linux/drivers/pci/hotplug/shpchp_core.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Standard 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 */
  15
  16#include <linux/module.h>
  17#include <linux/moduleparam.h>
  18#include <linux/kernel.h>
  19#include <linux/types.h>
  20#include <linux/slab.h>
  21#include <linux/pci.h>
  22#include "shpchp.h"
  23
  24/* Global variables */
  25bool shpchp_debug;
  26bool shpchp_poll_mode;
  27int shpchp_poll_time;
  28
  29#define DRIVER_VERSION  "0.4"
  30#define DRIVER_AUTHOR   "Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
  31#define DRIVER_DESC     "Standard Hot Plug PCI Controller Driver"
  32
  33MODULE_AUTHOR(DRIVER_AUTHOR);
  34MODULE_DESCRIPTION(DRIVER_DESC);
  35MODULE_LICENSE("GPL");
  36
  37module_param(shpchp_debug, bool, 0644);
  38module_param(shpchp_poll_mode, bool, 0644);
  39module_param(shpchp_poll_time, int, 0644);
  40MODULE_PARM_DESC(shpchp_debug, "Debugging mode enabled or not");
  41MODULE_PARM_DESC(shpchp_poll_mode, "Using polling mechanism for hot-plug events or not");
  42MODULE_PARM_DESC(shpchp_poll_time, "Polling mechanism frequency, in seconds");
  43
  44#define SHPC_MODULE_NAME "shpchp"
  45
  46static int set_attention_status(struct hotplug_slot *slot, u8 value);
  47static int enable_slot(struct hotplug_slot *slot);
  48static int disable_slot(struct hotplug_slot *slot);
  49static int get_power_status(struct hotplug_slot *slot, u8 *value);
  50static int get_attention_status(struct hotplug_slot *slot, u8 *value);
  51static int get_latch_status(struct hotplug_slot *slot, u8 *value);
  52static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
  53
  54static const struct hotplug_slot_ops shpchp_hotplug_slot_ops = {
  55        .set_attention_status = set_attention_status,
  56        .enable_slot =          enable_slot,
  57        .disable_slot =         disable_slot,
  58        .get_power_status =     get_power_status,
  59        .get_attention_status = get_attention_status,
  60        .get_latch_status =     get_latch_status,
  61        .get_adapter_status =   get_adapter_status,
  62};
  63
  64static int init_slots(struct controller *ctrl)
  65{
  66        struct slot *slot;
  67        struct hotplug_slot *hotplug_slot;
  68        char name[SLOT_NAME_SIZE];
  69        int retval;
  70        int i;
  71
  72        for (i = 0; i < ctrl->num_slots; i++) {
  73                slot = kzalloc(sizeof(*slot), GFP_KERNEL);
  74                if (!slot) {
  75                        retval = -ENOMEM;
  76                        goto error;
  77                }
  78
  79                hotplug_slot = &slot->hotplug_slot;
  80
  81                slot->hp_slot = i;
  82                slot->ctrl = ctrl;
  83                slot->bus = ctrl->pci_dev->subordinate->number;
  84                slot->device = ctrl->slot_device_offset + i;
  85                slot->hpc_ops = ctrl->hpc_ops;
  86                slot->number = ctrl->first_slot + (ctrl->slot_num_inc * i);
  87
  88                slot->wq = alloc_workqueue("shpchp-%d", 0, 0, slot->number);
  89                if (!slot->wq) {
  90                        retval = -ENOMEM;
  91                        goto error_slot;
  92                }
  93
  94                mutex_init(&slot->lock);
  95                INIT_DELAYED_WORK(&slot->work, shpchp_queue_pushbutton_work);
  96
  97                /* register this slot with the hotplug pci core */
  98                snprintf(name, SLOT_NAME_SIZE, "%d", slot->number);
  99                hotplug_slot->ops = &shpchp_hotplug_slot_ops;
 100
 101                ctrl_dbg(ctrl, "Registering domain:bus:dev=%04x:%02x:%02x hp_slot=%x sun=%x slot_device_offset=%x\n",
 102                         pci_domain_nr(ctrl->pci_dev->subordinate),
 103                         slot->bus, slot->device, slot->hp_slot, slot->number,
 104                         ctrl->slot_device_offset);
 105                retval = pci_hp_register(hotplug_slot,
 106                                ctrl->pci_dev->subordinate, slot->device, name);
 107                if (retval) {
 108                        ctrl_err(ctrl, "pci_hp_register failed with error %d\n",
 109                                 retval);
 110                        goto error_slotwq;
 111                }
 112
 113                get_power_status(hotplug_slot, &slot->pwr_save);
 114                get_attention_status(hotplug_slot, &slot->attention_save);
 115                get_latch_status(hotplug_slot, &slot->latch_save);
 116                get_adapter_status(hotplug_slot, &slot->presence_save);
 117
 118                list_add(&slot->slot_list, &ctrl->slot_list);
 119        }
 120
 121        return 0;
 122error_slotwq:
 123        destroy_workqueue(slot->wq);
 124error_slot:
 125        kfree(slot);
 126error:
 127        return retval;
 128}
 129
 130void cleanup_slots(struct controller *ctrl)
 131{
 132        struct slot *slot, *next;
 133
 134        list_for_each_entry_safe(slot, next, &ctrl->slot_list, slot_list) {
 135                list_del(&slot->slot_list);
 136                cancel_delayed_work(&slot->work);
 137                destroy_workqueue(slot->wq);
 138                pci_hp_deregister(&slot->hotplug_slot);
 139                kfree(slot);
 140        }
 141}
 142
 143/*
 144 * set_attention_status - Turns the Amber LED for a slot on, off or blink
 145 */
 146static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
 147{
 148        struct slot *slot = get_slot(hotplug_slot);
 149
 150        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
 151                 __func__, slot_name(slot));
 152
 153        slot->attention_save = status;
 154        slot->hpc_ops->set_attention_status(slot, status);
