1 /* 2 * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp. 3 * Copyright 2006-2007 Michael Ellerman, IBM Corp. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License 7 * as published by the Free Software Foundation; version 2 of the 8 * License. 9 * 10 */ 11 12 #include <linux/device.h> 13 #include <linux/irq.h> 14 #include <linux/msi.h> 15 16 #include <asm/rtas.h> 17 #include <asm/hw_irq.h> 18 #include <asm/ppc-pci.h> 19 #include <asm/machdep.h> 20 21 #include "pseries.h" 22 23 static int query_token, change_token; 24 25 #define RTAS_QUERY_FN 0 26 #define RTAS_CHANGE_FN 1 27 #define RTAS_RESET_FN 2 28 #define RTAS_CHANGE_MSI_FN 3 29 #define RTAS_CHANGE_MSIX_FN 4 30 #define RTAS_CHANGE_32MSI_FN 5 31 32 /* RTAS Helpers */ 33 34 static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs) 35 { 36 u32 addr, seq_num, rtas_ret[3]; 37 unsigned long buid; 38 int rc; 39 40 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); 41 buid = pdn->phb->buid; 42 43 seq_num = 1; 44 do { 45 if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN || 46 func == RTAS_CHANGE_32MSI_FN) 47 rc = rtas_call(change_token, 6, 4, rtas_ret, addr, 48 BUID_HI(buid), BUID_LO(buid), 49 func, num_irqs, seq_num); 50 else 51 rc = rtas_call(change_token, 6, 3, rtas_ret, addr, 52 BUID_HI(buid), BUID_LO(buid), 53 func, num_irqs, seq_num); 54 55 seq_num = rtas_ret[1]; 56 } while (rtas_busy_delay(rc)); 57 58 /* 59 * If the RTAS call succeeded, return the number of irqs allocated. 60 * If not, make sure we return a negative error code. 61 */ 62 if (rc == 0) 63 rc = rtas_ret[0]; 64 else if (rc > 0) 65 rc = -rc; 66 67 pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n", 68 func, num_irqs, rtas_ret[0], rc); 69 70 return rc; 71 } 72 73 static void rtas_disable_msi(struct pci_dev *pdev) 74 { 75 struct pci_dn *pdn; 76 77 pdn = pci_get_pdn(pdev); 78 if (!pdn) 79 return; 80 81 /* 82 * disabling MSI with the explicit interface also disables MSI-X 83 */ 84 if (rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, 0) != 0) { 85 /* 86 * may have failed because explicit interface is not 87 * present 88 */ 89 if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0) { 90 pr_debug("rtas_msi: Setting MSIs to 0 failed!\n"); 91 } 92 } 93 } 94 95 static int rtas_query_irq_number(struct pci_dn *pdn, int offset) 96 { 97 u32 addr, rtas_ret[2]; 98 unsigned long buid; 99 int rc; 100 101 addr = rtas_config_addr(pdn->busno, pdn->devfn, 0); 102 buid = pdn->phb->buid; 103 104 do { 105 rc = rtas_call(query_token, 4, 3, rtas_ret, addr, 106 BUID_HI(buid), BUID_LO(buid), offset); 107 } while (rtas_busy_delay(rc)); 108 109 if (rc) { 110 pr_debug("rtas_msi: error (%d) querying source number\n", rc); 111 return rc; 112 } 113 114 return rtas_ret[0]; 115 } 116 117 static void rtas_teardown_msi_irqs(struct pci_dev *pdev) 118 { 119 struct msi_desc *entry; 120 121 for_each_pci_msi_entry(entry, pdev) { 122 if (entry->irq == NO_IRQ) 123 continue; 124 125 irq_set_msi_desc(entry->irq, NULL); 126 irq_dispose_mapping(entry->irq); 127 } 128 129 rtas_disable_msi(pdev); 130 } 131 132 static int check_req(struct pci_dev *pdev, int nvec, char *prop_name) 133 { 134 struct device_node *dn; 135 struct pci_dn *pdn; 136 const __be32 *p; 137 u32 req_msi; 138 139 pdn = pci_get_pdn(pdev); 140 if (!pdn) 141 return -ENODEV; 142 143 dn = pdn->node; 144 145 p = of_get_property(dn, prop_name, NULL); 146 if (!p) { 147 pr_debug("rtas_msi: No %s on %s\n", prop_name, dn->full_name); 148 return -ENOENT; 149 } 150 151 req_msi = be32_to_cpup(p); 152 if (req_msi < nvec) { 153 pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec); 154 155 if (req_msi == 0) /* Be paranoid */ 156 return -ENOSPC; 157 158 return req_msi; 159 } 160 161 return 0; 162 } 163 164 static int check_req_msi(struct pci_dev *pdev, int nvec) 165 { 166 return check_req(pdev, nvec, "ibm,req#msi"); 167 } 168 169 static int check_req_msix(struct pci_dev *pdev, int nvec) 170 { 171 return check_req(pdev, nvec, "ibm,req#msi-x"); 172 } 173 174 /* Quota calculation */ 175 176 static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total) 177 { 178 struct device_node *dn; 179 const __be32 *p; 180 181 dn = of_node_get(pci_device_to_OF_node(dev)); 182 while (dn) { 183 p = of_get_property(dn, "ibm,pe-total-#msi", NULL); 184 if (p) { 185 pr_debug("rtas_msi: found prop on dn %s\n", 186 dn->full_name); 187 *total = be32_to_cpup(p); 188 return dn; 189 } 190 191 dn = of_get_next_parent(dn); 192 } 193 194 return NULL; 195 } 196 197 static struct device_node *find_pe_dn(struct pci_dev *dev, int *total) 198 { 199 struct device_node *dn; 200 struct pci_dn *pdn; 201 struct eeh_dev *edev; 202 203 /* Found our PE and assume 8 at that point. */ 204 205 dn = pci_device_to_OF_node(dev); 206 if (!dn) 207 return NULL; 208 209 /* Get the top level device in the PE */ 210 edev = pdn_to_eeh_dev(PCI_DN(dn)); 211 if (edev->pe) 212 edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list); 213 pdn = eeh_dev_to_pdn(edev); 214 dn = pdn ? pdn->node : NULL; 215 if (!dn) 216 return NULL; 217 218 /* We actually want the parent */ 219 dn = of_get_parent(dn); 220 if (!dn) 221 return NULL; 222 223 /* Hardcode of 8 for old firmwares */ 224 *total = 8; 225 pr_debug("rtas_msi: using PE dn %s\n", dn->full_name); 226 227 return dn; 228 } 229 230 struct msi_counts { 231 struct device_node *requestor; 232 int num_devices; 233 int request; 234 int quota; 235 int spare; 236 int over_quota; 237 }; 238 239 static void *count_non_bridge_devices(struct device_node *dn, void *data) 240 { 241 struct msi_counts *counts = data; 242 const __be32 *p; 243 u32 class; 244 245 pr_debug("rtas_msi: counting %s\n", dn->full_name); 246 247 p = of_get_property(dn, "class-code", NULL); 248 class = p ? be32_to_cpup(p) : 0; 249 250 if ((class >> 8) != PCI_CLASS_BRIDGE_PCI) 251 counts->num_devices++; 252 253 return NULL; 254 } 255 256 static void *count_spare_msis(struct device_node *dn, void *data) 257 { 258 struct msi_counts *counts = data; 259 const __be32 *p; 260 int req; 261 262 if (dn == counts->requestor) 263 req = counts->request; 264 else { 265 /* We don't know if a driver will try to use MSI or MSI-X, 266 * so we just have to punt and use the larger of the two. */ 267 req = 0; 268 p = of_get_property(dn, "ibm,req#msi", NULL); 269 if (p) 270 req = be32_to_cpup(p); 271 272 p = of_get_property(dn, "ibm,req#msi-x", NULL); 273 if (p) 274 req = max(req, (int)be32_to_cpup(p)); 275 } 276 277 if (req < counts->quota) 278 counts->spare += counts->quota - req; 279 else if (req > counts->quota) 280 counts->over_quota++; 281 282 return NULL; 283 } 284 285 static int msi_quota_for_device(struct pci_dev *dev, int request) 286 { 287 struct device_node *pe_dn; 288 struct msi_counts counts; 289 int total; 290 291 pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev), 292 request); 293 294 pe_dn = find_pe_total_msi(dev, &total); 295 if (!pe_dn) 