1 /* 2 * File: pci-acpi.c 3 * Purpose: Provide PCI support in ACPI 4 * 5 * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com> 6 * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com> 7 * Copyright (C) 2004 Intel Corp. 8 */ 9 10 #include <linux/delay.h> 11 #include <linux/init.h> 12 #include <linux/pci.h> 13 #include <linux/module.h> 14 #include <linux/pci-aspm.h> 15 #include <acpi/acpi.h> 16 #include <acpi/acpi_bus.h> 17 18 #include <linux/pci-acpi.h> 19 #include <linux/pm_runtime.h> 20 #include "pci.h" 21 22 static DEFINE_MUTEX(pci_acpi_pm_notify_mtx); 23 24 /** 25 * pci_acpi_wake_bus - Wake-up notification handler for root buses. 26 * @handle: ACPI handle of a device the notification is for. 27 * @event: Type of the signaled event. 28 * @context: PCI root bus to wake up devices on. 29 */ 30 static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context) 31 { 32 struct pci_bus *pci_bus = context; 33 34 if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus) 35 pci_pme_wakeup_bus(pci_bus); 36 } 37 38 /** 39 * pci_acpi_wake_dev - Wake-up notification handler for PCI devices. 40 * @handle: ACPI handle of a device the notification is for. 41 * @event: Type of the signaled event. 42 * @context: PCI device object to wake up. 43 */ 44 static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context) 45 { 46 struct pci_dev *pci_dev = context; 47 48 if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_dev) { 49 pci_check_pme_status(pci_dev); 50 pm_runtime_resume(&pci_dev->dev); 51 if (pci_dev->subordinate) 52 pci_pme_wakeup_bus(pci_dev->subordinate); 53 } 54 } 55 56 /** 57 * add_pm_notifier - Register PM notifier for given ACPI device. 58 * @dev: ACPI device to add the notifier for. 59 * @context: PCI device or bus to check for PME status if an event is signaled. 60 * 61 * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of 62 * PM wake-up events. For example, wake-up events may be generated for bridges 63 * if one of the devices below the bridge is signaling PME, even if the bridge 64 * itself doesn't have a wake-up GPE associated with it. 65 */ 66 static acpi_status add_pm_notifier(struct acpi_device *dev, 67 acpi_notify_handler handler, 68 void *context) 69 { 70 acpi_status status = AE_ALREADY_EXISTS; 71 72 mutex_lock(&pci_acpi_pm_notify_mtx); 73 74 if (dev->wakeup.flags.notifier_present) 75 goto out; 76 77 status = acpi_install_notify_handler(dev->handle, 78 ACPI_SYSTEM_NOTIFY, 79 handler, context); 80 if (ACPI_FAILURE(status)) 81 goto out; 82 83 dev->wakeup.flags.notifier_present = true; 84 85 out: 86 mutex_unlock(&pci_acpi_pm_notify_mtx); 87 return status; 88 } 89 90 /** 91 * remove_pm_notifier - Unregister PM notifier from given ACPI device. 92 * @dev: ACPI device to remove the notifier from. 93 */ 94 static acpi_status remove_pm_notifier(struct acpi_device *dev, 95 acpi_notify_handler handler) 96 { 97 acpi_status status = AE_BAD_PARAMETER; 98 99 mutex_lock(&pci_acpi_pm_notify_mtx); 100 101 if (!dev->wakeup.flags.notifier_present) 102 goto out; 103 104 status = acpi_remove_notify_handler(dev->handle, 105 ACPI_SYSTEM_NOTIFY, 106 handler); 107 if (ACPI_FAILURE(status)) 108 goto out; 109 110 dev->wakeup.flags.notifier_present = false; 111 112 out: 113 mutex_unlock(&pci_acpi_pm_notify_mtx); 114 return status; 115 } 116 117 /** 118 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus. 119 * @dev: ACPI device to add the notifier for. 120 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled. 121 */ 122 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev, 123 struct pci_bus *pci_bus) 124 { 125 return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus); 126 } 127 128 /** 129 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier. 130 * @dev: ACPI device to remove the notifier from. 131 */ 132 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev) 133 { 134 return remove_pm_notifier(dev, pci_acpi_wake_bus); 135 } 136 137 /** 138 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device. 