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 #include "../../pci.h"
  30
  31 /*
  32  * Version Information
  33  */
  34 #define DRIVER_VERSION "v1.0"
  35 #define DRIVER_AUTHOR "tom.l.nguyen@intel.com"
  36 #define DRIVER_DESC "Root Port Advanced Error Reporting Driver"
  37 MODULE_AUTHOR(DRIVER_AUTHOR);
  38 MODULE_DESCRIPTION(DRIVER_DESC);
  39 MODULE_LICENSE("GPL");
  40
  41 static int __devinit aer_probe (struct pcie_device *dev,
  42         const struct pcie_port_service_id *id );
  43 static void aer_remove(struct pcie_device *dev);
  44 static int aer_suspend(struct pcie_device *dev, pm_message_t state)
  45 {return 0;}
  46 static int aer_resume(struct pcie_device *dev) {return 0;}
  47 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
  48         enum pci_channel_state error);
  49 static void aer_error_resume(struct pci_dev *dev);
  50 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
  51
  52 /*
  53  * PCI Express bus's AER Root service driver data structure
  54  */
  55 static struct pcie_port_service_id aer_id[] = {
  56         {
  57         .vendor         = PCI_ANY_ID,
  58         .device         = PCI_ANY_ID,
  59         .port_type      = PCIE_RC_PORT,
  60         .service_type   = PCIE_PORT_SERVICE_AER,
  61         },
  62         { /* end: all zeroes */ }
  63 };
  64
  65 static struct pci_error_handlers aer_error_handlers = {
  66         .error_detected = aer_error_detected,
  67         .resume = aer_error_resume,
  68 };
  69
  70 static struct pcie_port_service_driver aerdriver = {
  71         .name           = "aer",
  72         .id_table       = &aer_id[0],
  73
  74         .probe          = aer_probe,
  75         .remove         = aer_remove,
  76
  77         .suspend        = aer_suspend,
  78         .resume         = aer_resume,
  79
  80         .err_handler    = &aer_error_handlers,
  81
  82         .reset_link     = aer_root_reset,
  83 };
  84
  85 static int pcie_aer_disable;
  86
  87 void pci_no_aer(void)
  88 {
  89         pcie_aer_disable = 1;   /* has priority over 'forceload' */
  90 }
  91
  92 /**
  93  * aer_irq - Root Port's ISR
  94  * @irq: IRQ assigned to Root Port
  95  * @context: pointer to Root Port data structure
  96  *
  97  * Invoked when Root Port detects AER messages.
  98  **/
  99 static irqreturn_t aer_irq(int irq, void *context)
 100 {
 101         unsigned int status, id;
 102         struct pcie_device *pdev = (struct pcie_device *)context;
 103         struct aer_rpc *rpc = get_service_data(pdev);
 104         int next_prod_idx;
 105         unsigned long flags;
 106         int pos;
 107
 108         pos = pci_find_aer_capability(pdev->port);
 109         /*
 110          * Must lock access to Root Error Status Reg, Root Error ID Reg,
 111          * and Root error producer/consumer index
 112          */
 113         spin_lock_irqsave(&rpc->e_lock, flags);
 114
 115         /* Read error status */
 116         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
 117         if (!(status & ROOT_ERR_STATUS_MASKS)) {
 118                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 119                 return IRQ_NONE;
 120         }
 121
 122         /* Read error source and clear error status */
 123         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_COR_SRC, &id);
 124         pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
 125
 126         /* Store error source for later DPC handler */
 127         next_prod_idx = rpc->prod_idx + 1;
 128         if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 129                 next_prod_idx = 0;
 130         if (next_prod_idx == rpc->cons_idx) {
 131                 /*
 132                  * Error Storm Condition - possibly the same error occurred.
 133                  * Drop the error.
 134                  */
 135                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 136                 return IRQ_HANDLED;
 137         }
 138         rpc->e_sources[rpc->prod_idx].status =  status;
 139         rpc->e_sources[rpc->prod_idx].id = id;
 140         rpc->prod_idx = next_prod_idx;
 141         spin_unlock_irqrestore(&rpc->e_lock, flags);
 142
 143         /*  Invoke DPC handler */
 144         schedule_work(&rpc->dpc_handler);
 145
 146         return IRQ_HANDLED;
 147 }
 148
 149 /**
 150  * aer_alloc_rpc - allocate Root Port data structure
 151  * @dev: pointer to the pcie_dev data structure
 152  *
 153  * Invoked when Root Port's AER service is loaded.
 154  **/
 155 static struct aer_rpc* aer_alloc_rpc(struct pcie_device *dev)
 156 {
 157         struct aer_rpc *rpc;
 158
 159         if (!(rpc = kzalloc(sizeof(struct aer_rpc),
 160                 GFP_KERNEL)))
 161                 return NULL;
 162
 163         /*
 164          * Initialize Root lock access, e_lock, to Root Error Status Reg,
 165          * Root Error ID Reg, and Root error producer/consumer index.
 166          */
 167         spin_lock_init(&rpc->e_lock);
 168
 169         rpc->rpd = dev;
 170         INIT_WORK(&rpc->dpc_handler, aer_isr);
 171         rpc->prod_idx = rpc->cons_idx = 0;
 172         mutex_init(&rpc->rpc_mutex);
 173         init_waitqueue_head(&rpc->wait_release);
 174
 175         /* Use PCIE bus function to store rpc into PCIE device */
 176         set_service_data(dev, rpc);
 177
 178         return rpc;
 179 }
 180
 181 /**
 182  * aer_remove - clean up resources
 183  * @dev: pointer to the pcie_dev data structure
 184  *
 185  * Invoked when PCI Express bus unloads or AER probe fails.
