Re: [PATCH v12 3/7] firmware: arm_rmm: Move RSI support out of arch/arm64

The RSI SMCCC function IDs describe a firmware ABI and are not arm64
architecture specific definitions. Follow-up changes need to use them from
non-arch code, including drivers/firmware/smccc and the Arm CCA guest
driver.

Move the complete Realm Service Interface (RSI) implementation from
arch/arm64 to drivers/firmware/arm_rmm. The RSI SMCCC definitions and
command helpers are also moved to include/linux so they can be shared by
architecture code and firmware or driver code. This also keeps the
firmware interface outside architecture code, as requested [1].

[1] https://lore.kernel.org/all/agsNO9cc7H-b0H8L@willie-the-truck (local)

Reviewed-by: Jonathan Cameron <redacted>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 MAINTAINERS                                   |  2 +
 arch/arm64/Kconfig                            |  1 +
 arch/arm64/include/asm/io.h                   |  2 +-
 arch/arm64/include/asm/mem_encrypt.h          |  2 +-
 arch/arm64/include/asm/pgtable-prot.h         |  2 +-
 arch/arm64/include/asm/rsi.h                  | 70 -----------------
 arch/arm64/kernel/Makefile                    |  2 +-
 arch/arm64/kernel/setup.c                     |  2 +-
 arch/arm64/mm/init.c                          |  3 +-
 drivers/firmware/Kconfig                      |  1 +
 drivers/firmware/Makefile                     |  1 +
 drivers/firmware/arm_rmm/Kconfig              | 17 ++++
 drivers/firmware/arm_rmm/Makefile             |  2 +
 .../kernel => drivers/firmware/arm_rmm}/rsi.c |  2 +-
 drivers/virt/coco/arm-cca-guest/Kconfig       |  2 +-
 .../virt/coco/arm-cca-guest/arm-cca-guest.c   |  5 +-
 .../linux/arm-rsi-cmds.h                      | 77 +++++++++++++++++--
 .../linux/arm-smccc-rsi.h                     |  6 +-
 18 files changed, 110 insertions(+), 89 deletions(-)
 delete mode 100644 arch/arm64/include/asm/rsi.h
 create mode 100644 drivers/firmware/arm_rmm/Kconfig
 create mode 100644 drivers/firmware/arm_rmm/Makefile
 rename {arch/arm64/kernel => drivers/firmware/arm_rmm}/rsi.c (99%)
 rename arch/arm64/include/asm/rsi_cmds.h => include/linux/arm-rsi-cmds.h (69%)
 rename arch/arm64/include/asm/rsi_smc.h => include/linux/arm-smccc-rsi.h (98%)

diff --git a/MAINTAINERS b/MAINTAINERS
index 42364c540f50..b867d537a579 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -3953,6 +3953,8 @@ F:	Documentation/arch/arm64/
 F:	arch/arm64/
 F:	drivers/virt/coco/arm-cca-guest/
 F:	drivers/virt/coco/pkvm-guest/
+F:	include/linux/arm-rsi-cmds.h
+F:	include/linux/arm-smccc-rsi.h
 F:	tools/testing/selftests/arm64/
 X:	arch/arm64/boot/dts/
 X:	arch/arm64/configs/defconfig