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Date:   Fri, 23 Feb 2018 17:42:32 -0600
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Oza Pawandeep <poza@codeaurora.org>
Cc:     Bjorn Helgaas <bhelgaas@google.com>,
        Philippe Ombredanne <pombredanne@nexb.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Kate Stewart <kstewart@linuxfoundation.org>,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        Dongdong Liu <liudongdong3@huawei.com>,
        Keith Busch <keith.busch@intel.com>, Wei Zhang <wzhang@fb.com>,
        Sinan Kaya <okaya@codeaurora.org>,
        Timur Tabi <timur@codeaurora.org>
Subject: Re: [PATCH v11 2/7] PCI/AER: factor out error reporting from AER
Message-ID: <20180223234232.GP14632@bhelgaas-glaptop.roam.corp.google.com>
References: <1519374244-20539-1-git-send-email-poza@codeaurora.org>
 <1519374244-20539-3-git-send-email-poza@codeaurora.org>
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On Fri, Feb 23, 2018 at 01:53:59PM +0530, Oza Pawandeep wrote:
> This patch factors out error reporting callbacks, which are currently
> tightly coupled with AER.

Add blank line between paragraphs.

> DPC should be able to register callbacks and attmept recovery when DPC
> trigger event occurs.

s/attmept/attempt/

This patch basically moves code from aerdrv_core.c to pcie-err.c.  Make it
do *only* that.

> Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
> 
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index fcd8191..abc514e 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -342,6 +342,9 @@ static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
>  
>  void pci_enable_acs(struct pci_dev *dev);
>  
> +/* PCI error reporting and recovery */
> +void pcie_do_recovery(struct pci_dev *dev, int severity);

Add this declaration in the first patch, the one where you rename the
function.

>  #ifdef CONFIG_PCIEASPM
>  void pcie_aspm_init_link_state(struct pci_dev *pdev);
>  void pcie_aspm_exit_link_state(struct pci_dev *pdev);
> diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
> index 223e4c3..d669497 100644
> --- a/drivers/pci/pcie/Makefile
> +++ b/drivers/pci/pcie/Makefile
> @@ -6,7 +6,7 @@
>  # Build PCI Express ASPM if needed
>  obj-$(CONFIG_PCIEASPM)		+= aspm.o
>  
> -pcieportdrv-y			:= portdrv_core.o portdrv_pci.o portdrv_bus.o
> +pcieportdrv-y			:= portdrv_core.o portdrv_pci.o portdrv_bus.o pcie-err.o

Can we name this just "drivers/pci/pcie/err.c"?  I know we have
pcie-dpc.c already, but it does get a little repetitious to type
"pci" THREE times in that path.

