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         return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
  49 }
  50
  51 static int pcie_port_runtime_resume(struct device *dev)
  52 {
  53         return 0;
  54 }
  55
  56 static int pcie_port_runtime_idle(struct device *dev)
  57 {
  58         /*
  59          * Assume the PCI core has set bridge_d3 whenever it thinks the port
  60          * should be good to go to D3.  Everything else, including moving
  61          * the port to D3, is handled by the PCI core.
  62          */
  63         return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
  64 }
  65
  66 static const struct dev_pm_ops pcie_portdrv_pm_ops = {
  67         .suspend        = pcie_port_device_suspend,
  68         .resume_noirq   = pcie_port_device_resume_noirq,
  69         .resume         = pcie_port_device_resume,
  70         .freeze         = pcie_port_device_suspend,
  71         .thaw           = pcie_port_device_resume,
  72         .poweroff       = pcie_port_device_suspend,
  73         .restore_noirq  = pcie_port_device_resume_noirq,
  74         .restore        = pcie_port_device_resume,
  75         .runtime_suspend = pcie_port_runtime_suspend,
  76         .runtime_resume = pcie_port_runtime_resume,
  77         .runtime_idle   = pcie_port_runtime_idle,
  78 };
  79
  80 #define PCIE_PORTDRV_PM_OPS     (&pcie_portdrv_pm_ops)
  81
  82 #else /* !PM */
  83
  84 #define PCIE_PORTDRV_PM_OPS     NULL
  85 #endif /* !PM */
  86
  87 /*
  88  * pcie_portdrv_probe - Probe PCI-Express port devices
  89  * @dev: PCI-Express port device being probed
  90  *
  91  * If detected invokes the pcie_port_device_register() method for
  92  * this port device.
  93  *
  94  */
  95 static int pcie_portdrv_probe(struct pci_dev *dev,
  96                                         const struct pci_device_id *id)
  97 {
  98         int status;
  99
 100         if (!pci_is_pcie(dev) ||
 101             ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
 102              (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM) &&
 103              (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
 104                 return -ENODEV;
 105
 106         status = pcie_port_device_register(dev);
 107         if (status)
 108                 return status;
 109
 110         pci_save_state(dev);
 111
 112         dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_SMART_SUSPEND |
 113                                            DPM_FLAG_LEAVE_SUSPENDED);
 114
 115         if (pci_bridge_d3_possible(dev)) {
 116                 /*
 117                  * Keep the port resumed 100ms to make sure things like
 118                  * config space accesses from userspace (lspci) will not
 119                  * cause the port to repeatedly suspend and resume.
 120                  */
 121                 pm_runtime_set_autosuspend_delay(&dev->dev, 100);
 122                 pm_runtime_use_autosuspend(&dev->dev);
 123                 pm_runtime_mark_last_busy(&dev->dev);
 124                 pm_runtime_put_autosuspend(&dev->dev);
 125                 pm_runtime_allow(&dev->dev);
 126         }
 127
 128         return 0;
 129 }
 130
 131 static void pcie_portdrv_remove(struct pci_dev *dev)
 132 {
 133         if (pci_bridge_d3_possible(dev)) {
 134                 pm_runtime_forbid(&dev->dev);
 135                 pm_runtime_get_noresume(&dev->dev);
 136                 pm_runtime_dont_use_autosuspend(&dev->dev);
 137         }
 138
 139         pcie_port_device_remove(dev);
 140 }
 141
 142 static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
 143                                         enum pci_channel_state error)
 144 {
 145         /* Root Port has no impact. Always recovers. */
 146         return PCI_ERS_RESULT_CAN_RECOVER;
 147 }
 148
 149 static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
 150 {
 151         return PCI_ERS_RESULT_RECOVERED;
 152 }
 153
 154 static int resume_iter(struct device *device, void *data)
 155 {
 156         struct pcie_device *pcie_device;
 157         struct pcie_port_service_driver *driver;
 158
 159         if (device->bus == &pcie_port_bus_type && device->driver) {
 160                 driver = to_service_driver(device->driver);
 161                 if (driver && driver->error_resume) {
 162                         pcie_device = to_pcie_device(device);
 163
 164                         /* Forward error message to service drivers */
 165                         driver->error_resume(pcie_device->port);
 166                 }
 167         }
 168
 169         return 0;
 170 }
 171
 172 static void pcie_portdrv_err_resume(struct pci_dev *dev)
 173 {
 174         device_for_each_child(&dev->dev, NULL, resume_iter);
 175 }
 176
 177 /*
 178  * LINUX Device Driver Model
 179  */
 180 static const struct pci_device_id port_pci_ids[] = { {
 181         /* handle any PCI-Express port */
 182         PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0),
 183         }, { /* end: all zeroes */ }
 184 };
 185
 186 static const struct pci_error_handlers pcie_portdrv_err_handler = {
 187         .error_detected = pcie_portdrv_error_detected,
 188         .mmio_enabled = pcie_portdrv_mmio_enabled,
 189         .resume = pcie_portdrv_err_resume,
 190 };
 191
 192 static struct pci_driver pcie_portdriver = {
 193         .name           = "pcieport",
 194         .id_table       = &port_pci_ids[0],
 195
 196         .probe          = pcie_portdrv_probe,
 197         .remove         = pcie_portdrv_remove,
 198         .shutdown       = pcie_portdrv_remove,
 199
 200         .err_handler    = &pcie_portdrv_err_handler,
 201
 202         .driver.pm      = PCIE_PORTDRV_PM_OPS,
 203 };
 204
 205 static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
 206 {
 207         pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
 208                   d->ident);
 209         pcie_pme_disable_msi();
 210         return 0;
 211 }
 212
 213 static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = {
 214         /*
 215          * Boxes that should not use MSI for PCIe PME signaling.
 216          */
 217         {
 218          .callback = dmi_pcie_pme_disable_msi,
 219          .ident = "MSI Wind U-100",
 220          .matches = {
 221                      DMI_MATCH(DMI_SYS_VENDOR,
 222                                 "MICRO-STAR INTERNATIONAL CO., LTD"),
 223                      DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
 224                      },
 225          },
 226          {}
 227 };
 228
 229 static void __init pcie_init_services(void)
 230 {
 231         pcie_aer_init();
 232         pcie_pme_init();
 233         pcie_dpc_init();
 234         pcie_hp_init();
 235 }
 236
 237 static int __init pcie_portdrv_init(void)
 238 {
 239         if (pcie_ports_disabled)
 240                 return -EACCES;
 241
 242         pcie_init_services();
 243         dmi_check_system(pcie_portdrv_dmi_table);
 244
 245         return pci_register_driver(&pcie_portdriver);
 246 }
 247 device_initcall(pcie_portdrv_init);