arm64: mm: Add top-level dispatcher for internal mem_encrypt API

Implementing the internal mem_encrypt API for arm64 depends entirely on
the Confidential Computing environment in which the kernel is running.

Introduce a simple dispatcher so that backend hooks can be registered
depending upon the environment in which the kernel finds itself.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240830130150.8568-4-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/mem_encrypt.h b/arch/arm64/include/asm/mem_encrypt.h
new file mode 100644
index 000000000000..b0c9a86b13a4
--- /dev/null
+++ b/arch/arm64/include/asm/mem_encrypt.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_MEM_ENCRYPT_H
+#define __ASM_MEM_ENCRYPT_H
+
+struct arm64_mem_crypt_ops {
+	int (*encrypt)(unsigned long addr, int numpages);
+	int (*decrypt)(unsigned long addr, int numpages);
+};
+
+int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops);
+
+int set_memory_encrypted(unsigned long addr, int numpages);
+int set_memory_decrypted(unsigned long addr, int numpages);
+
+#endif	/* __ASM_MEM_ENCRYPT_H */