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 <linux/pm_qos.h> 21 #include "pci.h" 22 23 /** 24 * pci_acpi_wake_bus - Wake-up notification handler for root buses. 25 * @handle: ACPI handle of a device the notification is for. 26 * @event: Type of the signaled event. 27 * @context: PCI root bus to wake up devices on. 28 */ 29 static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context) 30 { 31 struct pci_bus *pci_bus = context; 32 33 if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus) 34 pci_pme_wakeup_bus(pci_bus); 35 } 36 37 /** 38 * pci_acpi_wake_dev - Wake-up notification handler for PCI devices. 39 * @handle: ACPI handle of a device the notification is for. 40 * @event: Type of the signaled event. 41 * @context: PCI device object to wake up. 42 */ 43 static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context) 44 { 45 struct pci_dev *pci_dev = context; 46 47 if (event != ACPI_NOTIFY_DEVICE_WAKE || !pci_dev) 48 return; 49 50 if (pci_dev->pme_poll) 51 pci_dev->pme_poll = false; 52 53 if (pci_dev->current_state == PCI_D3cold) { 54 pci_wakeup_event(pci_dev); 55 pm_runtime_resume(&pci_dev->dev); 56 return; 57 } 58 59 /* Clear PME Status if set. */ 60 if (pci_dev->pme_support) 61 pci_check_pme_status(pci_dev); 62 63 pci_wakeup_event(pci_dev); 64 pm_runtime_resume(&pci_dev->dev); 65 66 if (pci_dev->subordinate) 67 pci_pme_wakeup_bus(pci_dev->subordinate); 68 } 69 70 /** 71 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus. 72 * @dev: ACPI device to add the notifier for. 73 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled. 74 */ 75 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev, 76 struct pci_bus *pci_bus) 77 { 78 return acpi_add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus); 79 } 80 81 /** 82 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier. 83 * @dev: ACPI device to remove the notifier from. 84 */ 85 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev) 86 { 87 return acpi_remove_pm_notifier(dev, pci_acpi_wake_bus); 88 } 89 90 /** 91 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device. 92 * @dev: ACPI device to add the notifier for. 93 * @pci_dev: PCI device to check for the PME status if an event is signaled. 94 */ 95 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev, 96 struct pci_dev *pci_dev) 97 { 98 return acpi_add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev); 99 } 100 101 /** 102 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier. 103 * @dev: ACPI device to remove the notifier from. 104 */ 105 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev) 106 { 107 return acpi_remove_pm_notifier(dev, pci_acpi_wake_dev); 108 } 109 110 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle) 111 { 112 acpi_status status = AE_NOT_EXIST; 113 unsigned long long mcfg_addr; 114 115 if (handle) 116 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA, 117 NULL, &mcfg_addr); 118 if (ACPI_FAILURE(status)) 119 return 0; 120 121 return (phys_addr_t)mcfg_addr; 122 } 123 124 /* 125 * _SxD returns the D-state with the highest power 126 * (lowest D-state number) supported in the S-state "x". 127 * 128 * If the devices does not have a _PRW 129 * (Power Resources for Wake) supporting system wakeup from "x" 130 * then the OS is free to choose a lower power (higher number 131 * D-state) than the return value from _SxD. 132 * 133 * But if _PRW is enabled at S-state "x", the OS 134 * must not choose a power lower than _SxD -- 135 * unless the device has an _SxW method specifying 136 * the lowest power (highest D-state number) the device 137 * may enter while still able to wake the system. 138 * 139 * ie. depending on global OS policy: 140 * 141 * if (_PRW at S-state x) 142 * choose from highest power _SxD to lowest power _SxW 143 * else // no _PRW at S-state x 144 * choose highest power _SxD or any lower power 145 */ 146 147 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) 148 { 149 int acpi_state, d_max; 150 151 if (pdev->no_d3cold) 152 d_max = ACPI_STATE_D3_HOT; 153 else 154 d_max = ACPI_STATE_D3_COLD; 155 acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max); 156 if (acpi_state < 0) 157 return PCI_POWER_ERROR; 158 159 switch (acpi_state) { 160 case ACPI_STATE_D0: 161 return PCI_D0; 162 case ACPI_STATE_D1: 163 return PCI_D1; 164 case ACPI_STATE_D2: 165 return PCI_D2; 166 case ACPI_STATE_D3_HOT: 167 return PCI_D3hot; 168 case ACPI_STATE_D3_COLD: 169 return PCI_D3cold; 170 } 171 return PCI_POWER_ERROR; 172 } 173 174 static bool acpi_pci_power_manageable(struct pci_dev *dev) 175 { 176 acpi_handle handle = ACPI_HANDLE(&dev->dev); 177 178 return handle ? acpi_bus_power_manageable(handle) : false; 179 } 180 181 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state) 182 { 183 acpi_handle handle = ACPI_HANDLE(&dev->dev); 184 static const u8 state_conv[] = { 185 [PCI_D0] = ACPI_STATE_D0, 186 [PCI_D1] = ACPI_STATE_D1, 187 [PCI_D2] = ACPI_STATE_D2, 188 [PCI_D3hot] = ACPI_STATE_D3_COLD, 189 [PCI_D3cold] = ACPI_STATE_D3_COLD, 190 }; 191 int error = -EINVAL; 192 193 /* If the ACPI device has _EJ0, ignore the device */ 194 if (!handle || acpi_has_method(handle, "_EJ0")) 195 return -ENODEV; 196 197 