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/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 MODULE_AUTHOR(DRIVER_AUTHOR);
  40 MODULE_DESCRIPTION(DRIVER_DESC);
  41 MODULE_LICENSE("GPL");
  42
  43 static int __devinit aer_probe(struct pcie_device *dev);
  44 static void aer_remove(struct pcie_device *dev);
  45 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
  46         enum pci_channel_state error);
  47 static void aer_error_resume(struct pci_dev *dev);
  48 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
  49
  50 static struct pci_error_handlers aer_error_handlers = {
  51         .error_detected = aer_error_detected,
  52         .resume         = aer_error_resume,
  53 };
  54
  55 static struct pcie_port_service_driver aerdriver = {
  56         .name           = "aer",
  57         .port_type      = PCI_EXP_TYPE_ROOT_PORT,
  58         .service        = PCIE_PORT_SERVICE_AER,
  59
  60         .probe          = aer_probe,
  61         .remove         = aer_remove,
  62
  63         .err_handler    = &aer_error_handlers,
  64
  65         .reset_link     = aer_root_reset,
  66 };
  67
  68 static int pcie_aer_disable;
  69
  70 void pci_no_aer(void)
  71 {
  72         pcie_aer_disable = 1;   /* has priority over 'forceload' */
  73 }
  74
  75 /**
  76  * aer_irq - Root Port's ISR
  77  * @irq: IRQ assigned to Root Port
  78  * @context: pointer to Root Port data structure
  79  *
  80  * Invoked when Root Port detects AER messages.
  81  **/
  82 irqreturn_t aer_irq(int irq, void *context)
  83 {
  84         unsigned int status, id;
  85         struct pcie_device *pdev = (struct pcie_device *)context;
  86         struct aer_rpc *rpc = get_service_data(pdev);
  87         int next_prod_idx;
  88         unsigned long flags;
  89         int pos;
  90
  91         pos = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR);
  92         /*
  93          * Must lock access to Root Error Status Reg, Root Error ID Reg,
  94          * and Root error producer/consumer index
  95          */
  96         spin_lock_irqsave(&rpc->e_lock, flags);
  97
  98         /* Read error status */
  99         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
 100         if (!(status & ROOT_ERR_STATUS_MASKS)) {
 101                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 102                 return IRQ_NONE;
 103         }
 104
 105         /* Read error source and clear error status */
 106         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_COR_SRC, &id);
 107         pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
 108
 109         /* Store error source for later DPC handler */
 110         next_prod_idx = rpc->prod_idx + 1;
 111         if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 112                 next_prod_idx = 0;
 113         if (next_prod_idx == rpc->cons_idx) {
 114                 /*
 115                  * Error Storm Condition - possibly the same error occurred.
 116                  * Drop the error.
 117                  */
 118                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 119                 return IRQ_HANDLED;
 120         }
 121         rpc->e_sources[rpc->prod_idx].status =  status;
 122         rpc->e_sources[rpc->prod_idx].id = id;
 123         rpc->prod_idx = next_prod_idx;
 124         spin_unlock_irqrestore(&rpc->e_lock, flags);
 125
 126         /*  Invoke DPC handler */
 127         schedule_work(&rpc->dpc_handler);
 128
 129         return IRQ_HANDLED;
 130 }
 131 EXPORT_SYMBOL_GPL(aer_irq);
 132
 133 /**
 134  * aer_alloc_rpc - allocate Root Port data structure
 135  * @dev: pointer to the pcie_dev data structure
 136  *
 137  * Invoked when Root Port's AER service is loaded.
 138  **/
 139 static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
 140 {
 141         struct aer_rpc *rpc;
 142
 143         rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
 144         if (!rpc)
 145                 return NULL;
 146
 147         /*
 148          * Initialize Root lock access, e_lock, to Root Error Status Reg,
 149          * Root Error ID Reg, and Root error producer/consumer index.
 150          */
 151         spin_lock_init(&rpc->e_lock);
 152
 153         rpc->rpd = dev;
 154         INIT_WORK(&rpc->dpc_handler, aer_isr);
 155         rpc->prod_idx = rpc->cons_idx = 0;
 156         mutex_init(&rpc->rpc_mutex);
 157         init_waitqueue_head(&rpc->wait_release);
 158
 159         /* Use PCIe bus function to store rpc into PCIe device */
 160         set_service_data(dev, rpc);
 161
 162         return rpc;
 163 }
 164
 165 /**
 166  * aer_remove - clean up resources
 167  * @dev: pointer to the pcie_dev data structure
 168  *
 169  * Invoked when PCI Express bus unloads or AER probe fails.
