// SPDX-License-Identifier: GPL-2.0 /* * Implement the AER root port service driver. The driver registers an IRQ * handler. When a root port triggers an AER interrupt, the IRQ handler * collects root port status and schedules work. * * Copyright (C) 2006 Intel Corp. * Tom Long Nguyen (tom.l.nguyen@intel.com) * Zhang Yanmin (yanmin.zhang@intel.com) */ #include #include #include #include #include #include #include #include #include #include #include "aerdrv.h" #include "../../pci.h" static int aer_probe(struct pcie_device *dev); static void aer_remove(struct pcie_device *dev); static void aer_error_resume(struct pci_dev *dev); static pci_ers_result_t aer_root_reset(struct pci_dev *dev); static struct pcie_port_service_driver aerdriver = { .name = "aer", .port_type = PCI_EXP_TYPE_ROOT_PORT, .service = PCIE_PORT_SERVICE_AER, .probe = aer_probe, .remove = aer_remove, .error_resume = aer_error_resume, .reset_link = aer_root_reset, }; static int pcie_aer_disable; void pci_no_aer(void) { pcie_aer_disable = 1; } bool pci_aer_available(void) { return !pcie_aer_disable && pci_msi_enabled(); } static int set_device_error_reporting(struct pci_dev *dev, void *data) { bool enable = *((bool *)data); int type = pci_pcie_type(dev); if ((type == PCI_EXP_TYPE_ROOT_PORT) || (type == PCI_EXP_TYPE_UPSTREAM) || (type == PCI_EXP_TYPE_DOWNSTREAM)) { if (enable) pci_enable_pcie_error_reporting(dev); else pci_disable_pcie_error_reporting(dev); } if (enable) pcie_set_ecrc_checking(dev); return 0; } /** * set_downstream_devices_error_reporting - enable/disable the error reporting bits on the root port and its downstream ports. * @dev: pointer to root port's pci_dev data structure * @enable: true = enable error reporting, false = disable error reporting. */ static void set_downstream_devices_error_reporting(struct pci_dev *dev, bool enable) { set_device_error_reporting(dev, &enable); if (!dev->subordinate) return; pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable); } /** * aer_enable_rootport - enable Root Port's interrupts when receiving messages * @rpc: pointer to a Root Port data structure * * Invoked when PCIe bus loads AER service driver. */ static void aer_enable_rootport(struct aer_rpc *rpc) { struct pci_dev *pdev = rpc->rpd->port; int aer_pos; u16 reg16; u32 reg32; /* Clear PCIe Capability's Device Status */ pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, ®16); pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16); /* Disable system error generation in response to error messages */ pcie_capability_clear_word(pdev, PCI_EXP_RTCTL, SYSTEM_ERROR_INTR_ON_MESG_MASK); aer_pos = pdev->aer_cap; /* Clear error status */ pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, ®32); pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32); pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, ®32); pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32); pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, ®32); pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32); /* * Enable error reporting for the root port device and downstream port * devices. */ set_downstream_devices_error_reporting(pdev, true); /* Enable Root Port's interrupt in response to error messages */ pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, ®32); reg32 |= ROOT_PORT_INTR_ON_MESG_MASK; pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32); } /** * aer_disable_rootport - disable Root Port's interrupts when receiving messages * @rpc: pointer to a Root Port data structure * * Invoked when PCIe bus unloads AER service driver. */ static void aer_disable_rootport(struct aer_rpc *rpc) { struct pci_dev *pdev = rpc->rpd->port; u32 reg32; int pos; /* * Disable error reporting for the root port device and downstream port * devices. */ set_downstream_devices_error_reporting(pdev, false); pos = pdev->aer_cap; /* Disable Root's interrupt in response to error messages */ pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, ®32); reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK; pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32); /* Clear Root's error status reg */ pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, ®32); pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32); } /** * aer_irq - Root Port's ISR * @irq: IRQ assigned to Root Port * @context: pointer to Root Port data structure * * Invoked when Root Port detects AER messages. */ irqreturn_t aer_irq(int irq, void *context) { unsigned int status, id; struct pcie_device *pdev = (struct pcie_device *)context; struct aer_rpc *rpc = get_service_data(pdev); int next_prod_idx; unsigned long flags; int pos; pos = pdev->port->aer_cap; /* * Must lock access to Root Error Status Reg, Root Error ID Reg, * and Root error producer/consumer index */ spin_lock_irqsave(&rpc->e_lock, flags); /* Read error