* [PATCH v2] PCI: Factor functions of PCI function reset
@ 2021-03-19 9:25 Yicong Yang
2021-03-19 17:09 ` Krzysztof Wilczyński
0 siblings, 1 reply; 3+ messages in thread
From: Yicong Yang @ 2021-03-19 9:25 UTC (permalink / raw)
To: helgaas, kw, linux-pci; +Cc: alex.williamson, prime.zeng, yangyicong, linuxarm
Previously we used pci_probe_reset_function() to probe whether a function
can be reset and use __pci_reset_function_locked() to perform a function
reset. These two functions have lots of common lines.
Factor the two functions and reduce the redundancy.
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
---
Change since v1:
- reword the comments a bit(Krzysztof)
- fix typos in the commit(Bjorn)
Link: https://lore.kernel.org/linux-pci/1605090123-14243-1-git-send-email-yangyicong@hisilicon.com/
drivers/pci/pci.c | 62 ++++++++++++++++-------------------------------------
drivers/pci/pci.h | 2 +-
drivers/pci/probe.c | 2 +-
3 files changed, 21 insertions(+), 45 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 16a1721..254bbe9 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5055,9 +5055,11 @@ static void pci_dev_restore(struct pci_dev *dev)
}
/**
- * __pci_reset_function_locked - reset a PCI device function while holding
- * the @dev mutex lock.
+ * pci_probe_reset_function - check whether the device can be safely reset
+ * or reset a PCI device function while holding
+ * the @dev mutex lock.
* @dev: PCI device to reset
+ * @probe: Probe or not whether the device can be reset.
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
@@ -5071,10 +5073,11 @@ static void pci_dev_restore(struct pci_dev *dev)
* device including MSI, bus mastering, BARs, decoding IO and memory spaces,
* etc.
*
- * Returns 0 if the device function was successfully reset or negative if the
- * device doesn't support resetting a single function.
+ * Returns 0 if the device function can be reset or was successfully
+ * reset, otherwise negative if the device doesn't support resetting
+ * a single function.
*/
-int __pci_reset_function_locked(struct pci_dev *dev)
+int pci_probe_reset_function(struct pci_dev *dev, int probe)
{
int rc;
@@ -5088,61 +5091,34 @@ int __pci_reset_function_locked(struct pci_dev *dev)
* other error, we're also finished: this indicates that further
* reset mechanisms might be broken on the device.
*/
- rc = pci_dev_specific_reset(dev, 0);
+ rc = pci_dev_specific_reset(dev, probe);
if (rc != -ENOTTY)
return rc;
if (pcie_has_flr(dev)) {
+ if (probe)
+ return 0;
rc = pcie_flr(dev);
if (rc != -ENOTTY)
return rc;
}
- rc = pci_af_flr(dev, 0);
+ rc = pci_af_flr(dev, probe);
if (rc != -ENOTTY)
return rc;
- rc = pci_pm_reset(dev, 0);
+ rc = pci_pm_reset(dev, probe);
if (rc != -ENOTTY)
return rc;
- rc = pci_dev_reset_slot_function(dev, 0);
+ rc = pci_dev_reset_slot_function(dev, probe);
if (rc != -ENOTTY)
return rc;
- return pci_parent_bus_reset(dev, 0);
+
+ return pci_parent_bus_reset(dev, probe);
}
-EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
-/**
- * pci_probe_reset_function - check whether the device can be safely reset
- * @dev: PCI device to reset
- *
- * Some devices allow an individual function to be reset without affecting
- * other functions in the same device. The PCI device must be responsive
- * to PCI config space in order to use this function.
- *
- * Returns 0 if the device function can be reset or negative if the
- * device doesn't support resetting a single function.
