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 #include <pthread.h>
  33
  34 /*
  35  * ICP: Presentation layer
  36  */
  37
  38 struct icp_server_state {
  39     uint32_t xirr;
  40     uint8_t pending_priority;
  41     uint8_t mfrr;
  42     qemu_irq output;
  43 };
  44
  45 #define XISR_MASK  0x00ffffff
  46 #define CPPR_MASK  0xff000000
  47
  48 #define XISR(ss)   (((ss)->xirr) & XISR_MASK)
  49 #define CPPR(ss)   (((ss)->xirr) >> 24)
  50
  51 struct ics_state;
  52
  53 struct icp_state {
  54     long nr_servers;
  55     struct icp_server_state *ss;
  56     struct ics_state *ics;
  57 };
  58
  59 static void ics_reject(struct ics_state *ics, int nr);
  60 static void ics_resend(struct ics_state *ics);
  61 static void ics_eoi(struct ics_state *ics, int nr);
  62
  63 static void icp_check_ipi(struct icp_state *icp, int server)
  64 {
  65     struct icp_server_state *ss = icp->ss + server;
  66
  67     if (XISR(ss) && (ss->pending_priority <= ss->mfrr)) {
  68         return;
  69     }
  70
  71     if (XISR(ss)) {
  72         ics_reject(icp->ics, XISR(ss));
  73     }
  74
  75     ss->xirr = (ss->xirr & ~XISR_MASK) | XICS_IPI;
  76     ss->pending_priority = ss->mfrr;
  77     qemu_irq_raise(ss->output);
  78 }
  79
  80 static void icp_resend(struct icp_state *icp, int server)
  81 {
  82     struct icp_server_state *ss = icp->ss + server;
  83
  84     if (ss->mfrr < CPPR(ss)) {
  85         icp_check_ipi(icp, server);
  86     }
  87     ics_resend(icp->ics);
  88 }
  89
  90 static void icp_set_cppr(struct icp_state *icp, int server, uint8_t cppr)
  91 {
  92     struct icp_server_state *ss = icp->ss + server;
  93     uint8_t old_cppr;
  94     uint32_t old_xisr;
  95
  96     old_cppr = CPPR(ss);
  97     ss->xirr = (ss->xirr & ~CPPR_MASK) | (cppr << 24);
  98
  99     if (cppr < old_cppr) {
 100         if (XISR(ss) && (cppr <= ss->pending_priority)) {
 101             old_xisr = XISR(ss);
 102             ss->xirr &= ~XISR_MASK; /* Clear XISR */
 103             qemu_irq_lower(ss->output);
 104             ics_reject(icp->ics, old_xisr);
 105         }
 106     } else {
 107         if (!XISR(ss)) {
 108             icp_resend(icp, server);
 109         }
 110     }
 111 }
 112
 113 static void icp_set_mfrr(struct icp_state *icp, int nr, uint8_t mfrr)
 114 {
 115     struct icp_server_state *ss = icp->ss + nr;
 116
 117     ss->mfrr = mfrr;
 118     if (mfrr < CPPR(ss)) {
 119         icp_check_ipi(icp, nr);
 120     }
 121 }
 122
 123 static uint32_t icp_accept(struct icp_server_state *ss)
 124 {
 125     uint32_t xirr;
 126
 127     qemu_irq_lower(ss->output);
 128     xirr = ss->xirr;
 129     ss->xirr = ss->pending_priority << 24;
 130     return xirr;
 131 }
 132
 133 static void icp_eoi(struct icp_state *icp, int server, uint32_t xirr)
 134 {
 135     struct icp_server_state *ss = icp->ss + server;
 136
 137     ics_eoi(icp->ics, xirr & XISR_MASK);
 138     /* Send EOI -> ICS */
 139     ss->xirr = (ss->xirr & ~CPPR_MASK) | (xirr & CPPR_MASK);
 140     if (!XISR(ss)) {
 141         icp_resend(icp, server);
 142     }
 143 }
 144
 145 static void icp_irq(struct icp_state *icp, int server, int nr, uint8_t priority)
 146 {
 147     struct icp_server_state *ss = icp->ss + server;
 148
 149     if ((priority >= CPPR(ss))