 170  **/
 171 static void aer_remove(struct pcie_device *dev)
 172 {
 173         struct aer_rpc *rpc = get_service_data(dev);
 174
 175         if (rpc) {
 176                 /* If register interrupt service, it must be free. */
 177                 if (rpc->isr)
 178                         free_irq(dev->irq, dev);
 179
 180                 wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
 181
 182                 aer_delete_rootport(rpc);
 183                 set_service_data(dev, NULL);
 184         }
 185 }
 186
 187 /**
 188  * aer_probe - initialize resources
 189  * @dev: pointer to the pcie_dev data structure
 190  * @id: pointer to the service id data structure
 191  *
 192  * Invoked when PCI Express bus loads AER service driver.
 193  **/
 194 static int __devinit aer_probe(struct pcie_device *dev)
 195 {
 196         int status;
 197         struct aer_rpc *rpc;
 198         struct device *device = &dev->device;
 199
 200         /* Init */
 201         status = aer_init(dev);
 202         if (status)
 203                 return status;
 204
 205         /* Alloc rpc data structure */
 206         rpc = aer_alloc_rpc(dev);
 207         if (!rpc) {
 208                 dev_printk(KERN_DEBUG, device, "alloc rpc failed\n");
 209                 aer_remove(dev);
 210                 return -ENOMEM;
 211         }
 212
 213         /* Request IRQ ISR */
 214         status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
 215         if (status) {
 216                 dev_printk(KERN_DEBUG, device, "request IRQ failed\n");
 217                 aer_remove(dev);
 218                 return status;
 219         }
 220
 221         rpc->isr = 1;
 222
 223         aer_enable_rootport(rpc);
 224
 225         return status;
 226 }
 227
 228 /**
 229  * aer_root_reset - reset link on Root Port
 230  * @dev: pointer to Root Port's pci_dev data structure
 231  *
 232  * Invoked by Port Bus driver when performing link reset at Root Port.
 233  **/
 234 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 235 {
 236         u16 p2p_ctrl;
 237         u32 status;
 238         int pos;
 239
 240         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 241
 242         /* Disable Root's interrupt in response to error messages */
 243         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, 0);
 244
 245         /* Assert Secondary Bus Reset */
 246         pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl);
 247         p2p_ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
 248         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 249
 250         /*
 251          * we should send hot reset message for 2ms to allow it time to
 252          * propogate to all downstream ports
 253          */
 254         msleep(2);
 255
 256         /* De-assert Secondary Bus Reset */
 257         p2p_ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
 258         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 259
 260         /*
 261          * System software must wait for at least 100ms from the end
 262          * of a reset of one or more device before it is permitted
 263          * to issue Configuration Requests to those devices.
 264          */
 265         msleep(200);
 266         dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
 267
 268         /* Enable Root Port's interrupt in response to error messages */
 269         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
 270         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
 271         pci_write_config_dword(dev,
 272                 pos + PCI_ERR_ROOT_COMMAND,
 273                 ROOT_PORT_INTR_ON_MESG_MASK);
 274
 275         return PCI_ERS_RESULT_RECOVERED;
 276 }
 277
 278 /**
 279  * aer_error_detected - update severity status
 280  * @dev: pointer to Root Port's pci_dev data structure
 281  * @error: error severity being notified by port bus
 282  *
 283  * Invoked by Port Bus driver during error recovery.
 284  **/
 285 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
 286                         enum pci_channel_state error)
 287 {
 288         /* Root Port has no impact. Always recovers. */
 289         return PCI_ERS_RESULT_CAN_RECOVER;
 290 }
 291
 292 /**
 293  * aer_error_resume - clean up corresponding error status bits
 294  * @dev: pointer to Root Port's pci_dev data structure
 295  *
 296  * Invoked by Port Bus driver during nonfatal recovery.
 297  **/
 298 static void aer_error_resume(struct pci_dev *dev)
 299 {
 300         int pos;
 301         u32 status, mask;
 302         u16 reg16;
 303
 304         /* Clean up Root device status */
 305         pos = pci_pcie_cap(dev);
 306         pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &reg16);
 307         pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);
 308
 309         /* Clean AER Root Error Status */
 310         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 311         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 312         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 313         if (dev->error_state == pci_channel_io_normal)
 314                 status &= ~mask; /* Clear corresponding nonfatal bits */
 315         else
 316                 status &= mask; /* Clear corresponding fatal bits */
 317         pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 318 }
 319
 320 /**
 321  * aer_service_init - register AER root service driver
 322  *
 323  * Invoked when AER root service driver is loaded.
 324  **/
 325 static int __init aer_service_init(void)
 326 {
 327         if (pcie_aer_disable)
 328                 return -ENXIO;
 329         if (!pci_msi_enabled())
 330                 return -ENXIO;
 331         return pcie_port_service_register(&aerdriver);
 332 }
 333
 334 /**
 335  * aer_service_exit - unregister AER root service driver
 336  *
 337  * Invoked when AER root service driver is unloaded.
 338  **/
 339 static void __exit aer_service_exit(void)
 340 {
 341         pcie_port_service_unregister(&aerdriver);
 342 }
 343
 344 module_init(aer_service_init);
 345 module_exit(aer_service_exit);