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