 150         || (XISR(ss) && (ss->pending_priority <= priority))) {
 151         ics_reject(icp->ics, nr);
 152     } else {
 153         if (XISR(ss)) {
 154             ics_reject(icp->ics, XISR(ss));
 155         }
 156         ss->xirr = (ss->xirr & ~XISR_MASK) | (nr & XISR_MASK);
 157         ss->pending_priority = priority;
 158         qemu_irq_raise(ss->output);
 159     }
 160 }
 161
 162 /*
 163  * ICS: Source layer
 164  */
 165
 166 struct ics_irq_state {
 167     int server;
 168     uint8_t priority;
 169     uint8_t saved_priority;
 170     /* int pending:1; */
 171     /* int presented:1; */
 172     int rejected:1;
 173     int masked_pending:1;
 174 };
 175
 176 struct ics_state {
 177     int nr_irqs;
 178     int offset;
 179     qemu_irq *qirqs;
 180     struct ics_irq_state *irqs;
 181     struct icp_state *icp;
 182 };
 183
 184 static int ics_valid_irq(struct ics_state *ics, uint32_t nr)
 185 {
 186     return (nr >= ics->offset)
 187         && (nr < (ics->offset + ics->nr_irqs));
 188 }
 189
 190 static void ics_set_irq_msi(void *opaque, int nr, int val)
 191 {
 192     struct ics_state *ics = (struct ics_state *)opaque;
 193     struct ics_irq_state *irq = ics->irqs + nr;
 194
 195     if (val) {
 196         if (irq->priority == 0xff) {
 197             irq->masked_pending = 1;
 198             /* masked pending */ ;
 199         } else  {
 200             icp_irq(ics->icp, irq->server, nr + ics->offset, irq->priority);
 201         }
 202     }
 203 }
 204
 205 static void ics_reject_msi(struct ics_state *ics, int nr)
 206 {
 207     struct ics_irq_state *irq = ics->irqs + nr - ics->offset;
 208
 209     irq->rejected = 1;
 210 }
 211
 212 static void ics_resend_msi(struct ics_state *ics)
 213 {
 214     int i;
 215
 216     for (i = 0; i < ics->nr_irqs; i++) {
 217         struct ics_irq_state *irq = ics->irqs + i;
 218
 219         /* FIXME: filter by server#? */
 220         if (irq->rejected) {
 221             irq->rejected = 0;
 222             if (irq->priority != 0xff) {
 223                 icp_irq(ics->icp, irq->server, i + ics->offset, irq->priority);
 224             }
 225         }
 226     }
 227 }
 228
 229 static void ics_write_xive_msi(struct ics_state *ics, int nr, int server,
 230                                uint8_t priority)
 231 {
 232     struct ics_irq_state *irq = ics->irqs + nr;
 233
 234     irq->server = server;
 235     irq->priority = priority;
 236
 237     if (!irq->masked_pending || (priority == 0xff)) {
 238         return;
 239     }
 240
 241     irq->masked_pending = 0;
 242     icp_irq(ics->icp, server, nr + ics->offset, priority);
 243 }
 244
 245 static void ics_reject(struct ics_state *ics, int nr)
 246 {
 247     ics_reject_msi(ics, nr);
 248 }
 249
 250 static void ics_resend(struct ics_state *ics)
 251 {
 252     ics_resend_msi(ics);
 253 }
 254
 255 static void ics_eoi(struct ics_state *ics, int nr)
 256 {
 257 }
 258
 259 /*
 260  * Exported functions
 261  */
 262
 263 qemu_irq xics_find_qirq(struct icp_state *icp, int irq)
 264 {
 265     if ((irq < icp->ics->offset)
 266         || (irq >= (icp->ics->offset + icp->ics->nr_irqs))) {
 267         return NULL;
 268     }
 269
 270     return icp->ics->qirqs[irq - icp->ics->offset];
 271 }
 272
 273 static target_ulong h_cppr(CPUState *env, sPAPREnvironment *spapr,