>  pcieportdrv-$(CONFIG_ACPI)	+= portdrv_acpi.o
>  
>  obj-$(CONFIG_PCIEPORTBUS)	+= pcieportdrv.o
> diff --git a/drivers/pci/pcie/aer/aerdrv.h b/drivers/pci/pcie/aer/aerdrv.h
> index 5449e5c..bc9db53 100644
> --- a/drivers/pci/pcie/aer/aerdrv.h
> +++ b/drivers/pci/pcie/aer/aerdrv.h
> @@ -76,36 +76,6 @@ struct aer_rpc {
>  					 */
>  };
>  
> -struct aer_broadcast_data {
> -	enum pci_channel_state state;
> -	enum pci_ers_result result;
> -};
> -
> -static inline pci_ers_result_t merge_result(enum pci_ers_result orig,
> -		enum pci_ers_result new)
> -{
> -	if (new == PCI_ERS_RESULT_NO_AER_DRIVER)
> -		return PCI_ERS_RESULT_NO_AER_DRIVER;
> -
> -	if (new == PCI_ERS_RESULT_NONE)
> -		return orig;
> -
> -	switch (orig) {
> -	case PCI_ERS_RESULT_CAN_RECOVER:
> -	case PCI_ERS_RESULT_RECOVERED:
> -		orig = new;
> -		break;
> -	case PCI_ERS_RESULT_DISCONNECT:
> -		if (new == PCI_ERS_RESULT_NEED_RESET)
> -			orig = PCI_ERS_RESULT_NEED_RESET;
> -		break;
> -	default:
> -		break;
> -	}
> -
> -	return orig;
> -}
> -
>  extern struct bus_type pcie_port_bus_type;
>  void aer_isr(struct work_struct *work);
>  void aer_print_error(struct pci_dev *dev, struct aer_err_info *info);
> diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c
> index aeb83a0..f60b1bb 100644
> --- a/drivers/pci/pcie/aer/aerdrv_core.c
> +++ b/drivers/pci/pcie/aer/aerdrv_core.c
> @@ -23,6 +23,7 @@
>  #include <linux/slab.h>
>  #include <linux/kfifo.h>
>  #include "aerdrv.h"
> +#include "../../pci.h"
>  
>  #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
>  				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
> @@ -230,191 +231,6 @@ static bool find_source_device(struct pci_dev *parent,
>  	return true;
>  }
>  
> -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.
> -			 */
> -			pci_printk(KERN_DEBUG, dev, "device has %s\n",
> -				   dev->driver ?
> -				   "no AER-aware driver" : "no driver");
> -		}
> -
> -		/*
> -		 * 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);
> -		pci_uevent_ers(dev, PCI_ERS_RESULT_NONE);
> -	}
> -
> -	result_data->result = merge_result(result_data->result, vote);
> -	device_unlock(&dev->dev);
> -	return 0;
> -}
> -
> -static int report_mmio_enabled(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);
> -	if (!dev->driver ||
> -		!dev->driver->err_handler ||
> -		!dev->driver->err_handler->mmio_enabled)
> -		goto out;
> -
> -	err_handler = dev->driver->err_handler;
> -	vote = err_handler->mmio_enabled(dev);
> -	result_data->result = merge_result(result_data->result, vote);
> -out:
> -	device_unlock(&dev->dev);
> -	return 0;
> -}
> -
> -static int report_slot_reset(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);
> -	if (!dev->driver ||
> -		!dev->driver->err_handler ||
> -		!dev->driver->err_handler->slot_reset)
> -		goto out;
> -
> -	err_handler = dev->driver->err_handler;
> -	vote = err_handler->slot_reset(dev);
> -	result_data->result = merge_result(result_data->result, vote);
> -out:
> -	device_unlock(&dev->dev);
> -	return 0;
> -}
> -
> -static int report_resume(struct pci_dev *dev, void *data)
> -{
> -	const struct pci_error_handlers *err_handler;
> -
> -	device_lock(&dev->dev);
> -	dev->error_state = pci_channel_io_normal;
> -
> -	if (!dev->driver ||
> -		!dev->driver->err_handler ||
> -		!dev->driver->err_handler->resume)
> -		goto out;
> -
> -	err_handler = dev->driver->err_handler;
> -	err_handler->resume(dev);
> -	pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED);
> -out:
> -	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
> - * @state: error state
> - * @error_mesg: message to print
> - * @cb: callback to be broadcasted
> - *
> - * Invoked during error recovery process. Once being invoked, the content
> - * of error severity will be broadcasted to all downstream drivers in a
> - * 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;
> -
> -	pci_printk(KERN_DEBUG, dev, "broadcast %s message\n", error_mesg);
> -	result_data.state = state;
> -	if (cb == report_error_detected)
> -		result_data.result = PCI_ERS_RESULT_CAN_RECOVER;
> -	else
> -		result_data.result = PCI_ERS_RESULT_RECOVERED;
> -
> -	if (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.
> -		 */
> -		if (cb == report_error_detected)
> -			dev->error_state = state;
> -		pci_walk_bus(dev->subordinate, cb, &result_data);
> -		if (cb == report_resume) {
> -			pci_cleanup_aer_uncorrect_error_status(dev);
> -			dev->error_state = pci_channel_io_normal;
> -		}
> -	} else {
> -		/*
> -		 * If the error is reported by an end point, we think this
> -		 * error is related to the upstream link of the end point.
> -		 */
> -		if (state == pci_channel_io_normal)
> -			/*
> -			 * the error is non fatal so the bus is ok, just invoke
> -			 * the callback for the function that logged the error.
> -			 */
> -			cb(dev, &result_data);
> -		else
> -			pci_walk_bus(dev->bus, cb, &result_data);
> -	}
> -
> -	return result_data.result;
> -}
> -
> -/**
> - * default_reset_link - default reset function
> - * @dev: pointer to pci_dev data structure
> - *
> - * Invoked when performing link reset on a Downstream Port or a
> - * Root Port with no aer driver.
> - */
> -static pci_ers_result_t default_reset_link(struct pci_dev *dev)
> -{
> -	pci_reset_bridge_secondary_bus(dev);
> -	pci_printk(KERN_DEBUG, dev, "downstream link has been reset\n");
> -	return PCI_ERS_RESULT_RECOVERED;
> -}
> -
>  static int find_aer_service_iter(struct device *device, void *data)
>  {
>  	struct pcie_port_service_driver *service_driver, **drv;
> @@ -432,7 +248,7 @@ static int find_aer_service_iter(struct device *device, void *data)
>  	return 0;
>  }
>  
> -static struct pcie_port_service_driver *find_aer_service(struct pci_dev *dev)
> +struct pcie_port_service_driver *pci_find_aer_service(struct pci_dev *dev)

Move this rename to a different patch.  The new name should probably
start with "pcie" like you did with pcie_do_recovery().

