err.no Git - linux-2.6/blob - arch/powerpc/platforms/pseries/xics.c

   1 /*
   2  * arch/powerpc/platforms/pseries/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/types.h>
  12 #include <linux/threads.h>
  13 #include <linux/kernel.h>
  14 #include <linux/irq.h>
  15 #include <linux/smp.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/signal.h>
  18 #include <linux/init.h>
  19 #include <linux/gfp.h>
  20 #include <linux/radix-tree.h>
  21 #include <linux/cpu.h>
  22 #include <asm/firmware.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/hvcall.h>
  29 #include <asm/machdep.h>
  30 #include <asm/i8259.h>
  31
  32 #include "xics.h"
  33
  34 /* This is used to map real irq numbers to virtual */
  35 static struct radix_tree_root irq_map = RADIX_TREE_INIT(GFP_ATOMIC);
  36
  37 #define XICS_IPI                2
  38 #define XICS_IRQ_SPURIOUS       0
  39
  40 /* Want a priority other than 0.  Various HW issues require this. */
  41 #define DEFAULT_PRIORITY        5
  42
  43 /*
  44  * Mark IPIs as higher priority so we can take them inside interrupts that
  45  * arent marked IRQF_DISABLED
  46  */
  47 #define IPI_PRIORITY            4
  48
  49 struct xics_ipl {
  50         union {
  51                 u32 word;
  52                 u8 bytes[4];
  53         } xirr_poll;
  54         union {
  55                 u32 word;
  56                 u8 bytes[4];
  57         } xirr;
  58         u32 dummy;
  59         union {
  60                 u32 word;
  61                 u8 bytes[4];
  62         } qirr;
  63 };
  64
  65 static struct xics_ipl __iomem *xics_per_cpu[NR_CPUS];
  66
  67 static int xics_irq_8259_cascade = 0;
  68 static int xics_irq_8259_cascade_real = 0;
  69 static unsigned int default_server = 0xFF;
  70 static unsigned int default_distrib_server = 0;
  71 static unsigned int interrupt_server_size = 8;
  72
  73 /*
  74  * XICS only has a single IPI, so encode the messages per CPU
  75  */
  76 struct xics_ipi_struct xics_ipi_message[NR_CPUS] __cacheline_aligned;
  77
  78 /* RTAS service tokens */
  79 static int ibm_get_xive;
  80 static int ibm_set_xive;
  81 static int ibm_int_on;
  82 static int ibm_int_off;
  83
  84
  85 /* Direct HW low level accessors */
  86
  87
  88 static inline int direct_xirr_info_get(int n_cpu)
  89 {
  90         return in_be32(&xics_per_cpu[n_cpu]->xirr.word);
  91 }
  92
  93 static inline void direct_xirr_info_set(int n_cpu, int value)
  94 {
  95         out_be32(&xics_per_cpu[n_cpu]->xirr.word, value);
  96 }
  97
  98 static inline void direct_cppr_info(int n_cpu, u8 value)
  99 {
 100         out_8(&xics_per_cpu[n_cpu]->xirr.bytes[0], value);
 101 }
 102
 103 static inline void direct_qirr_info(int n_cpu, u8 value)
 104 {
 105         out_8(&xics_per_cpu[n_cpu]->qirr.bytes[0], value);
 106 }
 107
 108
 109 /* LPAR low level accessors */
 110
 111
 112 static inline long plpar_eoi(unsigned long xirr)
 113 {
 114         return plpar_hcall_norets(H_EOI, xirr);
 115 }
 116
 117 static inline long plpar_cppr(unsigned long cppr)
 118 {
 119         return plpar_hcall_norets(H_CPPR, cppr);
 120 }
 121
 122 static inline long plpar_ipi(unsigned long servernum, unsigned long mfrr)
 123 {
 124         return plpar_hcall_norets(H_IPI, servernum, mfrr);
 125 }
 126
 127 static inline long plpar_xirr(unsigned long *xirr_ret)
 128 {
 129         unsigned long dummy;
 130         return plpar_hcall(H_XIRR, 0, 0, 0, 0, xirr_ret, &dummy, &dummy);
 131 }
 132
 133 static inline int lpar_xirr_info_get(int n_cpu)
 134 {
 135         unsigned long lpar_rc;
 136         unsigned long return_value;
 137
 138         lpar_rc = plpar_xirr(&return_value);
 139         if (lpar_rc != H_SUCCESS)
 140                 panic(" bad return code xirr - rc = %lx \n", lpar_rc);
 141         return (int)return_value;
 142 }
 143
