PCI-Express AER implemetation: AER core and aerdriver
Patch 3 implements the core part of PCI-Express AER and aerdrv
port service driver.
When a root port service device is probed, the aerdrv will call
request_irq to register irq handler for AER error interrupt.
When a device sends an PCI-Express error message to the root port,
the root port will trigger an interrupt, by either MSI or IO-APIC,
then kernel would run the irq handler. The handler collects root
error status register and schedules a work. The work will call
the core part to process the error based on its type
(Correctable/non-fatal/fatal).
As for Correctable errors, the patch chooses to just clear the correctable
error status register of the device.
As for the non-fatal error, the patch follows generic PCI error handler
rules to call the error callback functions of the endpoint's driver. If
the device is a bridge, the patch chooses to broadcast the error to
downstream devices.
As for the fatal error, the patch resets the pci-express link and
follows generic PCI error handler rules to call the error callback
functions of the endpoint's driver. If the device is a bridge, the patch
chooses to broadcast the error to downstream devices.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c
new file mode 100644
index 0000000..0d4ac02
--- /dev/null
+++ b/drivers/pci/pcie/aer/aerdrv.c
@@ -0,0 +1,346 @@
+/*
+ * drivers/pci/pcie/aer/aerdrv.c
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * This file implements the AER root port service driver. The driver will
+ * register an irq handler. When root port triggers an AER interrupt, the irq
+ * handler will collect root port status and schedule a work.
+ *
+ * Copyright (C) 2006 Intel Corp.
+ * Tom Long Nguyen (tom.l.nguyen@intel.com)
+ * Zhang Yanmin (yanmin.zhang@intel.com)
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/pm.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/pcieport_if.h>
+
+#include "aerdrv.h"
+
+/*
+ * Version Information
+ */
+#define DRIVER_VERSION "v1.0"
+#define DRIVER_AUTHOR "tom.l.nguyen@intel.com"
+#define DRIVER_DESC "Root Port Advanced Error Reporting Driver"
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+static int __devinit aer_probe (struct pcie_device *dev,
+ const struct pcie_port_service_id *id );
+static void aer_remove(struct pcie_device *dev);
+static int aer_suspend(struct pcie_device *dev, pm_message_t state)
+{return 0;}
+static int aer_resume(struct pcie_device *dev) {return 0;}
+static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
+ enum pci_channel_state error);
+static void aer_error_resume(struct pci_dev *dev);
+static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
+
+/*
+ * PCI Express bus's AER Root service driver data structure
+ */
+static struct pcie_port_service_id aer_id[] = {
+ {
+ .vendor = PCI_ANY_ID,
+ .device = PCI_ANY_ID,
+ .port_type = PCIE_RC_PORT,
+ .service_type = PCIE_PORT_SERVICE_AER,
+ },
+ { /* end: all zeroes */ }
+};
+
+static struct pci_error_handlers aer_error_handlers = {
+ .error_detected = aer_error_detected,
+ .resume = aer_error_resume,
+};
+
+static struct pcie_port_service_driver aerdrv = {
+ .name = "aer",
+ .id_table = &aer_id[0],
+
+ .probe = aer_probe,
+ .remove = aer_remove,
+
+ .suspend = aer_suspend,
+ .resume = aer_resume,
+
+ .err_handler = &aer_error_handlers,
+
+ .reset_link = aer_root_reset,
+};
+
+/**
+ * aer_irq - Root Port's ISR
+ * @irq: IRQ assigned to Root Port
+ * @context: pointer to Root Port data structure
+ * @r: pointer struct pt_regs
+ *
+ * Invoked when Root Port detects AER messages.
+ **/
+static irqreturn_t aer_irq(int irq, void *context, struct pt_regs * r)
+{
+ 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 = pci_find_aer_capability(pdev->port);
+ /*
+ * 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 & ROOT_ERR_STATUS_MASKS)) {
+ 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_COR_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;
+}
+
+/**
+ * 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;
+
+ if (!(rpc = (struct aer_rpc *)kmalloc(sizeof(struct aer_rpc),
+ GFP_KERNEL)))
+ return NULL;
+
+ memset(rpc, 0, sizeof(struct aer_rpc));
+ /*
+ * Initialize Root lock access, e_lock, to Root Error Status Reg,
+ * Root Error ID Reg, and Root error producer/consumer index.
