drivers/pci/pcie/portdrv_pci.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * File:        portdrv_pci.c
   4  * Purpose:     PCI Express Port Bus Driver
   5  * Author:      Tom Nguyen <tom.l.nguyen@intel.com>
   6  * Version:     v1.0
   7  *
   8  * Copyright (C) 2004 Intel
   9  * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
  10  */
  11
  12 #include <linux/pci.h>
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/pm.h>
  16 #include <linux/pm_runtime.h>
  17 #include <linux/init.h>
  18 #include <linux/pcieport_if.h>
  19 #include <linux/aer.h>
  20 #include <linux/dmi.h>
  21 #include <linux/pci-aspm.h>
  22
  23 #include "../pci.h"
  24 #include "portdrv.h"
  25
  26 /* If this switch is set, PCIe port native services should not be enabled. */
  27 bool pcie_ports_disabled;
  28
  29 /*
  30  * If this switch is set, ACPI _OSC will be used to determine whether or not to
  31  * enable PCIe port native services.
  32  */
  33 bool pcie_ports_auto = true;
  34
  35 static int __init pcie_port_setup(char *str)
  36 {
  37         if (!strncmp(str, "compat", 6)) {
  38                 pcie_ports_disabled = true;
  39         } else if (!strncmp(str, "native", 6)) {
  40                 pcie_ports_disabled = false;
  41                 pcie_ports_auto = false;
  42         } else if (!strncmp(str, "auto", 4)) {
  43                 pcie_ports_disabled = false;
  44                 pcie_ports_auto = true;
  45         }
  46
  47         return 1;
  48 }
  49 __setup("pcie_ports=", pcie_port_setup);
  50
  51 /* global data */
  52
  53 /**
  54  * pcie_clear_root_pme_status - Clear root port PME interrupt status.
  55  * @dev: PCIe root port or event collector.
  56  */
  57 void pcie_clear_root_pme_status(struct pci_dev *dev)
  58 {
  59         pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
  60 }
  61
  62 static int pcie_portdrv_restore_config(struct pci_dev *dev)
  63 {
  64         int retval;
  65
  66         retval = pci_enable_device(dev);
  67         if (retval)
  68                 return retval;
  69         pci_set_master(dev);
  70         return 0;
  71 }
  72
  73 #ifdef CONFIG_PM
  74 static int pcie_port_resume_noirq(struct device *dev)
  75 {
  76         struct pci_dev *pdev = to_pci_dev(dev);
  77
  78         /*
  79          * Some BIOSes forget to clear Root PME Status bits after system wakeup
  80          * which breaks ACPI-based runtime wakeup on PCI Express, so clear those
  81          * bits now just in case (shouldn't hurt).
  82          */
  83         if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
  84                 pcie_clear_root_pme_status(pdev);
  85         return 0;
  86 }
  87
  88 static int pcie_port_runtime_suspend(struct device *dev)
  89 {
  90         return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
  91 }
  92
  93 static int pcie_port_runtime_resume(struct device *dev)
  94 {
  95         return 0;
  96 }
  97
  98 static int pcie_port_runtime_idle(struct device *dev)
  99 {
 100         /*
 101          * Assume the PCI core has set bridge_d3 whenever it thinks the port
 102          * should be good to go to D3.  Everything else, including moving
 103          * the port to D3, is handled by the PCI core.
 104          */
 105         return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
 106 }
 107
 108 static const struct dev_pm_ops pcie_portdrv_pm_ops = {
 109         .suspend        = pcie_port_device_suspend,
 110         .resume         = pcie_port_device_resume,
 111         .freeze         = pcie_port_device_suspend,
 112         .thaw           = pcie_port_device_resume,
 113         .poweroff       = pcie_port_device_suspend,
 114         .restore        = pcie_port_device_resume,
 115         .resume_noirq   = pcie_port_resume_noirq,
 116         .runtime_suspend = pcie_port_runtime_suspend,
 117         .runtime_resume = pcie_port_runtime_resume,
 118         .runtime_idle   = pcie_port_runtime_idle,
 119 };
 120
 121 #define PCIE_PORTDRV_PM_OPS     (&pcie_portdrv_pm_ops)
 122
 123 #else /* !PM */
 124
 125 #define PCIE_PORTDRV_PM_OPS     NULL
 126 #endif /* !PM */
 127
 128 /*
 129  * pcie_portdrv_probe - Probe PCI-Express port devices
 130  * @dev: PCI-Express port device being probed
 131  *
 132  * If detected invokes the pcie_port_device_register() method for
 133  * this port device.
 134  *
 135  */
 136 static int pcie_portdrv_probe(struct pci_dev *dev,
 137                                         const struct pci_device_id *id)
 138 {
 139         int status;
 140
 141         if (!pci_is_pcie(dev) ||
 142             ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
 143              (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM) &&
 144              (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
 145                 return -ENODEV;
 146
 147         status = pcie_port_device_register(dev);
 148         if (status)
 149                 return status;
 150
 151         pci_save_state(dev);
 152
 153         if (pci_bridge_d3_possible(dev)) {
 154                 /*
 155                  * Keep the port resumed 100ms to make sure things like
 156                  * config space accesses from userspace (lspci) will not
 157                  * cause the port to repeatedly suspend and resume.