 274                            target_ulong opcode, target_ulong *args)
 275 {
 276     target_ulong cppr = args[0];
 277
 278     icp_set_cppr(spapr->icp, env->cpu_index, cppr);
 279     return H_SUCCESS;
 280 }
 281
 282 static target_ulong h_ipi(CPUState *env, sPAPREnvironment *spapr,
 283                           target_ulong opcode, target_ulong *args)
 284 {
 285     target_ulong server = args[0];
 286     target_ulong mfrr = args[1];
 287
 288     if (server >= spapr->icp->nr_servers) {
 289         return H_PARAMETER;
 290     }
 291
 292     icp_set_mfrr(spapr->icp, server, mfrr);
 293     return H_SUCCESS;
 294
 295 }
 296
 297 static target_ulong h_xirr(CPUState *env, sPAPREnvironment *spapr,
 298                            target_ulong opcode, target_ulong *args)
 299 {
 300     uint32_t xirr = icp_accept(spapr->icp->ss + env->cpu_index);
 301
 302     args[0] = xirr;
 303     return H_SUCCESS;
 304 }
 305
 306 static target_ulong h_eoi(CPUState *env, sPAPREnvironment *spapr,
 307                           target_ulong opcode, target_ulong *args)
 308 {
 309     target_ulong xirr = args[0];
 310
 311     icp_eoi(spapr->icp, env->cpu_index, xirr);
 312     return H_SUCCESS;
 313 }
 314
 315 static void rtas_set_xive(sPAPREnvironment *spapr, uint32_t token,
 316                           uint32_t nargs, target_ulong args,
 317                           uint32_t nret, target_ulong rets)
 318 {
 319     struct ics_state *ics = spapr->icp->ics;
 320     uint32_t nr, server, priority;
 321
 322     if ((nargs != 3) || (nret != 1)) {
 323         rtas_st(rets, 0, -3);
 324         return;
 325     }
 326
 327     nr = rtas_ld(args, 0);
 328     server = rtas_ld(args, 1);
 329     priority = rtas_ld(args, 2);
 330
 331     if (!ics_valid_irq(ics, nr) || (server >= ics->icp->nr_servers)
 332         || (priority > 0xff)) {
 333         rtas_st(rets, 0, -3);
 334         return;
 335     }
 336
 337     ics_write_xive_msi(ics, nr - ics->offset, server, priority);
 338
 339     rtas_st(rets, 0, 0); /* Success */
 340 }
 341
 342 static void rtas_get_xive(sPAPREnvironment *spapr, uint32_t token,
 343                           uint32_t nargs, target_ulong args,
 344                           uint32_t nret, target_ulong rets)
 345 {
 346     struct ics_state *ics = spapr->icp->ics;
 347     uint32_t nr;
 348
 349     if ((nargs != 1) || (nret != 3)) {
 350         rtas_st(rets, 0, -3);
 351         return;
 352     }
 353
 354     nr = rtas_ld(args, 0);
 355
 356     if (!ics_valid_irq(ics, nr)) {
 357         rtas_st(rets, 0, -3);
 358         return;
 359     }
 360
 361     rtas_st(rets, 0, 0); /* Success */
 362     rtas_st(rets, 1, ics->irqs[nr - ics->offset].server);
 363     rtas_st(rets, 2, ics->irqs[nr - ics->offset].priority);
 364 }
 365
 366 static void rtas_int_off(sPAPREnvironment *spapr, uint32_t token,
 367                          uint32_t nargs, target_ulong args,
 368                          uint32_t nret, target_ulong rets)
 369 {
 370     struct ics_state *ics = spapr->icp->ics;
 371     uint32_t nr;
 372
 373     if ((nargs != 1) || (nret != 1)) {
 374         rtas_st(rets, 0, -3);
 375         return;
 376     }
 377
 378     nr = rtas_ld(args, 0);
 379
 380     if (!ics_valid_irq(ics, nr)) {
 381         rtas_st(rets, 0, -3);
 382         return;
 383     }
 384
