2022-07-27 03:56:10

by Zhuo Chen

[permalink] [raw]
Subject: [PATCH v3] PCI/ERR: Use pcie_aer_is_native() to judge whether OS owns AER

Use pcie_aer_is_native() in place of "host->native_aer ||
pcie_ports_native" to judge whether OS has native control of AER
in pcie_do_recovery().

Replace "dev->aer_cap && (pcie_ports_native || host->native_aer)" in
get_port_device_capability() with pcie_aer_is_native(), which has no
functional changes.

Signed-off-by: Zhuo Chen <[email protected]>
---
Changelog:
v3:
- Simplify why we use pcie_aer_is_native().
- Revert modification of pci_aer_clear_nonfatal_status() and comments.
v2:
- Add details and note in commit log.
---
drivers/pci/pcie/err.c | 3 +--
drivers/pci/pcie/portdrv_core.c | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 0c5a143025af..121a53338e44 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -184,7 +184,6 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
int type = pci_pcie_type(dev);
struct pci_dev *bridge;
pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
- struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);

/*
* If the error was detected by a Root Port, Downstream Port, RCEC,
@@ -243,7 +242,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
* it is responsible for clearing this status. In that case, the
* signaling device may not even be visible to the OS.
*/
- if (host->native_aer || pcie_ports_native) {
+ if (pcie_aer_is_native(dev)) {
pcie_clear_device_status(dev);
pci_aer_clear_nonfatal_status(dev);
}
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 604feeb84ee4..98c18f4a01b2 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -221,8 +221,7 @@ static int get_port_device_capability(struct pci_dev *dev)
}

#ifdef CONFIG_PCIEAER
- if (dev->aer_cap && pci_aer_available() &&
- (pcie_ports_native || host->native_aer)) {
+ if (pcie_aer_is_native(dev) && pci_aer_available()) {
services |= PCIE_PORT_SERVICE_AER;

/*
--
2.30.1 (Apple Git-130)


Subject: Re: [PATCH v3] PCI/ERR: Use pcie_aer_is_native() to judge whether OS owns AER



On 7/26/22 8:53 PM, Zhuo Chen wrote:
> Use pcie_aer_is_native() in place of "host->native_aer ||
> pcie_ports_native" to judge whether OS has native control of AER
> in pcie_do_recovery().
>
> Replace "dev->aer_cap && (pcie_ports_native || host->native_aer)" in
> get_port_device_capability() with pcie_aer_is_native(), which has no
> functional changes.
>
> Signed-off-by: Zhuo Chen <[email protected]>
> ---

Patch looks better now. It looks like following two changes
can also be replaced with pcie_aer_is_native() check.

drivers/pci/pcie/aer.c:1407: if ((host->native_aer || pcie_ports_native) && aer) {
drivers/pci/pcie/aer.c:1426: if ((host->native_aer || pcie_ports_native) && aer) {



> Changelog:
> v3:
> - Simplify why we use pcie_aer_is_native().
> - Revert modification of pci_aer_clear_nonfatal_status() and comments.
> v2:
> - Add details and note in commit log.
> ---
> drivers/pci/pcie/err.c | 3 +--
> drivers/pci/pcie/portdrv_core.c | 3 +--
> 2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> index 0c5a143025af..121a53338e44 100644
> --- a/drivers/pci/pcie/err.c
> +++ b/drivers/pci/pcie/err.c
> @@ -184,7 +184,6 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> int type = pci_pcie_type(dev);
> struct pci_dev *bridge;
> pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
> - struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
>
> /*
> * If the error was detected by a Root Port, Downstream Port, RCEC,
> @@ -243,7 +242,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> * it is responsible for clearing this status. In that case, the
> * signaling device may not even be visible to the OS.
> */
> - if (host->native_aer || pcie_ports_native) {
> + if (pcie_aer_is_native(dev)) {
> pcie_clear_device_status(dev);
> pci_aer_clear_nonfatal_status(dev);
> }
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index 604feeb84ee4..98c18f4a01b2 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -221,8 +221,7 @@ static int get_port_device_capability(struct pci_dev *dev)
> }
>
> #ifdef CONFIG_PCIEAER
> - if (dev->aer_cap && pci_aer_available() &&
> - (pcie_ports_native || host->native_aer)) {
> + if (pcie_aer_is_native(dev) && pci_aer_available()) {
> services |= PCIE_PORT_SERVICE_AER;
>
> /*

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer

2022-07-27 05:59:25

by Zhuo Chen

[permalink] [raw]
Subject: Re: [PATCH v3] PCI/ERR: Use pcie_aer_is_native() to judge whether OS owns AER