296 pe_dn = find_pe_dn(dev, &total); 297 298 if (!pe_dn) { 299 pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev)); 300 goto out; 301 } 302 303 pr_debug("rtas_msi: found PE %s\n", pe_dn->full_name); 304 305 memset(&counts, 0, sizeof(struct msi_counts)); 306 307 /* Work out how many devices we have below this PE */ 308 traverse_pci_devices(pe_dn, count_non_bridge_devices, &counts); 309 310 if (counts.num_devices == 0) { 311 pr_err("rtas_msi: found 0 devices under PE for %s\n", 312 pci_name(dev)); 313 goto out; 314 } 315 316 counts.quota = total / counts.num_devices; 317 if (request <= counts.quota) 318 goto out; 319 320 /* else, we have some more calculating to do */ 321 counts.requestor = pci_device_to_OF_node(dev); 322 counts.request = request; 323 traverse_pci_devices(pe_dn, count_spare_msis, &counts); 324 325 /* If the quota isn't an integer multiple of the total, we can 326 * use the remainder as spare MSIs for anyone that wants them. */ 327 counts.spare += total % counts.num_devices; 328 329 /* Divide any spare by the number of over-quota requestors */ 330 if (counts.over_quota) 331 counts.quota += counts.spare / counts.over_quota; 332 333 /* And finally clamp the request to the possibly adjusted quota */ 334 request = min(counts.quota, request); 335 336 pr_debug("rtas_msi: request clamped to quota %d\n", request); 337 out: 338 of_node_put(pe_dn); 339 340 return request; 341 } 342 343 static int check_msix_entries(struct pci_dev *pdev) 344 { 345 struct msi_desc *entry; 346 int expected; 347 348 /* There's no way for us to express to firmware that we want 349 * a discontiguous, or non-zero based, range of MSI-X entries. 350 * So we must reject such requests. */ 351 352 expected = 0; 353 for_each_pci_msi_entry(entry, pdev) { 354 if (entry->msi_attrib.entry_nr != expected) { 355 pr_debug("rtas_msi: bad MSI-X entries.\n"); 356 return -EINVAL; 357 } 358 expected++; 359 } 360 361 return 0; 362 } 363 364 static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev) 365 { 366 u32 addr_hi, addr_lo; 367 368 /* 369 * We should only get in here for IODA1 configs. This is based on the 370 * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS 371 * support, and we are in a PCIe Gen2 slot. 372 */ 373 dev_info(&pdev->dev, 374 "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n"); 375 pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi); 376 addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4); 377 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo); 378 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0); 379 } 380 381 static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) 382 { 383 struct pci_dn *pdn; 384 int hwirq, virq, i, quota, rc; 385 struct msi_desc *entry; 386 struct msi_msg msg; 387 int nvec = nvec_in; 388 int use_32bit_msi_hack = 0; 389 390 if (type == PCI_CAP_ID_MSIX) 391 rc = check_req_msix(pdev, nvec); 392 else 393 rc = check_req_msi(pdev, nvec); 394 395 if (rc) 396 return rc; 397 398 quota = msi_quota_for_device(pdev, nvec); 399 400 if (quota && quota < nvec) 401 return quota; 402 403 if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev)) 404 return -EINVAL; 405 406 /* 407 * Firmware currently refuse any non power of two allocation 408 * so we round up if the quota will allow it. 409 */ 410 if (type == PCI_CAP_ID_MSIX) { 411 int m = roundup_pow_of_two(nvec); 412 quota = msi_quota_for_device(pdev, m); 413 414 if (quota >= m) 415 