2022-10-21 18:59:03

by Terry Bowman

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

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 <[email protected]>
---
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))
--
2.34.1

2022-10-21 23:04:26

by Dan Williams

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

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 <[email protected]>
> ---
> 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 [email protected] on patches that touch
drivers/acpi/

> @@ -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.

2022-10-25 16:37:25

by Terry Bowman

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

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 <[email protected]>
>> ---
>> 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 [email protected] 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.