[PATCH v11 4/7] arm64: realm: Move Realm memory encryption ops to RSI code
From: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>
Date: 2026-09-14 06:05:56
Also in:
linux-coco, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Realm memory encryption callbacks are CCA-specific. Keep the Realm callback registration with the RSI initialization code instead of pageattr.c, which only needs to provide the low-level page-attribute transition helper. Export __set_memory_enc_dec() within arm64 so the RSI code can wrap it with the Realm-specific encrypt/decrypt callbacks and warning policy. No functional changes in this patch. Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> --- arch/arm64/include/asm/mem_encrypt.h | 3 +-- arch/arm64/mm/pageattr.c | 38 +--------------------------- drivers/firmware/arm_rmm/rsi.c | 34 +++++++++++++++++++++++++ 3 files changed, 36 insertions(+), 39 deletions(-)
diff --git a/arch/arm64/include/asm/mem_encrypt.h b/arch/arm64/include/asm/mem_encrypt.h
index f03b9d7b83b4..ef8b8463e52b 100644
--- a/arch/arm64/include/asm/mem_encrypt.h
+++ b/arch/arm64/include/asm/mem_encrypt.h@@ -16,8 +16,7 @@ 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); - -int realm_register_memory_enc_ops(void); +int __set_memory_enc_dec(unsigned long addr, int numpages, bool encrypt); static inline bool force_dma_unencrypted(struct device *dev) {
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index bbe98ac9ad8c..14b2a3801f40 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c@@ -275,9 +275,7 @@ int set_direct_map_default_noflush(struct page *page) PAGE_SIZE, set_mask, clear_mask); } -static int __set_memory_enc_dec(unsigned long addr, - int numpages, - bool encrypt) +int __set_memory_enc_dec(unsigned long addr, int numpages, bool encrypt) { unsigned long set_prot = 0, clear_prot = 0; phys_addr_t start, end;
@@ -321,40 +319,6 @@ static int __set_memory_enc_dec(unsigned long addr, __pgprot(PTE_PRESENT_INVALID)); } -static int realm_set_memory_encrypted(unsigned long addr, int numpages) -{ - int ret = __set_memory_enc_dec(addr, numpages, true); - - /* - * If the request to change state fails, then the only sensible cause - * of action for the caller is to leak the memory - */ - WARN(ret, "Failed to encrypt memory, %d pages will be leaked", - numpages); - - return ret; -} - -static int realm_set_memory_decrypted(unsigned long addr, int numpages) -{ - int ret = __set_memory_enc_dec(addr, numpages, false); - - WARN(ret, "Failed to decrypt memory, %d pages will be leaked", - numpages); - - return ret; -} - -static const struct arm64_mem_crypt_ops realm_crypt_ops = { - .encrypt = realm_set_memory_encrypted, - .decrypt = realm_set_memory_decrypted, -}; - -int realm_register_memory_enc_ops(void) -{ - return arm64_mem_crypt_ops_register(&realm_crypt_ops); -} - int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid) { unsigned long addr = (unsigned long)page_address(page);
diff --git a/drivers/firmware/arm_rmm/rsi.c b/drivers/firmware/arm_rmm/rsi.c
index 8e716f1c1e31..ada139d0e344 100644
--- a/drivers/firmware/arm_rmm/rsi.c
+++ b/drivers/firmware/arm_rmm/rsi.c@@ -127,6 +127,40 @@ static int realm_ioremap_hook(phys_addr_t phys, size_t size, pgprot_t *prot) return 0; } +static int realm_set_memory_encrypted(unsigned long addr, int numpages) +{ + int ret = __set_memory_enc_dec(addr, numpages, true); + + /* + * If the request to change state fails, then the only sensible cause + * of action for the caller is to leak the memory + */ + WARN(ret, "Failed to encrypt memory, %d pages will be leaked", + numpages); + + return ret; +} + +static int realm_set_memory_decrypted(unsigned long addr, int numpages) +{ + int ret = __set_memory_enc_dec(addr, numpages, false); + + WARN(ret, "Failed to decrypt memory, %d pages will be leaked", + numpages); + + return ret; +} + +static const struct arm64_mem_crypt_ops realm_crypt_ops = { + .encrypt = realm_set_memory_encrypted, + .decrypt = realm_set_memory_decrypted, +}; + +static int realm_register_memory_enc_ops(void) +{ + return arm64_mem_crypt_ops_register(&realm_crypt_ops); +} + void __init arm64_rsi_init(void) { if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_SMC)
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2.43.0