 144 static inline void lpar_xirr_info_set(int n_cpu, int value)
 145 {
 146         unsigned long lpar_rc;
 147         unsigned long val64 = value & 0xffffffff;
 148
 149         lpar_rc = plpar_eoi(val64);
 150         if (lpar_rc != H_SUCCESS)
 151                 panic("bad return code EOI - rc = %ld, value=%lx\n", lpar_rc,
 152                       val64);
 153 }
 154
 155 static inline void lpar_cppr_info(int n_cpu, u8 value)
 156 {
 157         unsigned long lpar_rc;
 158
 159         lpar_rc = plpar_cppr(value);
 160         if (lpar_rc != H_SUCCESS)
 161                 panic("bad return code cppr - rc = %lx\n", lpar_rc);
 162 }
 163
 164 static inline void lpar_qirr_info(int n_cpu , u8 value)
 165 {
 166         unsigned long lpar_rc;
 167
 168         lpar_rc = plpar_ipi(get_hard_smp_processor_id(n_cpu), value);
 169         if (lpar_rc != H_SUCCESS)
 170                 panic("bad return code qirr - rc = %lx\n", lpar_rc);
 171 }
 172
 173
 174 /* High level handlers and init code */
 175
 176
 177 #ifdef CONFIG_SMP
 178 static int get_irq_server(unsigned int irq)
 179 {
 180         unsigned int server;
 181         /* For the moment only implement delivery to all cpus or one cpu */
 182         cpumask_t cpumask = irq_desc[irq].affinity;
 183         cpumask_t tmp = CPU_MASK_NONE;
 184
 185         if (!distribute_irqs)
 186                 return default_server;
 187
 188         if (cpus_equal(cpumask, CPU_MASK_ALL)) {
 189                 server = default_distrib_server;
 190         } else {
 191                 cpus_and(tmp, cpu_online_map, cpumask);
 192
 193                 if (cpus_empty(tmp))
 194                         server = default_distrib_server;
 195                 else
 196                         server = get_hard_smp_processor_id(first_cpu(tmp));
 197         }
 198
 199         return server;
 200
 201 }
 202 #else
 203 static int get_irq_server(unsigned int irq)
 204 {
 205         return default_server;
 206 }
 207 #endif
 208
 209
 210 static void xics_unmask_irq(unsigned int virq)
 211 {
 212         unsigned int irq;
 213         int call_status;
 214         unsigned int server;
 215
 216         irq = virt_irq_to_real(irq_offset_down(virq));
 217         WARN_ON(irq == NO_IRQ);
 218         if (irq == XICS_IPI || irq == NO_IRQ)
 219                 return;
 220
 221         server = get_irq_server(virq);
 222
 223         call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server,
 224                                 DEFAULT_PRIORITY);
 225         if (call_status != 0) {
 226                 printk(KERN_ERR "xics_enable_irq: irq=%u: ibm_set_xive "
 227                        "returned %d\n", irq, call_status);
 228                 printk("set_xive %x, server %x\n", ibm_set_xive, server);
 229                 return;
 230         }
 231
 232         /* Now unmask the interrupt (often a no-op) */
 233         call_status = rtas_call(ibm_int_on, 1, 1, NULL, irq);
 234         if (call_status != 0) {
 235                 printk(KERN_ERR "xics_enable_irq: irq=%u: ibm_int_on "
 236                        "returned %d\n", irq, call_status);
 237                 return;
 238         }
 239 }
 240
 241 static void xics_mask_real_irq(unsigned int irq)
 242 {
 243         int call_status;
 244         unsigned int server;
 245
 246         if (irq == XICS_IPI)
 247                 return;
 248
 249         call_status = rtas_call(ibm_int_off, 1, 1, NULL, irq);
 250         if (call_status != 0) {
 251                 printk(KERN_ERR "xics_disable_real_irq: irq=%u: "
 252                        "ibm_int_off returned %d\n", irq, call_status);
 253                 return;
 254         }
 255
 256         server = get_irq_server(irq);
 257         /* Have to set XIVE to 0xff to be able to remove a slot */
 258         call_status = rtas_call(ibm_set_xive, 3, 1, NULL, irq, server, 0xff);
