Re: [PATCH v9 4/7] arm64: realm: Move Realm memory encryption ops to RSI code

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.

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)