cpu")) {
 503                 ireg = (uint *)get_property(np, "reg", &ilen);
 504                 if (ireg && ireg[0] == hard_smp_processor_id()) {
 505                         ireg = (uint *)get_property(np, "ibm,ppc-interrupt-gserver#s", &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                         break;
 512                 }
 513         }
 514         of_node_put(np);
 515
 516         intr_base = inodes[0].addr;
 517         intr_size = (ulong)inodes[0].size;
 518
 519         np = of_find_node_by_type(NULL, "interrupt-controller");
 520         if (!np) {
 521                 printk(KERN_WARNING "xics: no ISA interrupt controller\n");
 522                 xics_irq_8259_cascade_real = -1;
 523                 xics_irq_8259_cascade = -1;
 524         } else {
 525                 ireg = (uint *) get_property(np, "interrupts", NULL);
 526                 if (!ireg)
 527                         panic("xics_init_IRQ: can't find ISA interrupts property");
 528
 529                 xics_irq_8259_cascade_real = *ireg;
 530                 xics_irq_8259_cascade
 531                         = virt_irq_create_mapping(xics_irq_8259_cascade_real);
 532                 of_node_put(np);
 533         }
 534
 535         if (systemcfg->platform == PLATFORM_PSERIES) {
 536 #ifdef CONFIG_SMP
 537                 for_each_cpu(i) {
 538                         /* FIXME: Do this dynamically! --RR */
 539                         if (!cpu_present(i))
 540                                 continue;
 541                         xics_per_cpu[i] = __ioremap((ulong)inodes[get_hard_smp_processor_id(i)].addr,
 542                                                     (ulong)inodes[get_hard_smp_processor_id(i)].size,
 543                                                     _PAGE_NO_CACHE);
 544                 }
 545 #else
 546                 xics_per_cpu[0] = __ioremap((ulong)intr_base, intr_size,
 547                                             _PAGE_NO_CACHE);
 548 #endif /* CONFIG_SMP */
 549         } else if (systemcfg->platform == PLATFORM_PSERIES_LPAR) {
 550                 ops = &pSeriesLP_ops;
 551         }
 552
 553         xics_8259_pic.enable = i8259_pic.enable;
 554         xics_8259_pic.disable = i8259_pic.disable;
 555         for (i = 0; i < 16; ++i)
 556                 get_irq_desc(i)->handler = &xics_8259_pic;
 557         for (; i < NR_IRQS; ++i)
 558                 get_irq_desc(i)->handler = &xics_pic;
 559
 560         ops->cppr_info(boot_cpuid, 0xff);
 561         iosync();
 562
 563         ppc64_boot_msg(0x21, "XICS Done");
 564 }
 565
 566 /*
 567  * We cant do this in init_IRQ because we need the memory subsystem up for
 568  * request_irq()
 569  */
 570 static int __init xics_setup_i8259(void)
 571 {
 572         if (naca->interrupt_controller == IC_PPC_XIC &&
 573             xics_irq_8259_cascade != -1) {
 574                 if (request_irq(irq_offset_up(xics_irq_8259_cascade),
 575                                 no_action, 0, "8259 cascade", NULL))
 576                         printk(KERN_ERR "xics_setup_i8259: couldn't get 8259 "
 577                                         "cascade\n");
 578                 i8259_init();
 579         }
 580         return 0;
 581 }
 582 arch_initcall(xics_setup_i8259);
 583
 584 #ifdef CONFIG_SMP
 585 void xics_request_IPIs(void)
 586 {
 587         virt_irq_to_real_map[XICS_IPI] = XICS_IPI;
 588
 589         /* IPIs are marked SA_INTERRUPT as they must run with irqs disabled */
 590         request_irq(irq_offset_up(XICS_IPI), xics_ipi_action, SA_INTERRUPT,
 591                     "IPI", NULL);
 592         get_irq_desc(irq_offset_up(XICS_IPI))->status |= IRQ_PER_CPU;
 593 }
 594 #endif
 595
 596 static void xics_set_affinity(unsigned int virq, cpumask_t cpumask)
 597 {
 598         unsigned int irq;
 599         int status;
 600         int xics_status[2];
 601         unsigned long newmask;
 602         cpumask_t tmp = CPU_MASK_NONE;
 603
 604         irq = virt_irq_to_real(irq_offset_down(virq));
 605         if (irq == XICS_IPI || irq == NO_IRQ)
 606                 return;
 607
 608         status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
 609
 610         if (status) {
