[PATCH 12/19] x86: define DPS root partition type UUIDs

[Vincent Mailhol]

DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.

Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for the x86
32/64-bit variants described by the specification and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.

[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/

Cc: Thomas Gleixner <tglx@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Signed-off-by: Vincent Mailhol <mailhol@xxxxxxxxxx>
---
 arch/x86/Kconfig                |  1 +
 arch/x86/include/asm/dps_root.h | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b875d2f27e48..6b6e7b56f972 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -82,6 +82,7 @@ config X86
 	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_OPS			if GART_IOMMU || XEN
+	select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
 	select ARCH_HAS_EARLY_DEBUG		if KGDB
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_EXECMEM_ROX		if X86_64 && STRICT_MODULE_RWX
diff --git a/arch/x86/include/asm/dps_root.h b/arch/x86/include/asm/dps_root.h
new file mode 100644
index 000000000000..7c6ba5519d88
--- /dev/null
+++ b/arch/x86/include/asm/dps_root.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_X86_DPS_ROOT_H
+#define _ASM_X86_DPS_ROOT_H
+
+#ifdef CONFIG_X86_64
+#define DPS_ROOT_PARTITION_TYPE_UUID "4f68bce3-e8cd-4db1-96e7-fbcaf984b709"
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "44479540-f297-41b2-9af7-d131d5f0458a"
+#endif
+
+#endif /* _ASM_X86_DPS_ROOT_H */

-- 
2.53.0