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) 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 const __be32 *p; 136 u32 req_msi; 137 138 dn = pci_device_to_OF_node(pdev); 139 140 p = of_get_property(dn, prop_name, NULL); 141 if (!p) { 142 pr_debug("rtas_msi: No %s on %pOF\n", prop_name, dn); 143 return -ENOENT; 144 } 145 146 req_msi = be32_to_cpup(p); 147 if (req_msi < nvec) { 148 pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec); 149 150 if (req_msi == 0) /* Be paranoid */ 151 return -ENOSPC; 152 153 return req_msi; 154 } 155 156 return 0; 157 } 158 159 static int check_req_msi(struct pci_dev *pdev, int nvec) 160 { 161 return check_req(pdev, nvec, "ibm,req#msi"); 162 } 163 164 static int check_req_msix(struct pci_dev *pdev, int nvec) 165 { 166 return check_req(pdev, nvec, "ibm,req#msi-x"); 167 } 168 169 /* Quota calculation */ 170 171 static struct device_node *find_pe_total_msi(struct pci_dev *dev, int *total) 172 { 173 struct device_node *dn; 174 const __be32 *p; 175 176 dn = of_node_get(pci_device_to_OF_node(dev)); 177 while (dn) { 178 p = of_get_property(dn, "ibm,pe-total-#msi", NULL); 179 if (p) { 180 pr_debug("rtas_msi: found prop on dn %pOF\n", 181 dn); 182 *total = be32_to_cpup(p); 183 return dn; 184 } 185 186 dn = of_get_next_parent(dn); 187 } 188 189 return NULL; 190 } 191 192 static struct device_node *find_pe_dn(struct pci_dev *dev, int *total) 193 { 194 struct device_node *dn; 195 struct eeh_dev *edev; 196 197 /* Found our PE and assume 8 at that point. */ 198 199 dn = pci_device_to_OF_node(dev); 200 if (!dn) 201 return NULL; 202 203 /* Get the top level device in the PE */ 204 edev = pdn_to_eeh_dev(PCI_DN(dn)); 205 if (edev->pe) 206 edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, 207 entry); 208 dn = pci_device_to_OF_node(edev->pdev); 209 if (!dn) 210 return NULL; 211 212 /* We actually want the parent */ 213 dn = of_get_parent(dn); 214 if (!dn) 215 return NULL; 216 217 /* Hardcode of 8 for old firmwares */ 218 *total = 8; 219 pr_debug("rtas_msi: using PE dn %pOF\n", dn); 220 221 return dn; 222 } 223 224 struct msi_counts { 225 struct device_node *requestor; 226 int num_devices; 227 int request; 228 int quota; 229 int spare; 230 int over_quota; 231 }; 232 233 static void *count_non_bridge_devices(struct device_node *dn, void *data) 234 { 235 struct msi_counts *counts = data; 236 const __be32 *p; 237 u32 class; 238 239 pr_debug("rtas_msi: counting %pOF\n", dn); 240 241 p = of_get_property(dn, "class-code", NULL); 242 class = p ? be32_to_cpup(p) : 0; 243 244 if ((class >> 8) != PCI_CLASS_BRIDGE_PCI) 245 counts->num_devices++; 246 247 return NULL; 248 } 249 250 static void *count_spare_msis(struct device_node *dn, void *data) 251 { 252 struct msi_counts *counts = data; 253 const __be32 *p; 254 int req; 255 256 if (dn == counts->requestor) 257 req = counts->request; 258 else { 259 /* We don't know if a driver will try to use MSI or MSI-X, 260 * so we just have to punt and use the larger of the two. */ 261 req = 0; 262 p = of_get_property(dn, "ibm,req#msi", NULL); 263 if (p) 264 req = be32_to_cpup(p); 265 266 p = of_get_property(dn, "ibm,req#msi-x", NULL); 267 if (p) 268 req = max(req, (int)be32_to_cpup(p)); 269 } 270 271 if (req < counts->quota) 272 counts->spare += counts->quota - req; 273 else if (req > counts->quota) 274 counts->over_quota++; 275 276 return NULL; 277 } 278 279 static int msi_quota_for_device(struct pci_dev *dev, int request) 280 { 281 struct device_node *pe_dn; 282 struct msi_counts counts; 