- */
-int pci_probe_reset_function(struct pci_dev *dev)
+int __pci_reset_function_locked(struct pci_dev *dev)
{
- int rc;
-
- might_sleep();
-
- rc = pci_dev_specific_reset(dev, 1);
- if (rc != -ENOTTY)
- return rc;
- if (pcie_has_flr(dev))
- return 0;
- rc = pci_af_flr(dev, 1);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_pm_reset(dev, 1);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_dev_reset_slot_function(dev, 1);
- if (rc != -ENOTTY)
- return rc;
-
- return pci_parent_bus_reset(dev, 1);
+ return pci_probe_reset_function(dev, 0);
}
+EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
/**
* pci_reset_function - quiesce and reset a PCI device function
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index ef7c466..f349d48 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -39,7 +39,7 @@ enum pci_mmap_api {
int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai,
enum pci_mmap_api mmap_api);
-int pci_probe_reset_function(struct pci_dev *dev);
+int pci_probe_reset_function(struct pci_dev *dev, int probe);
int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
int pci_bus_error_reset(struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 953f15a..cc0c21d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2404,7 +2404,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
pcie_report_downtraining(dev);
- if (pci_probe_reset_function(dev) == 0)
+ if (pci_probe_reset_function(dev, 1) == 0)
dev->reset_fn = 1;
}
--
2.8.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] PCI: Factor functions of PCI function reset
2021-03-19 9:25 [PATCH v2] PCI: Factor functions of PCI function reset Yicong Yang
@ 2021-03-19 17:09 ` Krzysztof Wilczyński
2021-03-22 11:56 ` Yicong Yang
0 siblings, 1 reply; 3+ messages in thread
From: Krzysztof Wilczyński @ 2021-03-19 17:09 UTC (permalink / raw)
To: Yicong Yang
Cc: helgaas, linux-pci, alex.williamson, prime.zeng, linuxarm, Amey Narkhede
[+cc Amey as he is workingo on a larger refactor of the reset functions]
Hi,
> Previously we used pci_probe_reset_function() to probe whether a function
> can be reset and use __pci_reset_function_locked() to perform a function
> reset. These two functions have lots of common lines.
>
> Factor the two functions and reduce the redundancy.
[...]
I wanted to bring the following thread to your attention as you are
working on the same code that it's being talked about there in the
on-going conversation, see:
https://lore.kernel.org/linux-pci/20210312173452.3855-1-ameynarkhede03@gmail.com/
I wonder if there would be some overlap, etc.
Krzysztof
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] PCI: Factor functions of PCI function reset
2021-03-19 17:09 ` Krzysztof Wilczyński
@ 2021-03-22 11:56 ` Yicong Yang
0 siblings, 0 replies; 3+ messages in thread
From: Yicong Yang @ 2021-03-22 11:56 UTC (permalink / raw)
To: Krzysztof Wilczyński
Cc: helgaas, linux-pci, alex.williamson, prime.zeng, linuxarm, Amey Narkhede
Hi Krzysztof,
On 2021/3/20 1:09, Krzysztof Wilczyński wrote:
> [+cc Amey as he is workingo on a larger refactor of the reset functions]
>
> Hi,
>
>> Previously we used pci_probe_reset_function() to probe whether a function
>> can be reset and use __pci_reset_function_locked() to perform a function
>> reset. These two functions have lots of common lines.
>>
>> Factor the two functions and reduce the redundancy.
> [...]
>
> I wanted to bring the following thread to your attention as you are
> working on the same code that it's being talked about there in the
> on-going conversation, see:
>
> https://lore.kernel.org/linux-pci/20210312173452.3855-1-ameynarkhede03@gmail.com/
>
> I wonder if there would be some overlap, etc.
thanks for the reminder. i roughly look through Amey's series and i think this little
refactor is unnecessary anymore. i'll follow on that series and i may need a further
understanding.
Thanks,
Yicong
>
> Krzysztof
>
> .
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-03-19 9:25 [PATCH v2] PCI: Factor functions of PCI function reset Yicong Yang
2021-03-19 17:09 ` Krzysztof Wilczyński
2021-03-22 11:56 ` Yicong Yang
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