>  {
>  	struct pcie_port_service_driver *drv = NULL;
>  
> @@ -440,107 +256,7 @@ static struct pcie_port_service_driver *find_aer_service(struct pci_dev *dev)
>  
>  	return drv;
>  }
> -
> -static pci_ers_result_t reset_link(struct pci_dev *dev)
> -{
> -	struct pci_dev *udev;
> -	pci_ers_result_t status;
> -	struct pcie_port_service_driver *driver;
> -
> -	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
> -		/* Reset this port for all subordinates */
> -		udev = dev;
> -	} else {
> -		/* Reset the upstream component (likely downstream port) */
> -		udev = dev->bus->self;
> -	}
> -
> -	/* Use the aer driver of the component firstly */
> -	driver = find_aer_service(udev);
> -
> -	if (driver && driver->reset_link) {
> -		status = driver->reset_link(udev);
> -	} else if (udev->has_secondary_link) {
> -		status = default_reset_link(udev);
> -	} else {
> -		pci_printk(KERN_DEBUG, dev, "no link-reset support at upstream device %s\n",
> -			pci_name(udev));
> -		return PCI_ERS_RESULT_DISCONNECT;
> -	}
> -
> -	if (status != PCI_ERS_RESULT_RECOVERED) {
> -		pci_printk(KERN_DEBUG, dev, "link reset at upstream device %s failed\n",
> -			pci_name(udev));
> -		return PCI_ERS_RESULT_DISCONNECT;
> -	}
> -
> -	return status;
> -}
> -
> -/**
> - * pcie_do_recovery - handle nonfatal/fatal error recovery process
> - * @dev: pointer to a pci_dev data structure of agent detecting an error
> - * @severity: error severity type
> - *
> - * 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.
> - */
> -static void pcie_do_recovery(struct pci_dev *dev, int severity)
> -{
> -	pci_ers_result_t status, result = PCI_ERS_RESULT_RECOVERED;
> -	enum pci_channel_state state;
> -
> -	if (severity == AER_FATAL)
> -		state = pci_channel_io_frozen;
> -	else
> -		state = pci_channel_io_normal;
> -
> -	status = broadcast_error_message(dev,
> -			state,
> -			"error_detected",
> -			report_error_detected);
> -
> -	if (severity == AER_FATAL) {
> -		result = reset_link(dev);
> -		if (result != PCI_ERS_RESULT_RECOVERED)
> -			goto failed;
> -	}
> -
> -	if (status == PCI_ERS_RESULT_CAN_RECOVER)
> -		status = broadcast_error_message(dev,
> -				state,
> -				"mmio_enabled",
> -				report_mmio_enabled);
> -
> -	if (status == PCI_ERS_RESULT_NEED_RESET) {
> -		/*
> -		 * TODO: Should call platform-specific
> -		 * functions to reset slot before calling
> -		 * drivers' slot_reset callbacks?
> -		 */
> -		status = broadcast_error_message(dev,
> -				state,
> -				"slot_reset",
> -				report_slot_reset);
> -	}
> -
> -	if (status != PCI_ERS_RESULT_RECOVERED)
> -		goto failed;
> -
> -	broadcast_error_message(dev,
> -				state,
> -				"resume",
> -				report_resume);
> -
> -	pci_info(dev, "AER: Device recovery successful\n");
> -	return;
> -
> -failed:
> -	pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
> -	/* TODO: Should kernel panic here? */
> -	pci_info(dev, "AER: Device recovery failed\n");
> -}
> +EXPORT_SYMBOL_GPL(pci_find_aer_service);

This is never called from a module, so I don't think you need to
export it at all.  If you do, it should be a separate patch, not
buried in the middle of this big one.

>  /**
>   * handle_error_source - handle logging error into an event log
> diff --git a/drivers/pci/pcie/pcie-err.c b/drivers/pci/pcie/pcie-err.c
> new file mode 100644
> index 0000000..fcd5add
> --- /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.

Wrap this so it fits in 80 columns.