nvec = m; 416 } 417 418 pdn = pci_get_pdn(pdev); 419 420 /* 421 * Try the new more explicit firmware interface, if that fails fall 422 * back to the old interface. The old interface is known to never 423 * return MSI-Xs. 424 */ 425 again: 426 if (type == PCI_CAP_ID_MSI) { 427 if (pdev->no_64bit_msi) { 428 rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec); 429 if (rc < 0) { 430 /* 431 * We only want to run the 32 bit MSI hack below if 432 * the max bus speed is Gen2 speed 433 */ 434 if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT) 435 return rc; 436 437 use_32bit_msi_hack = 1; 438 } 439 } else 440 rc = -1; 441 442 if (rc < 0) 443 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec); 444 445 if (rc < 0) { 446 pr_debug("rtas_msi: trying the old firmware call.\n"); 447 rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec); 448 } 449 450 if (use_32bit_msi_hack && rc > 0) 451 rtas_hack_32bit_msi_gen2(pdev); 452 } else 453 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); 454 455 if (rc != nvec) { 456 if (nvec != nvec_in) { 457 nvec = nvec_in; 458 goto again; 459 } 460 pr_debug("rtas_msi: rtas_change_msi() failed\n"); 461 return rc; 462 } 463 464 i = 0; 465 for_each_pci_msi_entry(entry, pdev) { 466 hwirq = rtas_query_irq_number(pdn, i++); 467 if (hwirq < 0) { 468 pr_debug("rtas_msi: error (%d) getting hwirq\n", rc); 469 return hwirq; 470 } 471 472 virq = irq_create_mapping(NULL, hwirq); 473 474 if (virq == NO_IRQ) { 475 pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); 476 return -ENOSPC; 477 } 478 479 dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq); 480 irq_set_msi_desc(virq, entry); 481 482 /* Read config space back so we can restore after reset */ 483 __pci_read_msi_msg(entry, &msg); 484 entry->msg = msg; 485 } 486 487 return 0; 488 } 489 490 static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev) 491 { 492 /* No LSI -> leave MSIs (if any) configured */ 493 if (pdev->irq == NO_IRQ) { 494 dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n"); 495 return; 496 } 497 498 /* No MSI -> MSIs can't have been assigned by fw, leave LSI */ 499 if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) { 500 dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n"); 501 return; 502 } 503 504 dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n"); 505 rtas_disable_msi(pdev); 506 } 507 508 static int rtas_msi_init(void) 509 { 510 struct pci_controller *phb; 511 512 query_token = rtas_token("ibm,query-interrupt-source-number"); 513 change_token = rtas_token("ibm,change-msi"); 514 515 if ((query_token == RTAS_UNKNOWN_SERVICE) || 516 (change_token == RTAS_UNKNOWN_SERVICE)) { 517 pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n"); 518 return -1; 519 } 520 521 pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n"); 522 523 WARN_ON(pseries_pci_controller_ops.setup_msi_irqs); 524 pseries_pci_controller_ops.setup_msi_irqs = rtas_setup_msi_irqs; 525 pseries_pci_controller_ops.teardown_msi_irqs = rtas_teardown_msi_irqs; 526 527 list_for_each_entry(phb, &hose_list, list_node) { 528 WARN_ON(phb->controller_ops.setup_msi_irqs); 529 phb->controller_ops.setup_msi_irqs = rtas_setup_msi_irqs; 530 phb->controller_ops.teardown_msi_irqs = rtas_teardown_msi_irqs; 531 } 532 533 WARN_ON(ppc_md.pci_irq_fixup); 534 ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup; 535 536 return 0; 537 } 538 machine_arch_initcall(pseries, rtas_msi_init); 539