1 /* 2 * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License as published by the Free 6 * Software Foundation; either version 2 of the License, or (at your option) 7 * any later version. 8 * 9 * This program is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 12 * more details. 13 * 14 * You should have received a copy of the GNU General Public License along with 15 * this program; if not, write to the Free Software Foundation, Inc., 59 16 * Temple Place - Suite 330, Boston, MA 02111-1307, USA. 17 * 18 * The full GNU General Public License is included in this distribution in the 19 * file called COPYING. 20 */ 21 22 /* 23 * This driver supports an interface for DCA clients and providers to meet. 24 */ 25 26 #include <linux/kernel.h> 27 #include <linux/notifier.h> 28 #include <linux/device.h> 29 #include <linux/dca.h> 30 #include <linux/slab.h> 31 32 #define DCA_VERSION "1.12.1" 33 34 MODULE_VERSION(DCA_VERSION); 35 MODULE_LICENSE("GPL"); 36 MODULE_AUTHOR("Intel Corporation"); 37 38 static DEFINE_SPINLOCK(dca_lock); 39 40 static LIST_HEAD(dca_domains); 41 42 static BLOCKING_NOTIFIER_HEAD(dca_provider_chain); 43 44 static int dca_providers_blocked; 45 46 static struct pci_bus *dca_pci_rc_from_dev(struct device *dev) 47 { 48 struct pci_dev *pdev = to_pci_dev(dev); 49 struct pci_bus *bus = pdev->bus; 50 51 while (bus->parent) 52 bus = bus->parent; 53 54 return bus; 55 } 56 57 static struct dca_domain *dca_allocate_domain(struct pci_bus *rc) 58 { 59 struct dca_domain *domain; 60 61 domain = kzalloc(sizeof(*domain), GFP_NOWAIT); 62 if (!domain) 63 return NULL; 64 65 INIT_LIST_HEAD(&domain->dca_providers); 66 domain->pci_rc = rc; 67 68 return domain; 69 } 70 71 static void dca_free_domain(struct dca_domain *domain) 72 { 73 list_del(&domain->node); 74 kfree(domain); 75 } 76 77 static int dca_provider_ioat_ver_3_0(struct device *dev) 78 { 79 struct pci_dev *pdev = to_pci_dev(dev); 80 81 return ((pdev->vendor == PCI_VENDOR_ID_INTEL) && 82 ((pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG0) || 83 (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG1) || 84 (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG2) || 85 (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG3) || 86 (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG4) || 87 (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG5) || 88 (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG6) || 89 (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG7))); 90 } 91 92 static void unregister_dca_providers(void) 93 { 94 struct dca_provider *dca, *_dca; 95 struct list_head unregistered_providers; 96 struct dca_domain *domain; 97 unsigned long flags; 98 99 blocking_notifier_call_chain(&dca_provider_chain, 100 DCA_PROVIDER_REMOVE, NULL); 101 102 INIT_LIST_HEAD(&unregistered_providers); 103 104 spin_lock_irqsave(&dca_lock, flags); 105 106 if (list_empty(&dca_domains)) { 107 spin_unlock_irqrestore(&dca_lock, flags); 108 return; 109 } 110 111 /* at this point only one domain in the list is expected */ 112 domain = list_first_entry(&dca_domains, struct dca_domain, node); 113 114 list_for_each_entry_safe(dca, _dca, &domain->dca_providers, node) 115 list_move(&dca->node, &unregistered_providers); 116 117 dca_free_domain(domain); 118 119 spin_unlock_irqrestore(&dca_lock, flags); 120 121 list_for_each_entry_safe(dca, _dca, &unregistered_providers, node) { 122 dca_sysfs_remove_provider(dca); 123 list_del(&dca->node); 124 } 125 } 126 127 static struct dca_domain *dca_find_domain(struct pci_bus *rc) 128 { 129 struct dca_domain *domain; 130 131 list_for_each_entry(domain, &dca_domains, node) 132 if (domain->pci_rc == rc) 133 return domain; 134 135 return NULL; 136 } 137 138 static struct dca_domain *dca_get_domain(struct device *dev) 139 { 140 struct pci_bus *rc; 141 struct dca_domain *domain; 142 143 rc = dca_pci_rc_from_dev(dev); 144 domain = dca_find_domain(rc); 145 146 if (!domain) { 