[PATCH v4 1/2] crypto: padlock-sha - Disable for Zhaoxin processor

[AlanSong-oc]

For Zhaoxin processors, the XSHA1 instruction requires the total memory
allocated at %rdi register must be 32 bytes, while the XSHA1 and
XSHA256 instruction doesn't perform any operation when %ecx is zero.

Due to these requirements, the current padlock-sha driver does not work
correctly with Zhaoxin processors. It cannot pass the self-tests and
therefore does not activate the driver on Zhaoxin processors. This issue
has been reported in Debian [1]. The self-tests fail with the
following messages [2]:

alg: shash: sha1-padlock-nano test failed (wrong result) on test vector 0, cfg="init+update+final aligned buffer"
alg: self-tests for sha1 using sha1-padlock-nano failed (rc=-22)
------------[ cut here ]------------

alg: shash: sha256-padlock-nano test failed (wrong result) on test vector 0, cfg="init+update+final aligned buffer"
alg: self-tests for sha256 using sha256-padlock-nano failed (rc=-22)
------------[ cut here ]------------

Disable the padlock-sha driver on Zhaoxin processors with the CPU family
0x07 and newer. Following the suggestion in [3], add support for the PHE
extensions to lib/crypto. Only XSHA256 support for SHA-256 is included,
since SHA-1 has been cryptographically broken, as recommended in [4].

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1103397
[2] https://linux-hardware.org/?probe=271fabb7a4&log=dmesg
[3] https://lore.kernel.org/linux-crypto/aUI4CGp6kK7mxgEr@xxxxxxxxxxxxxxxxxxx/
[4] https://lore.kernel.org/linux-crypto/20260116071513.12134-1-AlanSong-oc@xxxxxxxxxxx/T/#m49436c4849dd64454b3554c105197ef9c61db23e

Fixes: 63dc06cd12f9 ("crypto: padlock-sha - Use API partial block handling")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: AlanSong-oc <AlanSong-oc@xxxxxxxxxxx>
---
 drivers/crypto/padlock-sha.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c
index 329f60ad4..9214bbfc8 100644
--- a/drivers/crypto/padlock-sha.c
+++ b/drivers/crypto/padlock-sha.c
@@ -332,6 +332,13 @@ static int __init padlock_init(void)
 	if (!x86_match_cpu(padlock_sha_ids) || !boot_cpu_has(X86_FEATURE_PHE_EN))
 		return -ENODEV;
 
+	/*
+	 * Skip family 0x07 and newer used by Zhaoxin processors,
+	 * as the driver's self-tests fail on these CPUs.
+	 */
+	if (c->x86 >= 0x07)
+		return -ENODEV;
+
 	/* Register the newly added algorithm module if on *
 	* VIA Nano processor, or else just do as before */
 	if (c->x86_model < 0x0f) {
-- 
2.34.1