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 22static 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 */ 30static 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 */ 44static 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 pci_wakeup_event(pci_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 */ 67static 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 */ 95static 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 */ 123acpi_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 */ 133acpi_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 */ 143acpi_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 */ 153acpi_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 181static 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 } 199 return PCI_POWER_ERROR; 200} 201 202static bool acpi_pci_power_manageable(struct pci_dev *dev) 203{ 204 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 205 206 return handle ? acpi_bus_power_manageable(handle) : false; 207} 208 209static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state) 210{ 211 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 212 acpi_handle tmp; 213 static const u8 state_conv[] = { 214 [PCI_D0] = ACPI_STATE_D0, 215 [PCI_D1] = ACPI_STATE_D1, 216 [PCI_D2] = ACPI_STATE_D2, 217 [PCI_D3hot] = ACPI_STATE_D3, 218 [PCI_D3cold] = ACPI_STATE_D3 219 }; 220 int error = -EINVAL; 221 222 /* If the ACPI device has _EJ0, ignore the device */ 223 if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp))) 224 return -ENODEV; 225 226 switch (state) { 227 case PCI_D0: 228 case PCI_D1: 229 case PCI_D2: 230 case PCI_D3hot: 231 case PCI_D3cold: 232 error = acpi_bus_set_power(handle, state_conv[state]); 233 } 234 235 if (!error) 236 dev_printk(KERN_INFO, &dev->dev, 237 "power state changed by ACPI to D%d\n", state); 238 239 return error; 240} 241 242static bool acpi_pci_can_wakeup(struct pci_dev *dev) 243{ 244 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 245 246 return handle ? acpi_bus_can_wakeup(handle) : false; 247} 248 249static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable) 250{ 251 while (bus->parent) { 252 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable)) 253 return; 254 bus = bus->parent; 255 } 256 257 /* We have reached the root bus. */ 258 if (bus->bridge) 259 acpi_pm_device_sleep_wake(bus->bridge, enable); 260} 261 262static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable) 263{ 264 if (acpi_pci_can_wakeup(dev)) 265 return acpi_pm_device_sleep_wake(&dev->dev, enable); 266 267 acpi_pci_propagate_wakeup_enable(dev->bus, enable); 268 return 0; 269} 270 271/** 272 * acpi_dev_run_wake - Enable/disable wake-up for given device. 273 * @phys_dev: Device to enable/disable the platform to wake-up the system for. 274 * @enable: Whether enable or disable the wake-up functionality. 275 * 276 * Find the ACPI device object corresponding to @pci_dev and try to 277 * enable/disable the GPE associated with it. 278 */ 279static int acpi_dev_run_wake(struct device *phys_dev, bool enable) 280{ 281 struct acpi_device *dev; 282 acpi_handle handle; 283 int error = -ENODEV; 284 285 if (!device_run_wake(phys_dev)) 286 return -EINVAL; 287 288 handle = DEVICE_ACPI_HANDLE(phys_dev); 289 if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) { 290 dev_dbg(phys_dev, "ACPI handle has no context in %s!\n", 291 __func__); 292 return -ENODEV; 293 } 294 295 if (enable) { 296 if (!dev->wakeup.run_wake_count++) { 297 acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0); 298 acpi_enable_gpe(dev->wakeup.gpe_device, 299 dev->wakeup.gpe_number); 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_disable_wakeup_device_power(dev); 306 } 307 } else { 308 error = -EALREADY; 309 } 310 311 return error; 312} 313 314static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable) 315{ 316 while (bus->parent) { 317 struct pci_dev *bridge = bus->self; 318 319 if (bridge->pme_interrupt) 320 return; 321 if (!acpi_dev_run_wake(&bridge->dev, enable)) 322 return; 323 bus = bus->parent; 324 } 325 326 /* We have reached the root bus. */ 327 if (bus->bridge) 328 acpi_dev_run_wake(bus->bridge, enable); 329} 330 331static int acpi_pci_run_wake(struct pci_dev *dev, bool enable) 332{ 333 if (dev->pme_interrupt) 334 return 0; 335 336 if (!acpi_dev_run_wake(&dev->dev, enable)) 337 return 0; 338 339 acpi_pci_propagate_run_wake(dev->bus, enable); 340 return 0; 341} 342 343static struct pci_platform_pm_ops acpi_pci_platform_pm = { 344 .is_manageable = acpi_pci_power_manageable, 345 .set_state = acpi_pci_set_power_state, 346 .choose_state = acpi_pci_choose_state, 347 .can_wakeup = acpi_pci_can_wakeup, 348 .sleep_wake = acpi_pci_sleep_wake, 349 .run_wake = acpi_pci_run_wake, 350}; 351 352/* ACPI bus type */ 353static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) 354{ 355 struct pci_dev * pci_dev; 356 u64 addr; 357 358 pci_dev = to_pci_dev(dev); 359 /* Please ref to ACPI spec for the syntax of _ADR */ 360 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); 361 *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr); 362 if (!*handle) 363 return -ENODEV; 364 return 0; 365} 366 367static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle) 368{ 369 int num; 370 unsigned int seg, bus; 371 372 /* 373 * The string should be the same as root bridge's name 374 * Please look at 'pci_scan_bus_parented' 375 */ 376 num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus); 377 if (num != 2) 378 return -ENODEV; 379 *handle = acpi_get_pci_rootbridge_handle(seg, bus); 380 if (!*handle) 381 return -ENODEV; 382 return 0; 383} 384 385static struct acpi_bus_type acpi_pci_bus = { 386 .bus = &pci_bus_type, 387 .find_device = acpi_pci_find_device, 388 .find_bridge = acpi_pci_find_root_bridge, 389}; 390 391static int __init acpi_pci_init(void) 392{ 393 int ret; 394 395 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) { 396 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n"); 397 pci_no_msi(); 398 } 399 400 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { 401 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n"); 402 pcie_no_aspm(); 403 } 404 405 ret = register_acpi_bus_type(&acpi_pci_bus); 406 if (ret) 407 return 0; 408 pci_set_platform_pm(&acpi_pci_platform_pm); 409 return 0; 410} 411arch_initcall(acpi_pci_init); 412