hw/xics.c

   1 /*
   2  * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
   3  *
   4  * PAPR Virtualized Interrupt System, aka ICS/ICP aka xics
   5  *
   6  * Copyright (c) 2010,2011 David Gibson, IBM Corporation.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24  * THE SOFTWARE.
  25  *
  26  */
  27
  28 #include "hw.h"
  29 #include "hw/spapr.h"
  30 #include "hw/xics.h"
  31
  32 /*
  33  * ICP: Presentation layer
  34  */
  35
  36 struct icp_server_state {
  37     uint32_t xirr;
  38     uint8_t pending_priority;
  39     uint8_t mfrr;
  40     qemu_irq output;
  41 };
  42
  43 #define XISR_MASK  0x00ffffff
  44 #define CPPR_MASK  0xff000000
  45
  46 #define XISR(ss)   (((ss)->xirr) & XISR_MASK)
  47 #define CPPR(ss)   (((ss)->xirr) >> 24)
  48
  49 struct ics_state;
  50
  51 struct icp_state {
  52     long nr_servers;
  53     struct icp_server_state *ss;
  54     struct ics_state *ics;
  55 };
  56
  57 static void ics_reject(struct ics_state *ics, int nr);
  58 static void ics_resend(struct ics_state *ics);
  59 static void ics_eoi(struct ics_state *ics, int nr);
  60
  61 static void icp_check_ipi(struct icp_state *icp, int server)
  62 {
  63     struct icp_server_state *ss = icp->ss + server;
  64
  65     if (XISR(ss) && (ss->pending_priority <= ss->mfrr)) {
  66         return;
  67     }
  68
  69     if (XISR(ss)) {
  70         ics_reject(icp->ics, XISR(ss));
  71     }
  72
  73     ss->xirr = (ss->xirr & ~XISR_MASK) | XICS_IPI;
  74     ss->pending_priority = ss->mfrr;
  75     qemu_irq_raise(ss->output);
  76 }
  77
  78 static void icp_resend(struct icp_state *icp, int server)
  79 {
  80     struct icp_server_state *ss = icp->ss + server;
  81
  82     if (ss->mfrr < CPPR(ss)) {
  83         icp_check_ipi(icp, server);
  84     }
  85     ics_resend(icp->ics);
  86 }
  87
  88 static void icp_set_cppr(struct icp_state *icp, int server, uint8_t cppr)
  89 {
  90     struct icp_server_state *ss = icp->ss + server;
  91     uint8_t old_cppr;
  92     uint32_t old_xisr;
  93
  94     old_cppr = CPPR(ss);
  95     ss->xirr = (ss->xirr & ~CPPR_MASK) | (cppr << 24);
  96
  97     if (cppr < old_cppr) {
  98         if (XISR(ss) && (cppr <= ss->pending_priority)) {
  99             old_xisr = XISR(ss);
 100             ss->xirr &= ~XISR_MASK; /* Clear XISR */
 101             qemu_irq_lower(ss->output);
 102             ics_reject(icp->ics, old_xisr);
 103         }
 104     } else {
 105         if (!XISR(ss)) {
 106             icp_resend(icp, server);
 107         }
 108     }
 109 }
 110
 111 static void icp_set_mfrr(struct icp_state *icp, int nr, uint8_t mfrr)
 112 {
 113     struct icp_server_state *ss = icp->ss + nr;
 114
 115     ss->mfrr = mfrr;
 116     if (mfrr < CPPR(ss)) {
 117         icp_check_ipi(icp, nr);
 118     }
 119 }
 120
 121 static uint32_t icp_accept(struct icp_server_state *ss)
 122 {
 123     uint32_t xirr;
 124
 125     qemu_irq_lower(ss->output);
 126     xirr = ss->xirr;
 127     ss->xirr = ss->pending_priority << 24;
 128     return xirr;
 129 }
 130
 131 static void icp_eoi(struct icp_state *icp, int server, uint32_t xirr)
 132 {
 133     struct icp_server_state *ss = icp->ss + server;
 134
 135     /* Send EOI -> ICS */
 136     ss->xirr = (ss->xirr & ~CPPR_MASK) | (xirr & CPPR_MASK);
 137     ics_eoi(icp->ics, xirr & XISR_MASK);
 138     if (!XISR(ss)) {
 139         icp_resend(icp, server);
 140     }
 141 }
 142
 143 static void icp_irq(struct icp_state *icp, int server, int nr, uint8_t priority)
 144 {
 145     struct icp_server_state *ss = icp->ss + server;
 146
 147     if ((priority >= CPPR(ss))
 148         || (XISR(ss) && (ss->pending_priority <= priority))) {
 149         ics_reject(icp->ics, nr);
 150     } else {
 151         if (XISR(ss)) {
 152             ics_reject(icp->ics, XISR(ss));
 153         }
 154         ss->xirr = (ss->xirr & ~XISR_MASK) | (nr & XISR_MASK);
 155         ss->pending_priority = priority;
 156         qemu_irq_raise(ss->output);
