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->current_state == PCI_D3cold) { 51 pci_wakeup_event(pci_dev); 52 pm_runtime_resume(&pci_dev->dev); 53 return; 54 } 55 56 if (!pci_dev->pm_cap || !pci_dev->pme_support 57 || pci_check_pme_status(pci_dev)) { 58 if (pci_dev->pme_poll) 59 pci_dev->pme_poll = false; 60 61 pci_wakeup_event(pci_dev); 62 pm_runtime_resume(&pci_dev->dev); 63 } 64 65 if (pci_dev->subordinate) 66 pci_pme_wakeup_bus(pci_dev->subordinate); 67 } 68 69 /** 70 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus. 71 * @dev: ACPI device to add the notifier for. 72 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled. 73 */ 74 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev, 75 struct pci_bus *pci_bus) 76 { 77 return acpi_add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus); 78 } 79 80 /** 81 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier. 82 * @dev: ACPI device to remove the notifier from. 83 */ 84 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev) 85 { 86 return acpi_remove_pm_notifier(dev, pci_acpi_wake_bus); 87 } 88 89 /** 90 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device. 91 * @dev: ACPI device to add the notifier for. 92 * @pci_dev: PCI device to check for the PME status if an event is signaled. 93 */ 94 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev, 95 struct pci_dev *pci_dev) 96 { 97 return acpi_add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev); 98 } 99 100 /** 101 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier. 102 * @dev: ACPI device to remove the notifier from. 103 */ 104 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev) 105 { 106 return acpi_remove_pm_notifier(dev, pci_acpi_wake_dev); 107 } 108 109 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle) 110 { 111 acpi_status status = AE_NOT_EXIST; 112 unsigned long long mcfg_addr; 113 114 if (handle) 115 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA, 116 NULL, &mcfg_addr); 117 if (ACPI_FAILURE(status)) 118 return 0; 119 120 return (phys_addr_t)mcfg_addr; 121 } 122 123 /* 124 * _SxD returns the D-state with the highest power 125 * (lowest D-state number) supported in the S-state "x". 126 * 127 * If the devices does not have a _PRW 128 * (Power Resources for Wake) supporting system wakeup from "x" 129 * then the OS is free to choose a lower power (higher number 130 * D-state) than the return value from _SxD. 131 * 132 * But if _PRW is enabled at S-state "x", the OS 133 * must not choose a power lower than _SxD -- 134 * unless the device has an _SxW method specifying 135 * the lowest power (highest D-state number) the device 136 * may enter while still able to wake the system. 137 * 138 * ie. depending on global OS policy: 139 * 140 * if (_PRW at S-state x) 141 * choose from highest power _SxD to lowest power _SxW 142 * else // no _PRW at S-state x 143 * choose highest power _SxD or any lower power 144 */ 145 146 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev) 147 { 148 int acpi_state, d_max; 149 150 if (pdev->no_d3cold) 151 d_max = ACPI_STATE_D3_HOT; 152 else 153 d_max = ACPI_STATE_D3_COLD; 154 acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max); 155 if (acpi_state < 0) 156 return PCI_POWER_ERROR; 157 158 switch (acpi_state) { 159 case ACPI_STATE_D0: 160 return PCI_D0; 161 case ACPI_STATE_D1: 162 return PCI_D1; 163 case ACPI_STATE_D2: 164 return PCI_D2; 165 case ACPI_STATE_D3_HOT: 166 return PCI_D3hot; 167 case ACPI_STATE_D3_COLD: 168 return PCI_D3cold; 169 } 170 return PCI_POWER_ERROR; 171 } 172 173 static bool acpi_pci_power_manageable(struct pci_dev *dev) 174 { 175 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 176 177 return handle ? acpi_bus_power_manageable(handle) : false; 178 } 179 180 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state) 181 { 182 acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev); 183 acpi_handle tmp; 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, 189 [PCI_D3cold] = ACPI_STATE_D3 190 }; 191 int error = -EINVAL; 192 193 /* If the ACPI device has _EJ0, ignore the device */ 194 if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp))) 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_info(&dev->dev, "power state changed by ACPI to %s\n", 213 pci_power_name(state)); 214 215 return error; 216 } 217 218 static bool acpi_pci_can_wakeup(struct pci_dev *dev) 219 { 220 acpi_handle handle = DEVICE_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 .can_wakeup = acpi_pci_can_wakeup, 287 .sleep_wake = acpi_pci_sleep_wake, 288 .run_wake = acpi_pci_run_wake, 289 }; 290 291 /* ACPI bus type */ 292 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle) 293 { 294 struct pci_dev * pci_dev; 295 u64 addr; 296 297 pci_dev = to_pci_dev(dev); 298 /* Please ref to ACPI spec for the syntax of _ADR */ 299 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn); 300 *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr); 301 if (!*handle) 302 return -ENODEV; 303 return 0; 304 } 305 306 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle) 307 { 308 int num; 309 unsigned int seg, bus; 310 311 /* 312 * The string should be the same as root bridge's name 313 * Please look at 'pci_scan_bus_parented' 314 */ 315 num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus); 316 if (num != 2) 317 return -ENODEV; 318 *handle = acpi_get_pci_rootbridge_handle(seg, bus); 319 if (!*handle) 320 return -ENODEV; 321 return 0; 322 } 323 324 static struct acpi_bus_type acpi_pci_bus = { 325 .bus = &pci_bus_type, 326 .find_device = acpi_pci_find_device, 327 .find_bridge = acpi_pci_find_root_bridge, 328 }; 329 330 static int __init acpi_pci_init(void) 331 { 332 int ret; 333 334 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) { 335 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n"); 336 pci_no_msi(); 337 } 338 339 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { 340 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n"); 341 pcie_no_aspm(); 342 } 343 344 ret = register_acpi_bus_type(&acpi_pci_bus); 345 if (ret) 346 return 0; 347 pci_set_platform_pm(&acpi_pci_platform_pm); 348 return 0; 349 } 350 arch_initcall(acpi_pci_init); 351