drivers/pci/hotplug/pciehp_core.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * PCI Express Hot Plug Controller Driver
   4  *
   5  * Copyright (C) 1995,2001 Compaq Computer Corporation
   6  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
   7  * Copyright (C) 2001 IBM Corp.
   8  * Copyright (C) 2003-2004 Intel Corporation
   9  *
  10  * All rights reserved.
  11  *
  12  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
  13  *
  14  * Authors:
  15  *   Dan Zink <dan.zink@compaq.com>
  16  *   Greg Kroah-Hartman <greg@kroah.com>
  17  *   Dely Sy <dely.l.sy@intel.com>"
  18  */
  19
  20 #define pr_fmt(fmt) "pciehp: " fmt
  21 #define dev_fmt pr_fmt
  22
  23 #include <linux/moduleparam.h>
  24 #include <linux/kernel.h>
  25 #include <linux/slab.h>
  26 #include <linux/types.h>
  27 #include <linux/pci.h>
  28 #include "pciehp.h"
  29
  30 #include "../pci.h"
  31
  32 /* Global variables */
  33 bool pciehp_poll_mode;
  34 int pciehp_poll_time;
  35
  36 /*
  37  * not really modular, but the easiest way to keep compat with existing
  38  * bootargs behaviour is to continue using module_param here.
  39  */
  40 module_param(pciehp_poll_mode, bool, 0644);
  41 module_param(pciehp_poll_time, int, 0644);
  42 MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
  43 MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");
  44
  45 static int set_attention_status(struct hotplug_slot *slot, u8 value);
  46 static int get_power_status(struct hotplug_slot *slot, u8 *value);
  47 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
  48 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
  49
  50 static int init_slot(struct controller *ctrl)
  51 {
  52         struct hotplug_slot_ops *ops;
  53         char name[SLOT_NAME_SIZE];
  54         int retval;
  55
  56         /* Setup hotplug slot ops */
  57         ops = kzalloc(sizeof(*ops), GFP_KERNEL);
  58         if (!ops)
  59                 return -ENOMEM;
  60
  61         ops->enable_slot = pciehp_sysfs_enable_slot;
  62         ops->disable_slot = pciehp_sysfs_disable_slot;
  63         ops->get_power_status = get_power_status;
  64         ops->get_adapter_status = get_adapter_status;
  65         ops->reset_slot = pciehp_reset_slot;
  66         if (MRL_SENS(ctrl))
  67                 ops->get_latch_status = get_latch_status;
  68         if (ATTN_LED(ctrl)) {
  69                 ops->get_attention_status = pciehp_get_attention_status;
  70                 ops->set_attention_status = set_attention_status;
  71         } else if (ctrl->pcie->port->hotplug_user_indicators) {
  72                 ops->get_attention_status = pciehp_get_raw_indicator_status;
  73                 ops->set_attention_status = pciehp_set_raw_indicator_status;
  74         }
  75
  76         /* register this slot with the hotplug pci core */
  77         ctrl->hotplug_slot.ops = ops;
  78         snprintf(name, SLOT_NAME_SIZE, "%u", PSN(ctrl));
  79
  80         retval = pci_hp_initialize(&ctrl->hotplug_slot,
  81                                    ctrl->pcie->port->subordinate, 0, name);
  82         if (retval) {
  83                 ctrl_err(ctrl, "pci_hp_initialize failed: error %d\n", retval);
  84                 kfree(ops);
  85         }
  86         return retval;
  87 }
  88
  89 static void cleanup_slot(struct controller *ctrl)
  90 {
  91         struct hotplug_slot *hotplug_slot = &ctrl->hotplug_slot;
  92
  93         pci_hp_destroy(hotplug_slot);
  94         kfree(hotplug_slot->ops);
  95 }
  96
  97 /*
  98  * set_attention_status - Turns the Attention Indicator on, off or blinking
  99  */
 100 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
 101 {
 102         struct controller *ctrl = to_ctrl(hotplug_slot);
 103         struct pci_dev *pdev = ctrl->pcie->port;
 104
 105         if (status)
 106                 status <<= PCI_EXP_SLTCTL_ATTN_IND_SHIFT;
 107         else
 108                 status = PCI_EXP_SLTCTL_ATTN_IND_OFF;
 109
 110         pci_config_pm_runtime_get(pdev);
 111         pciehp_set_indicators(ctrl, INDICATOR_NOOP, status);
 112         pci_config_pm_runtime_put(pdev);
 113         return 0;
 114 }
 115
 116 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 117 {
 118         struct controller *ctrl = to_ctrl(hotplug_slot);
 119         struct pci_dev *pdev = ctrl->pcie->port;
 120
 121         pci_config_pm_runtime_get(pdev);
 122         pciehp_get_power_status(ctrl, value);
 123         pci_config_pm_runtime_put(pdev);
 124         return 0;
 125 }
 126
 127 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
 128 {
 129         struct controller *ctrl = to_ctrl(hotplug_slot);
 130         struct pci_dev *pdev = ctrl->pcie->port;
 131
 132         pci_config_pm_runtime_get(pdev);
 133         pciehp_get_latch_status(ctrl, value);
