crypto: qce - handle AES-XTS cases that qce fails

QCE hangs when presented with an AES-XTS request whose length is larger
than QCE_SECTOR_SIZE (512-bytes), and is not a multiple of it.  Let the
fallback cipher handle them.
Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/qce/common.c

@@ -15,8 +15,6 @@
 #include "regs-v5.h"
 #include "sha.h"
 
-#define QCE_SECTOR_SIZE		512
-
 static inline u32 qce_read(struct qce_device *qce, u32 offset)
 {
 	return readl(qce->base + offset);

drivers/crypto/qce/common.h

@@ -12,6 +12,9 @@
 #include <crypto/hash.h>
 #include <crypto/internal/skcipher.h>
 
+/* xts du size */
+#define QCE_SECTOR_SIZE			512
+
 /* key size in bytes */
 #define QCE_SHA_HMAC_KEY_SIZE		64
 #define QCE_MAX_CIPHER_KEY_SIZE		AES_KEYSIZE_256

drivers/crypto/qce/skcipher.c

@@ -227,9 +227,14 @@ static int qce_skcipher_crypt(struct skcipher_request *req, int encrypt)
 	rctx->flags |= encrypt ? QCE_ENCRYPT : QCE_DECRYPT;
 	keylen = IS_XTS(rctx->flags) ? ctx->enc_keylen >> 1 : ctx->enc_keylen;
 
+	/* qce is hanging when AES-XTS request len > QCE_SECTOR_SIZE and
+	 * is not a multiple of it; pass such requests to the fallback
+	 */
 	if (IS_AES(rctx->flags) &&
-	    ((keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_256) ||
-	     req->cryptlen <= aes_sw_max_len)) {
+	    (((keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_256) ||
+	      req->cryptlen <= aes_sw_max_len) ||
+	     (IS_XTS(rctx->flags) && req->cryptlen > QCE_SECTOR_SIZE &&
+	      req->cryptlen % QCE_SECTOR_SIZE))) {
 		SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
 
 		skcipher_request_set_sync_tfm(subreq, ctx->fallback);