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