139 * @dev: ACPI device to add the notifier for. 140 * @pci_dev: PCI device to check for the PME status if an event is signaled. 141 */ 142 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev, 143 struct pci_dev *pci_dev) 144 { 145 return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev); 146 } 147 148 /** 149 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier. 150 * @dev: ACPI device to remove the notifier from. 151 */ 152 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev) 153 { 154 return remove_pm_notifier(dev, pci_acpi_wake_dev); 155 } 156 157 /* 158 * _SxD returns the D-state with the highest power 159 * (lowest D-state number) supported in the S-state "x". 160 * 161 * If the devices does not have a _PRW 162 * (Power Resources for Wake) supporting system wakeup from "x" 163 * then the OS is free to choose a lower power (higher number 164 * D-state) than the return value from _SxD. 165 * 166 * But if _PRW is enabled at S-state "x", the OS 167 * must not choose a power lower than _SxD -- 168 * unless the device has an _SxW method specifying 169 * the lowest power (highest D-state number) the device 170 * may enter while still able to wake the system. 171 * 172 * ie. depending on global OS policy: 173 * 174 * if (_PRW at S-state x) 175 * choose from highest power _SxD to lowest power _SxW 176 * else // no _PRW at S-state x 177 * choose highest power _SxD or any lower power 178 */ 179 180 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) 181 { 182 int acpi_state; 183 184 acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL); 185 if (acpi_state < 0) 186 return PCI_POWER_ERROR; 187 188 switch (acpi_state) { 189 case ACPI_STATE_D0: 190 return PCI_D0; 191 case ACPI_STATE_D1: 192 return PCI_D1; 193 case ACPI_STATE_D2: 194 return PCI_D2; 195 case ACPI_STATE_D3: 196 return PCI_D3hot; 197 } 198 return PCI_POWER_ERROR; 199 } 200 201 static bool acpi_pci_power_manageable(struct pci_dev *dev) 202 { 203 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 204 205 return handle ? acpi_bus_power_manageable(handle) : false; 206 } 207 208 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state) 209 { 210 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 211 acpi_handle tmp; 212 static const u8 state_conv[] = { 213 [PCI_D0] = ACPI_STATE_D0, 214 [PCI_D1] = ACPI_STATE_D1, 215 [PCI_D2] = ACPI_STATE_D2, 216 [PCI_D3hot] = ACPI_STATE_D3, 217 [PCI_D3cold] = ACPI_STATE_D3 218 }; 219 int error = -EINVAL; 220 221 /* If the ACPI device has _EJ0, ignore the device */ 222 if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp))) 223 return -ENODEV; 224 225 switch (state) { 226 case PCI_D0: 227 case PCI_D1: 228 case PCI_D2: 229 case PCI_D3hot: 230 case PCI_D3cold: 231 error = acpi_bus_set_power(handle, state_conv[state]); 232 } 233 234 if (!error) 235 dev_printk(KERN_INFO, &dev->dev, 236 "power state changed by ACPI to D%d\n", state); 237 238 return error; 239 } 240 241 static bool acpi_pci_can_wakeup(struct pci_dev *dev) 242 { 243 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 244 245 return handle ? acpi_bus_can_wakeup(handle) : false; 246 } 247 248 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable) 249 { 250 while (bus->parent) { 251 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable)) 252 return; 253 bus = bus->parent; 254 } 255 256 /* We have reached the root bus. */ 257 if (bus->bridge) 258 acpi_pm_device_sleep_wake(bus->bridge, enable); 259 } 260 261 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable) 262 { 263 if (acpi_pci_can_wakeup(dev)) 264 return acpi_pm_device_sleep_wake(&dev->dev, enable); 265 266 acpi_pci_propagate_wakeup_enable(dev->bus, enable); 267 return 0; 268 } 269 270 /** 271 * acpi_dev_run_wake - Enable/disable wake-up for given device. 