 259         if (call_status != 0) {
 260                 printk(KERN_ERR "xics_disable_irq: irq=%u: ibm_set_xive(0xff)"
 261                        " returned %d\n", irq, call_status);
 262                 return;
 263         }
 264 }
 265
 266 static void xics_mask_irq(unsigned int virq)
 267 {
 268         unsigned int irq;
 269
 270         irq = virt_irq_to_real(irq_offset_down(virq));
 271         WARN_ON(irq == NO_IRQ);
 272         if (irq != NO_IRQ)
 273                 xics_mask_real_irq(irq);
 274 }
 275
 276 static void xics_set_irq_revmap(unsigned int virq)
 277 {
 278         unsigned int irq;
 279
 280         irq = irq_offset_down(virq);
 281         if (radix_tree_insert(&irq_map, virt_irq_to_real(irq),
 282                               &virt_irq_to_real_map[irq]) == -ENOMEM)
 283                 printk(KERN_CRIT "Out of memory creating real -> virtual"
 284                        " IRQ mapping for irq %u (real 0x%x)\n",
 285                        virq, virt_irq_to_real(irq));
 286 }
 287
 288 static unsigned int xics_startup(unsigned int virq)
 289 {
 290         xics_set_irq_revmap(virq);
 291         xics_unmask_irq(virq);
 292         return 0;
 293 }
 294
 295 static unsigned int real_irq_to_virt(unsigned int real_irq)
 296 {
 297         unsigned int *ptr;
 298
 299         ptr = radix_tree_lookup(&irq_map, real_irq);
 300         if (ptr == NULL)
 301                 return NO_IRQ;
 302         return ptr - virt_irq_to_real_map;
 303 }
 304
 305 static void xics_eoi_direct(unsigned int irq)
 306 {
 307         int cpu = smp_processor_id();
 308
 309         iosync();
 310         direct_xirr_info_set(cpu, ((0xff << 24) |
 311                                    (virt_irq_to_real(irq_offset_down(irq)))));
 312 }
 313
 314
 315 static void xics_eoi_lpar(unsigned int irq)
 316 {
 317         int cpu = smp_processor_id();
 318
 319         iosync();
 320         lpar_xirr_info_set(cpu, ((0xff << 24) |
 321                                  (virt_irq_to_real(irq_offset_down(irq)))));
 322
 323 }
 324
 325 static inline int xics_remap_irq(int vec)
 326 {
 327         int irq;
 328
 329         vec &= 0x00ffffff;
 330
 331         if (vec == XICS_IRQ_SPURIOUS)
 332                 return NO_IRQ;
 333
 334         irq = real_irq_to_virt(vec);
 335         if (irq == NO_IRQ)
 336                 irq = real_irq_to_virt_slowpath(vec);
 337         if (likely(irq != NO_IRQ))
 338                 return irq_offset_up(irq);
 339
 340         printk(KERN_ERR "Interrupt %u (real) is invalid,"
 341                " disabling it.\n", vec);
 342         xics_mask_real_irq(vec);
 343         return NO_IRQ;
 344 }
 345
 346 static int xics_get_irq_direct(struct pt_regs *regs)
 347 {
 348         unsigned int cpu = smp_processor_id();
 349
 350         return xics_remap_irq(direct_xirr_info_get(cpu));
 351 }
 352
 353 static int xics_get_irq_lpar(struct pt_regs *regs)
 354 {
 355         unsigned int cpu = smp_processor_id();
 356
 357         return xics_remap_irq(lpar_xirr_info_get(cpu));
 358 }
 359
 360 #ifdef CONFIG_SMP
 361
 362 static irqreturn_t xics_ipi_dispatch(int cpu, struct pt_regs *regs)
 363 {
 364         WARN_ON(cpu_is_offline(cpu));
 365
 366         while (xics_ipi_message[cpu].value) {
 367                 if (test_and_clear_bit(PPC_MSG_CALL_FUNCTION,
 368                                        &xics_ipi_message[cpu].value)) {
 369                         mb();
 370                         smp_message_recv(PPC_MSG_CALL_FUNCTION, regs);
 371                 }
 372                 if (test_and_clear_bit(PPC_MSG_RESCHEDULE,
 373                                        &xics_ipi_message[cpu].value)) {
 374                         mb();
 375                         smp_message_recv(PPC_MSG_RESCHEDULE, regs);
 376                 }
