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 <linux/pci-acpi.h> 16 #include <linux/pm_runtime.h> 17 #include <linux/pm_qos.h> 18 #include "pci.h" 19 20 /** 21 * pci_acpi_wake_bus - Root bus wakeup notification fork function. 22 * @work: Work item to handle. 23 */ 24 static void pci_acpi_wake_bus(struct work_struct *work) 25 { 26 struct acpi_device *adev; 27 struct acpi_pci_root *root; 28 29 adev = container_of(work, struct acpi_device, wakeup.context.work); 30 root = acpi_driver_data(adev); 31 pci_pme_wakeup_bus(root->bus); 32 } 33 34 /** 35 * pci_acpi_wake_dev - PCI device wakeup notification work function. 36 * @handle: ACPI handle of a device the notification is for. 37 * @work: Work item to handle. 38 */ 39 static void pci_acpi_wake_dev(struct work_struct *work) 40 { 41 struct acpi_device_wakeup_context *context; 42 struct pci_dev *pci_dev; 43 44 context = container_of(work, struct acpi_device_wakeup_context, work); 45 pci_dev = to_pci_dev(context->dev); 46 47 if (pci_dev->pme_poll) 48 pci_dev->pme_poll = false; 49 50 if (pci_dev->current_state == PCI_D3cold) { 51 pci_wakeup_event(pci_dev); 52 pm_runtime_resume(&pci_dev->dev); 53 return; 54 } 55 56 /* Clear PME Status if set. */ 57 if (pci_dev->pme_support) 58 pci_check_pme_status(pci_dev); 59 60 pci_wakeup_event(pci_dev); 61 pm_runtime_resume(&pci_dev->dev); 62 63 if (pci_dev->subordinate) 64 pci_pme_wakeup_bus(pci_dev->subordinate); 65 } 66 67 /** 68 * pci_acpi_add_bus_pm_notifier - Register PM notifier for root PCI bus. 69 * @dev: PCI root bridge ACPI device. 70 */ 71 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev) 72 { 73 return acpi_add_pm_notifier(dev, NULL, pci_acpi_wake_bus); 74 } 75 76 /** 77 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device. 78 * @dev: ACPI device to add the notifier for. 79 * @pci_dev: PCI device to check for the PME status if an event is signaled. 80 */ 81 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev, 82 struct pci_dev *pci_dev) 83 { 84 return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev); 85 } 86 87 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle) 88 { 89 acpi_status status = AE_NOT_EXIST; 90 unsigned long long mcfg_addr; 91 92 if (handle) 93 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA, 94 NULL, &mcfg_addr); 95 if (ACPI_FAILURE(status)) 96 return 0; 97 98 return (phys_addr_t)mcfg_addr; 99 } 100 101 /* 102 * _SxD returns the D-state with the highest power 103 * (lowest D-state number) supported in the S-state "x". 104 * 105 * If the devices does not have a _PRW 106 * (Power Resources for Wake) supporting system wakeup from "x" 107 * then the OS is free to choose a lower power (higher number 108 * D-state) than the return value from _SxD. 109 * 110 * But if _PRW is enabled at S-state "x", the OS 111 * must not choose a power lower than _SxD -- 112 * unless the device has an _SxW method specifying 113 * the lowest power (highest D-state number) the device 114 * may enter while still able to wake the system. 115 * 116 * ie. depending on global OS policy: 117 * 118 * if (_PRW at S-state x) 119 * choose from highest power _SxD to lowest power _SxW 120 * else // no _PRW at S-state x 121 * choose highest power _SxD or any lower power 122 */ 123 124 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) 125 { 126 int acpi_state, d_max; 127 128 if (pdev->no_d3cold) 129 d_max = ACPI_STATE_D3_HOT; 130 else 131 d_max = ACPI_STATE_D3_COLD; 132 acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max); 133 if (acpi_state < 0) 134 return PCI_POWER_ERROR; 135 136 switch (acpi_state) { 137 case ACPI_STATE_D0: 138 return PCI_D0; 139 case ACPI_STATE_D1: 140 return PCI_D1; 141 case ACPI_STATE_D2: 142 return PCI_D2; 143 case ACPI_STATE_D3_HOT: 144 return PCI_D3hot; 145 case ACPI_STATE_D3_COLD: 146 return PCI_D3cold; 147 } 148 return PCI_POWER_ERROR; 149 } 150 151 static bool acpi_pci_power_manageable(struct pci_dev *dev) 152 { 153 struct acpi_device *adev = ACPI_COMPANION(&dev->dev); 154 return adev ? acpi_device_power_manageable(adev) : false; 155 } 156 157 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state) 158 { 159 struct acpi_device *adev = ACPI_COMPANION(&dev->dev); 160 static const u8 state_conv[] = { 161 [PCI_D0] = ACPI_STATE_D0, 162 [PCI_D1] = ACPI_STATE_D1, 163 [PCI_D2] = ACPI_STATE_D2, 164 [PCI_D3hot] = ACPI_STATE_D3_COLD, 165 [PCI_D3cold] = ACPI_STATE_D3_COLD, 166 }; 167 int error = -EINVAL; 168 169 /* If the ACPI device has _EJ0, ignore the device */ 170 if (!adev || acpi_has_method(adev->handle, "_EJ0")) 171 return -ENODEV; 172 173 switch (state) { 174 case PCI_D3cold: 175 if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) == 176 PM_QOS_FLAGS_ALL) { 177 error = -EBUSY; 178 break; 179 } 180 case PCI_D0: 181 case