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 static void aer_remove(struct pcie_device *dev);
  43 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
  44         enum pci_channel_state error);
  45 static void aer_error_resume(struct pci_dev *dev);
  46 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
  47
  48 static struct pci_error_handlers aer_error_handlers = {
  49         .error_detected = aer_error_detected,
  50         .resume = aer_error_resume,
  51 };
  52
  53 static struct pcie_port_service_driver aerdriver = {
  54         .name           = "aer",
  55         .port_type      = PCIE_ANY_PORT,
  56         .service        = PCIE_PORT_SERVICE_AER,
  57
  58         .probe          = aer_probe,
  59         .remove         = aer_remove,
  60
  61         .err_handler    = &aer_error_handlers,
  62
  63         .reset_link     = aer_root_reset,
  64 };
  65
  66 static int pcie_aer_disable;
  67
  68 void pci_no_aer(void)
  69 {
  70         pcie_aer_disable = 1;   /* has priority over 'forceload' */
  71 }
  72
  73 /**
  74  * aer_irq - Root Port's ISR
  75  * @irq: IRQ assigned to Root Port
  76  * @context: pointer to Root Port data structure
  77  *
  78  * Invoked when Root Port detects AER messages.
  79  **/
  80 static irqreturn_t aer_irq(int irq, void *context)
  81 {
  82         unsigned int status, id;
  83         struct pcie_device *pdev = (struct pcie_device *)context;
  84         struct aer_rpc *rpc = get_service_data(pdev);
  85         int next_prod_idx;
  86         unsigned long flags;
  87         int pos;
  88
  89         pos = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR);
  90         /*
  91          * Must lock access to Root Error Status Reg, Root Error ID Reg,
  92          * and Root error producer/consumer index
  93          */
  94         spin_lock_irqsave(&rpc->e_lock, flags);
  95
  96         /* Read error status */
  97         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
  98         if (!(status & ROOT_ERR_STATUS_MASKS)) {
  99                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 100                 return IRQ_NONE;
 101         }
 102
 103         /* Read error source and clear error status */
 104         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_COR_SRC, &id);
 105         pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
 106
 107         /* Store error source for later DPC handler */
 108         next_prod_idx = rpc->prod_idx + 1;
 109         if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 110                 next_prod_idx = 0;
 111         if (next_prod_idx == rpc->cons_idx) {
 112                 /*
 113                  * Error Storm Condition - possibly the same error occurred.
 114                  * Drop the error.
 115                  */
 116                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 117                 return IRQ_HANDLED;
 118         }
 119         rpc->e_sources[rpc->prod_idx].status =  status;
 120         rpc->e_sources[rpc->prod_idx].id = id;
 121         rpc->prod_idx = next_prod_idx;
 122         spin_unlock_irqrestore(&rpc->e_lock, flags);
 123
 124         /*  Invoke DPC handler */
 125         schedule_work(&rpc->dpc_handler);
 126
 127         return IRQ_HANDLED;
 128 }
 129
 130 /**
 131  * aer_alloc_rpc - allocate Root Port data structure
 132  * @dev: pointer to the pcie_dev data structure
 133  *
 134  * Invoked when Root Port's AER service is loaded.
 135  **/
 136 static struct aer_rpc* aer_alloc_rpc(struct pcie_device *dev)
 137 {
 138         struct aer_rpc *rpc;
 139
 140         if (!(rpc = kzalloc(sizeof(struct aer_rpc),
 141                 GFP_KERNEL)))
 142                 return NULL;
 143
 144         /*
 145          * Initialize Root lock access, e_lock, to Root Error Status Reg,
 146          * Root Error ID Reg, and Root error producer/consumer index.
 147          */
 148         spin_lock_init(&rpc->e_lock);
 149
 150         rpc->rpd = dev;
 151         INIT_WORK(&rpc->dpc_handler, aer_isr);
 152         rpc->prod_idx = rpc->cons_idx = 0;
 153         mutex_init(&rpc->rpc_mutex);
 154         init_waitqueue_head(&rpc->wait_release);
 155
 156         /* Use PCIE bus function to store rpc into PCIE device */
 157         set_service_data(dev, rpc);
 158
 159         return rpc;
 160 }
 161
 162 /**
 163  * aer_remove - clean up resources
 164  * @dev: pointer to the pcie_dev data structure
 165  *
 166  * Invoked when PCI Express bus unloads or AER probe fails.