On 7/26/22 9:02 PM, Sathyanarayanan Kuppuswamy wrote:
>
>
> On 7/26/22 8:53 PM, Zhuo Chen wrote:
>> Use pcie_aer_is_native() in place of "host->native_aer ||
>> pcie_ports_native" to judge whether OS has native control of AER
>> in pcie_do_recovery().
>>
>> Replace "dev->aer_cap && (pcie_ports_native || host->native_aer)" in
>> get_port_device_capability() with pcie_aer_is_native(), which has no
>> functional changes.
>>
>> Signed-off-by: Zhuo Chen <[email protected]>
>> ---
>
> Patch looks better now. It looks like following two changes
> can also be replaced with pcie_aer_is_native() check.
>
> drivers/pci/pcie/aer.c:1407: if ((host->native_aer || pcie_ports_native) && aer) {
> drivers/pci/pcie/aer.c:1426: if ((host->native_aer || pcie_ports_native) && aer) {

Good advice. But I wonder is there a scenario that dev->rcec ("root") is
NULL meanwhile dev->aer_cap is not NULL? If so, replace
"(host->native_aer || pcie_ports_native) && aer" with
pcie_aer_is_native() will change original function.

>
>
>
>> Changelog:
>> v3:
>> - Simplify why we use pcie_aer_is_native().
>> - Revert modification of pci_aer_clear_nonfatal_status() and comments.
>> v2:
>> - Add details and note in commit log.
>> ---
>> drivers/pci/pcie/err.c | 3 +--
>> drivers/pci/pcie/portdrv_core.c | 3 +--
>> 2 files changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
>> index 0c5a143025af..121a53338e44 100644
>> --- a/drivers/pci/pcie/err.c
>> +++ b/drivers/pci/pcie/err.c
>> @@ -184,7 +184,6 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>> int type = pci_pcie_type(dev);
>> struct pci_dev *bridge;
>> pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
>> - struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
>>
>> /*
>> * If the error was detected by a Root Port, Downstream Port, RCEC,
>> @@ -243,7 +242,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>> * it is responsible for clearing this status. In that case, the
>> * signaling device may not even be visible to the OS.
>> */
>> - if (host->native_aer || pcie_ports_native) {
>> + if (pcie_aer_is_native(dev)) {
>> pcie_clear_device_status(dev);
>> pci_aer_clear_nonfatal_status(dev);
>> }
>> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
>> index 604feeb84ee4..98c18f4a01b2 100644
>> --- a/drivers/pci/pcie/portdrv_core.c
>> +++ b/drivers/pci/pcie/portdrv_core.c
>> @@ -221,8 +221,7 @@ static int get_port_device_capability(struct pci_dev *dev)
>> }
>>
>> #ifdef CONFIG_PCIEAER
>> - if (dev->aer_cap && pci_aer_available() &&
>> - (pcie_ports_native || host->native_aer)) {
>> + if (pcie_aer_is_native(dev) && pci_aer_available()) {
>> services |= PCIE_PORT_SERVICE_AER;
>>
>> /*
>

Thanks,
Zhuo Chen

2022-07-27 10:17:47

by Zhuo Chen

[permalink] [raw]
Subject: Re: [PATCH v3] PCI/ERR: Use pcie_aer_is_native() to judge whether OS owns AER



On 7/26/22 1:35 PM, Zhuo Chen wrote:
>
> On 7/26/22 9:02 PM, Sathyanarayanan Kuppuswamy wrote:
>>
>>
>> On 7/26/22 8:53 PM, Zhuo Chen wrote:
>>> Use pcie_aer_is_native() in place of "host->native_aer ||
>>> pcie_ports_native" to judge whether OS has native control of AER
>>> in pcie_do_recovery().
>>>
>>> Replace "dev->aer_cap && (pcie_ports_native || host->native_aer)" in
>>> get_port_device_capability() with pcie_aer_is_native(), which has no
>>> functional changes.
>>>
>>> Signed-off-by: Zhuo Chen <[email protected]>
>>> ---
>>
>> Patch looks better now. It looks like following two changes
>> can also be replaced with pcie_aer_is_native() check.
>>
>> drivers/pci/pcie/aer.c:1407:    if ((host->native_aer ||
>> pcie_ports_native) && aer) {
>> drivers/pci/pcie/aer.c:1426:    if ((host->native_aer ||
>> pcie_ports_native) && aer) {
>
> Good advice. But I wonder is there a scenario that dev->rcec ("root") is
> NULL meanwhile dev->aer_cap is not NULL? If so, replace
> "(host->native_aer || pcie_ports_native) && aer" with
> pcie_aer_is_native() will change original function.
>
Do you mean changing "if ((host->native_aer || pcie_ports_native) &&
aer)" into "if (pcie_aer_is_native(dev) && aer)" ?
I thought changing into "if (pcie_aer_is_native(dev))" before.

One another doubt. Not every pci device support aer. When dev->aer_cap
is NULL and root->aer_cap is not NULL in aer_root_reset(),
pcie_aer_is_native() will return false and OS cannot operate root
register. It's different from just using "(host->native_aer ||
pcie_ports_native)".

