drivers/pci/pcie/portdrv_pci.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Purpose:     PCI Express Port Bus Driver
   4  * Author:      Tom Nguyen <tom.l.nguyen@intel.com>
   5  *
   6  * Copyright (C) 2004 Intel
   7  * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
   8  */
   9
  10 #include <linux/pci.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/pm.h>
  14 #include <linux/pm_runtime.h>
  15 #include <linux/init.h>
  16 #include <linux/aer.h>
  17 #include <linux/dmi.h>
  18
  19 #include "../pci.h"
  20 #include "portdrv.h"
  21
  22 /* If this switch is set, PCIe port native services should not be enabled. */
  23 bool pcie_ports_disabled;
  24
  25 /*
  26  * If the user specified "pcie_ports=native", use the PCIe services regardless
  27  * of whether the platform has given us permission.  On ACPI systems, this
  28  * means we ignore _OSC.
  29  */
  30 bool pcie_ports_native;
  31
  32 static int __init pcie_port_setup(char *str)
  33 {
  34         if (!strncmp(str, "compat", 6))
  35                 pcie_ports_disabled = true;
  36         else if (!strncmp(str, "native", 6))
  37                 pcie_ports_native = true;
  38
  39         return 1;
  40 }
  41 __setup("pcie_ports=", pcie_port_setup);
  42
  43 /* global data */
  44
  45 #ifdef CONFIG_PM
  46 static int pcie_port_runtime_suspend(struct device *dev)
  47 {
  48         if (!to_pci_dev(dev)->bridge_d3)
  49                 return -EBUSY;
  50
  51         return pcie_port_device_runtime_suspend(dev);
  52 }
  53
  54 static int pcie_port_runtime_idle(struct device *dev)
  55 {
  56         /*
  57          * Assume the PCI core has set bridge_d3 whenever it thinks the port
  58          * should be good to go to D3.  Everything else, including moving
  59          * the port to D3, is handled by the PCI core.
  60          */
  61         return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
  62 }
  63
  64 static const struct dev_pm_ops pcie_portdrv_pm_ops = {
  65         .suspend        = pcie_port_device_suspend,
  66         .resume_noirq   = pcie_port_device_resume_noirq,
  67         .resume         = pcie_port_device_resume,
  68         .freeze         = pcie_port_device_suspend,
  69         .thaw           = pcie_port_device_resume,
  70         .poweroff       = pcie_port_device_suspend,
  71         .restore_noirq  = pcie_port_device_resume_noirq,
  72         .restore        = pcie_port_device_resume,
  73         .runtime_suspend = pcie_port_runtime_suspend,
  74         .runtime_resume = pcie_port_device_runtime_resume,
  75         .runtime_idle   = pcie_port_runtime_idle,
  76 };
  77
  78 #define PCIE_PORTDRV_PM_OPS     (&pcie_portdrv_pm_ops)
  79
  80 #else /* !PM */
  81
  82 #define PCIE_PORTDRV_PM_OPS     NULL
  83 #endif /* !PM */
  84
  85 /*
  86  * pcie_portdrv_probe - Probe PCI-Express port devices
  87  * @dev: PCI-Express port device being probed
  88  *
  89  * If detected invokes the pcie_port_device_register() method for
  90  * this port device.
  91  *
  92  */
  93 static int pcie_portdrv_probe(struct pci_dev *dev,
  94                                         const struct pci_device_id *id)
  95 {
  96         int status;
  97
  98         if (!pci_is_pcie(dev) ||
  99             ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
 100              (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM) &&
 101              (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
 102                 return -ENODEV;
 103
 104         status = pcie_port_device_register(dev);
 105         if (status)
 106                 return status;
 107
 108         pci_save_state(dev);
 109
 110         dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NEVER_SKIP |
 111                                            DPM_FLAG_SMART_SUSPEND);
 112
 113         if (pci_bridge_d3_possible(dev)) {
 114                 /*
 115                  * Keep the port resumed 100ms to make sure things like
 116                  * config space accesses from userspace (lspci) will not
 117                  * cause the port to repeatedly suspend and resume.
