linux/drivers/pci/pcie/portdrv_pci.c
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   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. */
  23bool 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 */
  30bool pcie_ports_native;
  31
  32/*
  33 * If the user specified "pcie_ports=dpc-native", use the Linux DPC PCIe
  34 * service even if the platform hasn't given us permission.
  35 */
  36bool pcie_ports_dpc_native;
  37
  38static int __init pcie_port_setup(char *str)
  39{
  40        if (!strncmp(str, "compat", 6))
  41                pcie_ports_disabled = true;
  42        else if (!strncmp(str, "native", 6))
  43                pcie_ports_native = true;
  44        else if (!strncmp(str, "dpc-native", 10))
  45                pcie_ports_dpc_native = true;
  46
  47        return 1;
  48}
  49__setup("pcie_ports=", pcie_port_setup);
  50
  51/* global data */
  52
  53#ifdef CONFIG_PM
  54static int pcie_port_runtime_suspend(struct device *dev)
  55{
  56        if (!to_pci_dev(dev)->bridge_d3)
  57                return -EBUSY;
  58
  59        return pcie_port_device_runtime_suspend(dev);
  60}
  61
  62static int pcie_port_runtime_idle(struct device *dev)
  63{
  64        /*
  65         * Assume the PCI core has set bridge_d3 whenever it thinks the port
  66         * should be good to go to D3.  Everything else, including moving
  67         * the port to D3, is handled by the PCI core.
  68         */
  69        return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
  70}
  71
  72static const struct dev_pm_ops pcie_portdrv_pm_ops = {
  73        .suspend        = pcie_port_device_suspend,
  74        .resume_noirq   = pcie_port_device_resume_noirq,
  75        .resume         = pcie_port_device_resume,
  76        .freeze         = pcie_port_device_suspend,
  77        .thaw           = pcie_port_device_resume,
  78        .poweroff       = pcie_port_device_suspend,
  79        .restore_noirq  = pcie_port_device_resume_noirq,
  80        .restore        = pcie_port_device_resume,
  81        .runtime_suspend = pcie_port_runtime_suspend,
  82        .runtime_resume = pcie_port_device_runtime_resume,
  83        .runtime_idle   = pcie_port_runtime_idle,
  84};
  85
  86#define PCIE_PORTDRV_PM_OPS     (&pcie_portdrv_pm_ops)
  87
  88#else /* !PM */
  89
  90#define PCIE_PORTDRV_PM_OPS     NULL
  91#endif /* !PM */
  92
  93/*
  94 * pcie_portdrv_probe - Probe PCI-Express port devices
  95 * @dev: PCI-Express port device being probed
  96 *
  97 * If detected invokes the pcie_port_device_register() method for
  98 * this port device.
  99 *
 100 */
 101static int pcie_portdrv_probe(struct pci_dev *dev,
 102                                        const struct pci_device_id *id)
 103{
 104        int type = pci_pcie_type(dev);
 105        int status;
 106
 107        if (!pci_is_pcie(dev) ||
 108            ((type != PCI_EXP_TYPE_ROOT_PORT) &&
 109             (type != PCI_EXP_TYPE_UPSTREAM) &&
 110             (type != PCI_EXP_TYPE_DOWNSTREAM) &&
 111             (type != PCI_EXP_TYPE_RC_EC)))
 112                return -ENODEV;
 113
 114        if (type == PCI_EXP_TYPE_RC_EC)
 115                pcie_link_rcec(dev);
 116
 117        status = pcie_port_device_register(dev);
 118        if (status)
 119                return status;
 120
 121        pci_save_state(dev);
 122
 123        dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NO_DIRECT_COMPLETE |
 124                                           DPM_FLAG_SMART_SUSPEND);
 125
 126        if (pci_bridge_d3_possible(dev)) {
 127                /*
 128                 * Keep the port resumed 100ms to make sure things like
 129                 * config space accesses from userspace (lspci) will not
 130                 * cause the port to repeatedly suspend and resume.
