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     ics_eoi(icp->ics, xirr & XISR_MASK);
 136     /* Send EOI -> ICS */
 137     ss->xirr = (ss->xirr & ~CPPR_MASK) | (xirr & CPPR_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     /* int pending:1; */
 169     /* int presented:1; */
 170     int rejected:1;
 171     int masked_pending:1;
 172 };
 173
 174 struct ics_state {
 175     int nr_irqs;
 176     int offset;
 177     qemu_irq *qirqs;
 178     struct ics_irq_state *irqs;
 179     struct icp_state *icp;
 180 };
 181
 182 static int ics_valid_irq(struct ics_state *ics, uint32_t nr)
 183 {
 184     return (nr >= ics->offset)
 185         && (nr < (ics->offset + ics->nr_irqs));
 186 }
 187
 188 static void ics_set_irq_msi(void *opaque, int nr, int val)
 189 {
 190     struct ics_state *ics = (struct ics_state *)opaque;
 191     struct ics_irq_state *irq = ics->irqs + nr;
 192
 193     if (val) {
 194         if (irq->priority == 0xff) {
 195             irq->masked_pending = 1;
 196             /* masked pending */ ;
 197         } else  {
 198             icp_irq(ics->icp, irq->server, nr + ics->offset, irq->priority);
 199         }
 200     }
 201 }
 202
 203 static void ics_reject_msi(struct ics_state *ics, int nr)
 204 {
 205     struct ics_irq_state *irq = ics->irqs + nr - ics->offset;
 206
 207     irq->rejected = 1;
 208 }
 209
 210 static void ics_resend_msi(struct ics_state *ics)
 211 {
 212     int i;
 213
 214     for (i = 0; i < ics->nr_irqs; i++) {
 215         struct ics_irq_state *irq = ics->irqs + i;
 216
 217         /* FIXME: filter by server#? */
 218         if (irq->rejected) {
 219             irq->rejected = 0;
 220             if (irq->priority != 0xff) {
 221                 icp_irq(ics->icp, irq->server, i + ics->offset, irq->priority);
 222             }
 223         }
 224     }
 225 }
 226
 227 static void ics_write_xive_msi(struct ics_state *ics, int nr, int server,
 228                                uint8_t priority)
 229 {
 230     struct ics_irq_state *irq = ics->irqs + nr;
 231
 232     irq->server = server;
 233     irq->priority = priority;
 234
 235     if (!irq->masked_pending || (priority == 0xff)) {
 236         return;
 237     }
 238
 239     irq->masked_pending = 0;
 240     icp_irq(ics->icp, server, nr + ics->offset, priority);
 241 }
 242
 243 static void ics_reject(struct ics_state *ics, int nr)
 244 {
 245     ics_reject_msi(ics, nr);
 246 }
 247
 248 static void ics_resend(struct ics_state *ics)
 249 {
 250     ics_resend_msi(ics);
 251 }
 252
 253 static void ics_eoi(struct ics_state *ics, int nr)
 254 {
 255 }
 256
 257 /*
 258  * Exported functions
 259  */
 260
 261 qemu_irq xics_find_qirq(struct icp_state *icp, int irq)
 262 {
 263     if ((irq < icp->ics->offset)
 264         || (irq >= (icp->ics->offset + icp->ics->nr_irqs))) {
 265         return NULL;
 266     }
 267
 268     return icp->ics->qirqs[irq - icp->ics->offset];
 269 }
 270
 271 static target_ulong h_cppr(CPUState *env, sPAPREnvironment *spapr,
 272                            target_ulong opcode, target_ulong *args)
 273 {
 274     target_ulong cppr = args[0];
 275
 276     icp_set_cppr(spapr->icp, env->cpu_index, cppr);
 277     return H_SUCCESS;
 278 }
 279
 280 static target_ulong h_ipi(CPUState *env, sPAPREnvironment *spapr,