 134         pci_config_pm_runtime_put(pdev);
 135         return 0;
 136 }
 137
 138 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 139 {
 140         struct controller *ctrl = to_ctrl(hotplug_slot);
 141         struct pci_dev *pdev = ctrl->pcie->port;
 142         int ret;
 143
 144         pci_config_pm_runtime_get(pdev);
 145         ret = pciehp_card_present_or_link_active(ctrl);
 146         pci_config_pm_runtime_put(pdev);
 147         if (ret < 0)
 148                 return ret;
 149
 150         *value = ret;
 151         return 0;
 152 }
 153
 154 /**
 155  * pciehp_check_presence() - synthesize event if presence has changed
 156  *
 157  * On probe and resume, an explicit presence check is necessary to bring up an
 158  * occupied slot or bring down an unoccupied slot.  This can't be triggered by
 159  * events in the Slot Status register, they may be stale and are therefore
 160  * cleared.  Secondly, sending an interrupt for "events that occur while
 161  * interrupt generation is disabled [when] interrupt generation is subsequently
 162  * enabled" is optional per PCIe r4.0, sec 6.7.3.4.
 163  */
 164 static void pciehp_check_presence(struct controller *ctrl)
 165 {
 166         int occupied;
 167
 168         down_read(&ctrl->reset_lock);
 169         mutex_lock(&ctrl->state_lock);
 170
 171         occupied = pciehp_card_present_or_link_active(ctrl);
 172         if ((occupied > 0 && (ctrl->state == OFF_STATE ||
 173                           ctrl->state == BLINKINGON_STATE)) ||
 174             (!occupied && (ctrl->state == ON_STATE ||
 175                            ctrl->state == BLINKINGOFF_STATE)))
 176                 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
 177
 178         mutex_unlock(&ctrl->state_lock);
 179         up_read(&ctrl->reset_lock);
 180 }
 181
 182 static int pciehp_probe(struct pcie_device *dev)
 183 {
 184         int rc;
 185         struct controller *ctrl;
 186
 187         /* If this is not a "hotplug" service, we have no business here. */
 188         if (dev->service != PCIE_PORT_SERVICE_HP)
 189                 return -ENODEV;
 190
 191         if (!dev->port->subordinate) {
 192                 /* Can happen if we run out of bus numbers during probe */
 193                 pci_err(dev->port,
 194                         "Hotplug bridge without secondary bus, ignoring\n");
 195                 return -ENODEV;
 196         }
 197
 198         ctrl = pcie_init(dev);
 199         if (!ctrl) {
 200                 pci_err(dev->port, "Controller initialization failed\n");
 201                 return -ENODEV;
 202         }
 203         set_service_data(dev, ctrl);
 204
 205         /* Setup the slot information structures */
 206         rc = init_slot(ctrl);
 207         if (rc) {
 208                 if (rc == -EBUSY)
 209                         ctrl_warn(ctrl, "Slot already registered by another hotplug driver\n");
 210                 else
 211                         ctrl_err(ctrl, "Slot initialization failed (%d)\n", rc);
 212                 goto err_out_release_ctlr;
 213         }
 214
 215         /* Enable events after we have setup the data structures */
 216         rc = pcie_init_notification(ctrl);
 217         if (rc) {
 218                 ctrl_err(ctrl, "Notification initialization failed (%d)\n", rc);
 219                 goto err_out_free_ctrl_slot;
 220         }
 221
 222         /* Publish to user space */
 223         rc = pci_hp_add(&ctrl->hotplug_slot);
 224         if (rc) {
 225                 ctrl_err(ctrl, "Publication to user space failed (%d)\n", rc);
 226                 goto err_out_shutdown_notification;
 227         }
 228
 229         pciehp_check_presence(ctrl);
 230
 231         return 0;
 232
 233 err_out_shutdown_notification:
 234         pcie_shutdown_notification(ctrl);
 235 err_out_free_ctrl_slot:
 236         cleanup_slot(ctrl);
 237 err_out_release_ctlr:
 238         pciehp_release_ctrl(ctrl);
 239         return -ENODEV;
 240 }
 241
 242 static void pciehp_remove(struct pcie_device *dev)
 243 {
 244         struct controller *ctrl = get_service_data(dev);
 245
 246         pci_hp_del(&ctrl->hotplug_slot);
 247         pcie_shutdown_notification(ctrl);
 248         cleanup_slot(ctrl);
 249         pciehp_release_ctrl(ctrl);
 250 }
 251
 252 #ifdef CONFIG_PM
 253 static bool pme_is_native(struct pcie_device *dev)
 254 {
 255         const struct pci_host_bridge *host;
 256
 257         host = pci_find_host_bridge(dev->port->bus);
 258         return pcie_ports_native || host->native_pme;
 259 }
 260
 261 static void pciehp_disable_interrupt(struct pcie_device *dev)
 262 {
 263         /*
 264          * Disable hotplug interrupt so that it does not trigger
 265          * immediately when the downstream link goes down.