 167  **/
 168 static void aer_remove(struct pcie_device *dev)
 169 {
 170         struct aer_rpc *rpc = get_service_data(dev);
 171
 172         if (rpc) {
 173                 /* If register interrupt service, it must be free. */
 174                 if (rpc->isr)
 175                         free_irq(dev->irq, dev);
 176
 177                 wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
 178
 179                 aer_delete_rootport(rpc);
 180                 set_service_data(dev, NULL);
 181         }
 182 }
 183
 184 /**
 185  * aer_probe - initialize resources
 186  * @dev: pointer to the pcie_dev data structure
 187  * @id: pointer to the service id data structure
 188  *
 189  * Invoked when PCI Express bus loads AER service driver.
 190  **/
 191 static int __devinit aer_probe (struct pcie_device *dev)
 192 {
 193         int status;
 194         struct aer_rpc *rpc;
 195         struct device *device = &dev->device;
 196
 197         /* Init */
 198         if ((status = aer_init(dev)))
 199                 return status;
 200
 201         /* Alloc rpc data structure */
 202         if (!(rpc = aer_alloc_rpc(dev))) {
 203                 dev_printk(KERN_DEBUG, device, "alloc rpc failed\n");
 204                 aer_remove(dev);
 205                 return -ENOMEM;
 206         }
 207
 208         /* Request IRQ ISR */
 209         if ((status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv",
 210                                 dev))) {
 211                 dev_printk(KERN_DEBUG, device, "request IRQ failed\n");
 212                 aer_remove(dev);
 213                 return status;
 214         }
 215
 216         rpc->isr = 1;
 217
 218         aer_enable_rootport(rpc);
 219
 220         return status;
 221 }
 222
 223 /**
 224  * aer_root_reset - reset link on Root Port
 225  * @dev: pointer to Root Port's pci_dev data structure
 226  *
 227  * Invoked by Port Bus driver when performing link reset at Root Port.
 228  **/
 229 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 230 {
 231         u16 p2p_ctrl;
 232         u32 status;
 233         int pos;
 234
 235         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 236
 237         /* Disable Root's interrupt in response to error messages */
 238         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, 0);
 239
 240         /* Assert Secondary Bus Reset */
 241         pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl);
 242         p2p_ctrl |= PCI_CB_BRIDGE_CTL_CB_RESET;
 243         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 244
 245         /* De-assert Secondary Bus Reset */
 246         p2p_ctrl &= ~PCI_CB_BRIDGE_CTL_CB_RESET;
 247         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 248
 249         /*
 250          * System software must wait for at least 100ms from the end
 251          * of a reset of one or more device before it is permitted
 252          * to issue Configuration Requests to those devices.
 253          */
 254         msleep(200);
 255         dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
 256
 257         /* Enable Root Port's interrupt in response to error messages */
 258         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
 259         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
 260         pci_write_config_dword(dev,
 261                 pos + PCI_ERR_ROOT_COMMAND,
 262                 ROOT_PORT_INTR_ON_MESG_MASK);
 263
 264         return PCI_ERS_RESULT_RECOVERED;
 265 }
 266
 267 /**
 268  * aer_error_detected - update severity status
 269  * @dev: pointer to Root Port's pci_dev data structure
 270  * @error: error severity being notified by port bus
 271  *
 272  * Invoked by Port Bus driver during error recovery.
 273  **/
 274 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
 275                         enum pci_channel_state error)
 276 {
 277         /* Root Port has no impact. Always recovers. */
 278         return PCI_ERS_RESULT_CAN_RECOVER;
 279 }
 280
 281 /**
 282  * aer_error_resume - clean up corresponding error status bits
 283  * @dev: pointer to Root Port's pci_dev data structure
 284  *
 285  * Invoked by Port Bus driver during nonfatal recovery.
 286  **/
 287 static void aer_error_resume(struct pci_dev *dev)
 288 {
 289         int pos;
 290         u32 status, mask;
 291         u16 reg16;
 292
 293         /* Clean up Root device status */
 294         pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
 295         pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &reg16);
 296         pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);
 297
 298         /* Clean AER Root Error Status */
 299         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 300         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 301         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 302         if (dev->error_state == pci_channel_io_normal)
 303                 status &= ~mask; /* Clear corresponding nonfatal bits */
 304         else
 305                 status &= mask; /* Clear corresponding fatal bits */
 306         pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 307 }
 308
 309 /**
 310  * aer_service_init - register AER root service driver
 311  *
 312  * Invoked when AER root service driver is loaded.
 313  **/
 314 static int __init aer_service_init(void)
 315 {
 316         if (pcie_aer_disable)
 317                 return -ENXIO;
 318         return pcie_port_service_register(&aerdriver);
 319 }
 320
 321 /**
 322  * aer_service_exit - unregister AER root service driver
 323  *
 324  * Invoked when AER root service driver is unloaded.
 325  **/
 326 static void __exit aer_service_exit(void)
 327 {
 328         pcie_port_service_unregister(&aerdriver);
 329 }
 330
 331 module_init(aer_service_init);
 332 module_exit(aer_service_exit);