 281                           target_ulong opcode, target_ulong *args)
 282 {
 283     target_ulong server = args[0];
 284     target_ulong mfrr = args[1];
 285
 286     if (server >= spapr->icp->nr_servers) {
 287         return H_PARAMETER;
 288     }
 289
 290     icp_set_mfrr(spapr->icp, server, mfrr);
 291     return H_SUCCESS;
 292
 293 }
 294
 295 static target_ulong h_xirr(CPUState *env, sPAPREnvironment *spapr,
 296                            target_ulong opcode, target_ulong *args)
 297 {
 298     uint32_t xirr = icp_accept(spapr->icp->ss + env->cpu_index);
 299
 300     args[0] = xirr;
 301     return H_SUCCESS;
 302 }
 303
 304 static target_ulong h_eoi(CPUState *env, sPAPREnvironment *spapr,
 305                           target_ulong opcode, target_ulong *args)
 306 {
 307     target_ulong xirr = args[0];
 308
 309     icp_eoi(spapr->icp, env->cpu_index, xirr);
 310     return H_SUCCESS;
 311 }
 312
 313 static void rtas_set_xive(sPAPREnvironment *spapr, uint32_t token,
 314                           uint32_t nargs, target_ulong args,
 315                           uint32_t nret, target_ulong rets)
 316 {
 317     struct ics_state *ics = spapr->icp->ics;
 318     uint32_t nr, server, priority;
 319
 320     if ((nargs != 3) || (nret != 1)) {
 321         rtas_st(rets, 0, -3);
 322         return;
 323     }
 324
 325     nr = rtas_ld(args, 0);
 326     server = rtas_ld(args, 1);
 327     priority = rtas_ld(args, 2);
 328
 329     if (!ics_valid_irq(ics, nr) || (server >= ics->icp->nr_servers)
 330         || (priority > 0xff)) {
 331         rtas_st(rets, 0, -3);
 332         return;
 333     }
 334
 335     ics_write_xive_msi(ics, nr - ics->offset, server, priority);
 336
 337     rtas_st(rets, 0, 0); /* Success */
 338 }
 339
 340 static void rtas_get_xive(sPAPREnvironment *spapr, uint32_t token,
 341                           uint32_t nargs, target_ulong args,
 342                           uint32_t nret, target_ulong rets)
 343 {
 344     struct ics_state *ics = spapr->icp->ics;
 345     uint32_t nr;
 346
 347     if ((nargs != 1) || (nret != 3)) {
 348         rtas_st(rets, 0, -3);
 349         return;
 350     }
 351
 352     nr = rtas_ld(args, 0);
 353
 354     if (!ics_valid_irq(ics, nr)) {
 355         rtas_st(rets, 0, -3);
 356         return;
 357     }
 358
 359     rtas_st(rets, 0, 0); /* Success */
 360     rtas_st(rets, 1, ics->irqs[nr - ics->offset].server);
 361     rtas_st(rets, 2, ics->irqs[nr - ics->offset].priority);
 362 }
 363
 364 static void rtas_int_off(sPAPREnvironment *spapr, uint32_t token,
 365                          uint32_t nargs, target_ulong args,
 366                          uint32_t nret, target_ulong rets)
 367 {
 368     struct ics_state *ics = spapr->icp->ics;
 369     uint32_t nr;
 370
 371     if ((nargs != 1) || (nret != 1)) {
 372         rtas_st(rets, 0, -3);
 373         return;
 374     }
 375
 376     nr = rtas_ld(args, 0);
 377
 378     if (!ics_valid_irq(ics, nr)) {
 379         rtas_st(rets, 0, -3);
 380         return;
 381     }
 382
 383     /* This is a NOP for now, since the described PAPR semantics don't
 384      * seem to gel with what Linux does */
 385 #if 0
 386     struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);
 387
 388     irq->saved_priority = irq->priority;