switch (state) { 198 case PCI_D3cold: 199 if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) == 200 PM_QOS_FLAGS_ALL) { 201 error = -EBUSY; 202 break; 203 } 204 case PCI_D0: 205 case PCI_D1: 206 case PCI_D2: 207 case PCI_D3hot: 208 error = acpi_bus_set_power(handle, state_conv[state]); 209 } 210 211 if (!error) 212 dev_dbg(&dev->dev, "power state changed by ACPI to %s\n", 213 acpi_power_state_string(state_conv[state])); 214 215 return error; 216 } 217 218 static bool acpi_pci_can_wakeup(struct pci_dev *dev) 219 { 220 acpi_handle handle = ACPI_HANDLE(&dev->dev); 221 222 return handle ? acpi_bus_can_wakeup(handle) : false; 223 } 224 225 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable) 226 { 227 while (bus->parent) { 228 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable)) 229 return; 230 bus = bus->parent; 231 } 232 233 /* We have reached the root bus. */ 234 if (bus->bridge) 235 acpi_pm_device_sleep_wake(bus->bridge, enable); 236 } 237 238 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable) 239 { 240 if (acpi_pci_can_wakeup(dev)) 241 return acpi_pm_device_sleep_wake(&dev->dev, enable); 242 243 acpi_pci_propagate_wakeup_enable(dev->bus, enable); 244 return 0; 245 } 246 247 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable) 248 { 249 while (bus->parent) { 250 struct pci_dev *bridge = bus->self; 251 252 if (bridge->pme_interrupt) 253 return; 254 if (!acpi_pm_device_run_wake(&bridge->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_run_wake(bus->bridge, enable); 262 } 263 264 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable) 265 { 266 /* 267 * Per PCI Express Base Specification Revision 2.0 section 268 * 5.3.3.2 Link Wakeup, platform support is needed for D3cold 269 * waking up to power on the main link even if there is PME 270 * support for D3cold 271 */ 272 if (dev->pme_interrupt && !dev->runtime_d3cold) 273 return 0; 274 275 if (!acpi_pm_device_run_wake(&dev->dev, enable)) 276 return 0; 277 278 acpi_pci_propagate_run_wake(dev->bus, enable); 279 return 0; 280 } 281 282 static struct pci_platform_pm_ops acpi_pci_platform_pm = { 283 .is_manageable = acpi_pci_power_manageable, 284 .set_state = acpi_pci_set_power_state, 285 .choose_state = acpi_pci_choose_state, 286 .sleep_wake = acpi_pci_sleep_wake, 287 .run_wake = acpi_pci_run_wake, 288 }; 289 290 void acpi_pci_add_bus(struct pci_bus *bus) 291 { 292 if (acpi_pci_disabled || !bus->bridge) 293 return; 294 295 acpi_pci_slot_enumerate(bus); 296 acpiphp_enumerate_slots(bus); 297 } 298 299 void acpi_pci_remove_bus(struct pci_bus *bus) 300 { 301 if (acpi_pci_disabled || !bus->bridge) 302 return; 303 304 acpiphp_remove_slots(bus); 305 acpi_pci_slot_remove(bus); 306 } 307 308 /* ACPI bus type */ 309 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) 310 { 311 struct pci_dev *pci_dev = to_pci_dev(dev); 312 bool is_bridge; 313 u64 addr; 314 315 /* 316 * pci_is_bridge() is not suitable here, because pci_dev->subordinate 317 * is set only after acpi_pci_find_device() has been called for the 318 * given device. 319 */ 320 is_bridge = pci_dev->hdr_type == PCI_HEADER_TYPE_BRIDGE 321 || pci_dev->hdr_type == PCI_HEADER_TYPE_CARDBUS; 322 /* Please ref to ACPI spec for the syntax of _ADR */ 323 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); 324 *handle = acpi_find_child(ACPI_HANDLE(dev->parent), addr, is_bridge); 325 if (!*handle) 326 return -ENODEV; 327 return 0; 328 } 329 330 static void pci_acpi_setup(struct device *dev) 331 { 332 struct pci_dev *pci_dev = to_pci_dev(dev); 333 acpi_handle handle = ACPI_HANDLE(dev); 334 struct acpi_device *adev; 335 336 if (acpi_bus_get_device(handle, &adev) || !adev->wakeup.flags.valid) 337 return; 338 339 device_set_wakeup_capable(dev, true); 340 acpi_pci_sleep_wake(pci_dev, false); 341 342 pci_acpi_add_pm_notifier(adev, pci_dev); 343 if (adev->wakeup.flags.run_wake) 344 device_set_run_wake(dev, true); 345 } 346 347 static void pci_acpi_cleanup(struct device *dev) 348 { 349 acpi_handle handle = ACPI_HANDLE(dev); 350 struct acpi_device *adev; 351 352 if (!acpi_bus_get_device(handle, &adev) && adev->wakeup.flags.valid) { 353 device_set_wakeup_capable(dev, false); 354 device_set_run_wake(dev, false); 355 pci_acpi_remove_pm_notifier(adev); 356 } 357 } 358 359 static bool pci_acpi_bus_match(struct device *dev) 360 { 361 return dev->bus == &pci_bus_type; 362 } 363 364 static struct acpi_bus_type acpi_pci_bus = { 365 .name = "PCI", 366 .match = pci_acpi_bus_match, 367 .find_device = acpi_pci_find_device, 368 .setup = pci_acpi_setup, 369 .cleanup = pci_acpi_cleanup, 370 }; 371 372 static int __init acpi_pci_init(void) 373 { 374 int ret; 375 376 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) { 377 pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n"); 378 pci_no_msi(); 379 } 380 381 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { 382 pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n"); 383 pcie_no_aspm(); 384 } 385 386 ret = register_acpi_bus_type(&acpi_pci_bus); 387 if (ret) 388 return 0; 389 390 pci_set_platform_pm(&acpi_pci_platform_pm); 391 acpi_pci_slot_init(); 392 acpiphp_init(); 393 394 return 0; 395 } 396 arch_initcall(acpi_pci_init); 397