ACPI / property: Allow multiple property compatible _DSD entries

It is possible to have _DSD entries where the data is compatible with
device properties format but are using different GUID for various reasons.
In addition to that there can be many such _DSD entries for a single device
such as for PCIe root port used to host a Thunderbolt hierarchy:

    Scope (\_SB.PCI0.RP21)
    {
        Name (_DSD, Package () {
            ToUUID ("6211e2c0-58a3-4af3-90e1-927a4e0c55a4"),
            Package () {
                Package () {"HotPlugSupportInD3", 1}
            },

            ToUUID ("efcc06cc-73ac-4bc3-bff0-76143807c389"),
            Package () {
                Package () {"ExternalFacingPort", 1},
                Package () {"UID", 0 }
            }
        })
    }

More information about these new _DSD entries can be found in:

  https://docs.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports

To make these available for drivers via unified device property APIs,
modify ACPI property core so that it supports multiple _DSD entries
organized in a linked list. We also store GUID of each _DSD entry in struct
acpi_device_properties in case there is need to differentiate between
entries. The supported GUIDs are then listed in prp_guids array.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index ba4dd54f2c82..cd35e3ce9a8b 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -346,10 +346,16 @@ struct acpi_device_physical_node {
 	bool put_online:1;
 };
 
+struct acpi_device_properties {
+	const guid_t *guid;
+	const union acpi_object *properties;
+	struct list_head list;
+};
+
 /* ACPI Device Specific Data (_DSD) */
 struct acpi_device_data {
 	const union acpi_object *pointer;
-	const union acpi_object *properties;
+	struct list_head properties;
 	const union acpi_object *of_compatible;
 	struct list_head subnodes;
 };