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
  29 #include "aerdrv.h"
  30 #include "../../pci.h"
  31
  32 /*
  33  * Version Information
  34  */
  35 #define DRIVER_VERSION "v1.0"
  36 #define DRIVER_AUTHOR "tom.l.nguyen@intel.com"
  37 #define DRIVER_DESC "Root Port Advanced Error Reporting Driver"
  38 MODULE_AUTHOR(DRIVER_AUTHOR);
  39 MODULE_DESCRIPTION(DRIVER_DESC);
  40 MODULE_LICENSE("GPL");
  41
  42 static int __devinit aer_probe(struct pcie_device *dev);
  43 static void aer_remove(struct pcie_device *dev);
  44 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
  45         enum pci_channel_state error);
  46 static void aer_error_resume(struct pci_dev *dev);
  47 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
  48
  49 static struct pci_error_handlers aer_error_handlers = {
  50         .error_detected = aer_error_detected,
  51         .resume         = aer_error_resume,
  52 };
  53
  54 static struct pcie_port_service_driver aerdriver = {
  55         .name           = "aer",
  56         .port_type      = PCIE_RC_PORT,
  57         .service        = PCIE_PORT_SERVICE_AER,
  58
  59         .probe          = aer_probe,
  60         .remove         = aer_remove,
  61
  62         .err_handler    = &aer_error_handlers,
  63
  64         .reset_link     = aer_root_reset,
  65 };
  66
  67 static int pcie_aer_disable;
  68
  69 void pci_no_aer(void)
  70 {
  71         pcie_aer_disable = 1;   /* has priority over 'forceload' */
  72 }
  73
  74 /**
  75  * aer_irq - Root Port's ISR
  76  * @irq: IRQ assigned to Root Port
  77  * @context: pointer to Root Port data structure
  78  *
  79  * Invoked when Root Port detects AER messages.
  80  **/
  81 irqreturn_t aer_irq(int irq, void *context)
  82 {
  83         unsigned int status, id;
  84         struct pcie_device *pdev = (struct pcie_device *)context;
  85         struct aer_rpc *rpc = get_service_data(pdev);
  86         int next_prod_idx;
  87         unsigned long flags;
  88         int pos;
  89
  90         pos = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR);
  91         /*
  92          * Must lock access to Root Error Status Reg, Root Error ID Reg,
  93          * and Root error producer/consumer index
  94          */
  95         spin_lock_irqsave(&rpc->e_lock, flags);
  96
  97         /* Read error status */
  98         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
  99         if (!(status & ROOT_ERR_STATUS_MASKS)) {
 100                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 101                 return IRQ_NONE;
 102         }
 103
 104         /* Read error source and clear error status */
 105         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_COR_SRC, &id);
 106         pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
 107
 108         /* Store error source for later DPC handler */
 109         next_prod_idx = rpc->prod_idx + 1;
 110         if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 111                 next_prod_idx = 0;
 112         if (next_prod_idx == rpc->cons_idx) {
 113                 /*
 114                  * Error Storm Condition - possibly the same error occurred.
 115                  * Drop the error.
 116                  */
 117                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 118                 return IRQ_HANDLED;
 119         }
 120         rpc->e_sources[rpc->prod_idx].status =  status;
 121         rpc->e_sources[rpc->prod_idx].id = id;
 122         rpc->prod_idx = next_prod_idx;
 123         spin_unlock_irqrestore(&rpc->e_lock, flags);
 124
 125         /*  Invoke DPC handler */
 126         schedule_work(&rpc->dpc_handler);
 127
 128         return IRQ_HANDLED;
 129 }
 130 EXPORT_SYMBOL_GPL(aer_irq);
 131
 132 /**
 133  * aer_alloc_rpc - allocate Root Port data structure
 134  * @dev: pointer to the pcie_dev data structure
 135  *
 136  * Invoked when Root Port's AER service is loaded.
 137  **/
 138 static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
 139 {
 140         struct aer_rpc *rpc;
 141
 142         rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
 143         if (!rpc)
 144                 return NULL;
 145
 146         /*
 147          * Initialize Root lock access, e_lock, to Root Error Status Reg,
 148          * Root Error ID Reg, and Root error producer/consumer index.
 149          */
 150         spin_lock_init(&rpc->e_lock);
 151
 152         rpc->rpd = dev;
 153         INIT_WORK(&rpc->dpc_handler, aer_isr);
 154         rpc->prod_idx = rpc->cons_idx = 0;
 155         mutex_init(&rpc->rpc_mutex);
 156         init_waitqueue_head(&rpc->wait_release);
 157
 158         /* Use PCIE bus function to store rpc into PCIE device */
 159         set_service_data(dev, rpc);
 160
 161         return rpc;
 162 }
 163
 164 /**
 165  * aer_remove - clean up resources
 166  * @dev: pointer to the pcie_dev data structure
 167  *
 168  * Invoked when PCI Express bus unloads or AER probe fails.
