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