PCI_D1: 182 case PCI_D2: 183 case PCI_D3hot: 184 error = acpi_device_set_power(adev, state_conv[state]); 185 } 186 187 if (!error) 188 dev_dbg(&dev->dev, "power state changed by ACPI to %s\n", 189 acpi_power_state_string(state_conv[state])); 190 191 return error; 192 } 193 194 static bool acpi_pci_can_wakeup(struct pci_dev *dev) 195 { 196 struct acpi_device *adev = ACPI_COMPANION(&dev->dev); 197 return adev ? acpi_device_can_wakeup(adev) : false; 198 } 199 200 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable) 201 { 202 while (bus->parent) { 203 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable)) 204 return; 205 bus = bus->parent; 206 } 207 208 /* We have reached the root bus. */ 209 if (bus->bridge) 210 acpi_pm_device_sleep_wake(bus->bridge, enable); 211 } 212 213 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable) 214 { 215 if (acpi_pci_can_wakeup(dev)) 216 return acpi_pm_device_sleep_wake(&dev->dev, enable); 217 218 acpi_pci_propagate_wakeup_enable(dev->bus, enable); 219 return 0; 220 } 221 222 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable) 223 { 224 while (bus->parent) { 225 struct pci_dev *bridge = bus->self; 226 227 if (bridge->pme_interrupt) 228 return; 229 if (!acpi_pm_device_run_wake(&bridge->dev, enable)) 230 return; 231 bus = bus->parent; 232 } 233 234 /* We have reached the root bus. */ 235 if (bus->bridge) 236 acpi_pm_device_run_wake(bus->bridge, enable); 237 } 238 239 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable) 240 { 241 /* 242 * Per PCI Express Base Specification Revision 2.0 section 243 * 5.3.3.2 Link Wakeup, platform support is needed for D3cold 244 * waking up to power on the main link even if there is PME 245 * support for D3cold 246 */ 247 if (dev->pme_interrupt && !dev->runtime_d3cold) 248 return 0; 249 250 if (!acpi_pm_device_run_wake(&dev->dev, enable)) 251 return 0; 252 253 acpi_pci_propagate_run_wake(dev->bus, enable); 254 return 0; 255 } 256 257 static struct pci_platform_pm_ops acpi_pci_platform_pm = { 258 .is_manageable = acpi_pci_power_manageable, 259 .set_state = acpi_pci_set_power_state, 260 .choose_state = acpi_pci_choose_state, 261 .sleep_wake = acpi_pci_sleep_wake, 262 .run_wake = acpi_pci_run_wake, 263 }; 264 265 void acpi_pci_add_bus(struct pci_bus *bus) 266 { 267 if (acpi_pci_disabled || !bus->bridge) 268 return; 269 270 acpi_pci_slot_enumerate(bus); 271 acpiphp_enumerate_slots(bus); 272 } 273 274 void acpi_pci_remove_bus(struct pci_bus *bus) 275 { 276 if (acpi_pci_disabled || !bus->bridge) 277 return; 278 279 acpiphp_remove_slots(bus); 280 acpi_pci_slot_remove(bus); 281 } 282 283 /* ACPI bus type */ 284 static struct acpi_device *acpi_pci_find_companion(struct device *dev) 285 { 286 struct pci_dev *pci_dev = to_pci_dev(dev); 287 bool check_children; 288 u64 addr; 289 290 check_children = pci_is_bridge(pci_dev); 291 /* Please ref to ACPI spec for the syntax of _ADR */ 292 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); 293 return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr, 294 check_children); 295 } 296 297 static void pci_acpi_setup(struct device *dev) 298 { 299 struct pci_dev *pci_dev = to_pci_dev(dev); 300 struct acpi_device *adev = ACPI_COMPANION(dev); 301 302 if (!adev) 303 return; 304 305 pci_acpi_add_pm_notifier(adev, pci_dev); 306 if (!adev->wakeup.flags.valid) 307 return; 308 309 device_set_wakeup_capable(dev, true); 310 acpi_pci_sleep_wake(pci_dev, false); 311 if (adev->wakeup.flags.run_wake) 312 device_set_run_wake(dev, true); 313 } 314 315 static void pci_acpi_cleanup(struct device *dev) 316 { 317 struct acpi_device *adev = ACPI_COMPANION(dev); 318 319 if (!adev) 320 return; 321 322 pci_acpi_remove_pm_notifier(adev); 323 if (adev->wakeup.flags.valid) { 324 device_set_wakeup_capable(dev, false); 325 device_set_run_wake(dev, false); 326 } 327 } 328 329 static bool pci_acpi_bus_match(struct device *dev) 330 { 331 return dev_is_pci(dev); 332 } 333 334 static struct acpi_bus_type acpi_pci_bus = { 335 .name = "PCI", 336 .match = pci_acpi_bus_match, 337 .find_companion = acpi_pci_find_companion, 338 .setup = pci_acpi_setup, 339 .cleanup = pci_acpi_cleanup, 340 }; 341 342 static int __init acpi_pci_init(void) 343 { 344 int ret; 345 346 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) { 347 pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n"); 348 pci_no_msi(); 349 } 350 351 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { 352 pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n"); 353 pcie_no_aspm(); 354 } 355 356 ret = register_acpi_bus_type(&acpi_pci_bus); 357 if (ret) 358 return 0; 359 360 pci_set_platform_pm(&acpi_pci_platform_pm); 361 acpi_pci_slot_init(); 362 acpiphp_init(); 363 364 return 0; 365 } 366 arch_initcall(acpi_pci_init); 367