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