Re: [PATCH v4 15/15] PCI/AER: Enable internal errors for CXL Upstream and Downstream Switch Ports

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Wed, 11 Dec 2024 17:40:02 -0600
Terry Bowman <terry.bowman@amd.com> wrote:

> The AER service driver enables PCIe Uncorrectable Internal Errors (UIE) and
> Correctable Internal errors (CIE) for CXL Root Ports and CXL RCEC's. The
> UIE and CIE are used in reporting CXL Protocol Errors. The same UIE/CIE
> enablement is needed for CXL PCIe Upstream and Downstream Ports inorder to
> notify the associated Root Port and OS.[1]
> 
> Export the AER service driver's pci_aer_unmask_internal_errors() function
> to CXL namespace.
> 
> Remove the function's dependency on the CONFIG_PCIEAER_CXL kernel config
> because it is now an exported function.
> 
> Call pci_aer_unmask_internal_errors() during RAS initialization in:
> cxl_uport_init_ras_reporting() and cxl_dport_init_ras_reporting().
> 
> [1] PCIe Base Spec r6.2-1.0, 6.2.3.2.2 Masking Individual Errors
> 
> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Whilst I'm in favor of just enabling this across all devices I guess
I can cope with this more minimal form and it will create fewer bug
reports :).
It is a little messy because we are tweaking it from the 'wrong' driver
but I guess that is fine.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

And on that note, happy Christmas / holidays etc all. My backlog
of review looks much less scary now but I need a beer!

Jonathan



> ---
>  drivers/cxl/core/pci.c | 2 ++
>  drivers/pci/pcie/aer.c | 5 +++--
>  include/linux/aer.h    | 1 +
>  3 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index 9734a4c55b29..740ac5d8809f 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -886,6 +886,7 @@ void cxl_uport_init_ras_reporting(struct cxl_port *port)
>  
>  	cxl_assign_port_error_handlers(pdev);
>  	devm_add_action_or_reset(port->uport_dev, cxl_clear_port_error_handlers, pdev);
> +	pci_aer_unmask_internal_errors(pdev);
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_uport_init_ras_reporting, CXL);
>  
> @@ -920,6 +921,7 @@ void cxl_dport_init_ras_reporting(struct cxl_dport *dport)
>  
>  	cxl_assign_port_error_handlers(pdev);
>  	devm_add_action_or_reset(dport_dev, cxl_clear_port_error_handlers, pdev);
> +	pci_aer_unmask_internal_errors(pdev);
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_dport_init_ras_reporting, CXL);
>  
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index 861521872318..0fa1b1ed48c9 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -949,7 +949,6 @@ static bool is_internal_error(struct aer_err_info *info)
>  	return info->status & PCI_ERR_UNC_INTN;
>  }
>  
> -#ifdef CONFIG_PCIEAER_CXL
>  /**
>   * pci_aer_unmask_internal_errors - unmask internal errors
>   * @dev: pointer to the pcie_dev data structure
> @@ -960,7 +959,7 @@ static bool is_internal_error(struct aer_err_info *info)
>   * Note: AER must be enabled and supported by the device which must be
>   * checked in advance, e.g. with pcie_aer_is_native().
>   */
> -static void pci_aer_unmask_internal_errors(struct pci_dev *dev)
> +void pci_aer_unmask_internal_errors(struct pci_dev *dev)
>  {
>  	int aer = dev->aer_cap;
>  	u32 mask;
> @@ -973,7 +972,9 @@ static void pci_aer_unmask_internal_errors(struct pci_dev *dev)
>  	mask &= ~PCI_ERR_COR_INTERNAL;
>  	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, mask);
>  }
> +EXPORT_SYMBOL_NS_GPL(pci_aer_unmask_internal_errors, CXL);
>  
> +#ifdef CONFIG_PCIEAER_CXL
>  static bool is_cxl_mem_dev(struct pci_dev *dev)
>  {
>  	/*
> diff --git a/include/linux/aer.h b/include/linux/aer.h
> index 4b97f38f3fcf..093293f9f12b 100644
> --- a/include/linux/aer.h
> +++ b/include/linux/aer.h
> @@ -55,5 +55,6 @@ void pci_print_aer(struct pci_dev *dev, int aer_severity,
>  int cper_severity_to_aer(int cper_severity);
>  void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
>  		       int severity, struct aer_capability_regs *aer_regs);
> +void pci_aer_unmask_internal_errors(struct pci_dev *dev);
>  #endif //_AER_H_
>