 186  **/
 187 static void aer_remove(struct pcie_device *dev)
 188 {
 189         struct aer_rpc *rpc = get_service_data(dev);
 190
 191         if (rpc) {
 192                 /* If register interrupt service, it must be free. */
 193                 if (rpc->isr)
 194                         free_irq(dev->irq, dev);
 195
 196                 wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
 197
 198                 aer_delete_rootport(rpc);
 199                 set_service_data(dev, NULL);
 200         }
 201 }
 202
 203 /**
 204  * aer_probe - initialize resources
 205  * @dev: pointer to the pcie_dev data structure
 206  * @id: pointer to the service id data structure
 207  *
 208  * Invoked when PCI Express bus loads AER service driver.
 209  **/
 210 static int __devinit aer_probe (struct pcie_device *dev,
 211                                 const struct pcie_port_service_id *id )
 212 {
 213         int status;
 214         struct aer_rpc *rpc;
 215         struct device *device = &dev->device;
 216
 217         /* Init */
 218         if ((status = aer_init(dev)))
 219                 return status;
 220
 221         /* Alloc rpc data structure */
 222         if (!(rpc = aer_alloc_rpc(dev))) {
 223                 dev_printk(KERN_DEBUG, device, "alloc rpc failed\n");
 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                 dev_printk(KERN_DEBUG, device, "request IRQ failed\n");
 232                 aer_remove(dev);
 233                 return status;
 234         }
 235
 236         rpc->isr = 1;
 237
 238         aer_enable_rootport(rpc);
 239
 240         return status;
 241 }
 242
 243 /**
 244  * aer_root_reset - reset link on Root Port
 245  * @dev: pointer to Root Port's pci_dev data structure
 246  *
 247  * Invoked by Port Bus driver when performing link reset at Root Port.
 248  **/
 249 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 250 {
 251         u16 p2p_ctrl;
 252         u32 status;
 253         int pos;
 254
 255         pos = pci_find_aer_capability(dev);
 256
 257         /* Disable Root's interrupt in response to error messages */
 258         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, 0);
 259
 260         /* Assert Secondary Bus Reset */
 261         pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl);
 262         p2p_ctrl |= PCI_CB_BRIDGE_CTL_CB_RESET;
 263         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 264
 265         /* De-assert Secondary Bus Reset */
 266         p2p_ctrl &= ~PCI_CB_BRIDGE_CTL_CB_RESET;
 267         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 268
 269         /*
 270          * System software must wait for at least 100ms from the end
 271          * of a reset of one or more device before it is permitted
 272          * to issue Configuration Requests to those devices.
 273          */
 274         msleep(200);
 275         dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
 276
 277         /* Enable Root Port's interrupt in response to error messages */
 278         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
 279         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
 280         pci_write_config_dword(dev,
 281                 pos + PCI_ERR_ROOT_COMMAND,
 282                 ROOT_PORT_INTR_ON_MESG_MASK);
 283
 284         return PCI_ERS_RESULT_RECOVERED;
 285 }
 286
 287 /**
 288  * aer_error_detected - update severity status
 289  * @dev: pointer to Root Port's pci_dev data structure
 290  * @error: error severity being notified by port bus
 291  *
 292  * Invoked by Port Bus driver during error recovery.
 293  **/
 294 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
 295                         enum pci_channel_state error)
 296 {
 297         /* Root Port has no impact. Always recovers. */
 298         return PCI_ERS_RESULT_CAN_RECOVER;
 299 }
 300
 301 /**
 302  * aer_error_resume - clean up corresponding error status bits
 303  * @dev: pointer to Root Port's pci_dev data structure
 304  *
 305  * Invoked by Port Bus driver during nonfatal recovery.
 306  **/
 307 static void aer_error_resume(struct pci_dev *dev)
 308 {
 309         int pos;
 310         u32 status, mask;
 311         u16 reg16;
 312
 313         /* Clean up Root device status */
 314         pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
 315         pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &reg16);
 316         pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);
 317
 318         /* Clean AER Root Error Status */
 319         pos = pci_find_aer_capability(dev);
 320         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 321         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 322         if (dev->error_state == pci_channel_io_normal)
 323                 status &= ~mask; /* Clear corresponding nonfatal bits */
 324         else
 325                 status &= mask; /* Clear corresponding fatal bits */
 326         pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 327 }
 328
 329 /**
 330  * aer_service_init - register AER root service driver
 331  *
 332  * Invoked when AER root service driver is loaded.
 333  **/
 334 static int __init aer_service_init(void)
 335 {
 336         if (pcie_aer_disable)
 337                 return -ENXIO;
 338         return pcie_port_service_register(&aerdriver);
 339 }
 340
 341 /**
 342  * aer_service_exit - unregister AER root service driver
 343  *
 344  * Invoked when AER root service driver is unloaded.
 345  **/
 346 static void __exit aer_service_exit(void)
 347 {
 348         pcie_port_service_unregister(&aerdriver);
 349 }
 350
 351 module_init(aer_service_init);
 352 module_exit(aer_service_exit);