+ */
+ rpc->e_lock = SPIN_LOCK_UNLOCKED;
+
+ rpc->rpd = dev;
+ INIT_WORK(&rpc->dpc_handler, aer_isr, (void *)dev);
+ rpc->prod_idx = rpc->cons_idx = 0;
+ mutex_init(&rpc->rpc_mutex);
+ init_waitqueue_head(&rpc->wait_release);
+
+ /* 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);
+
+ wait_event(rpc->wait_release, rpc->prod_idx == rpc->cons_idx);
+
+ aer_delete_rootport(rpc);
+ set_service_data(dev, NULL);
+ }
+}
+
+/**
+ * aer_probe - initialize resources
+ * @dev: pointer to the pcie_dev data structure
+ * @id: pointer to the service id data structure
+ *
+ * Invoked when PCI Express bus loads AER service driver.
+ **/
+static int __devinit aer_probe (struct pcie_device *dev,
+ const struct pcie_port_service_id *id )
+{
+ int status;
+ struct aer_rpc *rpc;
+ struct device *device = &dev->device;
+
+ /* Init */
+ if ((status = aer_init(dev)))
+ return status;
+
+ /* Alloc rpc data structure */
+ if (!(rpc = aer_alloc_rpc(dev))) {
+ printk(KERN_DEBUG "%s: Alloc rpc fails on PCIE device[%s]\n",
+ __FUNCTION__, device->bus_id);
+ aer_remove(dev);
+ return -ENOMEM;
+ }
+
+ /* Request IRQ ISR */
+ if ((status = request_irq(dev->irq, aer_irq, SA_SHIRQ, "aerdrv",
+ dev))) {
+ printk(KERN_DEBUG "%s: Request ISR fails on PCIE device[%s]\n",
+ __FUNCTION__, device->bus_id);
+ aer_remove(dev);
+ return status;
+ }
+
+ rpc->isr = 1;
+
+ aer_enable_rootport(rpc);
+
+ return status;
+}
+
+/**
+ * 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)
+{
+ u16 p2p_ctrl;
+ u32 status;
+ int pos;
+
+ pos = pci_find_aer_capability(dev);
+
+ /* Disable Root's interrupt in response to error messages */
+ pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, 0);
+
+ /* Assert Secondary Bus Reset */
+ pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl);
+ p2p_ctrl |= PCI_CB_BRIDGE_CTL_CB_RESET;
+ pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
+
+ /* De-assert Secondary Bus Reset */
+ p2p_ctrl &= ~PCI_CB_BRIDGE_CTL_CB_RESET;
+ pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
+
+ /*
+ * System software must wait for at least 100ms from the end
+ * of a reset of one or more device before it is permitted
+ * to issue Configuration Requests to those devices.
+ */
+ msleep(200);
+ printk(KERN_DEBUG "Complete link reset at Root[%s]\n", dev->dev.bus_id);
+
+ /* Enable Root Port's interrupt in response to error messages */
+ pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
+ pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
+ pci_write_config_dword(dev,
+ pos + PCI_ERR_ROOT_COMMAND,
+ ROOT_PORT_INTR_ON_MESG_MASK);
+
+ return PCI_ERS_RESULT_RECOVERED;
+}
+
+/**
+ * aer_error_detected - update severity status
+ * @dev: pointer to Root Port's pci_dev data structure
+ * @error: error severity being notified by port bus
+ *
+ * Invoked by Port Bus driver during error recovery.
+ **/
+static pci_ers_result_t aer_error_detected(struct pci_dev *dev,
+ enum pci_channel_state error)
+{
+ /* Root Port has no impact. Always recovers. */
+ return PCI_ERS_RESULT_CAN_RECOVER;
+}
+
+/**
+ * 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 */
+ pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
+ pci_read_config_word(dev, pos + PCI_EXP_DEVSTA, ®16);
+ pci_write_config_word(dev, pos + PCI_EXP_DEVSTA, reg16);
+
+ /* Clean AER Root Error Status */
+ pos = pci_find_aer_capability(dev);
+ pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
+ pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
+ if (dev->error_state == pci_channel_io_normal)
+ status &= ~mask; /* Clear corresponding nonfatal bits */
+ else
+ status &= mask; /* Clear corresponding fatal 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)
+{
+ return pcie_port_service_register(&aerdrv);
+}
+
+/**
+ * aer_service_exit - unregister AER root service driver
+ *
+ * Invoked when AER root service driver is unloaded.
+ **/
+static void __exit aer_service_exit(void)
+{
+ pcie_port_service_unregister(&aerdrv);
+}
+
+module_init(aer_service_init);
+module_exit(aer_service_exit);