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_wakeup_event(pci_dev); 50 pci_check_pme_status(pci_dev); 51 pm_runtime_resume(&pci_dev->dev); 52 if (pci_dev->subordinate) 53 pci_pme_wakeup_bus(pci_dev->subordinate); 54 } 55 } 56 57 /** 58 * add_pm_notifier - Register PM notifier for given ACPI device. 59 * @dev: ACPI device to add the notifier for. 60 * @context: PCI device or bus to check for PME status if an event is signaled. 61 * 62 * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of 63 * PM wake-up events. For example, wake-up events may be generated for bridges 64 * if one of the devices below the bridge is signaling PME, even if the bridge 65 * itself doesn't have a wake-up GPE associated with it. 66 */ 67 static acpi_status add_pm_notifier(struct acpi_device *dev, 68 acpi_notify_handler handler, 69 void *context) 70 { 71 acpi_status status = AE_ALREADY_EXISTS; 72 73 mutex_lock(&pci_acpi_pm_notify_mtx); 74 75 if (dev->wakeup.flags.notifier_present) 76 goto out; 77 78 status = acpi_install_notify_handler(dev->handle, 79 ACPI_SYSTEM_NOTIFY, 80 handler, context); 81 if (ACPI_FAILURE(status)) 82 goto out; 83 84 dev->wakeup.flags.notifier_present = true; 85 86 out: 87 mutex_unlock(&pci_acpi_pm_notify_mtx); 88 return status; 89 } 90 91 /** 92 * remove_pm_notifier - Unregister PM notifier from given ACPI device. 93 * @dev: ACPI device to remove the notifier from. 94 */ 95 static acpi_status remove_pm_notifier(struct acpi_device *dev, 96 acpi_notify_handler handler) 97 { 98 acpi_status status = AE_BAD_PARAMETER; 99 100 mutex_lock(&pci_acpi_pm_notify_mtx); 101 102 if (!dev->wakeup.flags.notifier_present) 103 goto out; 104 105 status = acpi_remove_notify_handler(dev->handle, 106 ACPI_SYSTEM_NOTIFY, 107 handler); 108 if (ACPI_FAILURE(status)) 109 goto out; 110 111 dev->wakeup.flags.notifier_present = false; 112 113 out: 114 mutex_unlock(&pci_acpi_pm_notify_mtx); 115 return status; 116 } 117 118 /** 119 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus. 120 * @dev: ACPI device to add the notifier for. 121 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled. 122 */ 123 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev, 124 struct pci_bus *pci_bus) 125 { 126 return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus); 127 } 128 129 /** 130 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier. 131 * @dev: ACPI device to remove the notifier from. 132 */ 133 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev) 134 { 135 return remove_pm_notifier(dev, pci_acpi_wake_bus); 136 } 137 138 /** 139 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device. 140 * @dev: ACPI device to add the notifier for. 141 * @pci_dev: PCI device to check for the PME status if an event is signaled. 142 */ 143 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev, 144 struct pci_dev *pci_dev) 145 { 146 return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev); 147 } 148 149 /** 150 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier. 151 * @dev: ACPI device to remove the notifier from. 152 */ 153 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev) 154 { 155 return remove_pm_notifier(dev, pci_acpi_wake_dev); 156 } 157 158 /* 159 * _SxD returns the D-state with the highest power 160 * (lowest D-state number) supported in the S-state "x". 161 * 162 * If the devices does not have a _PRW 163 * (Power Resources for Wake) supporting system wakeup from "x" 164 * then the OS is free to choose a lower power (higher number 165 * D-state) than the return value from _SxD. 166 * 167 * But if _PRW is enabled at S-state "x", the OS 168 * must not choose a power lower than _SxD -- 169 * unless the device has an _SxW method specifying 170 * the lowest power (highest D-state number) the device 171 * may enter while still able to wake the system. 172 * 173 * ie. depending on global OS policy: 174 * 175 * if (_PRW at S-state x) 176 * choose from highest power _SxD to lowest power _SxW 177 * else // no _PRW at S-state x 178 * choose highest power _SxD or any lower power 179 */ 180 181 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) 182 { 183 int acpi_state; 184 185 acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL); 186 if (acpi_state < 0) 187 return PCI_POWER_ERROR; 188 189 switch (acpi_state) { 190 case ACPI_STATE_D0: 191 return PCI_D0; 192 case ACPI_STATE_D1: 193 return PCI_D1; 194 case ACPI_STATE_D2: 195 return PCI_D2; 196 case ACPI_STATE_D3: 197 return PCI_D3hot; 198 case ACPI_STATE_D3_COLD: 199 return PCI_D3cold; 200 } 201 return PCI_POWER_ERROR; 202 } 203 204 static bool acpi_pci_power_manageable(struct pci_dev *dev) 205 { 206 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 207 208 return handle ? acpi_bus_power_manageable(handle) : false; 209 } 210 211 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state) 212 { 213 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 214 acpi_handle tmp; 215 static const u8 state_conv[] = { 216 [PCI_D0] = ACPI_STATE_D0, 217 [PCI_D1] = ACPI_STATE_D1, 218 [PCI_D2] = ACPI_STATE_D2, 219 [PCI_D3hot] = ACPI_STATE_D3, 220 [PCI_D3cold] = ACPI_STATE_D3 221 }; 222 int error = -EINVAL; 223 224 /* If the ACPI device has _EJ0, ignore the device */ 225 if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp))) 226 return -ENODEV; 227 228 switch (state) { 229 case PCI_D0: 230 case PCI_D1: 231 case PCI_D2: 232 case PCI_D3hot: 233 case PCI_D3cold: 234 error = acpi_bus_set_power(handle, state_conv[state]); 235 } 236 237 if (!error) 238 dev_printk(KERN_INFO, &dev->dev, 239 "power state changed by ACPI to D%d\n", state); 240 241 return error; 242 } 243 244 static bool acpi_pci_can_wakeup(struct pci_dev *dev) 245 { 246 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 247 248 return handle ? acpi_bus_can_wakeup(handle) : false; 249 } 250 251 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable) 252 { 253 while (bus->parent) { 254 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable)) 255 return; 256 bus = bus->parent; 257 } 258 259 /* We have reached the root bus. */ 260 if (bus->bridge) 261 acpi_pm_device_sleep_wake(bus->bridge, enable); 262 } 263 264 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable) 265 { 266 if (acpi_pci_can_wakeup(dev)) 267 return acpi_pm_device_sleep_wake(&dev->dev, enable); 268 269 acpi_pci_propagate_wakeup_enable(dev->bus, enable); 270 return 0; 271 } 272 273 /** 274 * acpi_dev_run_wake - Enable/disable wake-up for given device. 275 * @phys_dev: Device to enable/disable the platform to wake-up the system for. 276 * @enable: Whether enable or disable the wake-up functionality. 277 * 278 * Find the ACPI device object corresponding to @pci_dev and try to 279 * enable/disable the GPE associated with it. 280 */ 281 static int acpi_dev_run_wake(struct device *phys_dev, bool enable) 282 { 283 struct acpi_device *dev; 284 acpi_handle handle; 285 int error = -ENODEV; 286 287 if (!device_run_wake(phys_dev)) 288 return -EINVAL; 289 290 handle = DEVICE_ACPI_HANDLE(phys_dev); 291 if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) { 292 dev_dbg(phys_dev, "ACPI handle has no context in %s!\n", 293 __func__); 294 return -ENODEV; 295 } 296 297 if (enable) { 298 acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0); 299 acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number); 300 } else { 301 acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number); 302 acpi_disable_wakeup_device_power(dev); 303 } 304 305 return error; 306 } 307 308 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable) 309 { 310 while (bus->parent) { 311 struct pci_dev *bridge = bus->self; 312 313 if (bridge->pme_interrupt) 314 return; 315 if (!acpi_dev_run_wake(&bridge->dev, enable)) 316 return; 317 bus = bus->parent; 318 } 319 320 /* We have reached the root bus. */ 321 if (bus->bridge) 322 acpi_dev_run_wake(bus->bridge, enable); 323 } 324 325 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable) 326 { 327 if (dev->pme_interrupt) 328 return 0; 329 330 if (!acpi_dev_run_wake(&dev->dev, enable)) 331 return 0; 332 333 acpi_pci_propagate_run_wake(dev->bus, enable); 334 return 0; 335 } 336 337 static struct pci_platform_pm_ops acpi_pci_platform_pm = { 338 .is_manageable = acpi_pci_power_manageable, 339 .set_state = acpi_pci_set_power_state, 340 .choose_state = acpi_pci_choose_state, 341 .can_wakeup = acpi_pci_can_wakeup, 342 .sleep_wake = acpi_pci_sleep_wake, 343 .run_wake = acpi_pci_run_wake, 344 }; 345 346 /* ACPI bus type */ 347 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) 348 { 349 struct pci_dev * pci_dev; 350 u64 addr; 351 352 pci_dev = to_pci_dev(dev); 353 /* Please ref to ACPI spec for the syntax of _ADR */ 354 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); 355 *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr); 356 if (!*handle) 357 return -ENODEV; 358 return 0; 359 } 360 361 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle) 362 { 363 int num; 364 unsigned int seg, bus; 365 366 /* 367 * The string should be the same as root bridge's name 368 * Please look at 'pci_scan_bus_parented' 369 */ 370 num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus); 371 if (num != 2) 372 return -ENODEV; 373 *handle = acpi_get_pci_rootbridge_handle(seg, bus); 374 if (!*handle) 375 return -ENODEV; 376 return 0; 377 } 378 379 static struct acpi_bus_type acpi_pci_bus = { 380 .bus = &pci_bus_type, 381 .find_device = acpi_pci_find_device, 382 .find_bridge = acpi_pci_find_root_bridge, 383 }; 384 385 static int __init acpi_pci_init(void) 386 { 387 int ret; 388 389 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) { 390 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n"); 391 pci_no_msi(); 392 } 393 394 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { 395 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n"); 396 pcie_clear_aspm(); 397 pcie_no_aspm(); 398 } 399 400 ret = register_acpi_bus_type(&acpi_pci_bus); 401 if (ret) 402 return 0; 403 pci_set_platform_pm(&acpi_pci_platform_pm); 404 return 0; 405 } 406 arch_initcall(acpi_pci_init); 407