 389     ics_write_xive_msi(xics, nr - xics->offset, irq->server, 0xff);
 390 #endif
 391
 392     rtas_st(rets, 0, 0); /* Success */
 393 }
 394
 395 static void rtas_int_on(sPAPREnvironment *spapr, uint32_t token,
 396                         uint32_t nargs, target_ulong args,
 397                         uint32_t nret, target_ulong rets)
 398 {
 399     struct ics_state *ics = spapr->icp->ics;
 400     uint32_t nr;
 401
 402     if ((nargs != 1) || (nret != 1)) {
 403         rtas_st(rets, 0, -3);
 404         return;
 405     }
 406
 407     nr = rtas_ld(args, 0);
 408
 409     if (!ics_valid_irq(ics, nr)) {
 410         rtas_st(rets, 0, -3);
 411         return;
 412     }
 413
 414     /* This is a NOP for now, since the described PAPR semantics don't
 415      * seem to gel with what Linux does */
 416 #if 0
 417     struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);
 418
 419     ics_write_xive_msi(xics, nr - xics->offset,
 420                        irq->server, irq->saved_priority);
 421 #endif
 422
 423     rtas_st(rets, 0, 0); /* Success */
 424 }
 425
 426 struct icp_state *xics_system_init(int nr_irqs)
 427 {
 428     CPUState *env;
 429     int max_server_num;
 430     int i;
 431     struct icp_state *icp;
 432     struct ics_state *ics;
 433
 434     max_server_num = -1;
 435     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 436         if (env->cpu_index > max_server_num) {
 437             max_server_num = env->cpu_index;
 438         }
 439     }
 440
 441     icp = g_malloc0(sizeof(*icp));
 442     icp->nr_servers = max_server_num + 1;
 443     icp->ss = g_malloc0(icp->nr_servers*sizeof(struct icp_server_state));
 444
 445     for (i = 0; i < icp->nr_servers; i++) {
 446         icp->ss[i].mfrr = 0xff;
 447     }
 448
 449     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 450         struct icp_server_state *ss = &icp->ss[env->cpu_index];
 451
 452         switch (PPC_INPUT(env)) {
 453         case PPC_FLAGS_INPUT_POWER7:
 454             ss->output = env->irq_inputs[POWER7_INPUT_INT];
 455             break;
 456
 457         case PPC_FLAGS_INPUT_970:
 458             ss->output = env->irq_inputs[PPC970_INPUT_INT];
 459             break;
 460
 461         default:
 462             hw_error("XICS interrupt model does not support this CPU bus "
 463                      "model\n");
 464             exit(1);
 465         }
 466     }
 467
 468     ics = g_malloc0(sizeof(*ics));
 469     ics->nr_irqs = nr_irqs;
 470     ics->offset = 16;
 471     ics->irqs = g_malloc0(nr_irqs * sizeof(struct ics_irq_state));
 472
 473     icp->ics = ics;
 474     ics->icp = icp;
 475
 476     for (i = 0; i < nr_irqs; i++) {
 477         ics->irqs[i].priority = 0xff;
 478         ics->irqs[i].saved_priority = 0xff;
 479     }
 480
 481     ics->qirqs = qemu_allocate_irqs(ics_set_irq_msi, ics, nr_irqs);
 482
 483     spapr_register_hypercall(H_CPPR, h_cppr);
 484     spapr_register_hypercall(H_IPI, h_ipi);
 485     spapr_register_hypercall(H_XIRR, h_xirr);
 486     spapr_register_hypercall(H_EOI, h_eoi);
 487
 488     spapr_rtas_register("ibm,set-xive", rtas_set_xive);
 489     spapr_rtas_register("ibm,get-xive", rtas_get_xive);
 490     spapr_rtas_register("ibm,int-off", rtas_int_off);
 491     spapr_rtas_register("ibm,int-on", rtas_int_on);
 492
 493     return icp;
 494 }