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SubjectRe: [PATCH v11 2/7] PCI/AER: factor out error reporting from AER
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.
>
>> #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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