/*
* 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/sched.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 <linux/slab.h>
#include "aerdrv.h"
#include "../../pci.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);
static void aer_remove(struct pcie_device *dev);
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);
static struct pci_error_handlers aer_error_handlers = {
.error_detected = aer_error_detected,
.resume = aer_error_resume,
};
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,
.err_handler = &aer_error_handlers,
.reset_link = aer_root_reset,
};
static int pcie_aer_disable;
void pci_no_aer(void)
{
pcie_aer_disable = 1; /* has priority over 'forceload' */
}
/**
* 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 = pci_find_ext_capability(pdev->port, PCI_EXT_CAP_ID_ERR);
/*
* 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;
}
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,
* Root Error ID Reg, and Root error producer/consumer index.
*/
spin_lock_init(&rpc->e_lock);
rpc->rpd = dev;
INIT_WORK(&rpc->dpc_handler, aer_isr);
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)
{
int status;
struct aer_rpc *rpc;
struct device *device = &dev->device;
/* Init */
status = aer_init(dev);
if (status)
return status;
/* Alloc rpc data structure */
rpc = aer_alloc_rpc(dev);
if (!rpc) {
dev_printk(KERN_DEBUG, device, "alloc 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 IRQ failed\n");
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_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
/* 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_BRIDGE_CTL_BUS_RESET;
pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl);
/*
* we should send hot reset message for 2ms to allow it time to
* propogate to all downstream ports
*/
msleep(2);
/* De-assert Secondary Bus Reset */
p2p_ctrl &= ~PCI_BRIDGE_CTL_BUS_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);
dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");
/* 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_pcie_cap(dev);
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_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
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)
{
if (pcie_aer_disable)
return -ENXIO;
if (!pci_msi_enabled())
return -ENXIO;
return pcie_port_service_register(&aerdriver);
}
/**
* 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(&aerdriver);
}
module_init(aer_service_init);
module_exit(aer_service_exit);
