/*
* PCI Error Recovery Driver for RPA-compliant PPC64 platform.
* Copyright IBM Corp. 2004 2005
* Copyright Linas Vepstas <linas@linas.org> 2004, 2005
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send comments and feedback to Linas Vepstas <linas@austin.ibm.com>
*/
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <asm/eeh.h>
#include <asm/eeh_event.h>
#include <asm/ppc-pci.h>
#include <asm/pci-bridge.h>
#include <asm/prom.h>
#include <asm/rtas.h>
struct eeh_rmv_data {
struct list_head edev_list;
int removed;
};
/**
* eeh_pcid_name - Retrieve name of PCI device driver
* @pdev: PCI device
*
* This routine is used to retrieve the name of PCI device driver
* if that's valid.
*/
static inline const char *eeh_pcid_name(struct pci_dev *pdev)
{
if (pdev && pdev->dev.driver)
return pdev->dev.driver->name;
return "";
}
/**
* eeh_pcid_get - Get the PCI device driver
* @pdev: PCI device
*
* The function is used to retrieve the PCI device driver for
* the indicated PCI device. Besides, we will increase the reference
* of the PCI device driver to prevent that being unloaded on
* the fly. Otherwise, kernel crash would be seen.
*/
static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
{
if (!pdev || !pdev->driver)
return NULL;
if (!try_module_get(pdev->driver->driver.owner))
return NULL;
return pdev->driver;
}
/**
* eeh_pcid_put - Dereference on the PCI device driver
* @pdev: PCI device
*
* The function is called to do dereference on the PCI device
* driver of the indicated PCI device.
*/
static inline void eeh_pcid_put(struct pci_dev *pdev)
{
if (!pdev || !pdev->driver)
return;
module_put(pdev->driver->driver.owner);
}
/**
* eeh_disable_irq - Disable interrupt for the recovering device
* @dev: PCI device
*
* This routine must be called when reporting temporary or permanent
* error to the particular PCI device to disable interrupt of that
* device. If the device has enabled MSI or MSI-X interrupt, we needn't
* do real work because EEH should freeze DMA transfers for those PCI
* devices encountering EEH errors, which includes MSI or MSI-X.
*/
static void eeh_disable_irq(struct pci_dev *dev)
{
struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
/* Don't disable MSI and MSI-X interrupts. They are
* effectively disabled by the DMA Stopped state
* when an EEH error occurs.
*/
if (dev->msi_enabled || dev->msix_enabled)
return;
if (!irq_has_action(dev->irq))
return;
edev->mode |= EEH_DEV_IRQ_DISABLED;
disable_irq_nosync(dev->irq);
}
/**
* eeh_enable_irq - Enable interrupt for the recovering device
* @dev: PCI device
*
* This routine must be called to enable interrupt while failed
* device could be resumed.
*/
static void eeh_enable_irq(struct pci_dev *dev)
{
struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
if ((edev->mode) & EEH_DEV_IRQ_DISABLED) {
edev->mode &= ~EEH_DEV_IRQ_DISABLED;
/*
* FIXME !!!!!
*
* This is just ass backwards. This maze has
* unbalanced irq_enable/disable calls. So instead of
* finding the root cause it works around the warning
* in the irq_enable code by conditionally calling
* into it.
*
* That's just wrong.The warning in the core code is
* there to tell people to fix their asymmetries in
* their own code, not by abusing the core information
* to avoid it.
*
* I so wish that the assymetry would be the other way
* round and a few more irq_disable calls render that
* shit unusable forever.
*
* tglx
*/
if (irqd_irq_disabled(irq_get_irq_data(dev->irq)))
enable_irq(dev->irq);
}
}
static bool eeh_dev_removed(struct eeh_dev *edev)
{
/* EEH device removed ? */
if (!edev || (edev->mode & EEH_DEV_REMOVED))
return true;
return false;
}
static void *eeh_dev_save_state(void *data, void *userdata)
{
struct eeh_dev *edev = data;
struct pci_dev *pdev;
if (!edev)
return NULL;
/*
* We cannot access the config space on some adapters.
* Otherwise, it will cause fenced PHB. We don't save
* the content in their config space and will restore
* from the initial config space saved when the EEH
* device is created.
*/
if (edev->pe && (edev->pe->state & EEH_PE_CFG_RESTRICTED))
return NULL;
pdev = eeh_dev_to_pci_dev(edev);
if (!pdev)
return NULL;
pci_save_state(pdev);
return NULL;
}
/**
* eeh_report_error - Report pci error to each device driver
* @data: eeh device
* @userdata: return value
*
* Report an EEH error to each device driver, collect up and
* merge the device driver responses. Cumulative response
* passed back in "userdata".
*/
static void *eeh_report_error