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

Alejandro Lucero Palau
2024-12-12T09:45:03Z

On 12/11/24 23:40, Terry Bowman 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>
> ---
> 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

This ifdef move puzzles me. I would expect to use it when the next
function is invoked instead of moving it here.

It seems weird to have such a config but code using those related
functions not aware of it.

> /**
> * 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_
>