 158                  */
 159                 pm_runtime_set_autosuspend_delay(&dev->dev, 100);
 160                 pm_runtime_use_autosuspend(&dev->dev);
 161                 pm_runtime_mark_last_busy(&dev->dev);
 162                 pm_runtime_put_autosuspend(&dev->dev);
 163                 pm_runtime_allow(&dev->dev);
 164         }
 165
 166         return 0;
 167 }
 168
 169 static void pcie_portdrv_remove(struct pci_dev *dev)
 170 {
 171         if (pci_bridge_d3_possible(dev)) {
 172                 pm_runtime_forbid(&dev->dev);
 173                 pm_runtime_get_noresume(&dev->dev);
 174                 pm_runtime_dont_use_autosuspend(&dev->dev);
 175         }
 176
 177         pcie_port_device_remove(dev);
 178 }
 179
 180 static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
 181                                         enum pci_channel_state error)
 182 {
 183         /* Root Port has no impact. Always recovers. */
 184         return PCI_ERS_RESULT_CAN_RECOVER;
 185 }
 186
 187 static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
 188 {
 189         return PCI_ERS_RESULT_RECOVERED;
 190 }
 191
 192 static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
 193 {
 194         /* If fatal, restore cfg space for possible link reset at upstream */
 195         if (dev->error_state == pci_channel_io_frozen) {
 196                 dev->state_saved = true;
 197                 pci_restore_state(dev);
 198                 pcie_portdrv_restore_config(dev);
 199                 pci_enable_pcie_error_reporting(dev);
 200         }
 201
 202         return PCI_ERS_RESULT_RECOVERED;
 203 }
 204
 205 static int resume_iter(struct device *device, void *data)
 206 {
 207         struct pcie_device *pcie_device;
 208         struct pcie_port_service_driver *driver;
 209
 210         if (device->bus == &pcie_port_bus_type && device->driver) {
 211                 driver = to_service_driver(device->driver);
 212                 if (driver && driver->error_resume) {
 213                         pcie_device = to_pcie_device(device);
 214
 215                         /* Forward error message to service drivers */
 216                         driver->error_resume(pcie_device->port);
 217                 }
 218         }
 219
 220         return 0;
 221 }
 222
 223 static void pcie_portdrv_err_resume(struct pci_dev *dev)
 224 {
 225         device_for_each_child(&dev->dev, NULL, resume_iter);
 226 }
 227
 228 /*
 229  * LINUX Device Driver Model
 230  */
 231 static const struct pci_device_id port_pci_ids[] = { {
 232         /* handle any PCI-Express port */
 233         PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0),
 234         }, { /* end: all zeroes */ }
 235 };
 236
 237 static const struct pci_error_handlers pcie_portdrv_err_handler = {
 238         .error_detected = pcie_portdrv_error_detected,
 239         .mmio_enabled = pcie_portdrv_mmio_enabled,
 240         .slot_reset = pcie_portdrv_slot_reset,
 241         .resume = pcie_portdrv_err_resume,
 242 };
 243
 244 static struct pci_driver pcie_portdriver = {
 245         .name           = "pcieport",
 246         .id_table       = &port_pci_ids[0],
 247
 248         .probe          = pcie_portdrv_probe,
 249         .remove         = pcie_portdrv_remove,
 250
 251         .err_handler    = &pcie_portdrv_err_handler,
 252
 253         .driver.pm      = PCIE_PORTDRV_PM_OPS,
 254 };
 255
 256 static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
 257 {
 258         pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
 259                   d->ident);
 260         pcie_pme_disable_msi();
 261         return 0;
 262 }
 263
 264 static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = {
 265         /*
 266          * Boxes that should not use MSI for PCIe PME signaling.
 267          */
 268         {
 269          .callback = dmi_pcie_pme_disable_msi,
 270          .ident = "MSI Wind U-100",
 271          .matches = {
 272                      DMI_MATCH(DMI_SYS_VENDOR,
 273                                 "MICRO-STAR INTERNATIONAL CO., LTD"),
 274                      DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
 275                      },
 276          },
 277          {}
 278 };
 279
 280 static int __init pcie_portdrv_init(void)
 281 {
 282         int retval;
 283
 284         if (pcie_ports_disabled)
 285                 return pci_register_driver(&pcie_portdriver);
 286
 287         dmi_check_system(pcie_portdrv_dmi_table);
 288
 289         retval = pcie_port_bus_register();
 290         if (retval) {
 291                 printk(KERN_WARNING "PCIE: bus_register error: %d\n", retval);
 292                 goto out;
 293         }
 294         retval = pci_register_driver(&pcie_portdriver);
 295         if (retval)
 296                 pcie_port_bus_unregister();
 297  out:
 298         return retval;
 299 }
 300 device_initcall(pcie_portdrv_init);