s390/crypto: cpacf function detection

The CPACF code makes some assumptions about the availablity of hardware
support. E.g. if the machine supports KM(AES-256) without chaining it is
assumed that KMC(AES-256) with chaining is available as well. For the
existing CPUs this is true but the architecturally correct way is to
check each CPACF functions on its own. This is what the query function
of each instructions is all about.

Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 46 insertions, 31 deletions

diff --git a/arch/s390/crypto/des_s390.c b/arch/s390/crypto/des_s390.c
index b77a546..965587e 100644
--- a/arch/s390/crypto/des_s390.c
+++ b/arch/s390/crypto/des_s390.c
@@ -27,6 +27,8 @@
 static u8 *ctrblk;
 static DEFINE_SPINLOCK(ctrblk_lock);
 
+static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
+
 struct s390_des_ctx {
 	u8 iv[DES_BLOCK_SIZE];
 	u8 key[DES3_KEY_SIZE];
@@ -36,12 +38,12 @@ static int des_setkey(struct crypto_tfm *tfm, const u8 *key,
 		      unsigned int key_len)
 {
 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
-	u32 *flags = &tfm->crt_flags;
 	u32 tmp[DES_EXPKEY_WORDS];
 
 	/* check for weak keys */
-	if (!des_ekey(tmp, key) && (*flags & CRYPTO_TFM_REQ_WEAK_KEY)) {
-		*flags |= CRYPTO_TFM_RES_WEAK_KEY;
+	if (!des_ekey(tmp, key) &&
+	    (tfm->crt_flags & CRYPTO_TFM_REQ_WEAK_KEY)) {
+		tfm->crt_flags |= CRYPTO_TFM_RES_WEAK_KEY;
 		return -EINVAL;
 	}
 
@@ -238,13 +240,12 @@ static int des3_setkey(struct crypto_tfm *tfm, const u8 *key,
 		       unsigned int key_len)
 {
 	struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
-	u32 *flags = &tfm->crt_flags;
 
 	if (!(crypto_memneq(key, &key[DES_KEY_SIZE], DES_KEY_SIZE) &&
 	    crypto_memneq(&key[DES_KEY_SIZE], &key[DES_KEY_SIZE * 2],
 			  DES_KEY_SIZE)) &&
-	    (*flags & CRYPTO_TFM_REQ_WEAK_KEY)) {
-		*flags |= CRYPTO_TFM_RES_WEAK_KEY;
+	    (tfm->crt_flags & CRYPTO_TFM_REQ_WEAK_KEY)) {
+		tfm->crt_flags |= CRYPTO_TFM_RES_WEAK_KEY;
 		return -EINVAL;
 	}
 	memcpy(ctx->key, key, key_len);
@@ -554,39 +555,53 @@ static int __init des_s390_init(void)
 {
 	int ret;
 
-	if (!cpacf_query(CPACF_KM, CPACF_KM_DEA) ||
-	    !cpacf_query(CPACF_KM, CPACF_KM_TDEA_192))
-		return -EOPNOTSUPP;
-
-	ret = des_s390_register_alg(&des_alg);
-	if (ret)
-		goto out_err;
-	ret = des_s390_register_alg(&ecb_des_alg);
-	if (ret)
-		goto out_err;
-	ret = des_s390_register_alg(&cbc_des_alg);
-	if (ret)
-		goto out_err;
-	ret = des_s390_register_alg(&des3_alg);
-	if (ret)
-		goto out_err;
-	ret = des_s390_register_alg(&ecb_des3_alg);
-	if (ret)
-		goto out_err;
-	ret = des_s390_register_alg(&cbc_des3_alg);
-	if (ret)
-		goto out_err;
-
-	if (cpacf_query(CPACF_KMCTR, CPACF_KMCTR_DEA) &&
-	    cpacf_query(CPACF_KMCTR, CPACF_KMCTR_TDEA_192)) {
+	/* Query available functions for KM, KMC and KMCTR */
+	cpacf_query(CPACF_KM, &km_functions);
+	cpacf_query(CPACF_KMC, &kmc_functions);
+	cpacf_query(CPACF_KMCTR, &kmctr_functions);
+
+	if (cpacf_test_func(&km_functions, CPACF_KM_DEA)) {
+		ret = des_s390_register_alg(&des_alg);
+		if (ret)
+			goto out_err;
+		ret = des_s390_register_alg(&ecb_des_alg);
+		if (ret)
+			goto out_err;
+	}
+	if (cpacf_test_func(&kmc_functions, CPACF_KMC_DEA)) {
+		ret = des_s390_register_alg(&cbc_des_alg);
+		if (ret)
+			goto out_err;
+	}
+	if (cpacf_test_func(&km_functions, CPACF_KM_TDEA_192)) {
+		ret = des_s390_register_alg(&des3_alg);
+		if (ret)
+			goto out_err;
+		ret = des_s390_register_alg(&ecb_des3_alg);
+		if (ret)
+			goto out_err;
+	}
+	if (cpacf_test_func(&kmc_functions, CPACF_KMC_TDEA_192)) {
+		ret = des_s390_register_alg(&cbc_des3_alg);
+		if (ret)
+			goto out_err;
+	}
+
+	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_DEA) ||
+	    cpacf_test_func(&kmctr_functions, CPACF_KMCTR_TDEA_192)) {
 		ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
 		if (!ctrblk) {
 			ret = -ENOMEM;
 			goto out_err;
 		}
+	}
+
+	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_DEA)) {
 		ret = des_s390_register_alg(&ctr_des_alg);
 		if (ret)
 			goto out_err;
+	}
+	if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_TDEA_192)) {
 		ret = des_s390_register_alg(&ctr_des3_alg);
 		if (ret)
 			goto out_err;