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 #include <linux/moduleparam.h>
  21 #include <linux/kernel.h>
  22 #include <linux/slab.h>
  23 #include <linux/types.h>
  24 #include <linux/pci.h>
  25 #include "pciehp.h"
  26 #include <linux/interrupt.h>
  27 #include <linux/time.h>
  28
  29 #include "../pci.h"
  30
  31 /* Global variables */
  32 bool pciehp_debug;
  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_debug, bool, 0644);
  41 module_param(pciehp_poll_mode, bool, 0644);
  42 module_param(pciehp_poll_time, int, 0644);
  43 MODULE_PARM_DESC(pciehp_debug, "Debugging mode enabled or not");
  44 MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
  45 MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");
  46
  47 #define PCIE_MODULE_NAME "pciehp"
  48
  49 static int set_attention_status(struct hotplug_slot *slot, u8 value);
  50 static int enable_slot(struct hotplug_slot *slot);
  51 static int disable_slot(struct hotplug_slot *slot);
  52 static int get_power_status(struct hotplug_slot *slot, u8 *value);
  53 static int get_attention_status(struct hotplug_slot *slot, u8 *value);
  54 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
  55 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
  56 static int reset_slot(struct hotplug_slot *slot, int probe);
  57
  58 static int init_slot(struct controller *ctrl)
  59 {
  60         struct slot *slot = ctrl->slot;
  61         struct hotplug_slot *hotplug = NULL;
  62         struct hotplug_slot_info *info = NULL;
  63         struct hotplug_slot_ops *ops = NULL;
  64         char name[SLOT_NAME_SIZE];
  65         int retval = -ENOMEM;
  66
  67         hotplug = kzalloc(sizeof(*hotplug), GFP_KERNEL);
  68         if (!hotplug)
  69                 goto out;
  70
  71         info = kzalloc(sizeof(*info), GFP_KERNEL);
  72         if (!info)
  73                 goto out;
  74
  75         /* Setup hotplug slot ops */
  76         ops = kzalloc(sizeof(*ops), GFP_KERNEL);
  77         if (!ops)
  78                 goto out;
  79
  80         ops->enable_slot = enable_slot;
  81         ops->disable_slot = disable_slot;
  82         ops->get_power_status = get_power_status;
  83         ops->get_adapter_status = get_adapter_status;
  84         ops->reset_slot = reset_slot;
  85         if (MRL_SENS(ctrl))
  86                 ops->get_latch_status = get_latch_status;
  87         if (ATTN_LED(ctrl)) {
  88                 ops->get_attention_status = get_attention_status;
  89                 ops->set_attention_status = set_attention_status;
  90         } else if (ctrl->pcie->port->hotplug_user_indicators) {
  91                 ops->get_attention_status = pciehp_get_raw_indicator_status;
  92                 ops->set_attention_status = pciehp_set_raw_indicator_status;
  93         }
  94
  95         /* register this slot with the hotplug pci core */
  96         hotplug->info = info;
  97         hotplug->private = slot;
  98         hotplug->ops = ops;
  99         slot->hotplug_slot = hotplug;
 100         snprintf(name, SLOT_NAME_SIZE, "%u", PSN(ctrl));
 101
 102         retval = pci_hp_initialize(hotplug,
 103                                    ctrl->pcie->port->subordinate, 0, name);
 104         if (retval)
 105                 ctrl_err(ctrl, "pci_hp_initialize failed: error %d\n", retval);
 106 out:
 107         if (retval) {
