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 __devinit 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 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
  85         if ((dev->pcie_type == PCI_EXP_TYPE_ROOT_PORT) ||
  86             (dev->pcie_type == PCI_EXP_TYPE_UPSTREAM) ||
  87             (dev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM)) {
  88                 if (enable)
  89                         pci_enable_pcie_error_reporting(dev);
  90                 else
  91                         pci_disable_pcie_error_reporting(dev);
  92         }
  93
  94         if (enable)
  95                 pcie_set_ecrc_checking(dev);
  96
  97         return 0;
  98 }
  99
 100 /**
 101  * set_downstream_devices_error_reporting - enable/disable the error reporting  bits on the root port and its downstream ports.
 102  * @dev: pointer to root port's pci_dev data structure
 103  * @enable: true = enable error reporting, false = disable error reporting.
 104  */
 105 static void set_downstream_devices_error_reporting(struct pci_dev *dev,
 106                                                    bool enable)
 107 {
 108         set_device_error_reporting(dev, &enable);
 109
 110         if (!dev->subordinate)
 111                 return;
 112         pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);
 113 }
 114
 115 /**
 116  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
 117  * @rpc: pointer to a Root Port data structure
 118  *
 119  * Invoked when PCIe bus loads AER service driver.
 120  */
 121 static void aer_enable_rootport(struct aer_rpc *rpc)
 122 {
 123         struct pci_dev *pdev = rpc->rpd->port;
 124         int pos, aer_pos;
 125         u16 reg16;
 126         u32 reg32;
 127
 128         pos = pci_pcie_cap(pdev);
 129         /* Clear PCIe Capability's Device Status */
 130         pci_read_config_word(pdev, pos+PCI_EXP_DEVSTA, &reg16);
 131         pci_write_config_word(pdev, pos+PCI_EXP_DEVSTA, reg16);
 132
 133         /* Disable system error generation in response to error messages */
 134         pci_read_config_word(pdev, pos + PCI_EXP_RTCTL, &reg16);
 135         reg16 &= ~(SYSTEM_ERROR_INTR_ON_MESG_MASK);
 136         pci_write_config_word(pdev, pos + PCI_EXP_RTCTL, reg16);
 137
 138         aer_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
 139         /* Clear error status */
 140         pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, &reg32);
 141         pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32);
 142         pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, &reg32);
 143         pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32);
 144         pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, &reg32);
 145         pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);
 146
 147         /*
 148          * Enable error reporting for the root port device and downstream port
 149          * devices.
 150          */
 151         set_downstream_devices_error_reporting(pdev, true);
 152
 153         /* Enable Root Port's interrupt in response to error messages */
 154         pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, &reg32);
 155         reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 156         pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32);
 157 }
 158
 159 /**
 160  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
 161  * @rpc: pointer to a Root Port data structure
 162  *
 163  * Invoked when PCIe bus unloads AER service driver.
 164  */
 165 static void aer_disable_rootport(struct aer_rpc *rpc)
 166 {
 167         struct pci_dev *pdev = rpc->rpd->port;
 168         u32 reg32;
 169         int pos;
 170
 171         /*
 172          * Disable error reporting for the root port device and downstream port
 173          * devices.
 174          */
 175         set_downstream_devices_error_reporting(pdev, false);
 176
 177         pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ERR);
 178         /* Disable Root's interrupt in response to error messages */
 179         pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 180         reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 181         pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 182
 183         /* Clear Root's error status reg */
 184         pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 185         pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32);
 186 }
 187
 188 /**
 189  * aer_irq - Root Port's ISR
 190  * @irq: IRQ assigned to Root Port
 191  * @context: pointer to Root Port data structure
 192  *
 193  * Invoked when Root Port detects AER messages.
 194  */
 195 irqreturn_t aer_irq(int irq, void *context)
 196 {
 197         unsigned int status, id;
 198         struct pcie_device *pdev = (struct pcie_device *)context;
 199         struct aer_rpc *rpc = get_service_data(pdev);
 200         int next_prod_idx;
 201         unsigned long flags;
 202         int pos;
 203
 204         pos = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR);
 205         /*
 206          * Must lock access to Root Error Status Reg, Root Error ID Reg,
 207          * and Root error producer/consumer index
 208          */
 209         spin_lock_irqsave(&rpc->e_lock, flags);
 210
 211         /* Read error status */
 212         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
 213         if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) {
 214                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 215                 return IRQ_NONE;
 216         }
 217
 218         /* Read error source and clear error status */
 219         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id);
 220         pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
 221
 222         /* Store error source for later DPC handler */
 223         next_prod_idx = rpc->prod_idx + 1;
 224         if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 225                 next_prod_idx = 0;
 226         if (next_prod_idx == rpc->cons_idx) {
 227                 /*
 228                  * Error Storm Condition - possibly the same error occurred.
 229                  * Drop the error.
 230                  */
 231                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 232                 return IRQ_HANDLED;
 233         }
 234         rpc->e_sources[rpc->prod_idx].status =  status;
 235         rpc->e_sources[rpc->prod_idx].id = id;
 236         rpc->prod_idx = next_prod_idx;
 237         spin_unlock_irqrestore(&rpc->e_lock, flags);
 238
 239         /*  Invoke DPC handler */
 240         schedule_work(&rpc->dpc_handler);
 241
 242         return IRQ_HANDLED;
 243 }
 244 EXPORT_SYMBOL_GPL(aer_irq);
 245
 246 /**
 247  * aer_alloc_rpc - allocate Root Port data structure
 248  * @dev: pointer to the pcie_dev data structure
 249  *
 250  * Invoked when Root Port's AER service is loaded.
