Re: [PATCH 1/5] cxl/acpi: Set ACPI's CXL _OSC to indicate CXL1.1 support

From: Terry Bowman
Date: Tue Oct 25 2022 - 12:23:36 EST




On 10/21/22 17:39, Dan Williams wrote:
> Terry Bowman wrote:
>> ACPI includes a CXL _OSC support method 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@xxxxxxx>
>> ---
>> 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
>
> Be sure to copy linux-acpi@xxxxxxxxxxxxxxx on patches that touch
> drivers/acpi/
>

Ok, I will.

Regards,
Terry

>> @@ -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))
>
> This looks good to me though.