RE: [PATCH V4 1/9] PCI/CXL: Export native CXL error reporting control

From: Dan Williams
Date: Tue Dec 13 2022 - 14:14:10 EST


ira.weiny@ wrote:
> From: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> CXL _OSC Error Reporting Control is used by the OS to determine if
> Firmware has control of various CXL error reporting capabilities
> including the event logs.
>
> Expose the result of negotiating CXL Error Reporting Control in struct
> pci_host_bridge for consumption by the CXL drivers.
>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Lukas Wunner <lukas@xxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>

Looks good to me,

Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>

>
> ---
> Changes from V3:
> New patch split out
> ---
> drivers/acpi/pci_root.c | 3 +++
> drivers/pci/probe.c | 1 +
> include/linux/pci.h | 1 +
> 3 files changed, 5 insertions(+)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index b3c202d2a433..84030804a763 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -1047,6 +1047,9 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
> if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
> host_bridge->native_dpc = 0;
>
> + if (!(root->osc_ext_control_set & OSC_CXL_ERROR_REPORTING_CONTROL))
> + host_bridge->native_cxl_error = 0;
> +
> /*
> * Evaluate the "PCI Boot Configuration" _DSM Function. If it
> * exists and returns 0, we must preserve any PCI resource
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 2f4e88a44e8b..34c9fd6840c4 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -596,6 +596,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge)
> bridge->native_ltr = 1;
> bridge->native_dpc = 1;
> bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET;
> + bridge->native_cxl_error = 1;
>
> device_initialize(&bridge->dev);
> }
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 1f81807492ef..08c3ccd2617b 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -577,6 +577,7 @@ struct pci_host_bridge {
> unsigned int native_pme:1; /* OS may use PCIe PME */
> unsigned int native_ltr:1; /* OS may use PCIe LTR */
> unsigned int native_dpc:1; /* OS may use PCIe DPC */
> + unsigned int native_cxl_error:1; /* OS may use CXL RAS/Events */
> unsigned int preserve_config:1; /* Preserve FW resource setup */
> unsigned int size_windows:1; /* Enable root bus sizing */
> unsigned int msi_domain:1; /* Bridge wants MSI domain */
> --
> 2.37.2
>