 377 #if 0
 378                 if (test_and_clear_bit(PPC_MSG_MIGRATE_TASK,
 379                                        &xics_ipi_message[cpu].value)) {
 380                         mb();
 381                         smp_message_recv(PPC_MSG_MIGRATE_TASK, regs);
 382                 }
 383 #endif
 384 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
 385                 if (test_and_clear_bit(PPC_MSG_DEBUGGER_BREAK,
 386                                        &xics_ipi_message[cpu].value)) {
 387                         mb();
 388                         smp_message_recv(PPC_MSG_DEBUGGER_BREAK, regs);
 389                 }
 390 #endif
 391         }
 392         return IRQ_HANDLED;
 393 }
 394
 395 static irqreturn_t xics_ipi_action_direct(int irq, void *dev_id, struct pt_regs *regs)
 396 {
 397         int cpu = smp_processor_id();
 398
 399         direct_qirr_info(cpu, 0xff);
 400
 401         return xics_ipi_dispatch(cpu, regs);
 402 }
 403
 404 static irqreturn_t xics_ipi_action_lpar(int irq, void *dev_id, struct pt_regs *regs)
 405 {
 406         int cpu = smp_processor_id();
 407
 408         lpar_qirr_info(cpu, 0xff);
 409
 410         return xics_ipi_dispatch(cpu, regs);
 411 }
 412
 413 void xics_cause_IPI(int cpu)
 414 {
 415         if (firmware_has_feature(FW_FEATURE_LPAR))
 416                 lpar_qirr_info(cpu, IPI_PRIORITY);
 417         else
 418                 direct_qirr_info(cpu, IPI_PRIORITY);
 419 }
 420
 421 #endif /* CONFIG_SMP */
 422
 423 static void xics_set_cpu_priority(int cpu, unsigned char cppr)
 424 {
 425         if (firmware_has_feature(FW_FEATURE_LPAR))
 426                 lpar_cppr_info(cpu, cppr);
 427         else
 428                 direct_cppr_info(cpu, cppr);
 429         iosync();
 430 }
 431
 432 static void xics_set_affinity(unsigned int virq, cpumask_t cpumask)
 433 {
 434         unsigned int irq;
 435         int status;
 436         int xics_status[2];
 437         unsigned long newmask;
 438         cpumask_t tmp = CPU_MASK_NONE;
 439
 440         irq = virt_irq_to_real(irq_offset_down(virq));
 441         if (irq == XICS_IPI || irq == NO_IRQ)
 442                 return;
 443
 444         status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
 445
 446         if (status) {
 447                 printk(KERN_ERR "xics_set_affinity: irq=%u ibm,get-xive "
 448                        "returns %d\n", irq, status);
 449                 return;
 450         }
 451
 452         /* For the moment only implement delivery to all cpus or one cpu */
 453         if (cpus_equal(cpumask, CPU_MASK_ALL)) {
 454                 newmask = default_distrib_server;
 455         } else {
 456                 cpus_and(tmp, cpu_online_map, cpumask);
 457                 if (cpus_empty(tmp))
 458                         return;
 459                 newmask = get_hard_smp_processor_id(first_cpu(tmp));
 460         }
 461
 462         status = rtas_call(ibm_set_xive, 3, 1, NULL,
 463                                 irq, newmask, xics_status[1]);
 464
 465         if (status) {
 466                 printk(KERN_ERR "xics_set_affinity: irq=%u ibm,set-xive "
 467                        "returns %d\n", irq, status);
 468                 return;
 469         }
 470 }
 471
 472 static struct irq_chip xics_pic_direct = {
 473         .typename = " XICS     ",
 474         .startup = xics_startup,
 475         .mask = xics_mask_irq,
 476         .unmask = xics_unmask_irq,
 477         .eoi = xics_eoi_direct,
 478         .set_affinity = xics_set_affinity
 479 };
 480
 481
 482 static struct irq_chip xics_pic_lpar = {
 483         .typename = " XICS     ",
 484         .startup = xics_startup,
 485         .mask = xics_mask_irq,
 486         .unmask = xics_unmask_irq,
 487         .eoi = xics_eoi_lpar,
 488         .set_affinity = xics_set_affinity
