drivers/pci/pcie/aer/aerdrv.c

   1 /*
   2  * drivers/pci/pcie/aer/aerdrv.c
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * This file implements the AER root port service driver. The driver will
   9  * register an irq handler. When root port triggers an AER interrupt, the irq
  10  * handler will collect root port status and schedule a work.
  11  *
  12  * Copyright (C) 2006 Intel Corp.
  13  *      Tom Long Nguyen (tom.l.nguyen@intel.com)
  14  *      Zhang Yanmin (yanmin.zhang@intel.com)
  15  *
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/pci.h>
  20 #include <linux/pci-acpi.h>
  21 #include <linux/sched.h>
  22 #include <linux/kernel.h>
  23 #include <linux/errno.h>
  24 #include <linux/pm.h>
  25 #include <linux/init.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/delay.h>
  28 #include <linux/pcieport_if.h>
  29 #include <linux/slab.h>
  30
  31 #include "aerdrv.h"
  32 #include "../../pci.h"
  33
  34 /*
  35  * Version Information
  36  */
  37 #define DRIVER_VERSION "v1.0"
  38 #define DRIVER_AUTHOR "tom.l.nguyen@intel.com"
  39 #define DRIVER_DESC "Root Port Advanced Error Reporting Driver"
  40 MODULE_AUTHOR(DRIVER_AUTHOR);
  41 MODULE_DESCRIPTION(DRIVER_DESC);
  42 MODULE_LICENSE("GPL");
  43
  44 static int aer_probe(struct pcie_device *dev);
  45 static void aer_remove(struct pcie_device *dev);
  46 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
  47         enum pci_channel_state error);
  48 static void aer_error_resume(struct pci_dev *dev);
  49 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
  50
  51 static const struct pci_error_handlers aer_error_handlers = {
  52         .error_detected = aer_error_detected,
  53         .resume         = aer_error_resume,
  54 };
  55
  56 static struct pcie_port_service_driver aerdriver = {
  57         .name           = "aer",
  58         .port_type      = PCI_EXP_TYPE_ROOT_PORT,
  59         .service        = PCIE_PORT_SERVICE_AER,
  60
  61         .probe          = aer_probe,
  62         .remove         = aer_remove,
  63
  64         .err_handler    = &aer_error_handlers,
  65
  66         .reset_link     = aer_root_reset,
  67 };
  68
  69 static int pcie_aer_disable;
  70
  71 void pci_no_aer(void)
  72 {
  73         pcie_aer_disable = 1;   /* has priority over 'forceload' */
  74 }
  75
  76 bool pci_aer_available(void)
  77 {
  78         return !pcie_aer_disable && pci_msi_enabled();
  79 }
  80
  81 static int set_device_error_reporting(struct pci_dev *dev, void *data)
  82 {
  83         bool enable = *((bool *)data);
  84         int type = pci_pcie_type(dev);
  85
  86         if ((type == PCI_EXP_TYPE_ROOT_PORT) ||
  87             (type == PCI_EXP_TYPE_UPSTREAM) ||
  88             (type == PCI_EXP_TYPE_DOWNSTREAM)) {
  89                 if (enable)
  90                         pci_enable_pcie_error_reporting(dev);
  91                 else
  92                         pci_disable_pcie_error_reporting(dev);
  93         }
  94
  95         if (enable)
  96                 pcie_set_ecrc_checking(dev);
  97
  98         return 0;
  99 }
 100
 101 /**
 102  * set_downstream_devices_error_reporting - enable/disable the error reporting  bits on the root port and its downstream ports.
 103  * @dev: pointer to root port's pci_dev data structure
 104  * @enable: true = enable error reporting, false = disable error reporting.
 105  */
 106 static void set_downstream_devices_error_reporting(struct pci_dev *dev,
 107                                                    bool enable)
 108 {
 109         set_device_error_reporting(dev, &enable);
 110
 111         if (!dev->subordinate)
 112                 return;
 113         pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);
 114 }
 115
 116 /**
 117  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
 118  * @rpc: pointer to a Root Port data structure
 119  *
 120  * Invoked when PCIe bus loads AER service driver.
 121  */
 122 static void aer_enable_rootport(struct aer_rpc *rpc)
 123 {
 124         struct pci_dev *pdev = rpc->rpd->port;
 125         int aer_pos;
 126         u16 reg16;
 127         u32 reg32;
 128
 129         /* Clear PCIe Capability's Device Status */
 130         pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
 131         pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
 132
 133         /* Disable system error generation in response to error messages */
 134         pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
 135                                    SYSTEM_ERROR_INTR_ON_MESG_MASK);
 136
 137         aer_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
 138         /* Clear error status */
 139         pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, &reg32);
 140         pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32);
 141         pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, &reg32);
 142         pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32);
 143         pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, &reg32);
 144         pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);
 145
 146         /*
 147          * Enable error reporting for the root port device and downstream port
 148          * devices.
