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PCI/ERR: Handle fatal error recovery

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We don't need to be paranoid about the topology changing while handling an
error.  If the device has changed in a hotplug capable slot, we can rely on
the presence detection handling to react to a changing topology.

Restore the fatal error handling behavior that existed before merging DPC
with AER with 7e9084b367 ("PCI/AER: Handle ERR_FATAL with removal and
re-enumeration of devices").

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
This commit is contained in:
Keith Busch
2018-09-20 10:27:12 -06:00
committed by Bjorn Helgaas
parent c4eed62a21
commit bdb5ac8577
5 changed files with 28 additions and 102 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/pci/pcie/aer.c
View File

@@ -1010,9 +1010,11 @@ static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
info->status);
pci_aer_clear_device_status(dev);
} else if (info->severity == AER_NONFATAL)
pcie_do_nonfatal_recovery(dev);
pcie_do_recovery(dev, pci_channel_io_normal,
PCIE_PORT_SERVICE_AER);
else if (info->severity == AER_FATAL)
pcie_do_fatal_recovery(dev, PCIE_PORT_SERVICE_AER);
pcie_do_recovery(dev, pci_channel_io_frozen,
PCIE_PORT_SERVICE_AER);
pci_dev_put(dev);
}
@@ -1048,9 +1050,11 @@ static void aer_recover_work_func(struct work_struct *work)
}
cper_print_aer(pdev, entry.severity, entry.regs);
if (entry.severity == AER_NONFATAL)
pcie_do_nonfatal_recovery(pdev);
pcie_do_recovery(pdev, pci_channel_io_normal,
PCIE_PORT_SERVICE_AER);
else if (entry.severity == AER_FATAL)
pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_AER);
pcie_do_recovery(pdev, pci_channel_io_frozen,
PCIE_PORT_SERVICE_AER);
pci_dev_put(pdev);
}
}

4
drivers/pci/pcie/dpc.c
View File

@@ -216,7 +216,7 @@ static irqreturn_t dpc_handler(int irq, void *context)
reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN) >> 1;
ext_reason = (status & PCI_EXP_DPC_STATUS_TRIGGER_RSN_EXT) >> 5;
dev_warn(dev, "DPC %s detected, remove downstream devices\n",
dev_warn(dev, "DPC %s detected\n",
(reason == 0) ? "unmasked uncorrectable error" :
(reason == 1) ? "ERR_NONFATAL" :
(reason == 2) ? "ERR_FATAL" :
@@ -233,7 +233,7 @@ static irqreturn_t dpc_handler(int irq, void *context)
}
/* We configure DPC so it only triggers on ERR_FATAL */
pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_DPC);
pcie_do_recovery(pdev, pci_channel_io_frozen, PCIE_PORT_SERVICE_DPC);
return IRQ_HANDLED;
}

75
drivers/pci/pcie/err.c
View File

@@ -271,83 +271,20 @@ static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
return result_data.result;
}
/**
* pcie_do_fatal_recovery - handle fatal error recovery process
* @dev: pointer to a pci_dev data structure of agent detecting an error
*
* Invoked when an error is fatal. Once being invoked, removes the devices
* beneath this AER agent, followed by reset link e.g. secondary bus reset
* followed by re-enumeration of devices.
*/
void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service)
{
struct pci_dev *udev;
struct pci_bus *parent;
struct pci_dev *pdev, *temp;
pci_ers_result_t result;
if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
udev = dev;
else
udev = dev->bus->self;
parent = udev->subordinate;
pci_walk_bus(parent, pci_dev_set_disconnected, NULL);
pci_lock_rescan_remove();
pci_dev_get(dev);
list_for_each_entry_safe_reverse(pdev, temp, &parent->devices,
bus_list) {
pci_stop_and_remove_bus_device(pdev);
}
result = reset_link(udev, service);
if ((service == PCIE_PORT_SERVICE_AER) &&
(dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) {
/*
* If the error is reported by a bridge, we think this error
* is related to the downstream link of the bridge, so we
* do error recovery on all subordinates of the bridge instead
* of the bridge and clear the error status of the bridge.
*/
pci_aer_clear_fatal_status(dev);
pci_aer_clear_device_status(dev);
}
if (result == PCI_ERS_RESULT_RECOVERED) {
if (pcie_wait_for_link(udev, true))
pci_rescan_bus(udev->bus);
pci_info(dev, "Device recovery from fatal error successful\n");
} else {
pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
pci_info(dev, "Device recovery from fatal error failed\n");
}
pci_dev_put(dev);
pci_unlock_rescan_remove();
}
/**
* pcie_do_nonfatal_recovery - handle nonfatal error recovery process
* @dev: pointer to a pci_dev data structure of agent detecting an error
*
* Invoked when an error is nonfatal/fatal. Once being invoked, broadcast
* error detected message to all downstream drivers within a hierarchy in
* question and return the returned code.
*/
void pcie_do_nonfatal_recovery(struct pci_dev *dev)
void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
u32 service)
{
pci_ers_result_t status;
enum pci_channel_state state;
state = pci_channel_io_normal;
status = broadcast_error_message(dev,
state,
"error_detected",
report_error_detected);
if (state == pci_channel_io_frozen &&
reset_link(dev, service) != PCI_ERS_RESULT_RECOVERED)
goto failed;
if (status == PCI_ERS_RESULT_CAN_RECOVER)
status = broadcast_error_message(dev,
state,