 489 };
 490
 491
 492 void xics_setup_cpu(void)
 493 {
 494         int cpu = smp_processor_id();
 495
 496         xics_set_cpu_priority(cpu, 0xff);
 497
 498         /*
 499          * Put the calling processor into the GIQ.  This is really only
 500          * necessary from a secondary thread as the OF start-cpu interface
 501          * performs this function for us on primary threads.
 502          *
 503          * XXX: undo of teardown on kexec needs this too, as may hotplug
 504          */
 505         rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
 506                 (1UL << interrupt_server_size) - 1 - default_distrib_server, 1);
 507 }
 508
 509 void xics_init_IRQ(void)
 510 {
 511         int i;
 512         unsigned long intr_size = 0;
 513         struct device_node *np;
 514         uint *ireg, ilen, indx = 0;
 515         unsigned long intr_base = 0;
 516         struct xics_interrupt_node {
 517                 unsigned long addr;
 518                 unsigned long size;
 519         } intnodes[NR_CPUS];
 520         struct irq_chip *chip;
 521
 522         ppc64_boot_msg(0x20, "XICS Init");
 523
 524         ibm_get_xive = rtas_token("ibm,get-xive");
 525         ibm_set_xive = rtas_token("ibm,set-xive");
 526         ibm_int_on  = rtas_token("ibm,int-on");
 527         ibm_int_off = rtas_token("ibm,int-off");
 528
 529         np = of_find_node_by_type(NULL, "PowerPC-External-Interrupt-Presentation");
 530         if (!np)
 531                 panic("xics_init_IRQ: can't find interrupt presentation");
 532
 533 nextnode:
 534         ireg = (uint *)get_property(np, "ibm,interrupt-server-ranges", NULL);
 535         if (ireg) {
 536                 /*
 537                  * set node starting index for this node
 538                  */
 539                 indx = *ireg;
 540         }
 541
 542         ireg = (uint *)get_property(np, "reg", &ilen);
 543         if (!ireg)
 544                 panic("xics_init_IRQ: can't find interrupt reg property");
 545
 546         while (ilen) {
 547                 intnodes[indx].addr = (unsigned long)*ireg++ << 32;
 548                 ilen -= sizeof(uint);
 549                 intnodes[indx].addr |= *ireg++;
 550                 ilen -= sizeof(uint);
 551                 intnodes[indx].size = (unsigned long)*ireg++ << 32;
 552                 ilen -= sizeof(uint);
 553                 intnodes[indx].size |= *ireg++;
 554                 ilen -= sizeof(uint);
 555                 indx++;
 556                 if (indx >= NR_CPUS) break;
 557         }
 558
 559         np = of_find_node_by_type(np, "PowerPC-External-Interrupt-Presentation");
 560         if ((indx < NR_CPUS) && np) goto nextnode;
 561
 562         /* Find the server numbers for the boot cpu. */
 563         for (np = of_find_node_by_type(NULL, "cpu");
 564              np;
 565              np = of_find_node_by_type(np, "cpu")) {
 566                 ireg = (uint *)get_property(np, "reg", &ilen);
 567                 if (ireg && ireg[0] == get_hard_smp_processor_id(boot_cpuid)) {
 568                         ireg = (uint *)get_property(np, "ibm,ppc-interrupt-gserver#s",
 569                                                     &ilen);
 570                         i = ilen / sizeof(int);
 571                         if (ireg && i > 0) {
 572                                 default_server = ireg[0];
 573                                 default_distrib_server = ireg[i-1]; /* take last element */
 574                         }
 575                         ireg = (uint *)get_property(np,
 576                                         "ibm,interrupt-server#-size", NULL);
 577                         if (ireg)
 578                                 interrupt_server_size = *ireg;
 579                         break;
 580                 }
 581         }