Or we can change "if ((host->native_aer || pcie_ports_native) && aer)"
into "if (pcie_aer_is_native(root))". But in this way, argument NULL
pointer check should be added in pcie_aer_is_native().

>>
>>
>>
>>> Changelog:
>>> v3:
>>> - Simplify why we use pcie_aer_is_native().
>>> - Revert modification of pci_aer_clear_nonfatal_status() and comments.
>>> v2:
>>> - Add details and note in commit log.
>>> ---
>>>   drivers/pci/pcie/err.c          | 3 +--
>>>   drivers/pci/pcie/portdrv_core.c | 3 +--
>>>   2 files changed, 2 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
>>> index 0c5a143025af..121a53338e44 100644
>>> --- a/drivers/pci/pcie/err.c
>>> +++ b/drivers/pci/pcie/err.c
>>> @@ -184,7 +184,6 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev
>>> *dev,
>>>       int type = pci_pcie_type(dev);
>>>       struct pci_dev *bridge;
>>>       pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
>>> -    struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
>>>       /*
>>>        * If the error was detected by a Root Port, Downstream Port,
>>> RCEC,
>>> @@ -243,7 +242,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev
>>> *dev,
>>>        * it is responsible for clearing this status.  In that case, the
>>>        * signaling device may not even be visible to the OS.
>>>        */
>>> -    if (host->native_aer || pcie_ports_native) {
>>> +    if (pcie_aer_is_native(dev)) {
>>>           pcie_clear_device_status(dev);
>>>           pci_aer_clear_nonfatal_status(dev);
>>>       }
>>> diff --git a/drivers/pci/pcie/portdrv_core.c
>>> b/drivers/pci/pcie/portdrv_core.c
>>> index 604feeb84ee4..98c18f4a01b2 100644
>>> --- a/drivers/pci/pcie/portdrv_core.c
>>> +++ b/drivers/pci/pcie/portdrv_core.c
>>> @@ -221,8 +221,7 @@ static int get_port_device_capability(struct
>>> pci_dev *dev)
>>>       }
>>>   #ifdef CONFIG_PCIEAER
>>> -    if (dev->aer_cap && pci_aer_available() &&
>>> -        (pcie_ports_native || host->native_aer)) {
>>> +    if (pcie_aer_is_native(dev) && pci_aer_available()) {
>>>           services |= PCIE_PORT_SERVICE_AER;
>>>           /*
>>
>
> Thanks,
> Zhuo Chen

--
Thanks,
Zhuo Chen

Subject: Re: [PATCH v3] PCI/ERR: Use pcie_aer_is_native() to judge whether OS owns AER



On 7/27/22 2:37 AM, Zhuo Chen wrote:
>>
> Do you mean changing "if ((host->native_aer || pcie_ports_native) && aer)" into "if (pcie_aer_is_native(dev) && aer)" ?
> I thought changing into "if (pcie_aer_is_native(dev))" before.
>
> One another doubt. Not every pci device support aer. When dev->aer_cap is NULL and root->aer_cap is not NULL in aer_root_reset(), pcie_aer_is_native() will return false and OS cannot operate root register. It's different from just using "(host->native_aer || pcie_ports_native)".
>
> Or we can change "if ((host->native_aer || pcie_ports_native) && aer)" into "if (pcie_aer_is_native(root))". But in this way, argument NULL pointer check should be added in pcie_aer_is_native().

Looking into it again, I think it is better to leave it as it is. Please ignore my comment.

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer

2022-08-12 09:31:12

by Zhuo Chen

[permalink] [raw]
Subject: Re: [External] Re: [PATCH v3] PCI/ERR: Use pcie_aer_is_native() to judge whether OS owns AER



On 8/3/22 6:18 AM, Sathyanarayanan Kuppuswamy wrote:
>
>
> On 7/27/22 2:37 AM, Zhuo Chen wrote:
>>>
>> Do you mean changing "if ((host->native_aer || pcie_ports_native) && aer)" into "if (pcie_aer_is_native(dev) && aer)" ?
>> I thought changing into "if (pcie_aer_is_native(dev))" before.
>>
>> One another doubt. Not every pci device support aer. When dev->aer_cap is NULL and root->aer_cap is not NULL in aer_root_reset(), pcie_aer_is_native() will return false and OS cannot operate root register. It's different from just using "(host->native_aer || pcie_ports_native)".
>>
>> Or we can change "if ((host->native_aer || pcie_ports_native) && aer)" into "if (pcie_aer_is_native(root))". But in this way, argument NULL pointer check should be added in pcie_aer_is_native().
>
> Looking into it again, I think it is better to leave it as it is. Please ignore my comment.
>

Thanks! Is there anything else to improve and what's next for
the patch v3 ?

--
Thanks,
Zhuo Chen