283 int total; 284 285 pr_debug("rtas_msi: calc quota for %s, request %d\n", pci_name(dev), 286 request); 287 288 pe_dn = find_pe_total_msi(dev, &total); 289 if (!pe_dn) 290 pe_dn = find_pe_dn(dev, &total); 291 292 if (!pe_dn) { 293 pr_err("rtas_msi: couldn't find PE for %s\n", pci_name(dev)); 294 goto out; 295 } 296 297 pr_debug("rtas_msi: found PE %pOF\n", pe_dn); 298 299 memset(&counts, 0, sizeof(struct msi_counts)); 300 301 /* Work out how many devices we have below this PE */ 302 pci_traverse_device_nodes(pe_dn, count_non_bridge_devices, &counts); 303 304 if (counts.num_devices == 0) { 305 pr_err("rtas_msi: found 0 devices under PE for %s\n", 306 pci_name(dev)); 307 goto out; 308 } 309 310 counts.quota = total / counts.num_devices; 311 if (request <= counts.quota) 312 goto out; 313 314 /* else, we have some more calculating to do */ 315 counts.requestor = pci_device_to_OF_node(dev); 316 counts.request = request; 317 pci_traverse_device_nodes(pe_dn, count_spare_msis, &counts); 318 319 /* If the quota isn't an integer multiple of the total, we can 320 * use the remainder as spare MSIs for anyone that wants them. */ 321 counts.spare += total % counts.num_devices; 322 323 /* Divide any spare by the number of over-quota requestors */ 324 if (counts.over_quota) 325 counts.quota += counts.spare / counts.over_quota; 326 327 /* And finally clamp the request to the possibly adjusted quota */ 328 request = min(counts.quota, request); 329 330 pr_debug("rtas_msi: request clamped to quota %d\n", request); 331 out: 332 of_node_put(pe_dn); 333 334 return request; 335 } 336 337 static int check_msix_entries(struct pci_dev *pdev) 338 { 339 struct msi_desc *entry; 340 int expected; 341 342 /* There's no way for us to express to firmware that we want 343 * a discontiguous, or non-zero based, range of MSI-X entries. 344 * So we must reject such requests. */ 345 346 expected = 0; 347 for_each_pci_msi_entry(entry, pdev) { 348 if (entry->msi_attrib.entry_nr != expected) { 349 pr_debug("rtas_msi: bad MSI-X entries.\n"); 350 return -EINVAL; 351 } 352 expected++; 353 } 354 355 return 0; 356 } 357 358 static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev) 359 { 360 u32 addr_hi, addr_lo; 361 362 /* 363 * We should only get in here for IODA1 configs. This is based on the 364 * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS 365 * support, and we are in a PCIe Gen2 slot. 366 */ 367 dev_info(&pdev->dev, 368 "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n"); 369 pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi); 370 addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4); 371 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo); 372 pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0); 373 } 374 375 static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type) 376 { 377 struct pci_dn *pdn; 378 int hwirq, virq, i, quota, rc; 379 struct msi_desc *entry; 380 struct msi_msg msg; 381 int nvec = nvec_in; 382 int use_32bit_msi_hack = 0; 383 384 if (type == PCI_CAP_ID_MSIX) 385 rc = check_req_msix(pdev, nvec); 386 else 387 rc = check_req_msi(pdev, nvec); 388 389 if (rc) 390 return rc; 391 392 quota = msi_quota_for_device(pdev, nvec); 393 394 if (quota && quota < nvec) 395 return quota; 396 397 if (type == PCI_CAP_ID_MSIX && check_msix_entries(pdev)) 398 return -EINVAL; 399 400 /* 401 * Firmware currently refuse any non power of two allocation 402 * so we round up if the quota will allow it. 403 */ 404 if (type == PCI_CAP_ID_MSIX) { 405 int m = roundup_pow_of_two(nvec); 406 quota = msi_quota_for_device(pdev, m); 407 408 if (quota >= m) 409 nvec = m; 410 } 411 412 pdn = pci_get_pdn(pdev); 413 414 /* 415 * Try the new more explicit firmware interface, if that fails fall 416 * back to the old interface. The old interface is known to never 417 * return MSI-Xs. 418 */ 419 again: 420 if (type == PCI_CAP_ID_MSI) { 421 if (pdev->no_64bit_msi) { 422 rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec); 423 if (rc < 0) { 424 /* 425 * We only want to run the 32 bit MSI hack below if 426 * the max bus speed is Gen2 speed 427 */ 428 if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT) 429 return rc; 430 431 use_32bit_msi_hack = 1; 432 } 433 } else 434 rc = -1; 435 436 if (rc < 0) 437 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec); 438 439 if (rc < 0) { 440 pr_debug("rtas_msi: trying the old firmware call.\n"); 441 rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec); 442 } 443 444 if (use_32bit_msi_hack && rc > 0) 445 rtas_hack_32bit_msi_gen2(pdev); 446 } else 447 rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec); 448 449 if (rc != nvec) { 450 if (nvec != nvec_in) { 451 nvec = nvec_in; 452 goto again; 453 } 454 pr_debug("rtas_msi: rtas_change_msi() failed\n"); 455 return rc; 456 } 457 458 i = 0; 459 for_each_pci_msi_entry(entry, pdev) { 460 hwirq = rtas_query_irq_number(pdn, i++); 461 if (hwirq < 0) { 462 pr_debug("rtas_msi: error (%d) getting hwirq\n", rc); 463 return hwirq; 464 } 465 466 virq = irq_create_mapping(NULL, hwirq); 467 468 if (!virq) { 469 pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq); 470 return -ENOSPC; 471 } 472 473 dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq); 474 irq_set_msi_desc(virq, entry); 475 476 /* Read config space back so we can restore after reset */ 477 __pci_read_msi_msg(entry, &msg); 478 entry->msg = msg; 479 } 480 481 return 0; 482 } 483 484 static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev) 485 { 486 /* No LSI -> leave MSIs (if any) configured */ 487 if (!pdev->irq) { 488 dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n"); 489 return; 490 } 491 492 /* No MSI -> MSIs can't have been assigned by fw, leave LSI */ 493 if (check_req_msi(pdev, 1) && check_req_msix(pdev, 1)) { 494 dev_dbg(&pdev->dev, "rtas_msi: no req#msi/x, nothing to do.\n"); 495 return; 496 } 497 498 dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n"); 499 rtas_disable_msi(pdev); 500 } 501 502 static int rtas_msi_init(void) 503 { 504 struct pci_controller *phb; 505 506 query_token = rtas_token("ibm,query-interrupt-source-number"); 507 change_token = rtas_token("ibm,change-msi"); 508 509 if ((query_token == RTAS_UNKNOWN_SERVICE) || 510 (change_token == RTAS_UNKNOWN_SERVICE)) { 511 pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n"); 512 return -1; 513 } 514 515 pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n"); 516 517 WARN_ON(pseries_pci_controller_ops.setup_msi_irqs); 518 pseries_pci_controller_ops.setup_msi_irqs = rtas_setup_msi_irqs; 519 pseries_pci_controller_ops.teardown_msi_irqs = rtas_teardown_msi_irqs; 520 521 list_for_each_entry(phb, &hose_list, list_node) { 522 WARN_ON(phb->controller_ops.setup_msi_irqs); 523 phb->controller_ops.setup_msi_irqs = rtas_setup_msi_irqs; 524 phb->controller_ops.teardown_msi_irqs = rtas_teardown_msi_irqs; 525 } 526 527 WARN_ON(ppc_md.pci_irq_fixup); 528 ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup; 529 530 return 0; 531 } 532 machine_arch_initcall(pseries, rtas_msi_init); 533