[PATCH 11/19] s390: define DPS root partition type UUIDs

Vincent Mailhol <[email protected]> Mon, 15 Jun 2026 18:09:07 +0200
Newsgroups org.kernel.vger.linux-efi,org.kernel.vger.linux-block,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-s390
Message-ID <20260615-discoverable-root_partitions-v1-11-39c78fac42e2@kernel.org>
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 s390
(32-bit) and s390x (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: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: [email protected]
Signed-off-by: Vincent Mailhol <[email protected]>
---
 arch/s390/Kconfig                |  1 +
 arch/s390/include/asm/dps_root.h | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9921a3772bf7..af2cf67fffd7 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -91,6 +91,7 @@ config S390
 	select ARCH_HAS_DEBUG_WX
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_OPS if PCI
+	select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
 	select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/s390/include/asm/dps_root.h b/arch/s390/include/asm/dps_root.h
new file mode 100644
index 000000000000..e72e44a66097
--- /dev/null
+++ b/arch/s390/include/asm/dps_root.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_S390_DPS_ROOT_H
+#define _ASM_S390_DPS_ROOT_H
+
+#ifdef CONFIG_64BIT
+#define DPS_ROOT_PARTITION_TYPE_UUID "5eead9a9-fe09-4a1e-a1d7-520d00531306"
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "08a7acea-624c-4a20-91e8-6e0fa67d23f9"
+#endif
+
+#endif /* _ASM_S390_DPS_ROOT_H */

-- 
2.53.0