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/kernel.h>
  21 #include <linux/errno.h>
  22 #include <linux/pm.h>
  23 #include <linux/init.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/delay.h>
  26 #include <linux/pcieport_if.h>
  27
  28 #include "aerdrv.h"
  29
  30 /*
  31  * Version Information
  32  */
  33 #define DRIVER_VERSION "v1.0"
  34 #define DRIVER_AUTHOR "tom.l.nguyen@intel.com"
  35 #define DRIVER_DESC "Root Port Advanced Error Reporting Driver"
  36 MODULE_AUTHOR(DRIVER_AUTHOR);
  37 MODULE_DESCRIPTION(DRIVER_DESC);
  38 MODULE_LICENSE("GPL");
  39
  40 static int __devinit aer_probe (struct pcie_device *dev,
  41         const struct pcie_port_service_id *id );
  42 static void aer_remove(struct pcie_device *dev);
  43 static int aer_suspend(struct pcie_device *dev, pm_message_t state)
  44 {return 0;}
  45 static int aer_resume(struct pcie_device *dev) {return 0;}
  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 /*
  52  * PCI Express bus's AER Root service driver data structure
  53  */
  54 static struct pcie_port_service_id aer_id[] = {
  55         {
  56         .vendor         = PCI_ANY_ID,
  57         .device         = PCI_ANY_ID,
  58         .port_type      = PCIE_RC_PORT,
  59         .service_type   = PCIE_PORT_SERVICE_AER,
  60         },
  61         { /* end: all zeroes */ }
  62 };
  63
  64 static struct pci_error_handlers aer_error_handlers = {
  65         .error_detected = aer_error_detected,
  66         .resume = aer_error_resume,
  67 };
  68
  69 static struct pcie_port_service_driver aerdriver = {
  70         .name           = "aer",
  71         .id_table       = &aer_id[0],
  72
  73         .probe          = aer_probe,
  74         .remove         = aer_remove,
  75
  76         .suspend        = aer_suspend,
  77         .resume         = aer_resume,
  78
  79         .err_handler    = &aer_error_handlers,
  80
  81         .reset_link     = aer_root_reset,
  82 };
  83
  84 static int pcie_aer_disable;
  85
  86 void pci_no_aer(void)
  87 {
  88         pcie_aer_disable = 1;   /* has priority over 'forceload' */
  89 }
  90
  91 /**
  92  * aer_irq - Root Port's ISR
  93  * @irq: IRQ assigned to Root Port
  94  * @context: pointer to Root Port data structure
  95  *
  96  * Invoked when Root Port detects AER messages.
  97  **/
  98 static irqreturn_t aer_irq(int irq, void *context)
  99 {
 100         unsigned int status, id;
 101         struct pcie_device *pdev = (struct pcie_device *)context;
 102         struct aer_rpc *rpc = get_service_data(pdev);
 103         int next_prod_idx;
 104         unsigned long flags;
 105         int pos;
 106
 107         pos = pci_find_aer_capability(pdev->port);
 108         /*
 109          * Must lock access to Root Error Status Reg, Root Error ID Reg,
 110          * and Root error producer/consumer index
 111          */
 112         spin_lock_irqsave(&rpc->e_lock, flags);
 113
 114         /* Read error status */
 115         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
 116         if (!(status & ROOT_ERR_STATUS_MASKS)) {
 117                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 118                 return IRQ_NONE;
 119         }
 120
 121         /* Read error source and clear error status */
 122         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_COR_SRC, &id);
 123         pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
 124
 125         /* Store error source for later DPC handler */
 126         next_prod_idx = rpc->prod_idx + 1;
 127         if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 128                 next_prod_idx = 0;
 129         if (next_prod_idx == rpc->cons_idx) {
 130                 /*
 131                  * Error Storm Condition - possibly the same error occurred.
 132                  * Drop the error.
 133                  */
 134                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 135                 return IRQ_HANDLED;
 136         }
 137         rpc->e_sources[rpc->prod_idx].status =  status;
 138         rpc->e_sources[rpc->prod_idx].id = id;
 139         rpc->prod_idx = next_prod_idx;
 140         spin_unlock_irqrestore(&rpc->e_lock, flags);
 141
 142         /*  Invoke DPC handler */
 143         schedule_work(&rpc->dpc_handler);
 144
 145         return IRQ_HANDLED;
 146 }
 147
 148 /**
 149  * aer_alloc_rpc - allocate Root Port data structure
 150  * @dev: pointer to the pcie_dev data structure
 151  *
 152  * Invoked when Root Port's AER service is loaded.
 153  **/
 154 static struct aer_rpc* aer_alloc_rpc(struct pcie_device *dev)
 155 {
 156         struct aer_rpc *rpc;
 157
 158         if (!(rpc = kzalloc(sizeof(struct aer_rpc),
 159                 GFP_KERNEL)))
 160                 return NULL;
 161
 162         /*
 163          * Initialize Root lock access, e_lock, to Root Error Status Reg,
 164          * Root Error ID Reg, and Root error producer/consumer index.
 165          */
 166         spin_lock_init(&rpc->e_lock);
 167
 168         rpc->rpd = dev;
 169         INIT_WORK(&rpc->dpc_handler, aer_isr);
 170         rpc->prod_idx = rpc->cons_idx = 0;
 171         mutex_init(&rpc->rpc_mutex);
 172         init_waitqueue_head(&rpc->wait_release);
 173
 174         /* Use PCIE bus function to store rpc into PCIE device */
 175         set_service_data(dev, rpc);
 176
 177         return rpc;
 178 }
 179
 180 /**
 181  * aer_remove - clean up resources
 182  * @dev: pointer to the pcie_dev data structure
 183  *
 184  * Invoked when PCI Express bus unloads or AER probe fails.