 611                 printk(KERN_ERR "xics_set_affinity: irq=%d ibm,get-xive "
 612                        "returns %d\n", irq, status);
 613                 return;
 614         }
 615
 616         /* For the moment only implement delivery to all cpus or one cpu */
 617         if (cpus_equal(cpumask, CPU_MASK_ALL)) {
 618                 newmask = default_distrib_server;
 619         } else {
 620                 cpus_and(tmp, cpu_online_map, cpumask);
 621                 if (cpus_empty(tmp))
 622                         return;
 623                 newmask = get_hard_smp_processor_id(first_cpu(tmp));
 624         }
 625
 626         status = rtas_call(ibm_set_xive, 3, 1, NULL,
 627                                 irq, newmask, xics_status[1]);
 628
 629         if (status) {
 630                 printk(KERN_ERR "xics_set_affinity: irq=%d ibm,set-xive "
 631                        "returns %d\n", irq, status);
 632                 return;
 633         }
 634 }
 635
 636 #ifdef CONFIG_HOTPLUG_CPU
 637
 638 /* Interrupts are disabled. */
 639 void xics_migrate_irqs_away(void)
 640 {
 641         int set_indicator = rtas_token("set-indicator");
 642         const unsigned int giqs = 9005UL; /* Global Interrupt Queue Server */
 643         int status = 0;
 644         unsigned int irq, virq, cpu = smp_processor_id();
 645
 646         BUG_ON(set_indicator == RTAS_UNKNOWN_SERVICE);
 647
 648         /* Reject any interrupt that was queued to us... */
 649         ops->cppr_info(cpu, 0);
 650         iosync();
 651
 652         /* Refuse any new interrupts... */
 653         rtas_call(set_indicator, 3, 1, &status, giqs,
 654                   hard_smp_processor_id(), 0);
 655         WARN_ON(status != 0);
 656
 657         /* Allow IPIs again... */
 658         ops->cppr_info(cpu, DEFAULT_PRIORITY);
 659         iosync();
 660
 661         for_each_irq(virq) {
 662                 irq_desc_t *desc;
 663                 int xics_status[2];
 664                 unsigned long flags;
 665
 666                 /* We cant set affinity on ISA interrupts */
 667                 if (virq < irq_offset_value())
 668                         continue;
 669
 670                 desc = get_irq_desc(virq);
 671                 irq = virt_irq_to_real(irq_offset_down(virq));
 672
 673                 /* We need to get IPIs still. */
 674                 if (irq == XICS_IPI || irq == NO_IRQ)
 675                         continue;
 676
 677                 /* We only need to migrate enabled IRQS */
 678                 if (desc == NULL || desc->handler == NULL
 679                     || desc->action == NULL
 680                     || desc->handler->set_affinity == NULL)
 681                         continue;
 682
 683                 spin_lock_irqsave(&desc->lock, flags);
 684
 685                 status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
 686                 if (status) {
 687                         printk(KERN_ERR "migrate_irqs_away: irq=%d "
 688                                         "ibm,get-xive returns %d\n",
 689                                         virq, status);
 690                         goto unlock;
 691                 }
 692
 693                 /*
 694                  * We only support delivery to all cpus or to one cpu.
 695                  * The irq has to be migrated only in the single cpu
 696                  * case.
 697                  */
 698                 if (xics_status[0] != get_hard_smp_processor_id(cpu))
 699                         goto unlock;
 700
 701                 printk(KERN_WARNING "IRQ %d affinity broken off cpu %u\n",
 702                        virq, cpu);
 703
 704                 /* Reset affinity to all cpus */
 705                 xics_status[0] = default_distrib_server;
 706
 707                 status = rtas_call(ibm_set_xive, 3, 1, NULL, irq,
 708                                 xics_status[0], xics_status[1]);
 709                 if (status)
 710                         printk(KERN_ERR "migrate_irqs_away: irq=%d "
 711                                         "ibm,set-xive returns %d\n",
 712                                         virq, status);
 713
 714 unlock:
 715                 spin_unlock_irqrestore(&desc->lock, flags);
 716         }
 717 }
 718 #endif