Re: [PATCH v3 9/9] cxl/acpi: Set ACPI's CXL _OSC to indicate CXL1.1 support

Rafael J. Wysocki
2022-11-09T12:22:20Z

On Wed, Nov 9, 2022 at 11:41 AM Robert Richter <rrichter@amd.com> wrote:
>
> From: Terry Bowman <terry.bowman@amd.com>
>
> ACPI includes a CXL _OSC support procedure to communicate the available
> CXL support to FW. The CXL support _OSC includes a field to indicate
> CXL1.1 RCH RCD support. The OS sets this bit to 1 if it supports access
> to RCD and RCH Port registers.[1] FW can potentially change it's operation
> depending on the _OSC support setting reported by the OS.
>
> The ACPI driver does not currently set the ACPI _OSC support to indicate
> CXL1.1 RCD RCH support. Change the capability reported to include CXL1.1.
>
> [1] CXL3.0 Table 9-26 'Interpretation of CXL _OSC Support Field'
>
> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
> Signed-off-by: Robert Richter <rrichter@amd.com>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
> drivers/acpi/pci_root.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index c8385ef54c37..094a59b216ae 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -492,6 +492,7 @@ static u32 calculate_cxl_support(void)
> u32 support;
>
> support = OSC_CXL_2_0_PORT_DEV_REG_ACCESS_SUPPORT;
> + support |= OSC_CXL_1_1_PORT_REG_ACCESS_SUPPORT;
> if (pci_aer_available())
> support |= OSC_CXL_PROTOCOL_ERR_REPORTING_SUPPORT;
> if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
> --
> 2.30.2
>