 157     }
 158 }
 159
 160 /*
 161  * ICS: Source layer
 162  */
 163
 164 struct ics_irq_state {
 165     int server;
 166     uint8_t priority;
 167     uint8_t saved_priority;
 168     enum xics_irq_type type;
 169     int asserted:1;
 170     int sent:1;
 171     int rejected:1;
 172     int masked_pending:1;
 173 };
 174
 175 struct ics_state {
 176     int nr_irqs;
 177     int offset;
 178     qemu_irq *qirqs;
 179     struct ics_irq_state *irqs;
 180     struct icp_state *icp;
 181 };
 182
 183 static int ics_valid_irq(struct ics_state *ics, uint32_t nr)
 184 {
 185     return (nr >= ics->offset)
 186         && (nr < (ics->offset + ics->nr_irqs));
 187 }
 188
 189 static void resend_msi(struct ics_state *ics, int srcno)
 190 {
 191     struct ics_irq_state *irq = ics->irqs + srcno;
 192
 193     /* FIXME: filter by server#? */
 194     if (irq->rejected) {
 195         irq->rejected = 0;
 196         if (irq->priority != 0xff) {
 197             icp_irq(ics->icp, irq->server, srcno + ics->offset,
 198                     irq->priority);
 199         }
 200     }
 201 }
 202
 203 static void resend_lsi(struct ics_state *ics, int srcno)
 204 {
 205     struct ics_irq_state *irq = ics->irqs + srcno;
 206
 207     if ((irq->priority != 0xff) && irq->asserted && !irq->sent) {
 208         irq->sent = 1;
 209         icp_irq(ics->icp, irq->server, srcno + ics->offset, irq->priority);
 210     }
 211 }
 212
 213 static void set_irq_msi(struct ics_state *ics, int srcno, int val)
 214 {
 215     struct ics_irq_state *irq = ics->irqs + srcno;
 216
 217     if (val) {
 218         if (irq->priority == 0xff) {
 219             irq->masked_pending = 1;
 220             /* masked pending */ ;
 221         } else  {
 222             icp_irq(ics->icp, irq->server, srcno + ics->offset, irq->priority);
 223         }
 224     }
 225 }
 226
 227 static void set_irq_lsi(struct ics_state *ics, int srcno, int val)
 228 {
 229     struct ics_irq_state *irq = ics->irqs + srcno;
 230
 231     irq->asserted = val;
 232     resend_lsi(ics, srcno);
 233 }
 234
 235 static void ics_set_irq(void *opaque, int srcno, int val)
 236 {
 237     struct ics_state *ics = (struct ics_state *)opaque;
 238     struct ics_irq_state *irq = ics->irqs + srcno;
 239
 240     if (irq->type == XICS_LSI) {
 241         set_irq_lsi(ics, srcno, val);
 242     } else {
 243         set_irq_msi(ics, srcno, val);
 244     }
 245 }
 246
 247 static void write_xive_msi(struct ics_state *ics, int srcno)
 248 {
 249     struct ics_irq_state *irq = ics->irqs + srcno;
 250
 251     if (!irq->masked_pending || (irq->priority == 0xff)) {
 252         return;
 253     }
 254
 255     irq->masked_pending = 0;
 256     icp_irq(ics->icp, irq->server, srcno + ics->offset, irq->priority);
 257 }
 258
 259 static void write_xive_lsi(struct ics_state *ics, int srcno)
 260 {
 261     resend_lsi(ics, srcno);
 262 }
 263
 264 static void ics_write_xive(struct ics_state *ics, int nr, int server,
 265                            uint8_t priority)
 266 {
 267     int srcno = nr - ics->offset;
 268     struct ics_irq_state *irq = ics->irqs + srcno;
 269
 270     irq->server = server;
 271     irq->priority = priority;
 272
 273     if (irq->type == XICS_LSI) {
 274         write_xive_lsi(ics, srcno);
 275     } else {
 276         write_xive_msi(ics, srcno);
 277     }
 278 }
 279
 280 static void ics_reject(struct ics_state *ics, int nr)
 281 {
 282     struct ics_irq_state *irq = ics->irqs + nr - ics->offset;
 283
 284     irq->rejected = 1; /* Irrelevant but harmless for LSI */
 285     irq->sent = 0; /* Irrelevant but harmless for MSI */
 286 }
 287
 288 static void ics_resend(struct ics_state *ics)
 289 {
 290     int i;
 291
 292     for (i = 0; i < ics->nr_irqs; i++) {
 293         struct ics_irq_state *irq = ics->irqs + i;
 294
 295         /* FIXME: filter by server#? */
 296         if (irq->type == XICS_LSI) {
 297             resend_lsi(ics, i);
 298         } else {