272 * @phys_dev: Device to enable/disable the platform to wake-up the system for. 273 * @enable: Whether enable or disable the wake-up functionality. 274 * 275 * Find the ACPI device object corresponding to @pci_dev and try to 276 * enable/disable the GPE associated with it. 277 */ 278 static int acpi_dev_run_wake(struct device *phys_dev, bool enable) 279 { 280 struct acpi_device *dev; 281 acpi_handle handle; 282 int error = -ENODEV; 283 284 if (!device_run_wake(phys_dev)) 285 return -EINVAL; 286 287 handle = DEVICE_ACPI_HANDLE(phys_dev); 288 if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) { 289 dev_dbg(phys_dev, "ACPI handle has no context in %s!\n", 290 __func__); 291 return -ENODEV; 292 } 293 294 if (enable) { 295 if (!dev->wakeup.run_wake_count++) { 296 acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0); 297 acpi_enable_gpe(dev->wakeup.gpe_device, 298 dev->wakeup.gpe_number, 299 ACPI_GPE_TYPE_RUNTIME); 300 } 301 } else if (dev->wakeup.run_wake_count > 0) { 302 if (!--dev->wakeup.run_wake_count) { 303 acpi_disable_gpe(dev->wakeup.gpe_device, 304 dev->wakeup.gpe_number, 305 ACPI_GPE_TYPE_RUNTIME); 306 acpi_disable_wakeup_device_power(dev); 307 } 308 } else { 309 error = -EALREADY; 310 } 311 312 return error; 313 } 314 315 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable) 316 { 317 while (bus->parent) { 318 struct pci_dev *bridge = bus->self; 319 320 if (bridge->pme_interrupt) 321 return; 322 if (!acpi_dev_run_wake(&bridge->dev, enable)) 323 return; 324 bus = bus->parent; 325 } 326 327 /* We have reached the root bus. */ 328 if (bus->bridge) 329 acpi_dev_run_wake(bus->bridge, enable); 330 } 331 332 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable) 333 { 334 if (dev->pme_interrupt) 335 return 0; 336 337 if (!acpi_dev_run_wake(&dev->dev, enable)) 338 return 0; 339 340 acpi_pci_propagate_run_wake(dev->bus, enable); 341 return 0; 342 } 343 344 static struct pci_platform_pm_ops acpi_pci_platform_pm = { 345 .is_manageable = acpi_pci_power_manageable, 346 .set_state = acpi_pci_set_power_state, 347 .choose_state = acpi_pci_choose_state, 348 .can_wakeup = acpi_pci_can_wakeup, 349 .sleep_wake = acpi_pci_sleep_wake, 350 .run_wake = acpi_pci_run_wake, 351 }; 352 353 /* ACPI bus type */ 354 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) 355 { 356 struct pci_dev * pci_dev; 357 u64 addr; 358 359 pci_dev = to_pci_dev(dev); 360 /* Please ref to ACPI spec for the syntax of _ADR */ 361 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); 362 *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr); 363 if (!*handle) 364 return -ENODEV; 365 return 0; 366 } 367 368 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle) 369 { 370 int num; 371 unsigned int seg, bus; 372 373 /* 374 * The string should be the same as root bridge's name 375 * Please look at 'pci_scan_bus_parented' 376 */ 377 num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus); 378 if (num != 2) 379 return -ENODEV; 380 *handle = acpi_get_pci_rootbridge_handle(seg, bus); 381 if (!*handle) 382 return -ENODEV; 383 return 0; 384 } 385 386 static struct acpi_bus_type acpi_pci_bus = { 387 .bus = &pci_bus_type, 388 .find_device = acpi_pci_find_device, 389 .find_bridge = acpi_pci_find_root_bridge, 390 }; 391 392 static int __init acpi_pci_init(void) 393 { 394 int ret; 395 396 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) { 397 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n"); 398 pci_no_msi(); 399 } 400 401 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { 402 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n"); 403 pcie_no_aspm(); 404 } 405 406 ret = register_acpi_bus_type(&acpi_pci_bus); 407 if (ret) 408 return 0; 409 pci_set_platform_pm(&acpi_pci_platform_pm); 410 return 0; 411 } 412 arch_initcall(acpi_pci_init); 413