 118                  */
 119                 pm_runtime_set_autosuspend_delay(&dev->dev, 100);
 120                 pm_runtime_use_autosuspend(&dev->dev);
 121                 pm_runtime_mark_last_busy(&dev->dev);
 122                 pm_runtime_put_autosuspend(&dev->dev);
 123                 pm_runtime_allow(&dev->dev);
 124         }
 125
 126         return 0;
 127 }
 128
 129 static void pcie_portdrv_remove(struct pci_dev *dev)
 130 {
 131         if (pci_bridge_d3_possible(dev)) {
 132                 pm_runtime_forbid(&dev->dev);
 133                 pm_runtime_get_noresume(&dev->dev);
 134                 pm_runtime_dont_use_autosuspend(&dev->dev);
 135         }
 136
 137         pcie_port_device_remove(dev);
 138 }
 139
 140 static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
 141                                         enum pci_channel_state error)
 142 {
 143         /* Root Port has no impact. Always recovers. */
 144         return PCI_ERS_RESULT_CAN_RECOVER;
 145 }
 146
 147 static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
 148 {
 149         pci_restore_state(dev);
 150         pci_save_state(dev);
 151         return PCI_ERS_RESULT_RECOVERED;
 152 }
 153
 154 static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
 155 {
 156         return PCI_ERS_RESULT_RECOVERED;
 157 }
 158
 159 static int resume_iter(struct device *device, void *data)
 160 {
 161         struct pcie_device *pcie_device;
 162         struct pcie_port_service_driver *driver;
 163
 164         if (device->bus == &pcie_port_bus_type && device->driver) {
 165                 driver = to_service_driver(device->driver);
 166                 if (driver && driver->error_resume) {
 167                         pcie_device = to_pcie_device(device);
 168
 169                         /* Forward error message to service drivers */
 170                         driver->error_resume(pcie_device->port);
 171                 }
 172         }
 173
 174         return 0;
 175 }
 176
 177 static void pcie_portdrv_err_resume(struct pci_dev *dev)
 178 {
 179         device_for_each_child(&dev->dev, NULL, resume_iter);
 180 }
 181
 182 /*
 183  * LINUX Device Driver Model
 184  */
 185 static const struct pci_device_id port_pci_ids[] = { {
 186         /* handle any PCI-Express port */
 187         PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0),
 188         }, { /* end: all zeroes */ }
 189 };
 190
 191 static const struct pci_error_handlers pcie_portdrv_err_handler = {
 192         .error_detected = pcie_portdrv_error_detected,
 193         .slot_reset = pcie_portdrv_slot_reset,
 194         .mmio_enabled = pcie_portdrv_mmio_enabled,
 195         .resume = pcie_portdrv_err_resume,
 196 };
 197
 198 static struct pci_driver pcie_portdriver = {
 199         .name           = "pcieport",
 200         .id_table       = &port_pci_ids[0],
 201
 202         .probe          = pcie_portdrv_probe,
 203         .remove         = pcie_portdrv_remove,
 204         .shutdown       = pcie_portdrv_remove,
 205
 206         .err_handler    = &pcie_portdrv_err_handler,
 207
 208         .driver.pm      = PCIE_PORTDRV_PM_OPS,
 209 };
 210
 211 static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
 212 {
 213         pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
 214                   d->ident);
 215         pcie_pme_disable_msi();
 216         return 0;
 217 }
 218
 219 static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = {
 220         /*
 221          * Boxes that should not use MSI for PCIe PME signaling.
 222          */
 223         {
 224          .callback = dmi_pcie_pme_disable_msi,
 225          .ident = "MSI Wind U-100",
 226          .matches = {
 227                      DMI_MATCH(DMI_SYS_VENDOR,
 228                                 "MICRO-STAR INTERNATIONAL CO., LTD"),
 229                      DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
 230                      },
 231          },
 232          {}
 233 };
 234
 235 static void __init pcie_init_services(void)
 236 {
 237         pcie_aer_init();
 238         pcie_pme_init();
 239         pcie_dpc_init();
 240         pcie_hp_init();
 241 }
 242
 243 static int __init pcie_portdrv_init(void)
 244 {
 245         if (pcie_ports_disabled)
 246                 return -EACCES;
 247
 248         pcie_init_services();
 249         dmi_check_system(pcie_portdrv_dmi_table);
 250
 251         return pci_register_driver(&pcie_portdriver);
 252 }
 253 device_initcall(pcie_portdrv_init);