 131                 */
 132                pm_runtime_set_autosuspend_delay(&dev->dev, 100);
 133                pm_runtime_use_autosuspend(&dev->dev);
 134                pm_runtime_mark_last_busy(&dev->dev);
 135                pm_runtime_put_autosuspend(&dev->dev);
 136                pm_runtime_allow(&dev->dev);
 137        }
 138
 139        return 0;
 140}
 141
 142static void pcie_portdrv_remove(struct pci_dev *dev)
 143{
 144        if (pci_bridge_d3_possible(dev)) {
 145                pm_runtime_forbid(&dev->dev);
 146                pm_runtime_get_noresume(&dev->dev);
 147                pm_runtime_dont_use_autosuspend(&dev->dev);
 148        }
 149
 150        pcie_port_device_remove(dev);
 151}
 152
 153static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
 154                                        pci_channel_state_t error)
 155{
 156        if (error == pci_channel_io_frozen)
 157                return PCI_ERS_RESULT_NEED_RESET;
 158        return PCI_ERS_RESULT_CAN_RECOVER;
 159}
 160
 161static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
 162{
 163        pci_restore_state(dev);
 164        pci_save_state(dev);
 165        return PCI_ERS_RESULT_RECOVERED;
 166}
 167
 168static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
 169{
 170        return PCI_ERS_RESULT_RECOVERED;
 171}
 172
 173static int resume_iter(struct device *device, void *data)
 174{
 175        struct pcie_device *pcie_device;
 176        struct pcie_port_service_driver *driver;
 177
 178        if (device->bus == &pcie_port_bus_type && device->driver) {
 179                driver = to_service_driver(device->driver);
 180                if (driver && driver->error_resume) {
 181                        pcie_device = to_pcie_device(device);
 182
 183                        /* Forward error message to service drivers */
 184                        driver->error_resume(pcie_device->port);
 185                }
 186        }
 187
 188        return 0;
 189}
 190
 191static void pcie_portdrv_err_resume(struct pci_dev *dev)
 192{
 193        device_for_each_child(&dev->dev, NULL, resume_iter);
 194}
 195
 196/*
 197 * LINUX Device Driver Model
 198 */
 199static const struct pci_device_id port_pci_ids[] = {
 200        /* handle any PCI-Express port */
 201        { PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0) },
 202        /* subtractive decode PCI-to-PCI bridge, class type is 060401h */
 203        { PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x01), ~0) },
 204        /* handle any Root Complex Event Collector */
 205        { PCI_DEVICE_CLASS(((PCI_CLASS_SYSTEM_RCEC << 8) | 0x00), ~0) },
 206        { },
 207};
 208
 209static const struct pci_error_handlers pcie_portdrv_err_handler = {
 210        .error_detected = pcie_portdrv_error_detected,
 211        .slot_reset = pcie_portdrv_slot_reset,
 212        .mmio_enabled = pcie_portdrv_mmio_enabled,
 213        .resume = pcie_portdrv_err_resume,
 214};
 215
 216static struct pci_driver pcie_portdriver = {
 217        .name           = "pcieport",
 218        .id_table       = &port_pci_ids[0],
 219
 220        .probe          = pcie_portdrv_probe,
 221        .remove         = pcie_portdrv_remove,
 222        .shutdown       = pcie_portdrv_remove,
 223
 224        .err_handler    = &pcie_portdrv_err_handler,
 225
 226        .driver.pm      = PCIE_PORTDRV_PM_OPS,
 227};
 228
 229static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
 230{
 231        pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
 232                  d->ident);
 233        pcie_pme_disable_msi();
 234        return 0;
 235}
 236
 237static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = {
 238        /*
 239         * Boxes that should not use MSI for PCIe PME signaling.
 240         */
 241        {
 242         .callback = dmi_pcie_pme_disable_msi,
 243         .ident = "MSI Wind U-100",
 244         .matches = {
 245                     DMI_MATCH(DMI_SYS_VENDOR,
 246                                "MICRO-STAR INTERNATIONAL CO., LTD"),
 247                     DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
 248                     },
 249         },
 250         {}
 251};
 252
 253static void __init pcie_init_services(void)
 254{
 255        pcie_aer_init();
 256        pcie_pme_init();
 257        pcie_dpc_init();
 258        pcie_hp_init();
 259}
 260
 261static int __init pcie_portdrv_init(void)
 262{
 263        if (pcie_ports_disabled)
 264                return -EACCES;
 265
 266        pcie_init_services();
 267        dmi_check_system(pcie_portdrv_dmi_table);
 268
 269        return pci_register_driver(&pcie_portdriver);
 270}
 271device_initcall(pcie_portdrv_init);
 272