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 return; 50 51 if (pci_dev->current_state == PCI_D3cold) { 52 pci_wakeup_event(pci_dev); 53 pm_runtime_resume(&pci_dev->dev); 54 return; 55 } 56 57 if (!pci_dev->pm_cap || !pci_dev->pme_support 58 || pci_check_pme_status(pci_dev)) { 59 if (pci_dev->pme_poll) 60 pci_dev->pme_poll = false; 61 62 pci_wakeup_event(pci_dev); 63 pm_runtime_resume(&pci_dev->dev); 64 } 65 66 if (pci_dev->subordinate) 67 pci_pme_wakeup_bus(pci_dev->subordinate); 68 } 69 70 /** 71 * add_pm_notifier - Register PM notifier for given ACPI device. 72 * @dev: ACPI device to add the notifier for. 73 * @context: PCI device or bus to check for PME status if an event is signaled. 74 * 75 * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of 76 * PM wake-up events. For example, wake-up events may be generated for bridges 77 * if one of the devices below the bridge is signaling PME, even if the bridge 78 * itself doesn't have a wake-up GPE associated with it. 79 */ 80 static acpi_status add_pm_notifier(struct acpi_device *dev, 81 acpi_notify_handler handler, 82 void *context) 83 { 84 acpi_status status = AE_ALREADY_EXISTS; 85 86 mutex_lock(&pci_acpi_pm_notify_mtx); 87 88 if (dev->wakeup.flags.notifier_present) 89 goto out; 90 91 status = acpi_install_notify_handler(dev->handle, 92 ACPI_SYSTEM_NOTIFY, 93 handler, context); 94 if (ACPI_FAILURE(status)) 95 goto out; 96 97 dev->wakeup.flags.notifier_present = true; 98 99 out: 100 mutex_unlock(&pci_acpi_pm_notify_mtx); 101 return status; 102 } 103 104 /** 105 * remove_pm_notifier - Unregister PM notifier from given ACPI device. 106 * @dev: ACPI device to remove the notifier from. 107 */ 108 static acpi_status remove_pm_notifier(struct acpi_device *dev, 109 acpi_notify_handler handler) 110 { 111 acpi_status status = AE_BAD_PARAMETER; 112 113 mutex_lock(&pci_acpi_pm_notify_mtx); 114 115 if (!dev->wakeup.flags.notifier_present) 116 goto out; 117 118 status = acpi_remove_notify_handler(dev->handle, 119 ACPI_SYSTEM_NOTIFY, 120 handler); 121 if (ACPI_FAILURE(status)) 122 goto out; 123 124 dev->wakeup.flags.notifier_present = false; 125 126 out: 127 mutex_unlock(&pci_acpi_pm_notify_mtx); 128 return status; 129 } 130 131 /** 132 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus. 133 * @dev: ACPI device to add the notifier for. 134 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled. 135 */ 136 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev, 137 struct pci_bus *pci_bus) 138 { 139 return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus); 140 } 141 142 /** 143 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier. 144 * @dev: ACPI device to remove the notifier from. 145 */ 146 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev) 147 { 148 return remove_pm_notifier(dev, pci_acpi_wake_bus); 149 } 150 151 /** 152 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device. 153 * @dev: ACPI device to add the notifier for. 154 * @pci_dev: PCI device to check for the PME status if an event is signaled. 155 */ 156 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev, 157 struct pci_dev *pci_dev) 158 { 159 return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev); 160 } 161 162 /** 163 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier. 164 * @dev: ACPI device to remove the notifier from. 165 */ 166 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev) 167 { 168 return remove_pm_notifier(dev, pci_acpi_wake_dev); 169 } 170 171 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle) 172 { 173 acpi_status status = AE_NOT_EXIST; 174 unsigned long long mcfg_addr; 175 176 if (handle) 177 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA, 178 NULL, &mcfg_addr); 179 if (ACPI_FAILURE(status)) 180 return 0; 181 182 return (phys_addr_t)mcfg_addr; 183 } 184 185 /* 186 * _SxD returns the D-state with the highest power 187 * (lowest D-state number) supported in the S-state "x". 188 * 189 * If the devices does not have a _PRW 190 * (Power Resources for Wake) supporting system wakeup from "x" 191 * then the OS is free to choose a lower power (higher number 192 * D-state) than the return value from _SxD. 193 * 194 * But if _PRW is enabled at S-state "x", the OS 195 * must not choose a power lower than _SxD -- 196 * unless the device has an _SxW method specifying 197 * the lowest power (highest D-state number) the device 198 * may enter while still able to wake the system. 