 155
 156        return 0;
 157}
 158
 159static int enable_slot(struct hotplug_slot *hotplug_slot)
 160{
 161        struct slot *slot = get_slot(hotplug_slot);
 162
 163        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
 164                 __func__, slot_name(slot));
 165
 166        return shpchp_sysfs_enable_slot(slot);
 167}
 168
 169static int disable_slot(struct hotplug_slot *hotplug_slot)
 170{
 171        struct slot *slot = get_slot(hotplug_slot);
 172
 173        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
 174                 __func__, slot_name(slot));
 175
 176        return shpchp_sysfs_disable_slot(slot);
 177}
 178
 179static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 180{
 181        struct slot *slot = get_slot(hotplug_slot);
 182        int retval;
 183
 184        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
 185                 __func__, slot_name(slot));
 186
 187        retval = slot->hpc_ops->get_power_status(slot, value);
 188        if (retval < 0)
 189                *value = slot->pwr_save;
 190
 191        return 0;
 192}
 193
 194static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
 195{
 196        struct slot *slot = get_slot(hotplug_slot);
 197        int retval;
 198
 199        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
 200                 __func__, slot_name(slot));
 201
 202        retval = slot->hpc_ops->get_attention_status(slot, value);
 203        if (retval < 0)
 204                *value = slot->attention_save;
 205
 206        return 0;
 207}
 208
 209static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
 210{
 211        struct slot *slot = get_slot(hotplug_slot);
 212        int retval;
 213
 214        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
 215                 __func__, slot_name(slot));
 216
 217        retval = slot->hpc_ops->get_latch_status(slot, value);
 218        if (retval < 0)
 219                *value = slot->latch_save;
 220
 221        return 0;
 222}
 223
 224static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 225{
 226        struct slot *slot = get_slot(hotplug_slot);
 227        int retval;
 228
 229        ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
 230                 __func__, slot_name(slot));
 231
 232        retval = slot->hpc_ops->get_adapter_status(slot, value);
 233        if (retval < 0)
 234                *value = slot->presence_save;
 235
 236        return 0;
 237}
 238
 239static bool shpc_capable(struct pci_dev *bridge)
 240{
 241        /*
 242         * It is assumed that AMD GOLAM chips support SHPC but they do not
 243         * have SHPC capability.
 244         */
 245        if (bridge->vendor == PCI_VENDOR_ID_AMD &&
 246            bridge->device == PCI_DEVICE_ID_AMD_GOLAM_7450)
 247                return true;
 248
 249        if (pci_find_capability(bridge, PCI_CAP_ID_SHPC))
 250                return true;
 251
 252        return false;
 253}
 254
 255static int shpc_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 256{
 257        int rc;
 258        struct controller *ctrl;
 259
 260        if (!shpc_capable(pdev))
 261                return -ENODEV;
 262
 263        if (acpi_get_hp_hw_control_from_firmware(pdev))
 264                return -ENODEV;
 265
 266        ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
 267        if (!ctrl)
 268                goto err_out_none;
 269
 270        INIT_LIST_HEAD(&ctrl->slot_list);
 271
 272        rc = shpc_init(ctrl, pdev);
 273        if (rc) {
 274                ctrl_dbg(ctrl, "Controller initialization failed\n");
 275                goto err_out_free_ctrl;
 276        }
 277
 278        pci_set_drvdata(pdev, ctrl);
 279
 280        /* Setup the slot information structures */
 281        rc = init_slots(ctrl);
 282        if (rc) {
 283                ctrl_err(ctrl, "Slot initialization failed\n");
 284                goto err_out_release_ctlr;
 285        }
 286
 287        rc = shpchp_create_ctrl_files(ctrl);
 288        if (rc)
 289                goto err_cleanup_slots;
 290
 291        pdev->shpc_managed = 1;
 292        return 0;
 293
 294err_cleanup_slots:
 295        cleanup_slots(ctrl);
 296err_out_release_ctlr:
 297        ctrl->hpc_ops->release_ctlr(ctrl);
 298err_out_free_ctrl:
 299        kfree(ctrl);
 300err_out_none:
 301        return -ENODEV;
 302}
 303
 304static void shpc_remove(struct pci_dev *dev)
 305{
 306        struct controller *ctrl = pci_get_drvdata(dev);
 307
 308        dev->shpc_managed = 0;
 309        shpchp_remove_ctrl_files(ctrl);
 310        ctrl->hpc_ops->release_ctlr(ctrl);
 311        kfree(ctrl);
 312}
 313
 314static const struct pci_device_id shpcd_pci_tbl[] = {
 315        {PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0)},
 316        { /* end: all zeroes */ }
 317};
 318MODULE_DEVICE_TABLE(pci, shpcd_pci_tbl);
 319
 320static struct pci_driver shpc_driver = {
 321        .name =         SHPC_MODULE_NAME,
 322        .id_table =     shpcd_pci_tbl,
 323        .probe =        shpc_probe,
 324        .remove =       shpc_remove,
 325};
 326
 327static int __init shpcd_init(void)
 328{
 329        int retval;
 330
 331        retval = pci_register_driver(&shpc_driver);
 332        dbg("%s: pci_register_driver = %d\n", __func__, retval);
 333        info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
 334
 335        return retval;
 336}
 337
 338static void __exit shpcd_cleanup(void)
 339{
 340        dbg("unload_shpchpd()\n");
 341        pci_unregister_driver(&shpc_driver);
 342        info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
 343}
 344
 345module_init(shpcd_init);
 346module_exit(shpcd_cleanup);
 347