[PATCH] tpm: enable HMAC encryption for only x86-64 and aarch64

[Jarkko Sakkinen]

Let's be more conservative and enable HMAC by default only for the
platforms where it immediately makes sense, i.e. x86-64 and aarch64.
This can be relaxed later on, and obviously the kconfig option can be
set even if not default on a particular arch.

Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Fixes: d2add27cf2b8 ("tpm: Add NULL primary creation")
Closes: https://lore.kernel.org/linux-integrity/D1FCAPJSYLTS.R9VC1CXDCIHH@xxxxxxxxxx/
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
---
 drivers/char/tpm/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index e63a6a17793c..19e61dcfcbbe 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -29,7 +29,7 @@ if TCG_TPM
 
 config TCG_TPM2_HMAC
 	bool "Use HMAC and encrypted transactions on the TPM bus"
-	default y
+	default X86_64 || ARM64
 	select CRYPTO_ECDH
 	select CRYPTO_LIB_AESCFB
 	select CRYPTO_LIB_SHA256
-- 
2.45.1