drivers/pci/pcie/aer/aerdrv.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * drivers/pci/pcie/aer/aerdrv.c
   4  *
   5  * This file implements the AER root port service driver. The driver will
   6  * register an irq handler. When root port triggers an AER interrupt, the irq
   7  * handler will collect root port status and schedule a work.
   8  *
   9  * Copyright (C) 2006 Intel Corp.
  10  *      Tom Long Nguyen (tom.l.nguyen@intel.com)
  11  *      Zhang Yanmin (yanmin.zhang@intel.com)
  12  *
  13  */
  14
  15 #include <linux/pci.h>
  16 #include <linux/pci-acpi.h>
  17 #include <linux/sched.h>
  18 #include <linux/kernel.h>
  19 #include <linux/errno.h>
  20 #include <linux/pm.h>
  21 #include <linux/init.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/delay.h>
  24 #include <linux/pcieport_if.h>
  25 #include <linux/slab.h>
  26
  27 #include "aerdrv.h"
  28 #include "../../pci.h"
  29
  30 static int aer_probe(struct pcie_device *dev);
  31 static void aer_remove(struct pcie_device *dev);
  32 static void aer_error_resume(struct pci_dev *dev);
  33 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
  34
  35 static struct pcie_port_service_driver aerdriver = {
  36         .name           = "aer",
  37         .port_type      = PCI_EXP_TYPE_ROOT_PORT,
  38         .service        = PCIE_PORT_SERVICE_AER,
  39
  40         .probe          = aer_probe,
  41         .remove         = aer_remove,
  42         .error_resume   = aer_error_resume,
  43         .reset_link     = aer_root_reset,
  44 };
  45
  46 static int pcie_aer_disable;
  47
  48 void pci_no_aer(void)
  49 {
  50         pcie_aer_disable = 1;
  51 }
  52
  53 bool pci_aer_available(void)
  54 {
  55         return !pcie_aer_disable && pci_msi_enabled();
  56 }
  57
  58 static int set_device_error_reporting(struct pci_dev *dev, void *data)
  59 {
  60         bool enable = *((bool *)data);
  61         int type = pci_pcie_type(dev);
  62
  63         if ((type == PCI_EXP_TYPE_ROOT_PORT) ||
  64             (type == PCI_EXP_TYPE_UPSTREAM) ||
  65             (type == PCI_EXP_TYPE_DOWNSTREAM)) {
  66                 if (enable)
  67                         pci_enable_pcie_error_reporting(dev);
  68                 else
  69                         pci_disable_pcie_error_reporting(dev);
  70         }
  71
  72         if (enable)
  73                 pcie_set_ecrc_checking(dev);
  74
  75         return 0;
  76 }
  77
  78 /**
  79  * set_downstream_devices_error_reporting - enable/disable the error reporting  bits on the root port and its downstream ports.
  80  * @dev: pointer to root port's pci_dev data structure
  81  * @enable: true = enable error reporting, false = disable error reporting.
  82  */
  83 static void set_downstream_devices_error_reporting(struct pci_dev *dev,
  84                                                    bool enable)
  85 {
  86         set_device_error_reporting(dev, &enable);
  87
  88         if (!dev->subordinate)
  89                 return;
  90         pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);
  91 }
  92
  93 /**
  94  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
  95  * @rpc: pointer to a Root Port data structure
  96  *
  97  * Invoked when PCIe bus loads AER service driver.
  98  */
  99 static void aer_enable_rootport(struct aer_rpc *rpc)
 100 {
 101         struct pci_dev *pdev = rpc->rpd->port;
 102         int aer_pos;
 103         u16 reg16;
 104         u32 reg32;
 105
 106         /* Clear PCIe Capability's Device Status */
 107         pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
 108         pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);
 109
 110         /* Disable system error generation in response to error messages */
 111         pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
 112                                    SYSTEM_ERROR_INTR_ON_MESG_MASK);
 113
 114         aer_pos = pdev->aer_cap;
 115         /* Clear error status */
 116         pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, &reg32);
 117         pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32);
 118         pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, &reg32);
 119         pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32);
 120         pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, &reg32);
 121         pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);
 122
 123         /*
 124          * Enable error reporting for the root port device and downstream port
 125          * devices.
