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

Robert Richter
2022-11-09T10:42:02Z

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>
---
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