 185  **/
 186 static void aer_remove(struct pcie_device *dev)
 187 {
 188         struct aer_rpc *rpc = get_service_data(dev);
 189
 190         if (rpc) {
 191                 /* If register interrupt service, it must be free. */
 192                 if (rpc->isr)
 193                         free_irq(dev->irq, dev);
 194
 195                 wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
 196
 197                 aer_delete_rootport(rpc);
 198                 set_service_data(dev, NULL);
 199         }
 200 }
 201
 202 /**
 203  * aer_probe - initialize resources
 204  * @dev: pointer to the pcie_dev data structure
 205  * @id: pointer to the service id data structure
 206  *
 207  * Invoked when PCI Express bus loads AER service driver.
 208  **/
 209 static int __devinit aer_probe (struct pcie_device *dev,
 210                                 const struct pcie_port_service_id *id )
 211 {
 212         int status;
 213         struct aer_rpc *rpc;
 214         struct device *device = &dev->device;
 215
 216         /* Init */
 217         if ((status = aer_init(dev)))
 218                 return status;
 219
 220         /* Alloc rpc data structure */
 221         if (!(rpc = aer_alloc_rpc(dev))) {
 222                 printk(KERN_DEBUG "%s: Alloc rpc fails on PCIE device[%s]\n",
 223                         __func__, device->bus_id);
 224                 aer_remove(dev);
 225                 return -ENOMEM;
 226         }
 227
 228         /* Request IRQ ISR */
 229         if ((status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv",
 230                                 dev))) {
 231                 printk(KERN_DEBUG "%s: Request ISR fails on PCIE device[%s]\n",
 232                         __func__, device->bus_id);
 233                 aer_remove(dev);
 234                 return status;
 235         }
 236
 237         rpc->isr = 1;
 238
 239         aer_enable_rootport(rpc);
 240
 241         return status;
 242 }
 243
 244 /**
 245  * aer_root_reset - reset link on Root Port
 246  * @dev: pointer to Root Port's pci_dev data structure
 247  *
 248  * Invoked by Port Bus driver when performing link reset at Root Port.
 249  **/
 250 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 251 {
 252         u16 p2p_ctrl;
 253         u32 status;
 254         int pos;
 255
 256         pos = pci_find_aer_capability(dev);
 257
 258         /* Disable Root's interrupt in response to error messages */
 259         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, 0);
 260
 261         /* Assert Secondary Bus Reset */
 262         pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl);
 263         p2p_ctrl |= PCI_CB_BRIDGE_CTL_CB_RESET;
 264         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 265
 266         /* De-assert Secondary Bus Reset */
 267         p2p_ctrl &= ~PCI_CB_BRIDGE_CTL_CB_RESET;
 268         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 269
 270         /*
 271          * System software must wait for at least 100ms from the end
 272          * of a reset of one or more device before it is permitted
 273          * to issue Configuration Requests to those devices.
 274          */
 275         msleep(200);
 276         printk(KERN_DEBUG "Complete link reset at Root[%s]\n", dev->dev.bus_id);
 277
 278         /* Enable Root Port's interrupt in response to error messages */
 279         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
 280         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
 281         pci_write_config_dword(dev,
 282                 pos + PCI_ERR_ROOT_COMMAND,
 283                 ROOT_PORT_INTR_ON_MESG_MASK);
 284
 285         return PCI_ERS_RESULT_RECOVERED;
 286 }
 287
 288 /**
 289  * aer_error_detected - update severity status
 290  * @dev: pointer to Root Port's pci_dev data structure
 291  * @error: error severity being notified by port bus
 292  *
 293  * Invoked by Port Bus driver during error recovery.
 294  **/
 295 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
 296                         enum pci_channel_state error)
 297 {
 298         /* Root Port has no impact. Always recovers. */
 299         return PCI_ERS_RESULT_CAN_RECOVER;
 300 }
 301
 302 /**
 303  * aer_error_resume - clean up corresponding error status bits
 304  * @dev: pointer to Root Port's pci_dev data structure
 305  *
 306  * Invoked by Port Bus driver during nonfatal recovery.
 307  **/
 308 static void aer_error_resume(struct pci_dev *dev)
 309 {
 310         int pos;
 311         u32 status, mask;
 312         u16 reg16;
 313
 314         /* Clean up Root device status */
 315         pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
 316         pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &reg16);
 317         pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);
 318
 319         /* Clean AER Root Error Status */
 320         pos = pci_find_aer_capability(dev);
 321         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 322         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 323         if (dev->error_state == pci_channel_io_normal)
 324                 status &= ~mask; /* Clear corresponding nonfatal bits */
 325         else
 326                 status &= mask; /* Clear corresponding fatal bits */
 327         pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 328 }
 329
 330 /**
 331  * aer_service_init - register AER root service driver
 332  *
 333  * Invoked when AER root service driver is loaded.
 334  **/
 335 static int __init aer_service_init(void)
 336 {
 337         if (pcie_aer_disable)
 338                 return -ENXIO;
 339         return pcie_port_service_register(&aerdriver);
 340 }
 341
 342 /**
 343  * aer_service_exit - unregister AER root service driver
 344  *
 345  * Invoked when AER root service driver is unloaded.
 346  **/
 347 static void __exit aer_service_exit(void)
 348 {
 349         pcie_port_service_unregister(&aerdriver);
 350 }
 351
 352 module_init(aer_service_init);
 353 module_exit(aer_service_exit);