 582         of_node_put(np);
 583
 584         intr_base = intnodes[0].addr;
 585         intr_size = intnodes[0].size;
 586
 587         if (firmware_has_feature(FW_FEATURE_LPAR)) {
 588                 ppc_md.get_irq = xics_get_irq_lpar;
 589                 chip = &xics_pic_lpar;
 590         } else {
 591 #ifdef CONFIG_SMP
 592                 for_each_possible_cpu(i) {
 593                         int hard_id;
 594
 595                         /* FIXME: Do this dynamically! --RR */
 596                         if (!cpu_present(i))
 597                                 continue;
 598
 599                         hard_id = get_hard_smp_processor_id(i);
 600                         xics_per_cpu[i] = ioremap(intnodes[hard_id].addr,
 601                                                   intnodes[hard_id].size);
 602                 }
 603 #else
 604                 xics_per_cpu[0] = ioremap(intr_base, intr_size);
 605 #endif /* CONFIG_SMP */
 606                 ppc_md.get_irq = xics_get_irq_direct;
 607                 chip = &xics_pic_direct;
 608
 609         }
 610
 611         for (i = irq_offset_value(); i < NR_IRQS; ++i) {
 612                 /* All IRQs on XICS are level for now. MSI code may want to modify
 613                  * that for reporting purposes
 614                  */
 615                 get_irq_desc(i)->status |= IRQ_LEVEL;
 616                 set_irq_chip_and_handler(i, chip, handle_fasteoi_irq);
 617         }
 618
 619         xics_setup_cpu();
 620
 621         ppc64_boot_msg(0x21, "XICS Done");
 622 }
 623
 624 static int xics_setup_8259_cascade(void)
 625 {
 626         struct device_node *np;
 627         uint *ireg;
 628
 629         np = of_find_node_by_type(NULL, "interrupt-controller");
 630         if (np == NULL) {
 631                 printk(KERN_WARNING "xics: no ISA interrupt controller\n");
 632                 xics_irq_8259_cascade_real = -1;
 633                 xics_irq_8259_cascade = -1;
 634                 return 0;
 635         }
 636
 637         ireg = (uint *) get_property(np, "interrupts", NULL);
 638         if (!ireg)
 639                 panic("xics_init_IRQ: can't find ISA interrupts property");
 640
 641         xics_irq_8259_cascade_real = *ireg;
 642         xics_irq_8259_cascade = irq_offset_up
 643                 (virt_irq_create_mapping(xics_irq_8259_cascade_real));
 644         i8259_init(0, 0);
 645         of_node_put(np);
 646
 647         xics_set_irq_revmap(xics_irq_8259_cascade);
 648         set_irq_chained_handler(xics_irq_8259_cascade, pSeries_8259_cascade);
 649
 650         return 0;
 651 }
 652 arch_initcall(xics_setup_8259_cascade);
 653
 654
 655 #ifdef CONFIG_SMP
 656 void xics_request_IPIs(void)
 657 {
 658         virt_irq_to_real_map[XICS_IPI] = XICS_IPI;
 659
 660         /*
 661          * IPIs are marked IRQF_DISABLED as they must run with irqs
 662          * disabled
 663          */
 664         set_irq_handler(irq_offset_up(XICS_IPI), handle_percpu_irq);
 665         if (firmware_has_feature(FW_FEATURE_LPAR))
 666                 request_irq(irq_offset_up(XICS_IPI), xics_ipi_action_lpar,
 667                             SA_INTERRUPT, "IPI", NULL);
 668         else
 669                 request_irq(irq_offset_up(XICS_IPI), xics_ipi_action_direct,
 670                             SA_INTERRUPT, "IPI", NULL);
 671 }
 672 #endif /* CONFIG_SMP */
 673
 674 void xics_teardown_cpu(int secondary)
 675 {
 676         struct irq_desc *desc = get_irq_desc(irq_offset_up(XICS_IPI));
 677         int cpu = smp_processor_id();
 678
 679         xics_set_cpu_priority(cpu, 0);
 680
 681         /*
 682          * we need to EOI the IPI if we got here from kexec down IPI
 683          *
 684          * probably need to check all the other interrupts too
 685          * should we be flagging idle loop instead?