status */ pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status); if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) { spin_unlock_irqrestore(&rpc->e_lock, flags); return IRQ_NONE; } /* Read error source and clear error status */ pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id); pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status); /* Store error source for later DPC handler */ next_prod_idx = rpc->prod_idx + 1; if (next_prod_idx == AER_ERROR_SOURCES_MAX) next_prod_idx = 0; if (next_prod_idx == rpc->cons_idx) { /* * Error Storm Condition - possibly the same error occurred. * Drop the error. */ spin_unlock_irqrestore(&rpc->e_lock, flags); return IRQ_HANDLED; } rpc->e_sources[rpc->prod_idx].status = status; rpc->e_sources[rpc->prod_idx].id = id; rpc->prod_idx = next_prod_idx; spin_unlock_irqrestore(&rpc->e_lock, flags); /* Invoke DPC handler */ schedule_work(&rpc->dpc_handler); return IRQ_HANDLED; } EXPORT_SYMBOL_GPL(aer_irq); /** * aer_alloc_rpc - allocate Root Port data structure * @dev: pointer to the pcie_dev data structure * * Invoked when Root Port's AER service is loaded. */ static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev) { struct aer_rpc *rpc; rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL); if (!rpc) return NULL; /* Initialize Root lock access, e_lock, to Root Error Status Reg */ spin_lock_init(&rpc->e_lock); rpc->rpd = dev; INIT_WORK(&rpc->dpc_handler, aer_isr); mutex_init(&rpc->rpc_mutex); /* Use PCIe bus function to store rpc into PCIe device */ set_service_data(dev, rpc); return rpc; } /** * aer_remove - clean up resources * @dev: pointer to the pcie_dev data structure * * Invoked when PCI Express bus unloads or AER probe fails. */ static void aer_remove(struct pcie_device *dev) { struct aer_rpc *rpc = get_service_data(dev); if (rpc) { /* If register interrupt service, it must be free. */ if (rpc->isr) free_irq(dev->irq, dev); flush_work(&rpc->dpc_handler); aer_disable_rootport(rpc); kfree(rpc); set_service_data(dev, NULL); } } /** * aer_probe - initialize resources * @dev: pointer to the pcie_dev data structure * * Invoked when PCI Express bus loads AER service driver. */ static int aer_probe(struct pcie_device *dev) { int status; struct aer_rpc *rpc; struct device *device = &dev->port->dev; /* Alloc rpc data structure */ rpc = aer_alloc_rpc(dev); if (!rpc) { dev_printk(KERN_DEBUG, device, "alloc AER rpc failed\n"); aer_remove(dev); return -ENOMEM; } /* Request IRQ ISR */ status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev); if (status) { dev_printk(KERN_DEBUG, device, "request AER IRQ %d failed\n", dev->irq); aer_remove(dev); return status; } rpc->isr = 1; aer_enable_rootport(rpc); dev_info(device, "AER enabled with IRQ %d\n", dev->irq); return 0; } /** * aer_root_reset - reset link on Root Port * @dev: pointer to Root Port's pci_dev data structure * * Invoked by Port Bus driver when performing link reset at Root Port. */ static pci_ers_result_t aer_root_reset(struct pci_dev *dev) { u32 reg32; int pos; pos = dev->aer_cap; /* Disable Root's interrupt in response to error messages */ pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, ®32); reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK; pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32); pci_reset_bridge_secondary_bus(dev); pci_printk(KERN_DEBUG, dev, "Root Port link has been reset\n"); /* Clear Root Error Status */ pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, ®32); pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, reg32); /* Enable Root Port's interrupt in response to error messages */ pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, ®32); reg32 |= ROOT_PORT_INTR_ON_MESG_MASK; pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32); return PCI_ERS_RESULT_RECOVERED; } /** * aer_error_resume - clean up corresponding error status bits * @dev: pointer to Root Port's pci_dev data structure * * Invoked by Port Bus driver during nonfatal recovery. */ static void aer_error_resume(struct pci_dev *dev) { int pos; u32 status, mask; u16 reg16; /* Clean up Root device status */ pcie_capability_read_word(dev, PCI_EXP_DEVSTA, ®16); pcie_capability_write_word(dev, PCI_EXP_DEVSTA, reg16); /* Clean AER Root Error Status */ pos = dev->aer_cap; pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status); pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask); status &= ~mask; /* Clear corresponding nonfatal bits */ pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status); } /** * aer_service_init - register AER root service driver * * Invoked when AER root service driver is loaded. */ static int __init aer_service_init(void) { if (!pci_aer_available() || aer_acpi_firmware_first()) return -ENXIO; return pcie_port_service_register(&aerdriver); } device_initcall(aer_service_init);