 126          */
 127         set_downstream_devices_error_reporting(pdev, true);
 128
 129         /* Enable Root Port's interrupt in response to error messages */
 130         pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, &reg32);
 131         reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 132         pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32);
 133 }
 134
 135 /**
 136  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
 137  * @rpc: pointer to a Root Port data structure
 138  *
 139  * Invoked when PCIe bus unloads AER service driver.
 140  */
 141 static void aer_disable_rootport(struct aer_rpc *rpc)
 142 {
 143         struct pci_dev *pdev = rpc->rpd->port;
 144         u32 reg32;
 145         int pos;
 146
 147         /*
 148          * Disable error reporting for the root port device and downstream port
 149          * devices.
 150          */
 151         set_downstream_devices_error_reporting(pdev, false);
 152
 153         pos = pdev->aer_cap;
 154         /* Disable Root's interrupt in response to error messages */
 155         pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 156         reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 157         pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 158
 159         /* Clear Root's error status reg */
 160         pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 161         pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32);
 162 }
 163
 164 /**
 165  * aer_irq - Root Port's ISR
 166  * @irq: IRQ assigned to Root Port
 167  * @context: pointer to Root Port data structure
 168  *
 169  * Invoked when Root Port detects AER messages.
 170  */
 171 irqreturn_t aer_irq(int irq, void *context)
 172 {
 173         unsigned int status, id;
 174         struct pcie_device *pdev = (struct pcie_device *)context;
 175         struct aer_rpc *rpc = get_service_data(pdev);
 176         int next_prod_idx;
 177         unsigned long flags;
 178         int pos;
 179
 180         pos = pdev->port->aer_cap;
 181         /*
 182          * Must lock access to Root Error Status Reg, Root Error ID Reg,
 183          * and Root error producer/consumer index
 184          */
 185         spin_lock_irqsave(&rpc->e_lock, flags);
 186
 187         /* Read error status */
 188         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
 189         if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) {
 190                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 191                 return IRQ_NONE;
 192         }
 193
 194         /* Read error source and clear error status */
 195         pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id);
 196         pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);
 197
 198         /* Store error source for later DPC handler */
 199         next_prod_idx = rpc->prod_idx + 1;
 200         if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 201                 next_prod_idx = 0;
 202         if (next_prod_idx == rpc->cons_idx) {
 203                 /*
 204                  * Error Storm Condition - possibly the same error occurred.
 205                  * Drop the error.
 206                  */
 207                 spin_unlock_irqrestore(&rpc->e_lock, flags);
 208                 return IRQ_HANDLED;
 209         }
 210         rpc->e_sources[rpc->prod_idx].status =  status;
 211         rpc->e_sources[rpc->prod_idx].id = id;
 212         rpc->prod_idx = next_prod_idx;
 213         spin_unlock_irqrestore(&rpc->e_lock, flags);
 214
 215         /*  Invoke DPC handler */
 216         schedule_work(&rpc->dpc_handler);
 217
 218         return IRQ_HANDLED;
 219 }
 220 EXPORT_SYMBOL_GPL(aer_irq);
 221
 222 /**
 223  * aer_alloc_rpc - allocate Root Port data structure
 224  * @dev: pointer to the pcie_dev data structure
 225  *
 226  * Invoked when Root Port's AER service is loaded.
 227  */
 228 static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
 229 {
 230         struct aer_rpc *rpc;
 231
 232         rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
 233         if (!rpc)
 234                 return NULL;
 235
 236         /* Initialize Root lock access, e_lock, to Root Error Status Reg */
 237         spin_lock_init(&rpc->e_lock);
 238
 239         rpc->rpd = dev;
 240         INIT_WORK(&rpc->dpc_handler, aer_isr);
 241         mutex_init(&rpc->rpc_mutex);
 242
 243         /* Use PCIe bus function to store rpc into PCIe device */
 244         set_service_data(dev, rpc);
 245
 246         return rpc;
 247 }
 248
 249 /**
 250  * aer_remove - clean up resources
 251  * @dev: pointer to the pcie_dev data structure
 252  *
 253  * Invoked when PCI Express bus unloads or AER probe fails.