 686          * or creating some task to be scheduled?
 687          */
 688         if (desc->chip && desc->chip->eoi)
 689                 desc->chip->eoi(XICS_IPI);
 690
 691         /*
 692          * Some machines need to have at least one cpu in the GIQ,
 693          * so leave the master cpu in the group.
 694          */
 695         if (secondary)
 696                 rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
 697                         (1UL << interrupt_server_size) - 1 -
 698                         default_distrib_server, 0);
 699 }
 700
 701 #ifdef CONFIG_HOTPLUG_CPU
 702
 703 /* Interrupts are disabled. */
 704 void xics_migrate_irqs_away(void)
 705 {
 706         int status;
 707         unsigned int irq, virq, cpu = smp_processor_id();
 708
 709         /* Reject any interrupt that was queued to us... */
 710         xics_set_cpu_priority(cpu, 0);
 711
 712         /* remove ourselves from the global interrupt queue */
 713         status = rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
 714                 (1UL << interrupt_server_size) - 1 - default_distrib_server, 0);
 715         WARN_ON(status < 0);
 716
 717         /* Allow IPIs again... */
 718         xics_set_cpu_priority(cpu, DEFAULT_PRIORITY);
 719
 720         for_each_irq(virq) {
 721                 struct irq_desc *desc;
 722                 int xics_status[2];
 723                 unsigned long flags;
 724
 725                 /* We cant set affinity on ISA interrupts */
 726                 if (virq < irq_offset_value())
 727                         continue;
 728
 729                 desc = get_irq_desc(virq);
 730                 irq = virt_irq_to_real(irq_offset_down(virq));
 731
 732                 /* We need to get IPIs still. */
 733                 if (irq == XICS_IPI || irq == NO_IRQ)
 734                         continue;
 735
 736                 /* We only need to migrate enabled IRQS */
 737                 if (desc == NULL || desc->chip == NULL
 738                     || desc->action == NULL
 739                     || desc->chip->set_affinity == NULL)
 740                         continue;
 741
 742                 spin_lock_irqsave(&desc->lock, flags);
 743
 744                 status = rtas_call(ibm_get_xive, 1, 3, xics_status, irq);
 745                 if (status) {
 746                         printk(KERN_ERR "migrate_irqs_away: irq=%u "
 747                                         "ibm,get-xive returns %d\n",
 748                                         virq, status);
 749                         goto unlock;
 750                 }
 751
 752                 /*
 753                  * We only support delivery to all cpus or to one cpu.
 754                  * The irq has to be migrated only in the single cpu
 755                  * case.
 756                  */
 757                 if (xics_status[0] != get_hard_smp_processor_id(cpu))
 758                         goto unlock;
 759
 760                 printk(KERN_WARNING "IRQ %u affinity broken off cpu %u\n",
 761                        virq, cpu);
 762
 763                 /* Reset affinity to all cpus */
 764                 desc->chip->set_affinity(virq, CPU_MASK_ALL);
 765                 irq_desc[irq].affinity = CPU_MASK_ALL;
 766 unlock:
 767                 spin_unlock_irqrestore(&desc->lock, flags);
 768         }
 769 }
 770 #endif