> + * Copyright (C) 2006 Intel Corp.
> + *	Tom Long Nguyen (tom.l.nguyen@intel.com)
> + *	Zhang Yanmin (yanmin.zhang@intel.com)
> + *
> + */
> +
> +#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"
> +
> +struct aer_broadcast_data {
> +	enum pci_channel_state state;
> +	enum pci_ers_result result;
> +};
> +
> +static pci_ers_result_t merge_result(enum pci_ers_result orig,
> +				  enum pci_ers_result new)
> +{
> +	if (new == PCI_ERS_RESULT_NO_AER_DRIVER)
> +		return PCI_ERS_RESULT_NO_AER_DRIVER;
> +
> +	if (new == PCI_ERS_RESULT_NONE)
> +		return orig;
> +
> +	switch (orig) {
> +	case PCI_ERS_RESULT_CAN_RECOVER:
> +	case PCI_ERS_RESULT_RECOVERED:
> +		orig = new;
> +		break;
> +	case PCI_ERS_RESULT_DISCONNECT:
> +		if (new == PCI_ERS_RESULT_NEED_RESET)
> +			orig = PCI_ERS_RESULT_NEED_RESET;
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	return orig;
> +}
> +
> +static int report_mmio_enabled(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);
> +	if (!dev->driver ||
> +		!dev->driver->err_handler ||
> +		!dev->driver->err_handler->mmio_enabled)
> +		goto out;
> +
> +	err_handler = dev->driver->err_handler;
> +	vote = err_handler->mmio_enabled(dev);
> +	result_data->result = merge_result(result_data->result, vote);
> +out:
> +	device_unlock(&dev->dev);
> +	return 0;
> +}
> +
> +static int report_slot_reset(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);
> +	if (!dev->driver ||
> +		!dev->driver->err_handler ||
> +		!dev->driver->err_handler->slot_reset)
> +		goto out;
> +
> +	err_handler = dev->driver->err_handler;
> +	vote = err_handler->slot_reset(dev);
> +	result_data->result = merge_result(result_data->result, vote);
> +out:
> +	device_unlock(&dev->dev);
> +	return 0;
> +}
> +
> +static int report_resume(struct pci_dev *dev, void *data)
> +{
> +	const struct pci_error_handlers *err_handler;
> +
> +	device_lock(&dev->dev);
> +	dev->error_state = pci_channel_io_normal;
> +
> +	if (!dev->driver ||
> +		!dev->driver->err_handler ||
> +		!dev->driver->err_handler->resume)
> +		goto out;
> +
> +	err_handler = dev->driver->err_handler;
> +	err_handler->resume(dev);
> +out:
> +	device_unlock(&dev->dev);
> +	return 0;
> +}
> +
> +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");

This was a pci_printk() before you moved it and it should be the same here.

> +		}
> +
> +		/*
> +		 * 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;
> +}
> +
> +/**
> + * default_reset_link - default reset function
> + * @dev: pointer to pci_dev data structure
> + *
> + * Invoked when performing link reset on a Downstream Port or a
> + * Root Port with no aer driver.
> + */
> +static pci_ers_result_t default_reset_link(struct pci_dev *dev)
> +{
> +	pci_reset_bridge_secondary_bus(dev);
> +	dev_printk(KERN_DEBUG, &dev->dev, "downstream link has been reset\n");

This should be a pci_printk() as it was before the move.  There are more
below.

> +	return PCI_ERS_RESULT_RECOVERED;
> +}
> +
> +static pci_ers_result_t reset_link(struct pci_dev *dev)
> +{
> +	struct pci_dev *udev;
> +	pci_ers_result_t status;
> +	struct pcie_port_service_driver *driver = NULL;
> +
> +	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
> +		/* Reset this port for all subordinates */
> +		udev = dev;
> +	} else {
> +		/* Reset the upstream component (likely downstream port) */
> +		udev = dev->bus->self;
> +	}
> +
> +#if IS_ENABLED(CONFIG_PCIEAER)

AER can't be a module, so you can use just:

  #ifdef CONFIG_PCIEAER

This ifdef should be added in the patch where you add a caller from non-AER
code.  This patch should only move code, not change it.