 169  **/
 170 static void aer_remove(struct pcie_device *dev)
 171 {
 172         struct aer_rpc *rpc = get_service_data(dev);
 173
 174         if (rpc) {
 175                 /* If register interrupt service, it must be free. */
 176                 if (rpc->isr)
 177                         free_irq(dev->irq, dev);
 178
 179                 wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
 180
 181                 aer_delete_rootport(rpc);
 182                 set_service_data(dev, NULL);
 183         }
 184 }
 185
 186 /**
 187  * aer_probe - initialize resources
 188  * @dev: pointer to the pcie_dev data structure
 189  * @id: pointer to the service id data structure
 190  *
 191  * Invoked when PCI Express bus loads AER service driver.
 192  **/
 193 static int __devinit aer_probe(struct pcie_device *dev)
 194 {
 195         int status;
 196         struct aer_rpc *rpc;
 197         struct device *device = &dev->device;
 198
 199         /* Init */
 200         status = aer_init(dev);
 201         if (status)
 202                 return status;
 203
 204         /* Alloc rpc data structure */
 205         rpc = aer_alloc_rpc(dev);
 206         if (!rpc) {
 207                 dev_printk(KERN_DEBUG, device, "alloc rpc failed\n");
 208                 aer_remove(dev);
 209                 return -ENOMEM;
 210         }
 211
 212         /* Request IRQ ISR */
 213         status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
 214         if (status) {
 215                 dev_printk(KERN_DEBUG, device, "request IRQ failed\n");
 216                 aer_remove(dev);
 217                 return status;
 218         }
 219
 220         rpc->isr = 1;
 221
 222         aer_enable_rootport(rpc);
 223
 224         return status;
 225 }
 226
 227 /**
 228  * aer_root_reset - reset link on Root Port
 229  * @dev: pointer to Root Port's pci_dev data structure
 230  *
 231  * Invoked by Port Bus driver when performing link reset at Root Port.
 232  **/
 233 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 234 {
 235         u16 p2p_ctrl;
 236         u32 status;
 237         int pos;
 238
 239         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 240
 241         /* Disable Root's interrupt in response to error messages */
 242         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, 0);
 243
 244         /* Assert Secondary Bus Reset */
 245         pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl);
 246         p2p_ctrl |= PCI_CB_BRIDGE_CTL_CB_RESET;
 247         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 248
 249         /* De-assert Secondary Bus Reset */
 250         p2p_ctrl &= ~PCI_CB_BRIDGE_CTL_CB_RESET;
 251         pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
 252
 253         /*
 254          * System software must wait for at least 100ms from the end
 255          * of a reset of one or more device before it is permitted
 256          * to issue Configuration Requests to those devices.
 257          */
 258         msleep(200);
 259         dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
 260
 261         /* Enable Root Port's interrupt in response to error messages */
 262         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
 263         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
 264         pci_write_config_dword(dev,
 265                 pos + PCI_ERR_ROOT_COMMAND,
 266                 ROOT_PORT_INTR_ON_MESG_MASK);
 267
 268         return PCI_ERS_RESULT_RECOVERED;
 269 }
 270
 271 /**
 272  * aer_error_detected - update severity status
 273  * @dev: pointer to Root Port's pci_dev data structure
 274  * @error: error severity being notified by port bus
 275  *
 276  * Invoked by Port Bus driver during error recovery.
 277  **/
 278 static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
 279                         enum pci_channel_state error)
 280 {
 281         /* Root Port has no impact. Always recovers. */
 282         return PCI_ERS_RESULT_CAN_RECOVER;
 283 }
 284
 285 /**
 286  * aer_error_resume - clean up corresponding error status bits
 287  * @dev: pointer to Root Port's pci_dev data structure
 288  *
 289  * Invoked by Port Bus driver during nonfatal recovery.
 290  **/
 291 static void aer_error_resume(struct pci_dev *dev)
 292 {
 293         int pos;
 294         u32 status, mask;
 295         u16 reg16;
 296
 297         /* Clean up Root device status */
 298         pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
 299         pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, &reg16);
 300         pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);
 301
 302         /* Clean AER Root Error Status */
 303         pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 304         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 305         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 306         if (dev->error_state == pci_channel_io_normal)
 307                 status &= ~mask; /* Clear corresponding nonfatal bits */
 308         else
 309                 status &= mask; /* Clear corresponding fatal bits */
 310         pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 311 }
 312
 313 /**
 314  * aer_service_init - register AER root service driver
 315  *
 316  * Invoked when AER root service driver is loaded.
 317  **/
 318 static int __init aer_service_init(void)
 319 {
 320         if (pcie_aer_disable)
 321                 return -ENXIO;
 322         if (!pci_msi_enabled())
 323                 return -ENXIO;
 324         return pcie_port_service_register(&aerdriver);
 325 }
 326
 327 /**
 328  * aer_service_exit - unregister AER root service driver
 329  *
 330  * Invoked when AER root service driver is unloaded.
 331  **/
 332 static void __exit aer_service_exit(void)
 333 {
 334         pcie_port_service_unregister(&aerdriver);
 335 }
 336
 337 module_init(aer_service_init);
 338 module_exit(aer_service_exit);