147 if (dca_provider_ioat_ver_3_0(dev) && !list_empty(&dca_domains)) { 148 dca_providers_blocked = 1; 149 } else { 150 domain = dca_allocate_domain(rc); 151 if (domain) 152 list_add(&domain->node, &dca_domains); 153 } 154 } 155 156 return domain; 157 } 158 159 static struct dca_provider *dca_find_provider_by_dev(struct device *dev) 160 { 161 struct dca_provider *dca; 162 struct pci_bus *rc; 163 struct dca_domain *domain; 164 165 if (dev) { 166 rc = dca_pci_rc_from_dev(dev); 167 domain = dca_find_domain(rc); 168 if (!domain) 169 return NULL; 170 } else { 171 if (!list_empty(&dca_domains)) 172 domain = list_first_entry(&dca_domains, 173 struct dca_domain, 174 node); 175 else 176 return NULL; 177 } 178 179 list_for_each_entry(dca, &domain->dca_providers, node) 180 if ((!dev) || (dca->ops->dev_managed(dca, dev))) 181 return dca; 182 183 return NULL; 184 } 185 186 /** 187 * dca_add_requester - add a dca client to the list 188 * @dev - the device that wants dca service 189 */ 190 int dca_add_requester(struct device *dev) 191 { 192 struct dca_provider *dca; 193 int err, slot = -ENODEV; 194 unsigned long flags; 195 struct pci_bus *pci_rc; 196 struct dca_domain *domain; 197 198 if (!dev) 199 return -EFAULT; 200 201 spin_lock_irqsave(&dca_lock, flags); 202 203 /* check if the requester has not been added already */ 204 dca = dca_find_provider_by_dev(dev); 205 if (dca) { 206 spin_unlock_irqrestore(&dca_lock, flags); 207 return -EEXIST; 208 } 209 210 pci_rc = dca_pci_rc_from_dev(dev); 211 domain = dca_find_domain(pci_rc); 212 if (!domain) { 213 spin_unlock_irqrestore(&dca_lock, flags); 214 return -ENODEV; 215 } 216 217 list_for_each_entry(dca, &domain->dca_providers, node) { 218 slot = dca->ops->add_requester(dca, dev); 219 if (slot >= 0) 220 break; 221 } 222 223 spin_unlock_irqrestore(&dca_lock, flags); 224 225 if (slot < 0) 226 return slot; 227 228 err = dca_sysfs_add_req(dca, dev, slot); 229 if (err) { 230 spin_lock_irqsave(&dca_lock, flags); 231 if (dca == dca_find_provider_by_dev(dev)) 232 dca->ops->remove_requester(dca, dev); 233 spin_unlock_irqrestore(&dca_lock, flags); 234 return err; 235 } 236 237 return 0; 238 } 239 EXPORT_SYMBOL_GPL(dca_add_requester); 240 241 /** 242 * dca_remove_requester - remove a dca client from the list 243 * @dev - the device that wants dca service 244 */ 245 int dca_remove_requester(struct device *dev) 246 { 247 struct dca_provider *dca; 248 int slot; 249 unsigned long flags; 250 251 if (!dev) 252 return -EFAULT; 253 254 spin_lock_irqsave(&dca_lock, flags); 255 dca = dca_find_provider_by_dev(dev); 256 if (!dca) { 257 spin_unlock_irqrestore(&dca_lock, flags); 258 return -ENODEV; 259 } 260 slot = dca->ops->remove_requester(dca, dev); 261 spin_unlock_irqrestore(&dca_lock, flags); 262 263 if (slot < 0) 264 return slot; 265 266 dca_sysfs_remove_req(dca, slot); 267 268 return 0; 269 } 270 EXPORT_SYMBOL_GPL(dca_remove_requester); 271 272 /** 273 * dca_common_get_tag - return the dca tag (serves both new and old api) 274 * @dev - the device that wants dca service 275 * @cpu - the cpuid as returned by get_cpu() 276 */ 277 u8 dca_common_get_tag(struct device *dev, int cpu) 278 { 279 struct dca_provider *dca; 280 u8 tag; 281 unsigned long flags; 282 283 spin_lock_irqsave(&dca_lock, flags); 284 285 dca = dca_find_provider_by_dev(dev); 286 if (!dca) { 287 spin_unlock_irqrestore(&dca_lock, flags); 288 return -ENODEV; 289 } 290 tag = dca->ops->get_tag(dca, dev, cpu); 291 292 spin_unlock_irqrestore(&dca_lock, flags); 293 return tag; 294 } 295 296 /** 297 * dca3_get_tag - return the dca tag to the requester device 298 * for the given cpu (new api) 299 * @dev - the device that wants dca service 300 * @cpu - the cpuid as returned by get_cpu() 301 */ 302 u8 dca3_get_tag(struct device *dev, int cpu) 303 { 304 if (!dev) 305 return -EFAULT; 306 307 return dca_common_get_tag(dev, cpu); 308 } 309 EXPORT_SYMBOL_GPL(dca3_get_tag); 310 311 /** 312 * dca_get_tag - return the dca tag for the given cpu (old api) 313 * @cpu - the cpuid as returned by get_cpu() 314 */ 315 u8 dca_get_tag(int cpu) 316 { 317 struct device *dev = NULL; 318 319 return dca_common_get_tag(dev, cpu); 320 } 321 EXPORT_SYMBOL_GPL(dca_get_tag); 322 323 /** 324 * alloc_dca_provider - get data struct for describing a dca provider 325 * @ops - pointer to struct of dca operation function pointers 326 * @priv_size - size of extra mem to be added for provider's needs 327 */ 328 struct dca_provider *alloc_dca_provider(struct dca_ops *ops, int priv_size) 329 { 330 struct dca_provider *dca; 331 int alloc_size; 332 333 alloc_size = (sizeof(*dca) + priv_size); 334 dca = kzalloc(alloc_size, GFP_KERNEL); 335 if (!dca) 336 return NULL; 337 dca->ops = ops; 338 339 return dca; 340 } 341 EXPORT_SYMBOL_GPL(alloc_dca_provider); 342 343 /** 344 * free_dca_provider - release the dca provider data struct 345 * @ops - pointer to struct of dca operation function pointers 346 * @priv_size - size of extra mem to be added for provider's needs 347 */ 348 void free_dca_provider(struct dca_provider *dca) 349 { 350 kfree(dca); 351 } 352 EXPORT_SYMBOL_GPL(free_dca_provider); 353 354 /** 355 * register_dca_provider - register a dca provider 356 * @dca - struct created by alloc_dca_provider() 357 * @dev - device providing dca services 358 */ 359 int register_dca_provider(struct dca_provider *dca, struct device *dev) 360 { 361 int err; 362 unsigned long flags; 363 struct dca_domain *domain; 364 365 spin_lock_irqsave(&dca_lock, flags); 366 if (dca_providers_blocked) { 367 spin_unlock_irqrestore(&dca_lock, flags); 368 return -ENODEV; 369 } 370 spin_unlock_irqrestore(&dca_lock, flags); 371 372 err = dca_sysfs_add_provider(dca, dev); 373 if (err) 374 return err; 375 376 spin_lock_irqsave(&dca_lock, flags); 377 domain = dca_get_domain(dev); 378 if (!domain) { 379 if (dca_providers_blocked) { 380 spin_unlock_irqrestore(&dca_lock, flags); 381 dca_sysfs_remove_provider(dca); 382 unregister_dca_providers(); 383 } else { 384 spin_unlock_irqrestore(&dca_lock, flags); 385 } 386 return -ENODEV; 387 } 388 list_add(&dca->node, &domain->dca_providers); 389 spin_unlock_irqrestore(&dca_lock, flags); 390 391 blocking_notifier_call_chain(&dca_provider_chain, 392 DCA_PROVIDER_ADD, NULL); 393 return 0; 394 } 395 EXPORT_SYMBOL_GPL(register_dca_provider); 396 397 /** 398 * unregister_dca_provider - remove a dca provider 399 * @dca - struct created by alloc_dca_provider() 400 */ 401 void unregister_dca_provider(struct dca_provider *dca, struct device *dev) 402 { 403 unsigned long flags; 404 struct pci_bus *pci_rc; 405 struct dca_domain *domain; 406 407 blocking_notifier_call_chain(&dca_provider_chain, 408 DCA_PROVIDER_REMOVE, NULL); 409 410 spin_lock_irqsave(&dca_lock, flags); 411 412 list_del(&dca->node); 413 414 pci_rc = dca_pci_rc_from_dev(dev); 415 domain = dca_find_domain(pci_rc); 416 if (list_empty(&domain->dca_providers)) 417 dca_free_domain(domain); 418 419 spin_unlock_irqrestore(&dca_lock, flags); 420 421 dca_sysfs_remove_provider(dca); 422 } 423 EXPORT_SYMBOL_GPL(unregister_dca_provider); 424 425 /** 426 * dca_register_notify - register a client's notifier callback 427 */ 428 void dca_register_notify(struct notifier_block *nb) 429 { 430 blocking_notifier_chain_register(&dca_provider_chain, nb); 431 } 432 EXPORT_SYMBOL_GPL(dca_register_notify); 433 434 /** 435 * dca_unregister_notify - remove a client's notifier callback 436 */ 437 void dca_unregister_notify(struct notifier_block *nb) 438 { 439 blocking_notifier_chain_unregister(&dca_provider_chain, nb); 440 } 441 EXPORT_SYMBOL_GPL(dca_unregister_notify); 442 443 static int __init dca_init(void) 444 { 445 pr_info("dca service started, version %s\n", DCA_VERSION); 446 return dca_sysfs_init(); 447 } 448 449 static void __exit dca_exit(void) 450 { 451 dca_sysfs_exit(); 452 } 453 454 arch_initcall(dca_init); 455 module_exit(dca_exit); 456 457