[PATCH 1/2] riscv: efi: Power off via EFI runtime services when available

[Atish Patra <atish.patra@linux.dev>]

From: Atish Patra <atishp@meta.com>

When booted via UEFI with runtime services enabled, EFI Reset Shutdown is
the firmware-preferred shutdown path: it lets firmware run its own
shutdown hooks which may invoke SBI SRST extension internally. However,
RISC-V always powers off via the SBI SRST extension today and EFI runtime
path is never used even when firmware provides it.

Enable the poweroff via EFI by overriding efi_poweroff_required()

Signed-off-by: Atish Patra <atishp@meta.com>
---
 arch/riscv/kernel/efi.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/riscv/kernel/efi.c b/arch/riscv/kernel/efi.c
index b64bf1624a05..2d3cc57b4535 100644
--- a/arch/riscv/kernel/efi.c
+++ b/arch/riscv/kernel/efi.c
@@ -95,3 +95,8 @@ int __init efi_set_mapping_permissions(struct mm_struct *mm,
 				   md->num_pages << EFI_PAGE_SHIFT,
 				   set_permissions, md);
 }
+
+bool efi_poweroff_required(void)
+{
+	return efi_enabled(EFI_RUNTIME_SERVICES);
+}

-- 
2.53.0-Meta