linux-stable/arch/arm64/mm/mem_encrypt.c
Will Deacon e7bafbf717 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>
2024-08-30 16:30:41 +01:00

51 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Implementation of the memory encryption/decryption API.
*
* Since the low-level details of the operation depend on the
* Confidential Computing environment (e.g. pKVM, CCA, ...), this just
* acts as a top-level dispatcher to whatever hooks may have been
* registered.
*
* Author: Will Deacon <will@kernel.org>
* Copyright (C) 2024 Google LLC
*
* "Hello, boils and ghouls!"
*/
#include <linux/bug.h>
#include <linux/compiler.h>
#include <linux/err.h>
#include <linux/mm.h>
#include <asm/mem_encrypt.h>
static const struct arm64_mem_crypt_ops *crypt_ops;
int arm64_mem_crypt_ops_register(const struct arm64_mem_crypt_ops *ops)
{
if (WARN_ON(crypt_ops))
return -EBUSY;
crypt_ops = ops;
return 0;
}
int set_memory_encrypted(unsigned long addr, int numpages)
{
if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr)))
return 0;
return crypt_ops->encrypt(addr, numpages);
}
EXPORT_SYMBOL_GPL(set_memory_encrypted);
int set_memory_decrypted(unsigned long addr, int numpages)
{
if (likely(!crypt_ops) || WARN_ON(!PAGE_ALIGNED(addr)))
return 0;
return crypt_ops->decrypt(addr, numpages);
}
EXPORT_SYMBOL_GPL(set_memory_decrypted);