Re: [RESEND v13 22/25] CXL/PCI: Export and rename merge_result() to pci_ers_merge_result()

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, Nov 04, 2025 at 11:03:02AM -0600, Terry Bowman wrote:
> CXL uncorrectable errors (UCE) will soon be handled separately from the PCI
> AER handling. The merge_result() function can be made common to use in both
> handling paths.
> 
> Rename the PCI subsystem's merge_result() to be pci_ers_merge_result().
> Export pci_ers_merge_result() to make available for the CXL and other
> drivers to use.
> 
> Update pci_ers_merge_result() to support recently introduced PCI_ERS_RESULT_PANIC
> result.

Seems like this merge_result() change maybe should be in the same
patch that added PCI_ERS_RESULT_PANIC?  That would also solve the
problem that the subject line doesn't mention this important
functional change.

I haven't seen the user(s) of pci_ers_merge_result() yet, but this
seems like it might be a little too low level to be exported to
modules and in include/linux/pci.h.  Maybe there's no other way.

Wrap commit log to fit in 75 columns.

Suggest possible subject prefix of "PCI/ERR" since the only CXL
connection is that you want to *use* this from CXL.

> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
> 
> ---
> 
> Changes in v12->v13:
> - Renamed pci_ers_merge_result() to pcie_ers_merge_result().
>   pci_ers_merge_result() is already used in eeh driver. (Bot)
> 
> Changes in v11->v12:
> - Remove static inline pci_ers_merge_result() definition for !CONFIG_PCIEAER.
>   Is not needed. (Lukas)
> 
> Changes in v10->v11:
> - New patch
> - pci_ers_merge_result() - Change export to non-namespace and rename
>   to be pci_ers_merge_result()
> - Move pci_ers_merge_result() definition to pci.h. Needs pci_ers_result
> ---
>  drivers/pci/pcie/err.c | 14 +++++++++-----
>  include/linux/pci.h    |  7 +++++++
>  2 files changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> index bebe4bc111d7..9394bbdcf0fb 100644
> --- a/drivers/pci/pcie/err.c
> +++ b/drivers/pci/pcie/err.c
> @@ -21,9 +21,12 @@
>  #include "portdrv.h"
>  #include "../pci.h"
>  
> -static pci_ers_result_t merge_result(enum pci_ers_result orig,
> -				  enum pci_ers_result new)
> +pci_ers_result_t pcie_ers_merge_result(enum pci_ers_result orig,
> +				       enum pci_ers_result new)
>  {
> +	if (new == PCI_ERS_RESULT_PANIC)
> +		return PCI_ERS_RESULT_PANIC;
> +
>  	if (new == PCI_ERS_RESULT_NO_AER_DRIVER)
>  		return PCI_ERS_RESULT_NO_AER_DRIVER;
>  
> @@ -45,6 +48,7 @@ static pci_ers_result_t merge_result(enum pci_ers_result orig,
>  
>  	return orig;
>  }
> +EXPORT_SYMBOL(pcie_ers_merge_result);
>  
>  static int report_error_detected(struct pci_dev *dev,
>  				 pci_channel_state_t state,
> @@ -81,7 +85,7 @@ static int report_error_detected(struct pci_dev *dev,
>  		vote = err_handler->error_detected(dev, state);
>  	}
>  	pci_uevent_ers(dev, vote);
> -	*result = merge_result(*result, vote);
> +	*result = pcie_ers_merge_result(*result, vote);
>  	device_unlock(&dev->dev);
>  	return 0;
>  }
> @@ -139,7 +143,7 @@ static int report_mmio_enabled(struct pci_dev *dev, void *data)
>  
>  	err_handler = pdrv->err_handler;
>  	vote = err_handler->mmio_enabled(dev);
> -	*result = merge_result(*result, vote);
> +	*result = pcie_ers_merge_result(*result, vote);
>  out:
>  	device_unlock(&dev->dev);
>  	return 0;
> @@ -159,7 +163,7 @@ static int report_slot_reset(struct pci_dev *dev, void *data)
>  
>  	err_handler = pdrv->err_handler;
>  	vote = err_handler->slot_reset(dev);
> -	*result = merge_result(*result, vote);
> +	*result = pcie_ers_merge_result(*result, vote);
>  out:
>  	device_unlock(&dev->dev);
>  	return 0;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 33d16b212e0d..d3e3300f79ec 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1887,9 +1887,16 @@ static inline void pci_hp_unignore_link_change(struct pci_dev *pdev) { }
>  #ifdef CONFIG_PCIEAER
>  bool pci_aer_available(void);
>  void pcie_clear_device_status(struct pci_dev *dev);
> +pci_ers_result_t pcie_ers_merge_result(enum pci_ers_result orig,
> +				       enum pci_ers_result new);
>  #else
>  static inline bool pci_aer_available(void) { return false; }
>  static inline void pcie_clear_device_status(struct pci_dev *dev) { }
> +static inline pci_ers_result_t pcie_ers_merge_result(enum pci_ers_result orig,
> +						     enum pci_ers_result new)
> +{
> +	return PCI_ERS_RESULT_NONE;
> +}
>  #endif
>  
>  bool pci_ats_disabled(void);
> -- 
> 2.34.1
>