 149          */
 150         set_downstream_devices_error_reporting(pdev, true);
 151
 152         /* Enable Root Port's interrupt in response to error messages */
 153         pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, &reg32);
 154         reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 155         pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32);
 156 }
 157
 158 /**
 159  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
 160  * @rpc: pointer to a Root Port data structure
 161  *
 162  * Invoked when PCIe bus unloads AER service driver.
 163  */
 164 static void aer_disable_rootport(struct aer_rpc *rpc)
 165 {
 166         struct pci_dev *pdev = rpc->rpd->port;
 167         u32 reg32;
 168         int pos;
 169
 170         /*
 171          * Disable error reporting for the root port device and downstream port
 172          * devices.
 173          */
 174         set_downstream_devices_error_reporting(pdev, false);
 175
 176         pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
 177         /* Disable Root's interrupt in response to error messages */
 178         pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 179         reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 180         pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 181
 182         /* Clear Root's error status reg */
 183         pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 184         pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32);
 185 }
 186
 187 /**
 188  * aer_irq - Root Port's ISR
 189  * @irq: IRQ assigned to Root Port
 190  * @context: pointer to Root Port data structure
 191  *
 192  * Invoked when Root Port detects AER messages.
 193  */
 194 irqreturn_t aer_irq(int irq, void *context)
 195 {
 196         unsigned int status, id;
 197         struct pcie_device *pdev = (struct pcie_device *)context;
 198         struct aer_rpc *rpc = get_service_data(pdev);
 199         int next_prod_idx;
 200         unsigned long flags;
 201         int pos;
 202
 203         pos = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR);
 204         /*
 205          * Must lock access to Root Error Status Reg, Root Error ID Reg,
 206          * and Root error producer/consumer index
 207          */
 208         spin_lock_irqsave(&rpc->e_lock, flags);
 209
 210         /* Read error status */
 211         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
 212         if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) {
 213                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 214                 return IRQ_NONE;
 215         }
 216
 217         /* Read error source and clear error status */
 218         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id);
 219         pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
 220
 221         /* Store error source for later DPC handler */
 222         next_prod_idx = rpc->prod_idx + 1;
 223         if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 224                 next_prod_idx = 0;
 225         if (next_prod_idx == rpc->cons_idx) {
 226                 /*
 227                  * Error Storm Condition - possibly the same error occurred.
 228                  * Drop the error.
 229                  */
 230                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 231                 return IRQ_HANDLED;
 232         }
 233         rpc->e_sources[rpc->prod_idx].status =  status;
 234         rpc->e_sources[rpc->prod_idx].id = id;
 235         rpc->prod_idx = next_prod_idx;
 236         spin_unlock_irqrestore(&rpc->e_lock, flags);
 237
 238         /*  Invoke DPC handler */
 239         schedule_work(&rpc->dpc_handler);
 240
 241         return IRQ_HANDLED;
 242 }
 243 EXPORT_SYMBOL_GPL(aer_irq);
 244
 245 /**
 246  * aer_alloc_rpc - allocate Root Port data structure
 247  * @dev: pointer to the pcie_dev data structure
 248  *
 249  * Invoked when Root Port's AER service is loaded.
 250  */
 251 static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
 252 {
 253         struct aer_rpc *rpc;
 254
 255         rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
 256         if (!rpc)
 257                 return NULL;
 258
 259         /* Initialize Root lock access, e_lock, to Root Error Status Reg */
 260         spin_lock_init(&rpc->e_lock);
 261
 262         rpc->rpd = dev;
 263         INIT_WORK(&rpc->dpc_handler, aer_isr);
 264         mutex_init(&rpc->rpc_mutex);
 265         init_waitqueue_head(&rpc->wait_release);
 266
 267         /* Use PCIe bus function to store rpc into PCIe device */
 268         set_service_data(dev, rpc);
 269
 270         return rpc;
 271 }
 272
 273 /**
 274  * aer_remove - clean up resources
 275  * @dev: pointer to the pcie_dev data structure
 276  *
 277  * Invoked when PCI Express bus unloads or AER probe fails.
