Re: [PATCH v9 2/7] PCI/AER: factor out error reporting from AER

[poza]

On 2018-02-23 00:53, Randy Dunlap wrote:
> On 02/21/2018 11:46 PM, Oza Pawandeep wrote:
>
> Hi,
> Just minor stuff:
>
> > diff --git a/drivers/pci/pcie/pcie-err.c b/drivers/pci/pcie/pcie-err.c
> > new file mode 100644
> > index 0000000..a532fe0
> > --- /dev/null
> > +++ b/drivers/pci/pcie/pcie-err.c
> > @@ -0,0 +1,334 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * This file implements the error recovery as a core part of PCIe 
> > error reporting.
> > + * When a PCIe error is delivered, an error message will be collected 
> > and printed
> > + * to console, then, an error recovery procedure will be executed by 
> > following
> > + * the PCI error recovery rules.
> > + *
> > + * Copyright (C) 2006 Intel Corp.
> > + *	Tom Long Nguyen (tom.l.nguyen@xxxxxxxxx)
> > + *	Zhang Yanmin (yanmin.zhang@xxxxxxxxx)
> > + *
> > + */
> > +
> > +#include <linux/pci.h>
> > +#include <linux/module.h>
> > +#include <linux/pci.h>
> > +#include <linux/kernel.h>
> > +#include <linux/errno.h>
> > +#include <linux/aer.h>
> > +#include <linux/pcieport_if.h>
> > +#include "portdrv.h"
>
> > +static int report_error_detected(struct pci_dev *dev, void *data)
> > +{
> > +	pci_ers_result_t vote;
> > +	const struct pci_error_handlers *err_handler;
> > +	struct aer_broadcast_data *result_data;
> > +
> > +	result_data = (struct aer_broadcast_data *) data;
> > +
> > +	device_lock(&dev->dev);
> > +	dev->error_state = result_data->state;
> > +
> > +	if (!dev->driver ||
> > +		!dev->driver->err_handler ||
> > +		!dev->driver->err_handler->error_detected) {
> > +		if (result_data->state == pci_channel_io_frozen &&
> > +			dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
> > +			/*
> > +			 * In case of fatal recovery, if one of down-
> > +			 * stream device has no driver. We might be
> > +			 * unable to recover because a later insmod
> > +			 * of a driver for this device is unaware of
> > +			 * its hw state.
> > +			 */
> > +			dev_printk(KERN_DEBUG, &dev->dev, "device has %s\n",
> > +				   dev->driver ?
> > +				   "no error-aware driver" : "no driver");
>
> or:
> 			dev_printk(KERN_DEBUG, &dev->dev, "device has no%s driver\n",
> 				   dev->driver ? " error-aware" : "");

I might not be able to take care of this, because all the later patches
are dependent on this, and probably I might have to manually merge.
though I will give it a try :)

> > +		}
> > +
> > +		/*
> > +		 * If there's any device in the subtree that does not
> > +		 * have an error_detected callback, returning
> > +		 * PCI_ERS_RESULT_NO_AER_DRIVER prevents calling of
> > +		 * the subsequent mmio_enabled/slot_reset/resume
> > +		 * callbacks of "any" device in the subtree. All the
> > +		 * devices in the subtree are left in the error state
> > +		 * without recovery.
> > +		 */
> > +
> > +		if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE)
> > +			vote = PCI_ERS_RESULT_NO_AER_DRIVER;
> > +		else
> > +			vote = PCI_ERS_RESULT_NONE;
> > +	} else {
> > +		err_handler = dev->driver->err_handler;
> > +		vote = err_handler->error_detected(dev, result_data->state);
> > +	}
> > +
> > +	result_data->result = merge_result(result_data->result, vote);
> > +	device_unlock(&dev->dev);
> > +	return 0;
> > +}
>
> > +/**
> > + * broadcast_error_message - handle message broadcast to downstream 
> > drivers
> > + * @dev: pointer to from where in a hierarchy message is broadcasted 
> > down
>
>             I would drop ^^ "from" ...                   is broadcast 
> downstream
>
> > + * @state: error state
> > + * @error_mesg: message to print
> > + * @cb: callback to be broadcasted
>
>                     to be broadcast
>
> > + *
> > + * Invoked during error recovery process. Once being invoked, the 
> > content
> > + * of error severity will be broadcasted to all downstream drivers in 
> > a
>
>                         will be broadcast
>
> > + * hierarchy in question.
> > + */
> > +static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
> > +	enum pci_channel_state state,
> > +	char *error_mesg,
> > +	int (*cb)(struct pci_dev *, void *))
> > +{
> > +	struct aer_broadcast_data result_data;