199 * 200 * ie. depending on global OS policy: 201 * 202 * if (_PRW at S-state x) 203 * choose from highest power _SxD to lowest power _SxW 204 * else // no _PRW at S-state x 205 * choose highest power _SxD or any lower power 206 */ 207 208 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) 209 { 210 int acpi_state, d_max; 211 212 if (pdev->no_d3cold) 213 d_max = ACPI_STATE_D3_HOT; 214 else 215 d_max = ACPI_STATE_D3_COLD; 216 acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max); 217 if (acpi_state < 0) 218 return PCI_POWER_ERROR; 219 220 switch (acpi_state) { 221 case ACPI_STATE_D0: 222 return PCI_D0; 223 case ACPI_STATE_D1: 224 return PCI_D1; 225 case ACPI_STATE_D2: 226 return PCI_D2; 227 case ACPI_STATE_D3_HOT: 228 return PCI_D3hot; 229 case ACPI_STATE_D3_COLD: 230 return PCI_D3cold; 231 } 232 return PCI_POWER_ERROR; 233 } 234 235 static bool acpi_pci_power_manageable(struct pci_dev *dev) 236 { 237 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 238 239 return handle ? acpi_bus_power_manageable(handle) : false; 240 } 241 242 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state) 243 { 244 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 245 acpi_handle tmp; 246 static const u8 state_conv[] = { 247 [PCI_D0] = ACPI_STATE_D0, 248 [PCI_D1] = ACPI_STATE_D1, 249 [PCI_D2] = ACPI_STATE_D2, 250 [PCI_D3hot] = ACPI_STATE_D3, 251 [PCI_D3cold] = ACPI_STATE_D3 252 }; 253 int error = -EINVAL; 254 255 /* If the ACPI device has _EJ0, ignore the device */ 256 if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp))) 257 return -ENODEV; 258 259 switch (state) { 260 case PCI_D0: 261 case PCI_D1: 262 case PCI_D2: 263 case PCI_D3hot: 264 case PCI_D3cold: 265 error = acpi_bus_set_power(handle, state_conv[state]); 266 } 267 268 if (!error) 269 dev_info(&dev->dev, "power state changed by ACPI to %s\n", 270 pci_power_name(state)); 271 272 return error; 273 } 274 275 static bool acpi_pci_can_wakeup(struct pci_dev *dev) 276 { 277 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 278 279 return handle ? acpi_bus_can_wakeup(handle) : false; 280 } 281 282 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable) 283 { 284 while (bus->parent) { 285 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable)) 286 return; 287 bus = bus->parent; 288 } 289 290 /* We have reached the root bus. */ 291 if (bus->bridge) 292 acpi_pm_device_sleep_wake(bus->bridge, enable); 293 } 294 295 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable) 296 { 297 if (acpi_pci_can_wakeup(dev)) 298 return acpi_pm_device_sleep_wake(&dev->dev, enable); 299 300 acpi_pci_propagate_wakeup_enable(dev->bus, enable); 301 return 0; 302 } 303 304 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable) 305 { 306 while (bus->parent) { 307 struct pci_dev *bridge = bus->self; 308 309 if (bridge->pme_interrupt) 310 return; 311 if (!acpi_pm_device_run_wake(&bridge->dev, enable)) 312 return; 313 bus = bus->parent; 314 } 315 316 /* We have reached the root bus. */ 317 if (bus->bridge) 318 acpi_pm_device_run_wake(bus->bridge, enable); 319 } 320 321 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable) 322 { 323 /* 324 * Per PCI Express Base Specification Revision 2.0 section 325 * 5.3.3.2 Link Wakeup, platform support is needed for D3cold 326 * waking up to power on the main link even if there is PME 327 * support for D3cold 328 */ 329 if (dev->pme_interrupt && !dev->runtime_d3cold) 330 return 0; 331 332 if (!acpi_pm_device_run_wake(&dev->dev, enable)) 333 return 0; 334 335 acpi_pci_propagate_run_wake(dev->bus, enable); 336 return 0; 337 } 338 339 static struct pci_platform_pm_ops acpi_pci_platform_pm = { 340 .is_manageable = acpi_pci_power_manageable, 341 .set_state = acpi_pci_set_power_state, 342 .choose_state = acpi_pci_choose_state, 343 .can_wakeup = acpi_pci_can_wakeup, 344 .sleep_wake = acpi_pci_sleep_wake, 345 .run_wake = acpi_pci_run_wake, 346 }; 347 348 /* ACPI bus type */ 349 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) 350 { 351 struct pci_dev * pci_dev; 352 u64 addr; 353 354 pci_dev = to_pci_dev(dev); 355 /* Please ref to ACPI spec for the syntax of _ADR */ 356 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); 357 *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr); 358 if (!*handle) 359 return -ENODEV; 360 return 0; 361 } 362 363 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle) 364 { 365 int num; 366 unsigned int seg, bus; 367 368 /* 369 * The string should be the same as root bridge's name 370 * Please look at 'pci_scan_bus_parented' 371 */ 372 num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus); 373 if (num != 2) 374 return -ENODEV; 375 *handle = acpi_get_pci_rootbridge_handle(seg, bus); 376 if (!*handle) 377 return -ENODEV; 378 return 0; 379 } 380 381 static struct acpi_bus_type acpi_pci_bus = { 382 .bus = &pci_bus_type, 383 .find_device = acpi_pci_find_device, 384 .find_bridge = acpi_pci_find_root_bridge, 385 }; 386 387 static int __init acpi_pci_init(void) 388 { 389 int ret; 390 391 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) { 392 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n"); 393 pci_no_msi(); 394 } 395 396 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { 397 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n"); 398 pcie_no_aspm(); 399 } 400 401 ret = register_acpi_bus_type(&acpi_pci_bus); 402 if (ret) 403 return 0; 404 pci_set_platform_pm(&acpi_pci_platform_pm); 405 return 0; 406 } 407 arch_initcall(acpi_pci_init); 408