 299             resend_msi(ics, i);
 300         }
 301     }
 302 }
 303
 304 static void ics_eoi(struct ics_state *ics, int nr)
 305 {
 306     int srcno = nr - ics->offset;
 307     struct ics_irq_state *irq = ics->irqs + srcno;
 308
 309     if (irq->type == XICS_LSI) {
 310         irq->sent = 0;
 311     }
 312 }
 313
 314 /*
 315  * Exported functions
 316  */
 317
 318 qemu_irq xics_get_qirq(struct icp_state *icp, int irq)
 319 {
 320     if ((irq < icp->ics->offset)
 321         || (irq >= (icp->ics->offset + icp->ics->nr_irqs))) {
 322         return NULL;
 323     }
 324
 325     return icp->ics->qirqs[irq - icp->ics->offset];
 326 }
 327
 328 void xics_set_irq_type(struct icp_state *icp, int irq,
 329                        enum xics_irq_type type)
 330 {
 331     assert((irq >= icp->ics->offset)
 332            && (irq < (icp->ics->offset + icp->ics->nr_irqs)));
 333     assert((type == XICS_MSI) || (type == XICS_LSI));
 334
 335     icp->ics->irqs[irq - icp->ics->offset].type = type;
 336 }
 337
 338 static target_ulong h_cppr(CPUPPCState *env, sPAPREnvironment *spapr,
 339                            target_ulong opcode, target_ulong *args)
 340 {
 341     target_ulong cppr = args[0];
 342
 343     icp_set_cppr(spapr->icp, env->cpu_index, cppr);
 344     return H_SUCCESS;
 345 }
 346
 347 static target_ulong h_ipi(CPUPPCState *env, sPAPREnvironment *spapr,
 348                           target_ulong opcode, target_ulong *args)
 349 {
 350     target_ulong server = args[0];
 351     target_ulong mfrr = args[1];
 352
 353     if (server >= spapr->icp->nr_servers) {
 354         return H_PARAMETER;
 355     }
 356
 357     icp_set_mfrr(spapr->icp, server, mfrr);
 358     return H_SUCCESS;
 359
 360 }
 361
 362 static target_ulong h_xirr(CPUPPCState *env, sPAPREnvironment *spapr,
 363                            target_ulong opcode, target_ulong *args)
 364 {
 365     uint32_t xirr = icp_accept(spapr->icp->ss + env->cpu_index);
 366
 367     args[0] = xirr;
 368     return H_SUCCESS;
 369 }
 370
 371 static target_ulong h_eoi(CPUPPCState *env, sPAPREnvironment *spapr,
 372                           target_ulong opcode, target_ulong *args)
 373 {
 374     target_ulong xirr = args[0];
 375
 376     icp_eoi(spapr->icp, env->cpu_index, xirr);
 377     return H_SUCCESS;
 378 }
 379
 380 static void rtas_set_xive(sPAPREnvironment *spapr, uint32_t token,
 381                           uint32_t nargs, target_ulong args,
 382                           uint32_t nret, target_ulong rets)
 383 {
 384     struct ics_state *ics = spapr->icp->ics;
 385     uint32_t nr, server, priority;
 386
 387     if ((nargs != 3) || (nret != 1)) {
 388         rtas_st(rets, 0, -3);
 389         return;
 390     }
 391
 392     nr = rtas_ld(args, 0);
 393     server = rtas_ld(args, 1);
 394     priority = rtas_ld(args, 2);
 395
 396     if (!ics_valid_irq(ics, nr) || (server >= ics->icp->nr_servers)
 397         || (priority > 0xff)) {
 398         rtas_st(rets, 0, -3);
 399         return;
 400     }
 401
 402     ics_write_xive(ics, nr, server, priority);
 403
 404     rtas_st(rets, 0, 0); /* Success */
 405 }
 406
 407 static void rtas_get_xive(sPAPREnvironment *spapr, uint32_t token,
 408                           uint32_t nargs, target_ulong args,
 409                           uint32_t nret, target_ulong rets)
 410 {
 411     struct ics_state *ics = spapr->icp->ics;
 412     uint32_t nr;
 413
 414     if ((nargs != 1) || (nret != 3)) {
 415         rtas_st(rets, 0, -3);
 416         return;
 417     }
 418
 419     nr = rtas_ld(args, 0);
 420
 421     if (!ics_valid_irq(ics, nr)) {
 422         rtas_st(rets, 0, -3);
 423         return;
 424     }
 425
 426     rtas_st(rets, 0, 0); /* Success */
 427     rtas_st(rets, 1, ics->irqs[nr - ics->offset].server);
 428     rtas_st(rets, 2, ics->irqs[nr - ics->offset].priority);
 429 }
 430
 431 static void rtas_int_off(sPAPREnvironment *spapr, uint32_t token,
 432                          uint32_t nargs, target_ulong args,