 108                 kfree(ops);
 109                 kfree(info);
 110                 kfree(hotplug);
 111         }
 112         return retval;
 113 }
 114
 115 static void cleanup_slot(struct controller *ctrl)
 116 {
 117         struct hotplug_slot *hotplug_slot = ctrl->slot->hotplug_slot;
 118
 119         pci_hp_destroy(hotplug_slot);
 120         kfree(hotplug_slot->ops);
 121         kfree(hotplug_slot->info);
 122         kfree(hotplug_slot);
 123 }
 124
 125 /*
 126  * set_attention_status - Turns the Amber LED for a slot on, off or blink
 127  */
 128 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
 129 {
 130         struct slot *slot = hotplug_slot->private;
 131         struct pci_dev *pdev = slot->ctrl->pcie->port;
 132
 133         pci_config_pm_runtime_get(pdev);
 134         pciehp_set_attention_status(slot, status);
 135         pci_config_pm_runtime_put(pdev);
 136         return 0;
 137 }
 138
 139
 140 static int enable_slot(struct hotplug_slot *hotplug_slot)
 141 {
 142         struct slot *slot = hotplug_slot->private;
 143
 144         return pciehp_sysfs_enable_slot(slot);
 145 }
 146
 147
 148 static int disable_slot(struct hotplug_slot *hotplug_slot)
 149 {
 150         struct slot *slot = hotplug_slot->private;
 151
 152         return pciehp_sysfs_disable_slot(slot);
 153 }
 154
 155 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 156 {
 157         struct slot *slot = hotplug_slot->private;
 158         struct pci_dev *pdev = slot->ctrl->pcie->port;
 159
 160         pci_config_pm_runtime_get(pdev);
 161         pciehp_get_power_status(slot, value);
 162         pci_config_pm_runtime_put(pdev);
 163         return 0;
 164 }
 165
 166 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
 167 {
 168         struct slot *slot = hotplug_slot->private;
 169
 170         pciehp_get_attention_status(slot, value);
 171         return 0;
 172 }
 173
 174 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
 175 {
 176         struct slot *slot = hotplug_slot->private;
 177         struct pci_dev *pdev = slot->ctrl->pcie->port;
 178
 179         pci_config_pm_runtime_get(pdev);
 180         pciehp_get_latch_status(slot, value);
 181         pci_config_pm_runtime_put(pdev);
 182         return 0;
 183 }
 184
 185 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 186 {
 187         struct slot *slot = hotplug_slot->private;
 188         struct pci_dev *pdev = slot->ctrl->pcie->port;
 189
 190         pci_config_pm_runtime_get(pdev);
 191         pciehp_get_adapter_status(slot, value);
 192         pci_config_pm_runtime_put(pdev);
 193         return 0;
 194 }
 195
 196 static int reset_slot(struct hotplug_slot *hotplug_slot, int probe)
 197 {
 198         struct slot *slot = hotplug_slot->private;
 199
 200         return pciehp_reset_slot(slot, probe);
 201 }
 202
 203 /**
 204  * pciehp_check_presence() - synthesize event if presence has changed
 205  *
 206  * On probe and resume, an explicit presence check is necessary to bring up an
 207  * occupied slot or bring down an unoccupied slot.  This can't be triggered by
 208  * events in the Slot Status register, they may be stale and are therefore
 209  * cleared.  Secondly, sending an interrupt for "events that occur while
 210  * interrupt generation is disabled [when] interrupt generation is subsequently
 211  * enabled" is optional per PCIe r4.0, sec 6.7.3.4.