 251  */
 252 static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
 253 {
 254         struct aer_rpc *rpc;
 255
 256         rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
 257         if (!rpc)
 258                 return NULL;
 259
 260         /* Initialize Root lock access, e_lock, to Root Error Status Reg */
 261         spin_lock_init(&rpc->e_lock);
 262
 263         rpc->rpd = dev;
 264         INIT_WORK(&rpc->dpc_handler, aer_isr);
 265         mutex_init(&rpc->rpc_mutex);
 266         init_waitqueue_head(&rpc->wait_release);
 267
 268         /* Use PCIe bus function to store rpc into PCIe device */
 269         set_service_data(dev, rpc);
 270
 271         return rpc;
 272 }
 273
 274 /**
 275  * aer_remove - clean up resources
 276  * @dev: pointer to the pcie_dev data structure
 277  *
 278  * Invoked when PCI Express bus unloads or AER probe fails.
 279  */
 280 static void aer_remove(struct pcie_device *dev)
 281 {
 282         struct aer_rpc *rpc = get_service_data(dev);
 283
 284         if (rpc) {
 285                 /* If register interrupt service, it must be free. */
 286                 if (rpc->isr)
 287                         free_irq(dev->irq, dev);
 288
 289                 wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
 290
 291                 aer_disable_rootport(rpc);
 292                 kfree(rpc);
 293                 set_service_data(dev, NULL);
 294         }
 295 }
 296
 297 /**
 298  * aer_probe - initialize resources
 299  * @dev: pointer to the pcie_dev data structure
 300  * @id: pointer to the service id data structure
 301  *
 302  * Invoked when PCI Express bus loads AER service driver.
 303  */
 304 static int __devinit aer_probe(struct pcie_device *dev)
 305 {
 306         int status;
 307         struct aer_rpc *rpc;
 308         struct device *device = &dev->device;
 309
 310         /* Init */
 311         status = aer_init(dev);
 312         if (status)
 313                 return status;
 314
 315         /* Alloc rpc data structure */
 316         rpc = aer_alloc_rpc(dev);
 317         if (!rpc) {
 318                 dev_printk(KERN_DEBUG, device, "alloc rpc failed\n");
 319                 aer_remove(dev);
 320                 return -ENOMEM;
 321         }
 322
 323         /* Request IRQ ISR */
 324         status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
 325         if (status) {
 326                 dev_printk(KERN_DEBUG, device, "request IRQ failed\n");
 327                 aer_remove(dev);
 328                 return status;
 329         }
 330
 331         rpc->isr = 1;
 332
 333         aer_enable_rootport(rpc);
 334
 335         return status;
 336 }
 337
 338 /**
 339  * aer_root_reset - reset link on Root Port
 340  * @dev: pointer to Root Port's pci_dev data structure
 341  *
 342  * Invoked by Port Bus driver when performing link reset at Root Port.
 343  */
 344 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 345 {
 346         u32 reg32;
 347         int pos;
 348
 349         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 350
 351         /* Disable Root's interrupt in response to error messages */
 352         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 353         reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 354         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 355
 356         aer_do_secondary_bus_reset(dev);
 357         dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
 358
 359         /* Clear Root Error Status */
 360         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 361         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, reg32);
 362
 363         /* Enable Root Port's interrupt in response to error messages */
 364         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 365         reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 366         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 367
 368         return PCI_ERS_RESULT_RECOVERED;
 369 }
 370
 371 /**
 372  * aer_error_detected - update severity status
 373  * @dev: pointer to Root Port's pci_dev data structure
 374  * @error: error severity being notified by port bus
 375  *
 376  * Invoked by Port Bus driver during error recovery.
 377  */
 378 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
 379                         enum pci_channel_state error)
 380 {
 381         /* Root Port has no impact. Always recovers. */
 382         return PCI_ERS_RESULT_CAN_RECOVER;
 383 }
 384
 385 /**
 386  * aer_error_resume - clean up corresponding error status bits
 387  * @dev: pointer to Root Port's pci_dev data structure
 388  *
 389  * Invoked by Port Bus driver during nonfatal recovery.
 390  */
 391 static void aer_error_resume(struct pci_dev *dev)
 392 {
 393         int pos;
 394         u32 status, mask;
 395         u16 reg16;
 396
 397         /* Clean up Root device status */
 398         pos = pci_pcie_cap(dev);
 399         pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &reg16);
 400         pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);
 401
 402         /* Clean AER Root Error Status */
 403         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 404         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 405         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 406         if (dev->error_state == pci_channel_io_normal)
 407                 status &= ~mask; /* Clear corresponding nonfatal bits */
 408         else
 409                 status &= mask; /* Clear corresponding fatal bits */
 410         pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 411 }
 412
 413 /**
 414  * aer_service_init - register AER root service driver
 415  *
 416  * Invoked when AER root service driver is loaded.
 417  */
 418 static int __init aer_service_init(void)
 419 {
 420         if (!pci_aer_available() || aer_acpi_firmware_first())
 421                 return -ENXIO;
 422         return pcie_port_service_register(&aerdriver);
 423 }
 424
 425 /**
 426  * aer_service_exit - unregister AER root service driver
 427  *
 428  * Invoked when AER root service driver is unloaded.
 429  */
 430 static void __exit aer_service_exit(void)
 431 {
 432         pcie_port_service_unregister(&aerdriver);
 433 }
 434
 435 module_init(aer_service_init);
 436 module_exit(aer_service_exit);