 433                          uint32_t nret, target_ulong rets)
 434 {
 435     struct ics_state *ics = spapr->icp->ics;
 436     uint32_t nr;
 437
 438     if ((nargs != 1) || (nret != 1)) {
 439         rtas_st(rets, 0, -3);
 440         return;
 441     }
 442
 443     nr = rtas_ld(args, 0);
 444
 445     if (!ics_valid_irq(ics, nr)) {
 446         rtas_st(rets, 0, -3);
 447         return;
 448     }
 449
 450     /* This is a NOP for now, since the described PAPR semantics don't
 451      * seem to gel with what Linux does */
 452 #if 0
 453     struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);
 454
 455     irq->saved_priority = irq->priority;
 456     ics_write_xive_msi(xics, nr, irq->server, 0xff);
 457 #endif
 458
 459     rtas_st(rets, 0, 0); /* Success */
 460 }
 461
 462 static void rtas_int_on(sPAPREnvironment *spapr, uint32_t token,
 463                         uint32_t nargs, target_ulong args,
 464                         uint32_t nret, target_ulong rets)
 465 {
 466     struct ics_state *ics = spapr->icp->ics;
 467     uint32_t nr;
 468
 469     if ((nargs != 1) || (nret != 1)) {
 470         rtas_st(rets, 0, -3);
 471         return;
 472     }
 473
 474     nr = rtas_ld(args, 0);
 475
 476     if (!ics_valid_irq(ics, nr)) {
 477         rtas_st(rets, 0, -3);
 478         return;
 479     }
 480
 481     /* This is a NOP for now, since the described PAPR semantics don't
 482      * seem to gel with what Linux does */
 483 #if 0
 484     struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);
 485
 486     ics_write_xive_msi(xics, nr, irq->server, irq->saved_priority);
 487 #endif
 488
 489     rtas_st(rets, 0, 0); /* Success */
 490 }
 491
 492 struct icp_state *xics_system_init(int nr_irqs)
 493 {
 494     CPUPPCState *env;
 495     int max_server_num;
 496     int i;
 497     struct icp_state *icp;
 498     struct ics_state *ics;
 499
 500     max_server_num = -1;
 501     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 502         if (env->cpu_index > max_server_num) {
 503             max_server_num = env->cpu_index;
 504         }
 505     }
 506
 507     icp = g_malloc0(sizeof(*icp));
 508     icp->nr_servers = max_server_num + 1;
 509     icp->ss = g_malloc0(icp->nr_servers*sizeof(struct icp_server_state));
 510
 511     for (i = 0; i < icp->nr_servers; i++) {
 512         icp->ss[i].mfrr = 0xff;
 513     }
 514
 515     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 516         struct icp_server_state *ss = &icp->ss[env->cpu_index];
 517
 518         switch (PPC_INPUT(env)) {
 519         case PPC_FLAGS_INPUT_POWER7:
 520             ss->output = env->irq_inputs[POWER7_INPUT_INT];
 521             break;
 522
 523         case PPC_FLAGS_INPUT_970:
 524             ss->output = env->irq_inputs[PPC970_INPUT_INT];
 525             break;
 526
 527         default:
 528             hw_error("XICS interrupt model does not support this CPU bus "
 529                      "model\n");
 530             exit(1);
 531         }
 532     }
 533
 534     ics = g_malloc0(sizeof(*ics));
 535     ics->nr_irqs = nr_irqs;
 536     ics->offset = 16;
 537     ics->irqs = g_malloc0(nr_irqs * sizeof(struct ics_irq_state));
 538
 539     icp->ics = ics;
 540     ics->icp = icp;
 541
 542     for (i = 0; i < nr_irqs; i++) {
 543         ics->irqs[i].priority = 0xff;
 544         ics->irqs[i].saved_priority = 0xff;
 545     }
 546
 547     ics->qirqs = qemu_allocate_irqs(ics_set_irq, ics, nr_irqs);
 548
 549     spapr_register_hypercall(H_CPPR, h_cppr);
 550     spapr_register_hypercall(H_IPI, h_ipi);
 551     spapr_register_hypercall(H_XIRR, h_xirr);
 552     spapr_register_hypercall(H_EOI, h_eoi);
 553
 554     spapr_rtas_register("ibm,set-xive", rtas_set_xive);
 555     spapr_rtas_register("ibm,get-xive", rtas_get_xive);
 556     spapr_rtas_register("ibm,int-off", rtas_int_off);
 557     spapr_rtas_register("ibm,int-on", rtas_int_on);
 558
 559     return icp;
 560 }