 266          */
 267         if (pme_is_native(dev))
 268                 pcie_disable_interrupt(get_service_data(dev));
 269 }
 270
 271 #ifdef CONFIG_PM_SLEEP
 272 static int pciehp_suspend(struct pcie_device *dev)
 273 {
 274         /*
 275          * If the port is already runtime suspended we can keep it that
 276          * way.
 277          */
 278         if (dev_pm_smart_suspend_and_suspended(&dev->port->dev))
 279                 return 0;
 280
 281         pciehp_disable_interrupt(dev);
 282         return 0;
 283 }
 284
 285 static int pciehp_resume_noirq(struct pcie_device *dev)
 286 {
 287         struct controller *ctrl = get_service_data(dev);
 288
 289         /* pci_restore_state() just wrote to the Slot Control register */
 290         ctrl->cmd_started = jiffies;
 291         ctrl->cmd_busy = true;
 292
 293         /* clear spurious events from rediscovery of inserted card */
 294         if (ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE)
 295                 pcie_clear_hotplug_events(ctrl);
 296
 297         return 0;
 298 }
 299 #endif
 300
 301 static int pciehp_resume(struct pcie_device *dev)
 302 {
 303         struct controller *ctrl = get_service_data(dev);
 304
 305         if (pme_is_native(dev))
 306                 pcie_enable_interrupt(ctrl);
 307
 308         pciehp_check_presence(ctrl);
 309
 310         return 0;
 311 }
 312
 313 static int pciehp_runtime_suspend(struct pcie_device *dev)
 314 {
 315         pciehp_disable_interrupt(dev);
 316         return 0;
 317 }
 318
 319 static int pciehp_runtime_resume(struct pcie_device *dev)
 320 {
 321         struct controller *ctrl = get_service_data(dev);
 322
 323         /* pci_restore_state() just wrote to the Slot Control register */
 324         ctrl->cmd_started = jiffies;
 325         ctrl->cmd_busy = true;
 326
 327         /* clear spurious events from rediscovery of inserted card */
 328         if ((ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE) &&
 329              pme_is_native(dev))
 330                 pcie_clear_hotplug_events(ctrl);
 331
 332         return pciehp_resume(dev);
 333 }
 334 #endif /* PM */
 335
 336 static struct pcie_port_service_driver hpdriver_portdrv = {
 337         .name           = "pciehp",
 338         .port_type      = PCIE_ANY_PORT,
 339         .service        = PCIE_PORT_SERVICE_HP,
 340
 341         .probe          = pciehp_probe,
 342         .remove         = pciehp_remove,
 343
 344 #ifdef  CONFIG_PM
 345 #ifdef  CONFIG_PM_SLEEP
 346         .suspend        = pciehp_suspend,
 347         .resume_noirq   = pciehp_resume_noirq,
 348         .resume         = pciehp_resume,
 349 #endif
 350         .runtime_suspend = pciehp_runtime_suspend,
 351         .runtime_resume = pciehp_runtime_resume,
 352 #endif  /* PM */
 353 };
 354
 355 int __init pcie_hp_init(void)
 356 {
 357         int retval = 0;
 358
 359         retval = pcie_port_service_register(&hpdriver_portdrv);
 360         pr_debug("pcie_port_service_register = %d\n", retval);
 361         if (retval)
 362                 pr_debug("Failure to register service\n");
 363
 364         return retval;
 365 }