 278  */
 279 static void aer_remove(struct pcie_device *dev)
 280 {
 281         struct aer_rpc *rpc = get_service_data(dev);
 282
 283         if (rpc) {
 284                 /* If register interrupt service, it must be free. */
 285                 if (rpc->isr)
 286                         free_irq(dev->irq, dev);
 287
 288                 wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
 289
 290                 aer_disable_rootport(rpc);
 291                 kfree(rpc);
 292                 set_service_data(dev, NULL);
 293         }
 294 }
 295
 296 /**
 297  * aer_probe - initialize resources
 298  * @dev: pointer to the pcie_dev data structure
 299  * @id: pointer to the service id data structure
 300  *
 301  * Invoked when PCI Express bus loads AER service driver.
 302  */
 303 static int aer_probe(struct pcie_device *dev)
 304 {
 305         int status;
 306         struct aer_rpc *rpc;
 307         struct device *device = &dev->device;
 308
 309         /* Init */
 310         status = aer_init(dev);
 311         if (status)
 312                 return status;
 313
 314         /* Alloc rpc data structure */
 315         rpc = aer_alloc_rpc(dev);
 316         if (!rpc) {
 317                 dev_printk(KERN_DEBUG, device, "alloc rpc failed\n");
 318                 aer_remove(dev);
 319                 return -ENOMEM;
 320         }
 321
 322         /* Request IRQ ISR */
 323         status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
 324         if (status) {
 325                 dev_printk(KERN_DEBUG, device, "request IRQ failed\n");
 326                 aer_remove(dev);
 327                 return status;
 328         }
 329
 330         rpc->isr = 1;
 331
 332         aer_enable_rootport(rpc);
 333
 334         return status;
 335 }
 336
 337 /**
 338  * aer_root_reset - reset link on Root Port
 339  * @dev: pointer to Root Port's pci_dev data structure
 340  *
 341  * Invoked by Port Bus driver when performing link reset at Root Port.
 342  */
 343 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 344 {
 345         u32 reg32;
 346         int pos;
 347
 348         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 349
 350         /* Disable Root's interrupt in response to error messages */
 351         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 352         reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 353         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 354
 355         pci_reset_bridge_secondary_bus(dev);
 356         dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
 357
 358         /* Clear Root Error Status */
 359         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 360         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, reg32);
 361
 362         /* Enable Root Port's interrupt in response to error messages */
 363         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 364         reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 365         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 366
 367         return PCI_ERS_RESULT_RECOVERED;
 368 }
 369
 370 /**
 371  * aer_error_detected - update severity status
 372  * @dev: pointer to Root Port's pci_dev data structure
 373  * @error: error severity being notified by port bus
 374  *
 375  * Invoked by Port Bus driver during error recovery.
 376  */
 377 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
 378                         enum pci_channel_state error)
 379 {
 380         /* Root Port has no impact. Always recovers. */
 381         return PCI_ERS_RESULT_CAN_RECOVER;
 382 }
 383
 384 /**
 385  * aer_error_resume - clean up corresponding error status bits
 386  * @dev: pointer to Root Port's pci_dev data structure
 387  *
 388  * Invoked by Port Bus driver during nonfatal recovery.
 389  */
 390 static void aer_error_resume(struct pci_dev *dev)
 391 {
 392         int pos;
 393         u32 status, mask;
 394         u16 reg16;
 395
 396         /* Clean up Root device status */
 397         pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &reg16);
 398         pcie_capability_write_word(dev, PCI_EXP_DEVSTA, reg16);
 399
 400         /* Clean AER Root Error Status */
 401         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 402         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 403         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 404         if (dev->error_state == pci_channel_io_normal)
 405                 status &= ~mask; /* Clear corresponding nonfatal bits */
 406         else
 407                 status &= mask; /* Clear corresponding fatal bits */
 408         pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 409 }
 410
 411 /**
 412  * aer_service_init - register AER root service driver
 413  *
 414  * Invoked when AER root service driver is loaded.
 415  */
 416 static int __init aer_service_init(void)
 417 {
 418         if (!pci_aer_available() || aer_acpi_firmware_first())
 419                 return -ENXIO;
 420         return pcie_port_service_register(&aerdriver);
 421 }
 422
 423 /**
 424  * aer_service_exit - unregister AER root service driver
 425  *
 426  * Invoked when AER root service driver is unloaded.
 427  */
 428 static void __exit aer_service_exit(void)
 429 {
 430         pcie_port_service_unregister(&aerdriver);
 431 }
 432
 433 module_init(aer_service_init);
 434 module_exit(aer_service_exit);