 385     /* This is a NOP for now, since the described PAPR semantics don't
 386      * seem to gel with what Linux does */
 387 #if 0
 388     struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);
 389
 390     irq->saved_priority = irq->priority;
 391     ics_write_xive_msi(xics, nr - xics->offset, irq->server, 0xff);
 392 #endif
 393
 394     rtas_st(rets, 0, 0); /* Success */
 395 }
 396
 397 static void rtas_int_on(sPAPREnvironment *spapr, uint32_t token,
 398                         uint32_t nargs, target_ulong args,
 399                         uint32_t nret, target_ulong rets)
 400 {
 401     struct ics_state *ics = spapr->icp->ics;
 402     uint32_t nr;
 403
 404     if ((nargs != 1) || (nret != 1)) {
 405         rtas_st(rets, 0, -3);
 406         return;
 407     }
 408
 409     nr = rtas_ld(args, 0);
 410
 411     if (!ics_valid_irq(ics, nr)) {
 412         rtas_st(rets, 0, -3);
 413         return;
 414     }
 415
 416     /* This is a NOP for now, since the described PAPR semantics don't
 417      * seem to gel with what Linux does */
 418 #if 0
 419     struct ics_irq_state *irq = xics->irqs + (nr - xics->offset);
 420
 421     ics_write_xive_msi(xics, nr - xics->offset,
 422                        irq->server, irq->saved_priority);
 423 #endif
 424
 425     rtas_st(rets, 0, 0); /* Success */
 426 }
 427
 428 struct icp_state *xics_system_init(int nr_servers, CPUState *servers[],
 429                                    int nr_irqs)
 430 {
 431     int i;
 432     struct icp_state *icp;
 433     struct ics_state *ics;
 434
 435     icp = qemu_mallocz(sizeof(*icp));
 436     icp->nr_servers = nr_servers;
 437     icp->ss = qemu_mallocz(nr_servers * sizeof(struct icp_server_state));
 438
 439     for (i = 0; i < nr_servers; i++) {
 440         servers[i]->cpu_index = i;
 441
 442         switch (PPC_INPUT(servers[i])) {
 443         case PPC_FLAGS_INPUT_POWER7:
 444             icp->ss[i].output = servers[i]->irq_inputs[POWER7_INPUT_INT];
 445             break;
 446
 447         case PPC_FLAGS_INPUT_970:
 448             icp->ss[i].output = servers[i]->irq_inputs[PPC970_INPUT_INT];
 449             break;
 450
 451         default:
 452             hw_error("XICS interrupt model does not support this CPU bus "
 453                      "model\n");
 454             exit(1);
 455         }
 456
 457         icp->ss[i].mfrr = 0xff;
 458     }
 459
 460     ics = qemu_mallocz(sizeof(*ics));
 461     ics->nr_irqs = nr_irqs;
 462     ics->offset = 16;
 463     ics->irqs = qemu_mallocz(nr_irqs * sizeof(struct ics_irq_state));
 464
 465     icp->ics = ics;
 466     ics->icp = icp;
 467
 468     for (i = 0; i < nr_irqs; i++) {
 469         ics->irqs[i].priority = 0xff;
 470         ics->irqs[i].saved_priority = 0xff;
 471     }
 472
 473     ics->qirqs = qemu_allocate_irqs(ics_set_irq_msi, ics, nr_irqs);
 474
 475     spapr_register_hypercall(H_CPPR, h_cppr);
 476     spapr_register_hypercall(H_IPI, h_ipi);
 477     spapr_register_hypercall(H_XIRR, h_xirr);
 478     spapr_register_hypercall(H_EOI, h_eoi);
 479
 480     spapr_rtas_register("ibm,set-xive", rtas_set_xive);
 481     spapr_rtas_register("ibm,get-xive", rtas_get_xive);
 482     spapr_rtas_register("ibm,int-off", rtas_int_off);
 483     spapr_rtas_register("ibm,int-on", rtas_int_on);
 484
 485     return icp;
 486 }