> +	/* Use the aer driver of the component firstly */
> +	driver = pci_find_aer_service(udev);
> +#endif
> +
> +	if (driver && driver->reset_link) {
> +		status = driver->reset_link(udev);
> +	} else if (udev->has_secondary_link) {
> +		status = default_reset_link(udev);
> +	} else {
> +		dev_printk(KERN_DEBUG, &dev->dev,
> +			"no link-reset support at upstream device %s\n",
> +			pci_name(udev));
> +		return PCI_ERS_RESULT_DISCONNECT;
> +	}
> +
> +	if (status != PCI_ERS_RESULT_RECOVERED) {
> +		dev_printk(KERN_DEBUG, &dev->dev,
> +			"link reset at upstream device %s failed\n",
> +			pci_name(udev));
> +		return PCI_ERS_RESULT_DISCONNECT;
> +	}
> +
> +	return status;
> +}
> +
> +/**
> + * broadcast_error_message - handle message broadcast to downstream drivers
> + * @dev: pointer to where in a hierarchy message is broadcasted down
> + * @state: error state
> + * @error_mesg: message to print
> + * @cb: callback to be broadcast
> + *
> + * Invoked during error recovery process. Once being invoked, the content
> + * of error severity will be broadcast to all downstream drivers in a
> + * 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;
> +
> +	dev_printk(KERN_DEBUG, &dev->dev, "broadcast %s message\n", error_mesg);
> +	result_data.state = state;
> +	if (cb == report_error_detected)
> +		result_data.result = PCI_ERS_RESULT_CAN_RECOVER;
> +	else
> +		result_data.result = PCI_ERS_RESULT_RECOVERED;
> +
> +	if (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.
> +		 */
> +		if (cb == report_error_detected)
> +			dev->error_state = state;
> +		pci_walk_bus(dev->subordinate, cb, &result_data);
> +		if (cb == report_resume) {
> +			pci_cleanup_aer_uncorrect_error_status(dev);
> +			dev->error_state = pci_channel_io_normal;
> +		}
> +	} else {
> +		/*
> +		 * If the error is reported by an end point, we think this
> +		 * error is related to the upstream link of the end point.
> +		 */
> +		pci_walk_bus(dev->bus, cb, &result_data);
> +	}
> +
> +	return result_data.result;
> +}
> +
> +/**
> + * pcie_do_recovery - handle nonfatal/fatal error recovery process
> + * @dev: pointer to a pci_dev data structure of agent detecting an error
> + * @severity: error severity type
> + *
> + * 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_recovery(struct pci_dev *dev, int severity)
> +{
> +	pci_ers_result_t status, result = PCI_ERS_RESULT_RECOVERED;
> +	enum pci_channel_state state;
> +
> +	if (severity == AER_FATAL)
> +		state = pci_channel_io_frozen;
> +	else
> +		state = pci_channel_io_normal;
> +
> +	status = broadcast_error_message(dev,
> +			state,
> +			"error_detected",
> +			report_error_detected);
> +
> +	if (severity == AER_FATAL) {
> +		result = reset_link(dev);
> +		if (result != PCI_ERS_RESULT_RECOVERED)
> +			goto failed;
> +	}
> +
> +	if (status == PCI_ERS_RESULT_CAN_RECOVER)
> +		status = broadcast_error_message(dev,
> +				state,
> +				"mmio_enabled",
> +				report_mmio_enabled);
> +
> +	if (status == PCI_ERS_RESULT_NEED_RESET) {
> +		/*
> +		 * TODO: Should call platform-specific
> +		 * functions to reset slot before calling
> +		 * drivers' slot_reset callbacks?
> +		 */
> +		status = broadcast_error_message(dev,
> +				state,
> +				"slot_reset",
> +				report_slot_reset);
> +	}
> +
> +	if (status != PCI_ERS_RESULT_RECOVERED)
> +		goto failed;
> +
> +	broadcast_error_message(dev,
> +				state,
> +				"resume",
> +				report_resume);
> +
> +	dev_info(&dev->dev, "Device recovery successful\n");
> +	return;
> +
> +failed:
> +	/* TODO: Should kernel panic here? */
> +	dev_info(&dev->dev, "Device recovery failed\n");
> +}
> diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
> index a854bc5..4f1992d 100644
> --- a/drivers/pci/pcie/portdrv.h
> +++ b/drivers/pci/pcie/portdrv.h
> @@ -79,4 +79,5 @@ static inline void pcie_port_platform_notify(struct pci_dev *port, int *mask)
>  static inline void pcie_port_platform_notify(struct pci_dev *port, int *mask){}
>  #endif /* !CONFIG_ACPI */
>  
> +struct pcie_port_service_driver *pci_find_aer_service(struct pci_dev *dev);

Should be in a different patch, maybe the one where you rename it.

>  #endif /* _PORTDRV_H_ */
> -- 
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> a Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
>