 212  */
 213 static void pciehp_check_presence(struct controller *ctrl)
 214 {
 215         struct slot *slot = ctrl->slot;
 216         u8 occupied;
 217
 218         down_read(&ctrl->reset_lock);
 219         mutex_lock(&slot->lock);
 220
 221         pciehp_get_adapter_status(slot, &occupied);
 222         if ((occupied && (slot->state == OFF_STATE ||
 223                           slot->state == BLINKINGON_STATE)) ||
 224             (!occupied && (slot->state == ON_STATE ||
 225                            slot->state == BLINKINGOFF_STATE)))
 226                 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
 227
 228         mutex_unlock(&slot->lock);
 229         up_read(&ctrl->reset_lock);
 230 }
 231
 232 static int pciehp_probe(struct pcie_device *dev)
 233 {
 234         int rc;
 235         struct controller *ctrl;
 236         struct slot *slot;
 237
 238         /* If this is not a "hotplug" service, we have no business here. */
 239         if (dev->service != PCIE_PORT_SERVICE_HP)
 240                 return -ENODEV;
 241
 242         if (!dev->port->subordinate) {
 243                 /* Can happen if we run out of bus numbers during probe */
 244                 dev_err(&dev->device,
 245                         "Hotplug bridge without secondary bus, ignoring\n");
 246                 return -ENODEV;
 247         }
 248
 249         ctrl = pcie_init(dev);
 250         if (!ctrl) {
 251                 dev_err(&dev->device, "Controller initialization failed\n");
 252                 return -ENODEV;
 253         }
 254         set_service_data(dev, ctrl);
 255
 256         /* Setup the slot information structures */
 257         rc = init_slot(ctrl);
 258         if (rc) {
 259                 if (rc == -EBUSY)
 260                         ctrl_warn(ctrl, "Slot already registered by another hotplug driver\n");
 261                 else
 262                         ctrl_err(ctrl, "Slot initialization failed (%d)\n", rc);
 263                 goto err_out_release_ctlr;
 264         }
 265
 266         /* Enable events after we have setup the data structures */
 267         rc = pcie_init_notification(ctrl);
 268         if (rc) {
 269                 ctrl_err(ctrl, "Notification initialization failed (%d)\n", rc);
 270                 goto err_out_free_ctrl_slot;
 271         }
 272
 273         /* Publish to user space */
 274         slot = ctrl->slot;
 275         rc = pci_hp_add(slot->hotplug_slot);
 276         if (rc) {
 277                 ctrl_err(ctrl, "Publication to user space failed (%d)\n", rc);
 278                 goto err_out_shutdown_notification;
 279         }
 280
 281         pciehp_check_presence(ctrl);
 282
 283         return 0;
 284
 285 err_out_shutdown_notification:
 286         pcie_shutdown_notification(ctrl);
 287 err_out_free_ctrl_slot:
 288         cleanup_slot(ctrl);
 289 err_out_release_ctlr:
 290         pciehp_release_ctrl(ctrl);
 291         return -ENODEV;
 292 }
 293
 294 static void pciehp_remove(struct pcie_device *dev)
 295 {
 296         struct controller *ctrl = get_service_data(dev);
 297
 298         pci_hp_del(ctrl->slot->hotplug_slot);
 299         pcie_shutdown_notification(ctrl);
 300         cleanup_slot(ctrl);
 301         pciehp_release_ctrl(ctrl);
 302 }
 303
 304 #ifdef CONFIG_PM
 305 static int pciehp_suspend(struct pcie_device *dev)
 306 {
 307         return 0;
 308 }
 309
 310 static int pciehp_resume_noirq(struct pcie_device *dev)
 311 {
 312         struct controller *ctrl = get_service_data(dev);
 313         struct slot *slot = ctrl->slot;
 314
 315         /* pci_restore_state() just wrote to the Slot Control register */
 316         ctrl->cmd_started = jiffies;
 317         ctrl->cmd_busy = true;
 318
 319         /* clear spurious events from rediscovery of inserted card */
 320         if (slot->state == ON_STATE || slot->state == BLINKINGOFF_STATE)
 321                 pcie_clear_hotplug_events(ctrl);
 322
 323         return 0;
 324 }
 325
 326 static int pciehp_resume(struct pcie_device *dev)
 327 {
 328         struct controller *ctrl = get_service_data(dev);
 329
 330         pciehp_check_presence(ctrl);
 331
 332         return 0;
 333 }
 334 #endif /* PM */
 335
 336 static struct pcie_port_service_driver hpdriver_portdrv = {
 337         .name           = PCIE_MODULE_NAME,
 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         .suspend        = pciehp_suspend,
 346         .resume_noirq   = pciehp_resume_noirq,
 347         .resume         = pciehp_resume,
 348 #endif  /* PM */
 349 };
 350
 351 static int __init pcied_init(void)
 352 {
 353         int retval = 0;
 354
 355         retval = pcie_port_service_register(&hpdriver_portdrv);
 356         dbg("pcie_port_service_register = %d\n", retval);
 357         if (retval)
 358                 dbg("Failure to register service\n");
 359
 360         return retval;
 361 }
 362 device_initcall(pcied_init);