 254  */
 255 static void aer_remove(struct pcie_device *dev)
 256 {
 257         struct aer_rpc *rpc = get_service_data(dev);
 258
 259         if (rpc) {
 260                 /* If register interrupt service, it must be free. */
 261                 if (rpc->isr)
 262                         free_irq(dev->irq, dev);
 263
 264                 flush_work(&rpc->dpc_handler);
 265                 aer_disable_rootport(rpc);
 266                 kfree(rpc);
 267                 set_service_data(dev, NULL);
 268         }
 269 }
 270
 271 /**
 272  * aer_probe - initialize resources
 273  * @dev: pointer to the pcie_dev data structure
 274  *
 275  * Invoked when PCI Express bus loads AER service driver.
 276  */
 277 static int aer_probe(struct pcie_device *dev)
 278 {
 279         int status;
 280         struct aer_rpc *rpc;
 281         struct device *device = &dev->port->dev;
 282
 283         /* Alloc rpc data structure */
 284         rpc = aer_alloc_rpc(dev);
 285         if (!rpc) {
 286                 dev_printk(KERN_DEBUG, device, "alloc AER rpc failed\n");
 287                 aer_remove(dev);
 288                 return -ENOMEM;
 289         }
 290
 291         /* Request IRQ ISR */
 292         status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
 293         if (status) {
 294                 dev_printk(KERN_DEBUG, device, "request AER IRQ %d failed\n",
 295                            dev->irq);
 296                 aer_remove(dev);
 297                 return status;
 298         }
 299
 300         rpc->isr = 1;
 301
 302         aer_enable_rootport(rpc);
 303         dev_info(device, "AER enabled with IRQ %d\n", dev->irq);
 304         return 0;
 305 }
 306
 307 /**
 308  * aer_root_reset - reset link on Root Port
 309  * @dev: pointer to Root Port's pci_dev data structure
 310  *
 311  * Invoked by Port Bus driver when performing link reset at Root Port.
 312  */
 313 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 314 {
 315         u32 reg32;
 316         int pos;
 317
 318         pos = dev->aer_cap;
 319
 320         /* Disable Root's interrupt in response to error messages */
 321         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 322         reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 323         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 324
 325         pci_reset_bridge_secondary_bus(dev);
 326         pci_printk(KERN_DEBUG, dev, "Root Port link has been reset\n");
 327
 328         /* Clear Root Error Status */
 329         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 330         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, reg32);
 331
 332         /* Enable Root Port's interrupt in response to error messages */
 333         pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 334         reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 335         pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 336
 337         return PCI_ERS_RESULT_RECOVERED;
 338 }
 339
 340 /**
 341  * aer_error_resume - clean up corresponding error status bits
 342  * @dev: pointer to Root Port's pci_dev data structure
 343  *
 344  * Invoked by Port Bus driver during nonfatal recovery.
 345  */
 346 static void aer_error_resume(struct pci_dev *dev)
 347 {
 348         int pos;
 349         u32 status, mask;
 350         u16 reg16;
 351
 352         /* Clean up Root device status */
 353         pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &reg16);
 354         pcie_capability_write_word(dev, PCI_EXP_DEVSTA, reg16);
 355
 356         /* Clean AER Root Error Status */
 357         pos = dev->aer_cap;
 358         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 359         pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 360         if (dev->error_state == pci_channel_io_normal)
 361                 status &= ~mask; /* Clear corresponding nonfatal bits */
 362         else
 363                 status &= mask; /* Clear corresponding fatal bits */
 364         pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 365 }
 366
 367 /**
 368  * aer_service_init - register AER root service driver
 369  *
 370  * Invoked when AER root service driver is loaded.
 371  */
 372 static int __init aer_service_init(void)
 373 {
 374         if (!pci_aer_available() || aer_acpi_firmware_first())
 375                 return -ENXIO;
 376         return pcie_port_service_register(&aerdriver);
 377 }
 378 device_initcall(aer_service_init);