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; 142 143 pci_config_pm_runtime_get(pdev); 144 *value = pciehp_card_present_or_link_active(ctrl); 145 pci_config_pm_runtime_put(pdev); 146 return 0; 147 } 148 149 /** 150 * pciehp_check_presence() - synthesize event if presence has changed 151 * 152 * On probe and resume, an explicit presence check is necessary to bring up an 153 * occupied slot or bring down an unoccupied slot. This can't be triggered by 154 * events in the Slot Status register, they may be stale and are therefore 155 * cleared. Secondly, sending an interrupt for "events that occur while 156 * interrupt generation is disabled [when] interrupt generation is subsequently 157 * enabled" is optional per PCIe r4.0, sec 6.7.3.4. 158 */ 159 static void pciehp_check_presence(struct controller *ctrl) 160 { 161 bool occupied; 162 163 down_read(&ctrl->reset_lock); 164 mutex_lock(&ctrl->state_lock); 165 166 occupied = pciehp_card_present_or_link_active(ctrl); 167 if ((occupied && (ctrl->state == OFF_STATE || 168 ctrl->state == BLINKINGON_STATE)) || 169 (!occupied && (ctrl->state == ON_STATE || 170 ctrl->state == BLINKINGOFF_STATE))) 171 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC); 172 173 mutex_unlock(&ctrl->state_lock); 174 up_read(&ctrl->reset_lock); 175 } 176 177 static int pciehp_probe(struct pcie_device *dev) 178 { 179 int rc; 180 struct controller *ctrl; 181 182 /* If this is not a "hotplug" service, we have no business here. */ 183 if (dev->service != PCIE_PORT_SERVICE_HP) 184 return -ENODEV; 185 186 if (!dev->port->subordinate) { 187 /* Can happen if we run out of bus numbers during probe */ 188 pci_err(dev->port, 189 "Hotplug bridge without secondary bus, ignoring\n"); 190 return -ENODEV; 191 } 192 193 ctrl = pcie_init(dev); 194 if (!ctrl) { 195 pci_err(dev->port, "Controller initialization failed\n"); 196 return -ENODEV; 197 } 198 set_service_data(dev, ctrl); 199 200 /* Setup the slot information structures */ 201 rc = init_slot(ctrl); 202 if (rc) { 203 if (rc == -EBUSY) 204 ctrl_warn(ctrl, "Slot already registered by another hotplug driver\n"); 205 else 206 ctrl_err(ctrl, "Slot initialization failed (%d)\n", rc); 207 goto err_out_release_ctlr; 208 } 209 210 /* Enable events after we have setup the data structures */ 211 rc = pcie_init_notification(ctrl); 212 if (rc) { 213 ctrl_err(ctrl, "Notification initialization failed (%d)\n", rc); 214 goto err_out_free_ctrl_slot; 215 } 216 217 /* Publish to user space */ 218 rc = pci_hp_add(&ctrl->hotplug_slot); 219 if (rc) { 220 ctrl_err(ctrl, "Publication to user space failed (%d)\n", rc); 221 goto err_out_shutdown_notification; 222 } 223 224 pciehp_check_presence(ctrl); 225 226 return 0; 227 228 err_out_shutdown_notification: 229 pcie_shutdown_notification(ctrl); 230 err_out_free_ctrl_slot: 231 cleanup_slot(ctrl); 232 err_out_release_ctlr: 233 pciehp_release_ctrl(ctrl); 234 return -ENODEV; 235 } 236 237 static void pciehp_remove(struct pcie_device *dev) 238 { 239 struct controller *ctrl = get_service_data(dev); 240 241 pci_hp_del(&ctrl->hotplug_slot); 242 pcie_shutdown_notification(ctrl); 243 cleanup_slot(ctrl); 244 pciehp_release_ctrl(ctrl); 245 } 246 247 #ifdef CONFIG_PM 248 static bool pme_is_native(struct pcie_device *dev) 249 { 250 const struct pci_host_bridge *host; 251 252 host = pci_find_host_bridge(dev->port->bus); 253 return pcie_ports_native || host->native_pme; 254 } 255 256 static int pciehp_suspend(struct pcie_device *dev) 257 { 258 /* 259 * Disable hotplug interrupt so that it does not trigger 260 * immediately when the downstream link goes down. 261 */ 262 if (pme_is_native(dev)) 263 pcie_disable_interrupt(get_service_data(dev)); 264 265 return 0; 266 } 267 268 static int pciehp_resume_noirq(struct pcie_device *dev) 269 { 270 struct controller *ctrl = get_service_data(dev); 271 272 /* pci_restore_state() just wrote to the Slot Control register */ 273 ctrl->cmd_started = jiffies; 274 ctrl->cmd_busy = true; 275 276 /* clear spurious events from rediscovery of inserted card */ 277 if (ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE) 278 pcie_clear_hotplug_events(ctrl); 279 280 return 0; 281 } 282 283 static int pciehp_resume(struct pcie_device *dev) 284 { 285 struct controller *ctrl = get_service_data(dev); 286 287 if (pme_is_native(dev)) 288 pcie_enable_interrupt(ctrl); 289 290 pciehp_check_presence(ctrl); 291 292 return 0; 293 } 294 295 static int pciehp_runtime_resume(struct pcie_device *dev) 296 { 297 struct controller *ctrl = get_service_data(dev); 298 299 /* pci_restore_state() just wrote to the Slot Control register */ 300 ctrl->cmd_started = jiffies; 301 ctrl->cmd_busy = true; 302 303 /* clear spurious events from rediscovery of inserted card */ 304 if ((ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE) && 305 pme_is_native(dev)) 306 pcie_clear_hotplug_events(ctrl); 307 308 return pciehp_resume(dev); 309 } 310 #endif /* PM */ 311 312 static struct pcie_port_service_driver hpdriver_portdrv = { 313 .name = "pciehp", 314 .port_type = PCIE_ANY_PORT, 315 .service = PCIE_PORT_SERVICE_HP, 316 317 .probe = pciehp_probe, 318 .remove = pciehp_remove, 319 320 #ifdef CONFIG_PM 321 .suspend = pciehp_suspend, 322 .resume_noirq = pciehp_resume_noirq, 323 .resume = pciehp_resume, 324 .runtime_suspend = pciehp_suspend, 325 .runtime_resume = pciehp_runtime_resume, 326 #endif /* PM */ 327 }; 328 329 int __init pcie_hp_init(void) 330 { 331 int retval = 0; 332 333 retval = pcie_port_service_register(&hpdriver_portdrv); 334 pr_debug("pcie_port_service_register = %d\n", retval); 335 if (retval) 336 pr_debug("Failure to register service\n"); 337 338 return retval; 339 } 340