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SubjectRe: [PATCH v11 2/7] PCI/AER: factor out error reporting from AER
On 2018-02-26 11:02, poza@codeaurora.org wrote:
> On 2018-02-24 05:12, Bjorn Helgaas wrote:
>> 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.
>>
>
> sure.
>
>>> 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.
>>
>
> done.
>
>>> #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-$(CONFIG_PCIEASPM) += aspm.o
>>>
>>> -pcieportdrv-y := portdrv_core.o portdrv_pci.o portdrv_bus.o
>>> +pcieportdrv-y := portdrv_core.o portdrv_pci.o portdrv_bus.o
>>> pcie-err.o
>>
>> Can we name this just "drivers/pci/pcie/err.c"? I know we have
>> pcie-dpc.c already, but it does get a little repetitious to type
>> "pci" THREE times in that path.
>>
>
> sure, will rename.
>
>>> pcieportdrv-$(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().
>>
>
> sure, will do that.
>
>>> {
>>> 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.
>>
>
> got it, will see if its really required to be exported.
> but certainly, will remove it from this patch.
>
>>> /**
>>> * 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.
>
> I thought of keeping the way it was before (hence did not change it)
> I would change it now.
>
>>
>>> + * 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.
>>
>
> sure, will correct this.
>
>>> + }
>>> +
>>> + /*
>>> + * 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.
>>
>
> yes all will be corrected.
> thanks.
>
>>> + 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.
>
> ok, it can remain unchanged. but reset_link() is called by
> pcie_do_recovery()
> and pcie_do_recovery can be called by various agents such as AER, DPC.
> so let us say if DPC calls pcie_do_recovery, then DPC has no way of
> knowing that AER is enabled or not.
> in fact it should not know, but err.c/reset_link() should take care
> somehow.
>
> I can make it a separate patch to do #ifdef CONFIG_PCIEAER inside
> reset_link()
> or
> I can add severity parameter in reset_link() so based on severity it
> can find the service.
>
> but I think you have comment to unify the find_aer_service and
> find_dpc_service into a pcie_find_service (routine)
> so I will see how I can club and take care of this comment. [without
> the need of #ifdef]
>
>>
>>> + /* 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.

this can not be in a different patch I suppose, because this patch would
not compile saying

error: implicit declaration of function ‘find_aer_service’
[-Werror=implicit-function-declaration]
driver = find_aer_service(udev);

err.c calls find_aer_service() so it needs to find declaration
somewhere.
Though I will make a separate patch renaming this as you suggested.

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

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